REVIEW | doi:10.20944/preprints202110.0318.v1
Subject: Medicine & Pharmacology, Other Keywords: Chronic rhinosinusitis; probiotics; microbiome; nasal microbiota; microbiome therapy
Online: 21 October 2021 (23:00:15 CEST)
Chronic rhinosinusitis (CRS) is a significant health problem. It affects 5%–12% of the general population. The causes that underlie the onset of CRS are not yet well known. However, many factors may contribute to its onset, such as environmental factors and the host’s condition. Medical treatment mainly uses local corticosteroids, nasal irrigation, and antibiotics. In recent years, a new therapeutic approach that employs the use of probiotics emerged. Probiotics have been extensively studied as a therapy for dysbiosis and inflammatory pathologies of various parts of the body . We aimed to examine the studies in the existing literature to update probiotics’ role in rhinosinusitis chronic medical treatment.
ARTICLE | doi:10.20944/preprints202005.0500.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: skin microbiome; skincare; cosmetic products; ecobiology; microbiome friendly
Online: 31 May 2020 (20:12:40 CEST)
Background: Skincare products are used daily to maintain a healthy skin (cleansing, moisturizing, protecting…), but their impact on this first layer, which corresponds to the skin microbiome, is still poorly understood. Preserving natural resources and mechanisms of the skin ecosystem is essential; an original approach based on these premises, called ecobiology, has recently emerged in skincare. Ecobiology considers the skin as an ever-evolving ecosystem which hosts human and microbial cells that interact together with their environment. In this context, we evaluated the impact on the skin microbiome of three types of leave-on face skincare products: a hydrophilic sterile solution, a micellar solution, and an oil-in-water emulsion. Materials and Methods: The individual microbial profiles of 20 Caucasian females were investigated. Samples were obtained twenty-four hours and four days following a daily application of the skincare products versus control area where no product was applied. To analyze the bacterial diversity and abundance of skin microbiome, a 16SrRNA gene sequencing was performed using the Illumina MiSeq platform. Results: Our results confirm the overall diversity of skin microbiome as previously observed and notably reveal the prevalence of Cutibacterium spp. and Staphylococcus spp. on sebaceous site (the back). Bacterial diversity and abundance were not affected by the products either twenty-four hours or four days after application, as indicated by comparison with the control. Moreover, no dissimilarity was observed between the three products versus their control, neither between each product. Conclusions: These preliminary results demonstrated for the first time that three different types of leave-on face skincare products such as a hydrophilic sterile solution, a micellar solution, and an emulsion have no impact on skin microbiome and can be considered as “microbiome friendly”.
CONCEPT PAPER | doi:10.20944/preprints202104.0560.v1
Subject: Biology, Anatomy & Morphology Keywords: MIGI; microbiome-inspired green infrastructure; microbiome; urban microbiome; nature-based intervention; biodiversity; greenspace; green infrastructure; multispecies urbanism; EcoHealth
Online: 21 April 2021 (09:01:13 CEST)
Background: Microbiome-Inspired Green Infrastructure (MIGI) was recently proposed as an integrative system to promote healthy urban ecosystems, through multidisciplinary design. Specifically, MIGI is defined as nature-centric infrastructure restored and/or designed and managed to enhance health-promoting interactions between humans and environmental microbiomes, whilst sustaining microbially-mediated ecosystem functionality and resilience. MIGI also aims to stimulate a research agenda that focuses on considerations for the importance of urban environmental microbiomes. Objectives: In this paper we provide details of what MIGI entails from a bioscience and biodesign perspective, highlighting the potential dual benefits for human and ecosystem health. We present ‘what is known’ about the relationship between urban microbiomes, green infrastructure and environmental factors that may affect urban ecosystem health (ecosystem functionality and resilience as well as human health). We discuss how to start operationalising the MIGI concept based on current available knowledge, and present a horizon scan of emerging and future considerations in research and practice. We conclude by highlighting challenges to the implementation of MIGI and propose a series of workshops to discuss multi-stakeholder needs and opportunities. Discussion: This article will enable urban landscape managers to incorporate initial considerations for the microbiome in their development projects to promote human and ecosystem health. However, overcoming the challenges to operationalising MIGI will be essential to furthering its practical development. Although the research is in its infancy, there is considerable potential for MIGI to help deliver sustainable urban development driven by considerations for reciprocal relations between humans and the foundations of our ecosystems –– the microorganisms.
REVIEW | doi:10.20944/preprints202205.0199.v1
Online: 16 May 2022 (08:05:43 CEST)
Allergic diseases are becoming a major healthcare issue in many developed nations, where living environment and lifestyle are most predominantly distinct. Such differences include urbanized, industrialized living environments, overused hygiene products, antibiotics, stationary lifestyle, and fast-food based diets tend to reduce microbial diversity and lead to impared immune protection, which further increase the development of allergic diseases. In the same time, studies also showed that modulating microbiomes can ameliorate allergic symptoms. Therefore, in this paper, we aimed to review recent findings on the potential role of the human microbiome in the gastrointestinal tract, surface of skin and respiratory tract for the development of allergic diseases. Furthermore, we addressed a potential therapeutic or even preventive strategy for such allergic diseases by modulating the human microbial composition.
REVIEW | doi:10.20944/preprints202003.0293.v1
Online: 19 March 2020 (02:23:21 CET)
Recently scientific research began to shift their focus on looking at both the gut and the skin microbiota as having a reciprocal and integral relationship with one another, rather than assessing them as separate and unrelated fields. In the past five years, the field of microbial endocrinology emerged, which examines how our gut microbiota influences and modulates hormones. We’ve known for decades that hormones greatly affect the condition of the skin, and many skin conditions are often treated with oral hormonal therapy as means to internally treat skin conditions visible on the dermis. Now, a growing body research and discourse examining this triad of biological spheres – gut microbiota, skin microbiota, and the endocrine system – as interconnected rather than binary and unrelated. While there is ample research established and being conducted examining the gut-skin axis, the gut-brain axis, and the gut-hormone axis, through this paper I will review and synthesize some of the significant advancements in this emerging and inclusive field of science to suggest that the fields need to expand the axis and their modality for researching these fields as a connected whole in order to better understand the role of the microbiota in disease prevention as a whole.
ARTICLE | doi:10.20944/preprints201810.0209.v1
Online: 10 October 2018 (08:14:24 CEST)
The application of 16S rRNA gene pyrosequencing has expanded our knowledge about the respiratory tract microbiome originally obtained using conventional, culture-based methods. In this study, we employed DNA-based molecular techniques for examining the sputum microbiome in bronchiectasis patients in relation to disease severity. Of 63 study subjects, 42 had mild and 21 had moderate or severe bronchiectasis, which was classified by calculating the FACED score based on FEV1 (forced expiratory volume in 1 s, %) (F, 0–2 points), age (A, 0–2 points), chronic colonization by Pseudomonas aeruginosa (C, 0-1 point), radiographic extension (E, 0–1 point), and dyspnoea (D, 0–1 point). Bronchiectasis was defined as mild at 0–2 points, moderate at 3–4 points, and severe at 5–7 points. The mean age was 68.0 ± 9.3 years; 33 patients were women. Haemophilus (p=0.005) and Rothia (p=0.043) were significantly more abundant in the mild bronchiectasis group, whereas Pseudomonas (p=0.031) was significantly more abundant in the moderate or severe group. However, the alpha or beta diversity did not significantly differ among sputum microbiota, i.e. the same dominating genera were found in all samples. Further large-scale studies are needed to investigate the sputum microbiome in bronchiectasis.
REVIEW | doi:10.20944/preprints201807.0526.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: psychiatry; gut microbiome; probiotics
Online: 27 July 2018 (03:22:02 CEST)
The microbiome gut brain (MGB) axis involves bidirectional routes of communication and has emerged as a potential therapeutic target for multiple medical specialities including psychiatry. Significant numbers of preclinical trials have taken place with some transitioning to clinical studies in more recent years. Some positive results have been reported secondary to probiotic administration in both healthy populations and specific patient groups. This review aims to summarise the current understanding of the MGB axis and the preclinical and clinical findings relevant to psychiatry. The link between the gut microbiome and irritable bowel syndrome (IBS) is well established. Significant differences have been identified between the microbiome of patients with a diagnosis of depressive disorder and healthy controls. Similar findings have occurred in patients diagnosed with bipolar affective disorder. A probiotic containing Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium bifidum produced clinically measurable symptom improvement in patients with depressive disorder. To date some promising results have suggested that probiotics could play a role in the treatment of stress-related psychiatric disease. However, more well-controlled clinical trials are required to determine which clinical conditions are likely to benefit most significantly from this novel approach.
ARTICLE | doi:10.20944/preprints202202.0350.v1
Online: 28 February 2022 (08:53:11 CET)
Bifidobacterium are a beneficial and dominant member of the breast-fed infant gut microbiome. However, the health benefits of Bifidobacterium are partially species dependent. Here we characterize the species and subspecies of Bifidobacterium present in breastfed infants around the world. Across populations, three distinct patterns of Bifidobacterium colonization emerged: 1) Dominance of Bifidobacterium longum subspecies infantis, 2) Prevalent Bifidobacterium of multiple species, and 3) Frequent absence of Bifidobacterium. These patterns appear related to country history of breastfeeding, with infants in countries with historically high rates of long duration breastfeeding more likely to be colonized by B. longum subspecies infantis compared with infants in countries with histories of shorter duration breastfeeding. These findings highlight the need to consider historical and cultural influences on gut commensal survival influence present day colonization patterns in order to understand epidemiological transmission patterns of Bifidobacterium and other major gut commensals.
REVIEW | doi:10.20944/preprints202012.0628.v1
Online: 24 December 2020 (13:58:40 CET)
Ruminants perhaps appeared about 50 million years ago (Ma). Five ruminant families had been extinct and about 200 species in 6 ruminant families are living today. The first ruminant family probably was small omnivore without functional ruminal microbiota to digest fiber. Subsequently, other ruminant families evolved around 18-23 Ma along with woodlands and grasslands. Probably, ruminants started to consume selective and highly nutritious plant leaves and grasses similar to concentrates. By 5-11 Ma, grasslands expanded and some ruminants used more grass in their diets with comparatively low nutritive values and high fibers. Historically, humans have domesticated 9 ruminant species that are mostly utilizer of low quality forages for human benefits. Thus, the non-functional rumen microbiota to predominantly concentrate fermenting microbiota, followed by predominantly fiber digesting microbiota had evolved for mutual complementary benefits of holobiont over the million years. The core microbiome of ruminant species seems the resultant of hologenome interaction in an evolutionary unit. The inertia and resilience properties of ruminal ecosystem seem to be due to this core microbiota, which makes the ecosystem most stable in response to perturbations because this core microbiota has evolutionary advantages with logically more generalists (i.e., wide metabolic versatile and redundancy). Also, a part of the ruminal microbiome shows highly plasticity, which is likely useful for evolutionary adaptability of holobiont. This review discusses ecological characteristics of ruminal microbial community in evolutionary perspectives. The updated understanding of ecological traits of ruminal microbiome would be helpful to better modulate the ruminal fermentation favorably for human benefits.
ARTICLE | doi:10.20944/preprints201903.0089.v1
Subject: Biology, Other Keywords: Signalling, rhizosphere microbiome, plant hormones
Online: 7 March 2019 (11:58:15 CET)
Signalling is a strongly influenced area trending to be applied in almost every focus of biological sciences. The part of signalling or communication from cellular level to a whole organism including plant as well as animal drags a vast diversity of wealthy structural compounds. There is immense demand for new bioactive compounds for the pharmaceutical, agro and food industries. Plant-associated microbes present an attractive and promising source. The concept of the microbiome and the significance it has to host health, diseases state, and the role of immune have been the hub of research that has led to advances in our understanding of the massive power of the small unseen majority of the microbes (Peterson Andrew H., 2013). Before we say about microbiome—plant relation, it is important to first understand the working concept of the microbiome. Every organism on earth counts on their neighbours to sustain life. Microbiome can be considered a community of microorgasims who can prove to be loveable and hateful. The analysis of microbiome structure and function was protagonise in studies of human hosts and has been extensively documented as essential to genetic and functional capacity attributed to the host, comprehending aspects of metabolism and physiology. Plants are crowded with microbial organisms, counting those that colonize internal tissues, also those that adhere to external surfaces. The wide diversity of microorganisms in the soil rhizosphere is collectively plant–soil-associated microbes cover the plant microbiome. The intricate involvement of microbiome serves to plant health and as a tank of additional genes that plants can access when needed.
ARTICLE | doi:10.20944/preprints201711.0135.v1
Subject: Life Sciences, Microbiology Keywords: rice; endophyte; sustainable agriculture; plant microbiome; simplified bacterial community; syncom; taxonomic profiling; core plant microbiome
Online: 21 November 2017 (03:33:00 CET)
Rice is currently the most important food crop in the world and we are only just beginning to study the bacterial associated microbiome. It is of importance to perform screenings of the core rice microbiota and also to develop new plant-microbe models and simplified communities for increasing our understanding about the formation and function of its microbiome. In order to begin to address this aspect, we have performed the isolation of bacterial strains from the endorhizosphere of two rice cultivars from Venezuela. The validation of plant-growth promoting bacterial activities in vitro has led us to select and characterize 15 isolates for in planta studies such as germination test, endophytism ability and plant growth promotion. Consequently, a set of 10 isolates was selected for the set-up of an endophytic consortium as a simplified model of the natural rice bacterial endomicrobiota. Upon inoculation, the colonization and abundance of each strain within the rice roots was tracked by a culture-independent technique in gnotobiotic conditions in a 30 days period. Four strains belonging to Pseudomonas, Agrobacterium and Delftia genera have shown a promising capacity for colonizing and coexistence in root tissues. On the other hand, a bacterial community taxonomic profiling of the rhizosphere and the endorhizosphere of both cultivars were obtained and are discussed. This study is part of a growing body of research on core crops microbiome and simplified microbiomes, which strengthens the formation process of the endophytic community leading to a better understanding of the rice microbiome.
ARTICLE | doi:10.20944/preprints201709.0031.v1
Subject: Biology, Other Keywords: rice; endophyte; sustainable agriculture; plant microbiome; simplified bacterial community; syncomm; taxonomic profiling; core plant microbiome
Online: 8 September 2017 (14:02:56 CEST)
Rice is currently the most important food crop in the world and we are only just beginning to study the bacterial associated microbiome. It is of importance to perform screenings of the core rice microbiota and also to develop new plant-microbe models and simplified communities for increasing our understanding about the formation and function of its microbiome. In order to begin to address this aspect, we have performed the isolation of hundreds bacterial isolates obtained from endorhizosphere of two rice cultivars from Venezuela. The validation of plant-growth promoting bacterial activities in vitro has led us to select and characterize 15 isolates for in planta studies such as germination test, endophytism ability and plant growth promotion. Consequently, a set of 10 isolates was selected for the set-up of an endophytic consortium as a simplified model of the natural rice bacterial endomicrobiota. Upon inoculation, the colonization and abundance of each strain within the rice roots was tracked by a culture-independent technique in gnotobiotic conditions in a 30 days period. Four strains belonging to Pseudomonas, Agrobacterium and Delftia genera have shown a promising capacity for colonizing and coexistence in root tissues. On the other hand, a bacterial community taxonomic profiling of the rhizosphere and the endorhizosphere of both cultivars were obtained and are discussed. This study is part of a growing body of research on core crops microbiome and simplified microbiomes, which strengthens the formation process of the endophytic community leading to a better understanding of the rice microbiome.
ARTICLE | doi:10.20944/preprints202208.0436.v1
Online: 25 August 2022 (13:21:39 CEST)
Indole and indole-3-lactate are known dominant microbial tryptophan catabolites (MICT). In obesity, the fecal indole concentration corresponds to the normal one, and that of indole-3-lactate significantly decreases along with other MICT, while it increases in blood plasma. During the analysis of the «enzymatic landscape» of the intestinal microbiota we find an almost twofold increase in the correlation between the concentrations of fecal MICT and the «enzymatic landscape», with indole-3-lactate having the closest relationships with the “enzymatic landscape” of all MICT. Here, we report statistically significant correlations of indole-3-lactate and the gut microbial enzymes for fructose, amino sugars, nucleotides, polyamines metabolism, and sulfoglycolysis. We also demonstrate that indole-3-lactate producing microbiota representatives increase three-fold in obesity. The phenotype of the microbiotic population is thus represented by completely different genera and species of microorganisms in obese individuals compared to healthy donors.
REVIEW | doi:10.20944/preprints202208.0032.v1
Subject: Life Sciences, Microbiology Keywords: Microbiota; Microbiome; Adhesions; Pili; Curli; Enterotoxins
Online: 2 August 2022 (04:07:33 CEST)
The relationship between human health and gut microbiota is becoming more apparent. It is now widely believed that healthy gut flora plays a vital role in the overall well-being of the individual. There are spatial and temporal variations in the distribution of microbes from the esophagus to the rectum throughout an individual's lifetime. Through the development of genome sequencing technologies, scientists have been able to study the interactions between different microorganisms and their hosts to improve the health and disease of individuals. The normal gut microbiota provides various functions to the host, whereas the host, in turn, provides nutrients and promotes the development of healthy and resilient microbiota communities. Thus, the microbiota provides and maintains the gut's structural integrity and protects the gut against pathogens. The development of the normal gut microbiota is influenced by various factors. Some of these include the mode of delivery, diet, and antibiotics. In addition, the environment can also affect the development of the gut microbiota. For example, one of the main concerns of antibiotic use is the alteration of the gut microbiota, which could lead to the development of multidrug-resistant organisms. When microbes are disturbed, it can potentially lead to various diseases. Depending on the species' ability to adapt to the human body's environment, the fate of the microbes in the host and their relationship with the human body are decided. This review aims to provide a comprehensive analysis of microbe, microbes-host immune interactions, and factors that can disturb their interactions.
REVIEW | doi:10.20944/preprints202207.0374.v1
Subject: Medicine & Pharmacology, Clinical Neurology Keywords: probiotic; stroke; gut microbiome; meta-analysis
Online: 25 July 2022 (11:37:22 CEST)
Background: Pharmacologic and non-pharmacologic treatments for stroke are essential but could be costly or harmful whereas probiotic has been a promising alternative. This scoping review aimed to synthesize the in vitro and in vivo evidence of probiotics on stroke-related neurological, biochemical, and histochemical outcomes. Method: We searched in PubMed, Embase, and Cochrane Central Register of Clinical up to May 7, 2021, and screened by two independent reviewers. We included the use of probiotics, prebiotics, and symbiotics both in vitro and in vivo for the prevention or treatment of the stroke-related model. Result: Of 6,293 articles, 4,990 passed the initial screen, of which 36 theme-related full-texts were assessed and 13 were included in this review. Probiotics could ameliorate the neurological deficit and show their property as an anti-inflammation and anti-oxidative stress. Histopathologically decreased loss of cerebral volume and inhibition of neuronal apoptosis were found. Conclusion: There are potential cognitive benefits of probiotic supplementation, especially among animal models, on decreasing cerebral volume, increasing neurological score, and decreasing the inflammatory response. However, further investigation is needed to validate these conclusions in various populations.
REVIEW | doi:10.20944/preprints202111.0157.v1
Subject: Life Sciences, Microbiology Keywords: Microbiome; Cattle; Johne’s disease; Dysbiosis; Mastitis
Online: 8 November 2021 (15:17:16 CET)
: Cattle farming is an ancient practice, with roots in the early Neolithic era that has retained its status in the food industry today, with global beef market revenue amounting to $385.7B, as of 2018. Hence, cattle maintenance is naturally essential to cater to nutritional requirements of modern civilization. This extensive review aims to provide a holistic overview of cattle microbiome, analysing the native microbial composition within respiratory tract, gastrointestinal tract, reproductive tract, and skin. The dysbiosis associated with various diseases such as bovine respiratory disease, bovine digital dermatitis, mastitis, Johne's disease, uterine diseases (metritis and endometritis) and metabolic disorders (ruminal acidosis and ketosis) has been discussed. Moreover, various non-antibiotic microbial therapies including phage therapy, prebiotics and probiotics have been examined as potential means to reduce disease-associated dysbiosis. In general, this review highlights the importance of the microbiome in maintenance of health in cattle and its potential in alleviating bovine diseases, with an aim to enhance cattle health and production.
REVIEW | doi:10.20944/preprints202102.0393.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Microbiome; Personalized Medicine; Integrative Oncology; Oncobiotic
Online: 17 February 2021 (13:29:27 CET)
Sound evidence recognizes the microbiota as one of the major players in human health and disease, including cancer. Every human being is an holobiont, a shared human and microbial ecosystem, in which microbial composition is individually set by behaviours and environmental factors during the first years of life. Thereafter it is modulated by diet, physical activity, emotions and drugs (in particularly antibiotics and chemotherapeutics). As a consequence, a shift in medicine is needed toward a more comprehensive practice that takes into account every individual's genoma and, in addition, his or her metagenome, known as microbiome: a "microbiota revolution". As regards breast cancer (BC), a clear link between microbiota and oncogenesis is still to be confirmed. Specific microbes display unique features regulating their host niche in a number of body sites, which can result in an increased risk of cancer; in addition, gut microbiota composition plays a role in immune modulation within the intestinal barrier, affecting local and systemic inflammation, recognized drivers of cancer. Moreover, part of the bacterial gene mass inside the gut, constituting the so called “estrobolome”, influences the sexual hormonal balance and subsequentely may impact on the onset, progression and treatment of hormonal dependent cancers. Microbiota is also clearly involved in modulating the response to anticancer treatments, and above all to the emerging immunotherapy. Based on these premises, the microbiome is becoming a potential target, in order to enhance efficacy of antitumoral treatments as well as to lower their toxicity. The complex scenario that links microbiome composition to oncogenesis and response to anticancer treatments defines the frames of a new “oncobiotic” perspective.
ARTICLE | doi:10.20944/preprints202101.0455.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Knee Osteoarthritis; Vitamin D; gut microbiome
Online: 22 January 2021 (14:29:58 CET)
Background: A Few preclinical studies have shown that Knee osteoarthritis (KOA) is linked to gut microbiome dysbiosis and chronic inflammation. This pilot study was designed to look at the gut microbiome composition in KOA patients and normal individuals with or without vitamin D deficiency (VDD, serum vitamin D <30 ng/ml). Methods: This pilot study was conducted prospectively in 24 participants. The faecal samples of all the participants were taken for DNA extraction. The V3-V4 region of 16s rRNA was amplified and the library was prepared and sequenced on the Illumina Miseq platform. Results: The mean (±SD) age was 45.5 (±10.2) years with no defined co-morbidities. Of 447 total Operational Taxonomic Units (OTUs), a differential abundance of 16 nominally significant OTUs between the groups were observed. Linear discriminate analysis (LEfSe) revealed a significant difference in bacteria among the study groups. Pseudobutyrivibrio and Odoribacter were specific for VDD while Parabacteroides, Butyricimonas, and Gordonibacter were abundant in the KOA_VDD group and Peptococcus, Intestimonas, Delftia, and Oribacterium were abundant in the KOA group. About 80% of bacterial species were common among different groups and hence labeled as core bacterial species. However, the core microbiome of KOA and VDD groups were not seen in the KOA_VDD group, suggesting that these bacterial groups were affected by the interaction of the KOA and VDD factors. Conclusion: Parabacteroides, Butyricimonas, Pseudobutyrivibrio, Odoribacter, and Gordonibacter are the predominant bacteria in vitamin D deficient patients with or without KOA. Together these results indicate an association between the gut microbiome, vitamin D, and knee osteoarthritis.
Subject: Biology, Anatomy & Morphology Keywords: probiotic; pig; poultry; microbiota; microbiome; intestine
Online: 19 November 2020 (10:26:23 CET)
The intestinal microbiota and its functions are regarded as critical for host health and disease. Probiotics can influence the gut microbiome and its interactions with the host, and are currently defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”. Probiotics have become common components of strategies to promote livestock health, welfare and productivity, not least due to restrictions on the use of antimicrobial drugs. Common probiotic organisms are considered commensals and are ‘generally recognized as safe’ (GRAS) via oral administration. This review outlines potential probiotic mechanisms, including recent findings. These mechanisms include those interactions primarily occurring between the supplemented probiotic microorganisms and the indigenous intestinal microbiota, perhaps within the gut lumen, as well as more direct interactions with the host via mucosal receptors or more distally following absorption of microbial components. There is good evidence that the gut microbiome is relatively stable in ‘healthy’ individuals and resistant to ‘colonisation’ by exogenous microbes, which helps exclude pathogens, but has implications for the establishment of probiotics, and could increase the importance of microbe-microbe interactions. However, such microbiomes may be receptive to complementary microbes or functions, while supplemented probiotics may dominate luminal populations, particularly in less populated regions of the intestine. Moreover, host-adapted microbes or microbiomes may elicit different host responses and/or be more effective. Some considerations for the interpretation of study results, including extrapolation from different models or microbial strains, are also included. In addition, notable mechanistic and/or pathogen challenge studies from pigs and poultry are highlighted to underline the recognised potential of probiotics in these species, particularly as the appropriate selection of microorganisms and their application continues to be better understood and improve.
ARTICLE | doi:10.20944/preprints201911.0147.v1
Subject: Life Sciences, Microbiology Keywords: endometriosis; microbiome; 16s-rrna sequencing; atopobium
Online: 13 November 2019 (11:42:32 CET)
Abstract Objective: Endometriosis is a chronic disease characterized by the growth of endometrial cells outside the uterine cavity. The dysfunction of the immune system is strongly associated with the progression of endometriosis, and is also correlated to the diversity of microbiota in the genital tract. According to previous studies, the microbiota significantly contributes to multi-systemic function, but the evidence of endometriosis and adenomyosis remains insufficient. Thus, the present study attempted to identify the characteristics of microbiota in endometriosis patients, and the connection between microbiota and immunological dysfunction. Methods: In order to compare and explore the potential microbiota correlated to endometriosis and adenomyosis in the genital tract, 134 samples obtained from the cervical canal, posterior fornix and uterine cavity were analyzed by 16s-rRNA sequencing. The raw data was filtered, analyzed and visualized, and bio-information methods were used to identify the different and distinctive characteristics of microbiota. Results: Two different locations near the cervix, cervical canal and posterior fornix, exhibited no differences in alpha diversity. Among the different disease groups, five microbiota were distinctive in the genus level, and Atopobium presented with the greatest significance in adenomyoisis-endometriosis patients. The LEfSe analysis failed to identify the special biomarkers, while several characteristic functions were identified through PICRUSt. Conclusion: Lactobacillus is dominant in the female lower genital tract, and Atopobium is distinctively higher in patients with endometriosis combined with adenomyosis. Several different functions of microbiota were explored, and these are found to be associated with endometriosis and adenomyosis. These findings may provide a new concept of microbiota/immune system/endometriosis system. There is an urgent need to investigate the potential microbial biomarkers of endometriosis in the future.
ARTICLE | doi:10.20944/preprints201806.0249.v1
Online: 15 June 2018 (09:54:47 CEST)
Tomato (Solanum lycopersicum L.) is widely consumed around the world is mostly affected by stresses and diseases that reduce yield and production. Research on sustainable technologies like the use of beneficial microorganismsis crucial to development sustainable management strategies. Endophytic bacteria might increase production as well as plant health.. In this work we studied the endobiome of tomato seeds of different cultivars since the plant genotype might affect the microbial community structure in terms of plant growth promoters as well as organisms for biocontrol. The conditions prevailing within seeds along the maturation period might have affected bacterial survival. This is such that seed endophytes share features, which are different from those of bacteria from other plant tissues. The community associated with different cultivars reflects the different resources available in the seed and its potential to prevent the attack of pathogens and to promote plant growth.
ARTICLE | doi:10.20944/preprints201710.0171.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: prebiotic; microbiota; fermentation; dietary fiber; microbiome
Online: 27 October 2017 (15:33:12 CEST)
Prebiotic dietary fiber supplements are commonly consumed to help meet fiber recommendations and improve gastrointestinal health by stimulating beneficial bacteria and the production of short-chain fatty acids (SCFAs), molecules beneficial to host health. The objective of this research project was to compare potential prebiotic effects and fermentability of five commonly consumed fibers using an in vitro fermentation system measuring changes in fecal microbiota, total gas production and formation of common SCFAs. Fecal donations were collected from three healthy volunteers. Materials analyzed included: pure beta-glucan, Oatwell (commercially available oat-bran containing 22% oat β-glucan), xylooligosaccharides (XOS), WholeFiber (dried chicory root containing inulin, pectin, and hemi/celluloses), and pure inulin. Oatwell had the highest production of propionate at 12 h (4.76 μmol/mL) compared to inulin, WholeFiber and XOS samples (p<0.03). Oatwell’s effect was similar to those of the pure beta-glucan samples, both samples promoted the highest mean propionate production at 24 h. XOS resulted in a significant increase in the genus Bifidobacterium after 24 h of fermentation (0 h: 0.67 OTUs; 24 h: 5.22 OTUs; p = 0.038). Inulin and WholeFiber increased the beneficial genus Collinsella, consistent with findings in clinical studies. All analyzed compounds were fermentable and promoted the formation of beneficial SCFAs.
ARTICLE | doi:10.20944/preprints202008.0206.v1
Subject: Life Sciences, Microbiology Keywords: tongue microbiome; salivary microbiome; amplicon sequence variant (ASV); operational taxonomical unit (OTU); denoising; DADA2; taxonomic classifier
Online: 8 August 2020 (09:29:46 CEST)
The bacterial composition of oral samples has traditionally been determined by PCR amplicon sequencing of 16S rRNA genes. Recent amplicon sequence variant (ASV)-based analyses of 16S rRNA genes differ from that based on operational taxonomic unit (OTU) clustering in the way it deals with sequences having potential errors. However, little information is available on its application in oral microbiome studies. Here, we conducted ASV-based analysis of oral microbiome samples using QIIME 2. We investigated the optimal parameters for sequence denoising, using DADA2, and found the trimming of the first 20 nucleotides from 5′-end of both paired reads avoided excessive sequence loss during chimera removal. Truncating reads at positions 240–245 allowed the removal of low-quality sequences while maintaining sufficient length to merge matching paired ends. Taxonomic assignment, using the naïve Bayes classifier trained with the V3-V4 region of reference 16S rRNA sequences in the extended human oral microbiome database (eHOMD), resulted in bacterial compositions similar to those of OTU-based analyses. Contrary to OTU-based clustering, ASV-based analysis showed taxonomic abundance at the genus or species level to not differ significantly in tongue microbiomes, regardless of brushing. QIIME 2 can, therefore, be a standard pipeline for ASV-based analysis of oral microbiomes.
ARTICLE | doi:10.20944/preprints202208.0026.v1
Subject: Biology, Plant Sciences Keywords: rhizosphere; phyllosphere; endophyte; plant microbiome; plant mycobiome; rare microbiome; fungi; bacteria; microbes; soil microbiology; inoculum; microbial ecology
Online: 1 August 2022 (15:22:30 CEST)
A plant’s health and productivity is influenced by its associated microbes. Although the common microbiome is often thought to be the most influential, significant numbers of rare or uncommon microbes (eg. specialized endosymbionts) may also play an important role in the health and productivity of certain plants in certain environments. To help identify rare/specialized bacteria and fungi in the most important angiosperm plants, we contrasted microbiomes of the shoots, roots and rhizospheres of Arabidopsis, Brachypodium, maize, wheat, sugarcane, rice, tomato, coffee, common bean, cassava, soybean, switchgrass, sunflower, Brachiaria, barley, sorghum, and pea. Plants were grown inside sealed jars on sterile sand or field soil. About 95% and 86% of fungal and bacterial diversity inside plants was uncommon, however judging by read abundance, up to half of the mycobiome consists of uncommon fungal cells, while less than 11% of bacterial endophytes are rare. Uncommon seed transmitted microbiomes consisted mostly of Proteobacteria, Firmicutes, Bacteriodetes, Ascomycetes and Basidiomycetes that most heavily colonized shoots, to a lesser extent roots and least of all rhizospheres. Soil served as a more diverse source of rare microbes than seeds, replacing or excluding the majority of the uncommon seed transmitted microbiome. With the rarest microbes, their colonization pattern could either be the result of stringent biotic filtering by most plants, or uneven/stochastic inoculum distribution in seeds or soil. Several strong plant-microbe associations were observed such as seed transmission to shoots, roots and/or rhizospheres of Sarocladium zeae (maize), Penicillium (pea and Phaseolus), and Curvularia (sugarcane), while robust bacterial colonization from cassava field soil occurred with the cyanobacteria Leptolyngbya into Arabidopsis and Panicum roots, and Streptomyces into cassava roots. Some abundant microbes such as Sakaguchia in rice shoots or Vermispora in Arabidopsis roots appeared in no other samples, suggesting they were infrequent, stochastically deposited propagules from either soil or seed (impossible to know based on the available data). Future experiments with culturing and cross inoculation of these microbes between plants may help us better understand host preferences and their role in plant productivity, perhaps leading to their use in crop microbiome engineering and enhancement of agricultural production.
REVIEW | doi:10.20944/preprints202205.0218.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: Microbiome; Endocrine disruptors; Estrobolome; Personalized medicine; Oncobiotic
Online: 17 May 2022 (03:25:56 CEST)
The microbiota is now recognized as one of the major players in human health and disease, in-cluding cancer. As regards breast cancer (BC), a clear link between microbiota and oncogenesis is still to be confirmed. Yet, part of the bacterial gene mass inside the gut, constituting the so called “estrobolome”, influences the sexual hormonal balance and, since the increased exposure to estrogens is associated with an increased risk, it may impact on the onset, progression, and treatment of hormonal dependent cancers, which account for more than 70% of all BCs. The hormonal dependent BCs are also affected by environmental and dietary endocrine disruptors and phytoestrogens which interact with microbiota in a bidirectional way: on one side disruptors can alter the composition and functions of the estrobolome, on the other the gut microbiota influences the metabolism of endocrine active food components. This review highlights the current evidence about the complex interplay between endocrine disruptors, phytoestrogens, microbiome, and BC, within the frames of a new “oncobiotic” perspective.
ARTICLE | doi:10.20944/preprints202202.0189.v1
Subject: Life Sciences, Microbiology Keywords: cyanosphere; cyanobacteria; Llayta; Nostoc macrocolonies; metagenomics; microbiome
Online: 15 February 2022 (20:25:40 CET)
Cyanobacteria biomasses are sources of secondary metabolites and nutritious ingredients such as vitamins, essential amino acids, and unsaturated fatty acids. Biochemical composition, presence of cyanotoxins and contaminants are major concerns to be addressed on such edible biomasses. Macrocolonies of a filamentous diazotrophic Nostoc species known as Llayta are found at Andean wetlands and consumed since pre-Columbian times in South America. Its biochemical composition has been previously conducted to assess their nutritious quality and cyanotoxicity. Macrocolonies of filamentous cyanobacteria are niches for colonization by diverse microorganisms; however, the Llayta microcolonies cyanosphere is unknown. Based on a culture-independent approach, we report the identification of members of the resilient microflora associated with Llayta trichomes after Gentamicin treatments. We have also reconstructed the genomes of the Llayta macrocolony-forming Nostoc sp. cyanobacterium (6,781,030 bp; GC content of 41.2%) and the genomes of five dominant bacteria genera (Mesorhizobium, Microvirga, Paracoccus, Aquimonas, and Blastomonas). The detection of genes and genes clusters involved in primary and secondary metabolism is described. Our results provide new insights on the metabolic capabilities and biotechnological potential of the Andean Nostoc cyanobacterium, and the ecological role and adaptive strategies of microorganisms living under extreme environmental conditions at the Andean wetlands.
ARTICLE | doi:10.20944/preprints202201.0296.v1
Online: 20 January 2022 (10:28:07 CET)
Human gut microbiome is associated with various diseases, including autism spectrum disorders (ASD). Variations of the taxonomical composition in the gut microbiome of children with ASD have been observed repeatedly. However, features and parameters of the CRISPR-Cas systems in the gut microbiome of children with ASD have not been investigated yet. Here we demonstrate such an analysis in comparison with the healthy microbiome. For the identification of CRISPR-Cas systems, we used a combination of the publicly available tools suited for completed genomes with subsequent filtrations. In all considered datasets, the microbiomes of children with ASD contained fewer arrays per Gb of assembly, than the control group, but the arrays included more spacers on average. These patterns were observed systematically in our datasets, although their statistical significance hardly matched the thresholds. CRISPR arrays from the microbiomes of children with ASD differed from the control group neither in the fractions of spacers with protospacers from known genomes, nor in the sets of known bacteriophages providing protospacers. The majority of bacterial protospacers of the gut microbiome systems for both children with ASD and the healthy ones was located in the prophage islands.
Subject: Biology, Anatomy & Morphology Keywords: uremia; uremic toxins; microbiome; chronic kidney disease
Online: 14 July 2021 (13:04:35 CEST)
Uremic toxins are the compounds that emerge in the blood when kidney excretory function is impaired. The cumulative detrimental effect of uremic toxins results in numerous health problems and eventually death during acute or chronic uremia, especially in end-stage renal disease. More than 100 different solutes rise during uremia; however, the exact origin for most of them is still discussable. There are 3 main sources for such compounds: exogenous ones are consumed with food, whereas endogenous are produced by host metabolism or by symbiotic microbiota metabolism. In this article, we identified uremic toxins presumably of gut microbiota origin. We analyzed various databases to get information on enzymatic reactions in bacteria and human organism potentially yielded uremic toxins and to determine what toxins could be synthetized in bacteria residing in human gut. We selected biochemical pathways resulting in uremic toxins synthesis related to specific bacterial strains, and revealed links between toxin concentration in uremia and the proportion of different bacteria species, which can synthesize it. Moreover, we defined the relative abundance of human toxin-generating enzymes as well as the possibility of a particular toxin synthesis by the human metabolism. Finally, we analyzed which bacteria are potentially producing the biggest number of uremic toxins as well as which bacteria are decomposing them. Our study presents a bioinformatics-based approach for both elucidation of the origin of uremic toxins and search of the most likely human microbiome producers of toxins that can be targeted and used for the therapy of adverse consequences of uremia.
Subject: Life Sciences, Biochemistry Keywords: digestible energy; growth performance; microbiome; metabolome; donkey
Online: 1 March 2021 (13:28:35 CET)
Little information is available regarding the impacts of dietary energy level on the gut microbiota and metabolites of donkeys. This studied aimed to explore the effects of dietary energy content on growth performance, intestinal microbiome and metabolome of Dezhou donkeys. Thirty-six 9-month-old male Dezhou donkeys were assigned to two groups fed low or high content energy diets (LE or HE). Results showed that donkeys fed HE had improved (P < 0.05) the average daily gain (ADG) and feed efficiency (G/F), compared with those receiving LE diet. Compared to the LE group, feeding HE specially increased the abundances of unidentified_Prevotellaceae (P = 0.02) while decreased the richness of unidentified_Ruminococcaceae (P = 0.05) of donkeys. Compared to LE group, feeding HE diet significantly (P < 0.05) affected the metabolic pathways involving the aspartate metabolism and urea cycle. In addition, the increased bacteria and metabolites in the HE-fed group exhibited a positive correlation with improved growth performance of donkeys. Taken together, feeding HE diet increased the richness of some specific bacteria and upregulated growth-related metabolic pathways, which contributed to the augmented growth performance of donkeys. Thus, it is a recommendable dietary strategy to feed HE diet to fattening donkey for superior production performance and feed efficiency.
ARTICLE | doi:10.20944/preprints202101.0047.v1
Subject: Biology, Anatomy & Morphology Keywords: Stool; Fecal; Microbiome; Microbiota; Heterogeneous; Homogeneous; Sample
Online: 4 January 2021 (13:29:00 CET)
Background. Inferior quality of biological material compromises data, slows discovery, and wastes research funds. The gut microbiome plays a critical role in human health and disease, yet little attention has been given to optimizing collection and processing methods of human stool. Methods. We collected the entire bowel movement from 2 healthy volunteers: one to examine stool sample heterogeneity and one to test stool sample handling parameters. Sequencing and bi-oinformatic analyses were used to examine the microbiome composition. Results. The microbiome profile varied depending on where the subsample was obtained from the stool. The exterior cortex of the stool was rich in specific phyla and deficient in others while the interior core of the stool revealed opposite microbiome profiles. Sample processing also re-sulted in varying microbiome profiles. Homogenization and stabilization at 4°C gave superior microbial diversity profiles compared to the fresh or frozen subsamples of the same stool sample. Bacterial proliferation continued in the fresh subsample when processed at ambient temperature. Bacteroidetes proliferated and Firmicutes diminished during the 30-minute processing of fresh sample. The frozen sample had good overall diversity but Proteobacteria diminished likely be-cause of the freeze/thaw. Conclusions. The microbiome profile is specific to the section of the stool being sampled. Stool sample collection, homogenization, and stabilization at 4°C for 24 hours provides a “neat”, high-quality sample of sufficient quantity that can be banked into aliquots with nearly identical microbial diversity profiles. This collection pipeline is essential to accelerate our understanding of the gut microbiome in health and disease.
Subject: Life Sciences, Microbiology Keywords: Computational methods; machine learning; microbiome-host interactions
Online: 7 September 2020 (14:50:42 CEST)
The microbiome, by virtue of its interactions with the host, is implicated in various host functions including its influence on inflammation, nutrition, and homeostasis. Although driven by a complex combination of intrinsic and extrinsic factors, many chronic diseases such as diabetes, cancer, Inflammatory Bowel Disease among others are characterized by a disruption of microbial communities in at least one biological niche/organ system. Various molecular mechanisms between microbial and host components such as proteins, RNAs, metabolites etc have recently been elucidated, thus filling many gaps in our understanding of how the microbiome modulates host processes. Concurrently, high throughput technologies have enabled the profiling of heterogeneous datasets capturing community level changes in the microbiome as well as the host responses. However, due to pragmatic limitations with respect to parallel sampling and analytical procedures, big gaps still exist in terms of how the microbiome mechanistically influences host functions at a systems and community level. In the past decade, various computational biology and machine learning methodologies and approaches have been developed with an aim to fill these existing gaps. Due to the agnostic nature of the tools, they have been applied in various disease contexts to analyze and infer the interactions between the microbiome and host molecular components, and in the case of a few selected tools, on downstream host processes. Generally, most of the tools are enabled by frameworks to statistically or mechanistically integrate different types of -omic and meta -omic datasets followed by functional/biological interpretation. In this review, we provide an overview of the landscape of computational approaches for investigating mechanistic microbiome-host interactions and their potential benefit for basic and clinical research. These could include but are not limited to the development of activity and mechanism based biomarkers, uncovering mechanisms for therapeutic interventions and generating integrated signatures to stratify patients.
ARTICLE | doi:10.20944/preprints202004.0404.v1
Subject: Medicine & Pharmacology, Pediatrics Keywords: milk; human; microbiota; microbiome; extracellular vesicle; breastfeeding
Online: 23 April 2020 (05:11:19 CEST)
The microbiota of human breast milk (HBM) contributes to infant gut colonization; however, whether bacterial extracellular vesicles (EVs) are present in HBM or might contribute to this process remains unknown. In the present study, we characterized the HBM microbiota of healthy Korean mothers and measured the key bacteria likely affecting infant gut colonization by analyzing both the microbiota and bacterial EVs. A total of 22 HBM samples were collected from lactating mothers. The DNA of bacteria and bacteria-derived EVs was extracted from each sample. Gene analysis was performed using Illumina MiSeq. Firmicutes accounted for the largest portion among the phyla, followed by Proteobacteria, Bacteroides, and Actinobacteria in both bacteria and bacterial EV samples. At the genus level, Streptococcus (25.1%) and Staphylococcus (10.7%) were predominant in bacterial samples, whereas Bacteroides (9.1%), Acinetobacter (6.9%), and Lactobacillaceae(f) (5.5%) were prevalent in bacterial EV samples. Several genera including Bifidobacterium were significantly positively correlated between the two samples. Our findings reveal the diverse bacterial communities in HBM of healthy lactating mothers and suggest the presence of key bacteria with metabolic activity in HBM and that EVs derived from these bacteria may contribute to the vertical transfer of gut microbiota from mother to infant.
ARTICLE | doi:10.20944/preprints202002.0192.v1
Subject: Biology, Animal Sciences & Zoology Keywords: bacteria; fungi; livestock; microbiome; next generation sequencing
Online: 14 February 2020 (10:32:54 CET)
Ruminal microorganisms play a pivotal role in cattle nutrition. The discovery of the main microbes responsible for enhancing the gain of weight in beef cattle might be used in therapeutic approaches to increase animal performance and cause less environmental damages. Here, we examined differences in bacterial and fungal composition of rumen samples of Braford heifers raised in a natural grassland from Pampa Biome in Brazil. We aimed to detect microbial patterns in the rumen that could be correlated with the gain of weight. 16S and ITS1 genes were amplified from ruminal samples and sequenced to identify the closest microbial relatives within the microbial communities. A predictive model based on microbes responsible for the gain of weight was build and further tested using the entire dataset. The model detected a set of microorganisms associated with animals in the high gain of weight group, including the bacterial taxa RFN20, Prevotella, Anaeroplasma and RF16 and the fungal taxa Aureobasidium, Cryptococcus, Sarocladium, Pleosporales and Tremellales. Most of these organisms have been correlated to the production of substances that improve the ruminal digestion process. These findings provide new insights about cattle nutrition and suggest the use of these microbes to improve beef cattle breeding.
REVIEW | doi:10.20944/preprints202001.0228.v1
Subject: Medicine & Pharmacology, Other Keywords: autoimmune disease; autoimmunity; dysbiosis; Mediterranean diet; microbiome
Online: 21 January 2020 (02:58:57 CET)
The nutritional habits regulate the gut microbiota and may provoke and/or prevent autoimmune disease. Western diet is rich in sugars, meat and poly-unsaturated fatty acids, which lead to dysbiosis of intestinal microbiota, disruption of gut epithelial barrier and chronic mucosal inflammation. On the other hand, Mediterranean Diet (MedDiet) is rich in ω3 fatty acids, fruits and vegetables and has anti-inflammatory properties, which can restore gut eubiosis. The effect of MedDiet and its components in health and disease states have been thoroughly analyzed in several studies. Moreover, several studies have specifically investigated the association between MedDiet, microbiota and risk for autoimmune diseases. Furthermore, the MedDiet has been associated with lower risk of cardiovascular diseases, which plays a critical role in reducing mortality in patients suffering from autoimmune diseases with comorbidities. The aim of the present review is to specifically highlight current knowledge regarding possible interactions of MedDiet with the patterns of intestinal microbiota focusing on autoimmunity and a blueprint through dietary modulations for the prevention and management of diseases’s activity and progression.
Subject: Life Sciences, Biophysics Keywords: microbiome; complex networks; species diversity; criticality; RSA; information flow; transitions
Online: 28 March 2019 (09:10:18 CET)
The human microbiome is an extremely complex ecosystem considering the amount of bacterial species, their interactions, and its variability over time. Here we untangle the complexity of the human microbiome for the Irritable Bowel Syndrome (IBS) that is the most prevalent functional gastrointestinal disorder in human populations. Based on a novel information theoretic network inference model we detect species interaction networks that are functionally and structurally different for healthy and unhealthy individuals. Healthy networks are characterized by a neutral symmetrical pattern of species interactions and scale-free topology versus random unhealthy networks. We detect an inverse scaling relationship between species total outgoing information flow, meaningful of node interactivity, and relative species abundance (RSA). The top ten interacting species are also the least relatively abundant for the healthy microbiome and the most detrimental. These findings support the idea about the diminishing role of network hubs and hubs should be defined considering the total outgoing information flow rather than the node degree. Macroecologically, the healthy microbiome is characterized by the highest total species diversity growth rate, the lowest species turnover, and the smallest variability of RSA for all species. This result challenges current views that posit a universal association between healthy states and the highest absolute species diversity in ecosystems. Additionally, we show how the transitory microbiome is unstable and microbiome criticality is not at the phase transition between healthy and unhealthy states. We stress out the importance of considering interacting pairs versus single node dynamics when characterizing the microbiome and of ranking these pairs in terms of their dynamics. Interactions (i.e. species collective behavior) shape transition from healthy to unhealthy states.\\ The macroecological characterization of the microbiome is useful for diagnostic purposes and disease etiognosis, while species-specific analyses can detect species that are more beneficial leading to personalized design of pre- and pro-biotic treatments and microbiome engineering.
ARTICLE | doi:10.20944/preprints201807.0128.v1
Subject: Life Sciences, Microbiology Keywords: human virome; human microbiome; bacteriophage; elderly adults
Online: 9 July 2018 (10:50:10 CEST)
The human virome is an area of increasing interest with relation to human health and disease. It has been demonstrated to alter in concert with the bacterial microbiome in early life and was also found to be different in patients with certain diseases such as inflammatory bowel disease. However, all virome analyses are hampered by a lack of annotated representative database sequences, often referred to as the ‘viral dark matter’. Here we provide the first description of the gut DNA virome in elderly individuals (>65 years old) as well as the description of novel bacteriophages not present in current reference databases. Diversity analysis comparing elderly persons from different residence locations (community living vs long term care facilities) did not reveal any difference in their virome diversity profiles despite the reported differences at the bacteriome level. An abundance of Microviridae of the subfamily Gokushovirinae were present in the faeces of elderly individuals. Several novel members of the order Caudovirales were also characterized and annotated. Assignment of host bacteria to detected viral genomes was attempted using a combination of CRISPR spacers, tRNA genes and a probabilistic approach. Further characterization of the viral dark matter is necessary for developing tools and expanding databases to study the human virome. This study focused on the virome of an aging human cohort with the goal of illuminating part of the viral dark matter.
REVIEW | doi:10.20944/preprints201801.0081.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: insulin resistance; diet; exercise; microbiome; metabolic disorders
Online: 9 January 2018 (10:05:09 CET)
Insulin resistance is a prominent pathophysiologic syndrome in a plethora of metabolic disorders including obesity, prediabetes, type 2 Diabetes Mellitus (Ten et al., 2007), impaired glucose tolerance, dyslipidemia, polycystic ovary syndrome and hypercoagulability (Smith & LeRoith, 2004). It is strongly associated with obstructive sleep apnea, hypoventilation syndrome, pancreatitis, nonalcoholic fatty liver disease, steatohepatitis, cirrhosis, gall bladder disease, multiple cancers (breasts, uterus, cervix prostate, kidney, colon, esophagus, pancreas and liver), stroke, cataracts, coronary heart disease, and hypertension. It is also associated with causation of abnormal menses, infertility, polycystic ovary syndrome, osteoarthritis, phlebitis and other venous diseases. Insulin resistance is thought to be caused by intrinsic and extrinsic factors that contribute to its development. Once present, insulin resistance affects the metabolism, behavior, physical appearance and has lasting effects. This paper will review the latest evidence in development of insulin resistance, its pathogenesis and manifestation and its relation to other conditions. The final aim is to raise awareness of its role on diet, metabolic, genetics and microbiome.
Subject: Medicine & Pharmacology, Dermatology Keywords: topical steroid withdrawal; topical steroids; eczema; atopic dermatitis; skin microbiome; gut mi-crobiome; microbiome; biodiversity; skin allergy epidemic;
Online: 8 September 2021 (20:19:35 CEST)
We set up this preliminary study to evaluate one main question: could strengthening the microbiome have potential benefits for patients suffering with adverse effects after stopping long term topical steroid use? We aim to turn it into a much larger study if the results show promise. After commonly being prescribed for eczema, cessation of topical steroid use, especially after long periods of inappropriate use, can leave lasting adverse effects on the body and skin, known by some as topical steroid withdrawal (TSW). Furthermore, the subsequent withdrawal the body experiences when coming off the drug can leave lasting adverse effects on the body and skin, known by some as topical steroid withdrawal (TSW). This preliminary study involved seven human participants suffering with skin problems associated with TSW who approached Dr. Anja Gijsberts-Veens of their own volition because they were interested in more natural recovery methods. Five completed the study in full. Progress in skin condition was tracked by self-assessed symptom severity questionnaires filled out at the beginning and end of the study. The skin microbiome was addressed by using a 100% natural product shown in previous work to significantly increase skin microbiome biodiversity. Three participants implemented dietary changes and supplementation in response to guidance after fecal sample analysis to improve their gut health and biodiversity. The average improvement in skin symptoms for all participants was 40% and average symptom improvement ranged from 14% for Patient 5 to 92% for Patient 1. On average, the participants saw an improvement in 85% of their symptoms and a stagnation or regression in 11% and 4% respectively. We believe these results show enough promise to warrant expansion of this research to use a larger sample size, preferably 50+ participants, in future work. We also aim to swab the skin of participants to assess the effect on the skin microbiome from skin and gut treatments, as well as including more in-depth analysis of skin and gut microbiomes.
REVIEW | doi:10.20944/preprints202209.0113.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: Cancer; Immunotherapy; Microbiome; Immune Checkpoint Inhibitor; Immunology; Therapy
Online: 7 September 2022 (12:42:28 CEST)
Abstract: The gut microbiome refers to microorganisms and their genetic material influencing local and systemic inflammation. Inflammation is known to contribute to cancer development, progression, and treatment. Evidence suggests that modulating the gut microbiome may affect responses to various cancer therapies. The gut microbiota has been suggested to have an impact on immunotherapy efficacy, especially the currently widely used immune checkpoint inhibitors in various malignancies. Microbial Interventions like fecal microbiota transplantation, various probiotics, or even antibiotics can increase or de-crease the tumor's sensitivity to immunotherapy. However, not all tumors react in the same manner, highlighting the tumor microenvironment heterogeneity across tumor types and the influence this has on the crosstalk between the microbiome and therapy outcomes. In this study, we intend to review the association between the gut microbiota and immunotherapy response in cancer patients and the factors regulating this interaction.
REVIEW | doi:10.20944/preprints202112.0447.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: cancer; immunotherapy; biomarker; microenvironment; microbiome; flow cytometry; cytokine
Online: 28 December 2021 (11:13:13 CET)
Immune Checkpoint Inhibitors are monoclonal antibodies that are used to treat over one in three cancer patients. While they have changed the natural history of disease, prolonging life and preserving quality of life, they are highly active in less than 40% of patients, even in the most responsive malignancies such as melanoma, and cause significant autoimmune side effects. Licenced biomarkers include tumour Programmed Death Ligand 1 expression by immunohistochemistry, microsatellite instability, and Tumour Mutational Burden, none of which are particularly sensitive or specific. Emerging tumour and immune tissue biomarkers such as novel immunohistochemistry scores, tumour, stromal and immune cell gene expression profiling, and liquid biomarkers such as systemic inflammatory markers, kynurenine/tryptophan ratio, circulating immune cells, cytokines and DNA are discussed in this review. We also examine the influence of the faecal microbiome on treatment outcome and its use as a biomarker of response and toxicity.
REVIEW | doi:10.20944/preprints202112.0069.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: microbiome; golf turf; turfgrasses; biocontrol; microbial communities; endophytes
Online: 6 December 2021 (12:19:16 CET)
Golf courses have a significant environmental impact. High water demands and the intensive use of agricultural chemicals have been a concern for decades and are therefore in the focus of efforts to make golf courses more environmentally sustainable. Products based on modifying or using plant-associated microbiota are one of the fastest growing sectors in agriculture, but their application on turfgrasses on golf courses is so far negligible. In this review, we summarize the limited knowledge on microbiomes of golf turf ecosystems and show that the lack of holistic studies addressing structure and function of golf turf microbiomes, including their responses to intense turf management procedures, is currently the main bottleneck for development and improvement of reliable, well-functioning microbial products. We further highlight the endosphere of turfgrasses, which is easily accessible for microbial cultivation through constant mowing, as the most stable and protected micro-environment. Many grass species do possess endophytic bacteria and fungi that have shown to improve the plants’ resistance towards microbial pathogens and insect pests, and several products using endophyte-enhanced grass varieties are commercially successful. We anticipated that this trend would tee-off on golf courses, too, once a more comprehensive understanding of golf turf microbiomes is available.
ARTICLE | doi:10.20944/preprints202106.0339.v1
Subject: Life Sciences, Biochemistry Keywords: microbiota; microbiome; manipulation; fiber; diet; prebiotic; nutrition; supplement
Online: 14 June 2021 (09:19:54 CEST)
Consumption of prebiotic fibers to modulate the human gut microbiome is a promising strategy to positively impact health. Nevertheless, given the compositional complexity of the microbiome and its inter-individual variances, generalized recommendations on the source or amount of fiber supplements remain vague. This problem is further compounded by availability of tractable in vitro and in vivo models to validate certain fibers. We employed a gnotobiotic mouse model containing an a priori characterized 14-member synthetic human gut microbiome (SM) for their ability to metabolize a suit of fibers in vitro; the SM contains 14 different strains belonging to five distinct phyla. Since soluble purified fibers have been a common subject of studies, we specifically investigated the effects of concentrated raw fibers (CRFs)—containing fibers from pea, oat, psyllium, wheat and apple—on the compositional and functional alterations in the SM. We demonstrate that, compared to a fiber-free diet, CRF supplementation increased the abundance of fiber-degraders namely Eubacterium rectale, Roseburia intestinalis and Bacteroides ovatus and decreased the abundance of the mucin-degrader Akkermansia muciniphila. These results were corroborated by a general increase of bacterial fiber-degrading α-glucosidase enzyme activity. Overall, our results highlight the ability of CRFs to enhance the microbial fiber-degrading capacity.
REVIEW | doi:10.20944/preprints202105.0372.v1
Subject: Life Sciences, Biochemistry Keywords: Aging; Microbiome; Probiotics; Cellular senescence; SASP; Stress; Immunity
Online: 17 May 2021 (08:51:53 CEST)
The significance of diversity, composition, and functional attributes of the gut microbiota is recognized in human health and disease. Studies have also shown that the gut microbiota is related to human aging, and a causal relationship between gut microflora dysbiosis and chronic age-related disorders is also becoming apparent. Further, emerging evidence indicates that age-associated changes in the gut microbiome are predictors of human survival and longevity. Recent advances in our understanding of the cellular and molecular aspects of biological aging have revealed a cellular senescence-centric view of the aging process. However, the association between gut microbiome and cellular senescence is only beginning to be understood. The present review provides an integrative view of the emerging relationship between the gut microbiome and cellular senescence in aging and disease. Evidence relating to microbiome-mediated modulation of senescent cells, as well as senescent cells-mediated changes in intestinal homeostasis have been discussed. Unanswered questions and future research directions have also been deliberated to truly ascertain the relationship of the gut microbiome and cellular senescence for developing microbiome-based age-delaying and longevity promoting therapies.
Subject: Life Sciences, Biochemistry Keywords: Gut-Brain Axis; Nutrition; Microbiome; SCFA; Gut dysbiosis
Online: 13 May 2021 (13:30:00 CEST)
Diet plays a pivotal role in the overall health of an individual. Not only does it help carry out and regulate certain physiological functions, but it also can determine the composition of the gut microbiome. While the relative number of microorganisms that make up the gut microbiome vary between individuals and can be dependent on different environmental factors, there is evidence to suggest that composition of the microbiome can correlate with overall health or disease. When the GI microbiome is disturbed or suddenly changes it results in microbiome dysbiosis, a condition that correlates with the presence of certain diseases. Diseases linked to microbiome dysbiosis range from metabolic disorders, inflammatory bowel diseases to disorders of the brain. Many of these diseases are linked to the connection between the brain and the gut, known as the brain-gut axis. This bidirectional communication is important to maintain normal intestinal function, but is also responsible for the GI response to emotions as well as the emotional response to GI disturbances. By exploiting the interaction between microbiome health and nutrition, diet can be used to alleviate disease symptoms, protect against the development of certain conditions, and better maintain overall health. This review will examine the effects of nutrition on the microbiome, diseases linked to disruption of the normal microbiome, and the way that altering the diet can mitigate symptoms or prevent disease.
Subject: Biology, Anatomy & Morphology Keywords: chicken; coccidiosis; Eimeria; immunity; microbiome; phytogenics; probiotics; prebiotics
Online: 1 December 2020 (17:31:40 CET)
Coccidiosis remains a major disease and economic challenge for the global poultry industry. Coccidiosis in chickens is caused by seven Eimeria species that target specific regions of the gastrointestinal tract and cause malabsorptive or haemorrhagic disease. These Eimeria species infect segment-specific epithelial cells and thus need to navigate the host’s indigenous microbiome and intestinal defences to establish an infection and cause disease. Good husbandry practices, prophylactic use of anticoccidial drugs and/or live parasite vaccination have been the primary control measures employed but there are challenges with vaccination and growing constraints on anticoccidial drug use. This review, therefore, considers available information on the key steps of the infection process, notable microbiome- or host-related changes occurring, and the (potential) influence of dietary ‘alternatives’ to anticoccidial drugs. There is good available evidence to indicate that some phytogenics, prebiotics, probiotics, betaine, n-3 fatty acids, as well as carbohydrase enzymes and anti-IL-10 antibodies, can (beneficially) modulate at least some of these features in coccidiosis-specific challenge studies. As a minimum, these anticoccidial drug ‘alternatives’ could support the establishment of a desirable host microbiome and optimum immune system development. It is important to better understand the potential of these ‘alternatives’ in commercial production and how they can complement, or reduce, the use of anticoccidial drugs.
ARTICLE | doi:10.20944/preprints202007.0338.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: bacteriophage; Bifidobacterium; gut microbiota; intestinal health; microbiome; probiotic
Online: 15 July 2020 (12:32:41 CEST)
Probiotics are increasingly used by consumers and practitioners to reduce gastrointestinal (GI) distress and improve gut function. Here, we sought to determine whether addition of supplemental bacteriophages (PreforPro) could enhance the effects of a common probiotic, Bifidobacterium animalis subsp. lactis (B. lactis) on GI health. We conducted a 4-week, randomized, parallel-arm, double-blind, placebo-controlled trial where primary outcomes included self-assessments of GI health, a daily stool log, and 16s rRNA analysis of gut microbial populations. We observed within group improvements in GI inflammation (p=0.01) and a trending improvement in colon pain (p=0.08) in individuals consuming B. lactis with PreforPro, but not in the group consuming only the probiotic. There was also a larger increase in Lactobacillus and short chain fatty acid-producing microbial taxa detected in stool of participants taking PreforPro with B. lactis compared to the probiotic alone. Overall, these results suggest the addition of PreforPro as a combination therapy may alter gut ecology to extend the GI benefits of consuming B. lactis or other probiotics.
REVIEW | doi:10.20944/preprints202007.0068.v1
Subject: Life Sciences, Other Keywords: Microbiome; Plant Immunity; Priming; Transgenerational Immune Priming (TGIP)
Online: 5 July 2020 (11:35:04 CEST)
One of the biggest demanding situations for food security in the 21st century is to enhance crop yield stability through the improvement of diseases-resistant crops. Managing plant health is a major challenge for modern food production and compounded by the lack of common ground among the many disease control disciplines involved. All plants simultaneously engage with billions of microbes which can be collectively referred to as the plant microbiome. Most microbes inside the plant microbiome are harmless or even beneficial to the plant as they promote plant growth or provide protection in opposition to diseases. However, some of these microbes also cause disease with devastating effects on crop yields. To prevent pathogen infection, plants have evolved an advanced innate immune system that recognizes conserved cell surface molecules that most pathogen possesses. Activation of the plant immune system stops the invading pathogen, however this comes with fitness cost that significantly reduces plant growth and leads to yield penalty. Apart from their innate immune system controlling pre-programmed defense reactions, plants can also increase the responsiveness of their immune system in response to selected environmental signals. This phenomenon is known as “defense priming”. Although defense priming rarely provides full protection, its broad-spectrum effectiveness, low-fitness cost, long‐lasting durability and inherited to future generations make it attractive for sustainable crop protection.
ARTICLE | doi:10.20944/preprints201909.0070.v1
Subject: Life Sciences, Microbiology Keywords: Microbiome, Inferred functions, Database, 16S, Metagenomics, Comparative metagenomics
Online: 6 September 2019 (09:44:29 CEST)
Motivation: 16S rRNA gene amplicon based sequencing has significantly expanded the scope of metagenomics research by enabling microbial community analyses in a cost-effective manner. The possibility to infer functional potential of a microbiome through amplicon sequencing derived taxonomic abundance profiles has further strengthened the utility of 16S sequencing. In fact, a surge in 'inferred function metagenomic analysis' has recently taken place, wherein most 16S microbiome studies include inferred functional insights in addition to taxonomic characterization. Tools like PICRUSt, Tax4Fun, Vikodak and iVikodak have significantly eased the process of inferring function potential of a microbiome using the taxonomic abundance profile. A platform that can enable hosting of inferred function 'metagenomic studies' with comprehensive metadata driven search utilities (of a typical database), coupled with on-the-fly comparative analytics between studies of interest, can be a major improvement to the state of art. ReFDash represents an effort in the proposed direction. Methods: This work introduces ReFDash - a Repository of Functional Dashboards. ReFDash, developed as a significant extension of iVikodak (function inference tool), provides three broad unique offerings in inferred function space - (i) a platform that hosts a database of inferred function data being continously updated using public 16S metagenomic studies (ii) a tool to search studies of interest and compare upto three metagenomic environments on the fly (iii) a community initiative wherein users can contribute their own inferred function data to the platform. ReFDash therefore provides a first-of-its-kind community-driven frame-work for scientific collaboration, data analytics, and sharing in this area of microbiome research. Results: Overall, the ReFDash database is aimed at compiling together a global ensemble of 16S-derived Functional Metagenomics projects. ReFDash currently hosts close to 50 ready-to-use, re-analyzable functional dashboards representing data from approximately 18,000 microbiome samples sourced from various published studies. Each entry also provides direct downloadable links to associated taxonomic files and metadata employed for analysis. Conclusion: The vision behind ReFDash is creation of a framework, wherein users can not only analyze their microbiome datasets in functional terms, but also contribute towards building an information base by submitting their functional analyses to ReFDash database. ReFDash web-server may be freely accessed at https://web.rniapps.net/iVikodak/refdash/
COMMUNICATION | doi:10.20944/preprints201908.0034.v1
Subject: Biology, Entomology Keywords: freshwater insects; gut microbiome; nitrogen provisioning; nitrate reduction
Online: 5 August 2019 (00:48:14 CEST)
Biological nitrogen (N) provisioning is a seminal function of the gut microbes in several terrestrial insects, given the unbalanced carbon (C) and N ratios of their diets. Although freshwater insects face comparable dietary N limitations like terrestrial insects, little is known about this function by their gut microbiomes. In this study, we investigated microbial nitrate reduction to ammonium pathways as possible routes of biological N provisioning in two freshwater insects; filter-feeding Hydropsychidae and grazers/collectors Baetidae. After incubation in filtered (microbe-free) artificial stream water (ASW) containing dissolved 15N-labeled nitrate (treatment) or standard nitrate (control), bulk δ15N values of treatment samples (Baetidae = 100.62 ± 10.23, mean ± S.E.; Hydropsychidae = 76.82 ± 7.20) were significantly higher than controls (Baetidae = 10.14 ± 0.12 ; Hydropsychidae = 9.03 ± 0.20) in both functional feeding groups (F (3, 13) = 296, P < 0.0001). The treatment δ15N values are cautiously interpreted as reflecting uptake and incorporation of microbe-derived 15N-metabolites (15NH4 or 15N-amino acids) into host tissues following nitrate reduction to ammonium pathways in the gut lumen. Microbial nitrate reduction to ammonium activities was assessed via the quantification of dissimilatory (nrfA) and assimilatory (nasA) nitrate reduction to ammonium gene transcripts. There were no significant differences between control and treatment groups within each insect groups. Overall, this study provides a demonstration of the feasibility of applying 15N-stable isotope analysis for investigating, potential symbiotic functions of freshwater insect gut microbiomes, despite the preliminary nature of the results.
ARTICLE | doi:10.20944/preprints201807.0101.v1
Subject: Life Sciences, Microbiology Keywords: Human virome; human microbiome; elderly; viral dark matter
Online: 5 July 2018 (16:23:36 CEST)
The human virome is an area of increasing interest with relation to human health and disease. It has been demonstrated to alter in concert with the bacterial microbiome in early life and was also found to be different in patients with certain diseases such as inflammatory bowel disease. However, all virome analyses are hampered by a lack of annotated representative database sequences, often referred to as the ‘viral dark matter’. Here we provide the first description of the gut DNA virome in elderly individuals (>65 years old) as well as the description of novel bacteriophages not present in current reference databases. Diversity analysis comparing elderly persons from different residence locations (community living vs long term care facilities) did not reveal any difference in their virome diversity profiles despite the reported differences at the bacteriome level. An abundance of Microviridae of the subfamily Gokushovirinae were present in the faeces of elderly individuals. Several novel members of the order Caudovirales were also characterized and annotated. Assignment of host bacteria to detected viral genomes was attempted using a combination of CRISPR spacers, tRNA genes and a probabilistic approach. Further characterization of the viral dark matter is necessary for developing tools and expanding databases to study the human virome. This study focused on the virome of an aging human cohort with the goal of illuminating part of the viral dark matter.
REVIEW | doi:10.20944/preprints201803.0064.v2
Subject: Medicine & Pharmacology, Nutrition Keywords: western diet; microbiome; food processing; inflammation; metabolic diasease
Online: 19 March 2018 (07:31:47 CET)
The dietary pattern that characterizes the Western diet is strongly associated with obesity and related metabolic diseases, but biological mechanisms supporting these associations remain largely unknown. We argue that the Western diet promotes inflammation that arises from both structural and behavioral changes in the resident microbiome. The environment created in the gut by ultra-processed foods, a hallmark of the Western diet, is an evolutionarily unique selection ground for microbes that can promote diverse forms of inflammatory disease. Recognizing the importance of the microbiome in the development of diet-related disease has implications for future research, public dietary advice as well as food production practices. Research into food patterns suggests that whole foods are a common denominator of diets associated with a low level of diet-related disease. Hence, by studying how ultra-processing changes the properties of whole foods and how these foods affect the gut microbiome, more useful dietary guidelines can be made. Innovations in food production should be focusing on enabling health in the super-organism of man and microbe, and stronger regulation of potentially hazardous components of food products is warranted.
REVIEW | doi:10.20944/preprints201705.0062.v1
Subject: Life Sciences, Immunology Keywords: microbiome; probiotics, dietary supplements; nutrition; HIV infection, inflammation
Online: 8 May 2017 (12:10:17 CEST)
Microbiota plays a key role in various body’s functions, physiological, metabolic and immunological processes, through different mechanisms such as the regulation of the development and/or functions of different types of immune cells in the intestines. Several evidences indicate that alteration in the gut microbiota can influence infectious and non-infectious diseases. Bacteria that resides on the mucosal surface or within the mucus layer participate in interactions with the host immune system, and a healthy gut microbiota is essential for the development of mucosal immunity. The immunomodulatory activity of probiotics has been proposed in several bowel disorders or in aging-related dysfunctions. In HIV infected patients, the intestinal immune system is affected and inflammation persists during ART therapy too. Several studies are in progress to investigate the ability of probiotics to modulate epithelial barrier functions, microbiota composition and microbial translocation in HIV infection. This mini-review aims to suggest how the use of probiotics is beneficial not only in maintaining a healthy status but also to improve conditions in HIV subjects.
ARTICLE | doi:10.20944/preprints201703.0030.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: bacteria; bacteriome; carcinoma; microbiome; mouth; smokeless; snuff; tobacco
Online: 6 March 2017 (07:18:27 CET)
Smokeless tobacco (ST) products vary significantly in their oral carcinogenicity. Much is known about the differences in chemical, but not bacterial, constituents of these products. In this study, we explore the composition and function of the bacteriome in ST products from 4 countries using q-PCR and 16S rRNA-based next generation sequencing. The bacterial load (16S rRNA copies/gram) was lowest in Swedish snus (3.4E+6) and highest in Yemeni shammah (6.6E+11). A total of 491 species-level taxa, many of which are potentially novel, belonging to 178 genera and 11 phyla were identified. Species richness and diversity were highest for Swedish snus and lowest for Yemeni shammah. Bacillus, Paenibacillus, and Oceanobacillus spp. were the most abundant in American snuff; species of Pseudomonas, Massilia, Propionibacterium, Puniceispirillum and Gloeothece predominated in Swedish snus. In Sudanese toombak, Facklamia, Desemzia, Atopostipes and Lysinibacillus spp. accounted for the majority of the bacteriome. Yemeni shammah exclusively contained Bacillus spp. PICRUSt functional prediction showed that genes encoding cadmium/zinc and nickel transport systems were enriched in the presumptively “high carcinogenicity” products. The bacteriome of ST products thus differed qualitatively, quantitatively and functionally. The relevance of these differences, particularly with respect to nickel and cadmium, to oral carcinogenesis warrants further investigation.
REVIEW | doi:10.20944/preprints202207.0306.v2
Subject: Biology, Ecology Keywords: Coral symbiosis; immunity; microbiome; global change; coral holobiont; Symbiodiniaceae
Online: 14 September 2022 (15:33:09 CEST)
Tropical corals construct the three-dimensional framework for one of the most diverse ecosystems on the planet, providing habitat to a plethora of species across taxa. However, these ecosystem engineers are facing unprecedented challenges, such as increasing disease prevalence and marine heatwaves associated with anthropogenic global change. As a result, major declines in coral cover and health are being observed across the world's oceans, often due to the breakdown of coral-associated symbioses. Here, we review the interactions between the major symbiotic partners of the coral holobiont – the cnidarian host, algae in the family Symbiodiniaceae, and the microbiome – that influence trait variation, including the molecular mechanisms that underlie symbiosis and the resulting physiological benefits of different microbial partnerships. In doing so, we highlight the current framework for the formation and maintenance of cnidarian-Symbiodiniaceae symbiosis, and the role that immunity pathways play in this relationship. We emphasize that understanding these complex interactions is challenging when you consider the vast genetic variation of the cnidarian host and algal symbiont, as well as their highly diverse microbiome, which is also an important player in coral holobiont health. Given the complex interactions between and among symbiotic partners, we propose several research directions and approaches focused on symbiosis model systems and emerging technologies that will broaden our understanding of how these partner interactions may facilitate the prediction of coral holobiont phenotype, especially under rapid environmental change.
ARTICLE | doi:10.20944/preprints202206.0389.v1
Subject: Life Sciences, Microbiology Keywords: Ricefish; Microbiome; Ampicillin; Erythromycin; Immune and Stress-Related Genes
Online: 29 June 2022 (03:05:46 CEST)
Antibiotics have been used in various fields such as livestock farm and fish farm as well as hospital in order to treat diseases caused by bacteria. However, the antibiotics that are not completely decomposed, but remains as residue and discharge to aquatic environment, can cause an imbalance in the gut flora of host, as well as regulate abnormal host gene regulatory system. We investigated the effects of chronic exposure with the low concentrations of erythromycin and ampicillin on gut microbiome and immune and stress-related gene expression using Korea native ricefish (Oryzias latipes). As a result of microbiome analysis, the proportion of Proteobacteria was increased in the ricefish when exposed to erythromycin and ampicillin chronically, whereas the proportion of other bacterial phyla decreased. In addition, the immune and stress-related genes were significantly influenced in the ricefish under the chronic antibiotics exposure. These results show that the internal microbial flora and the host gene expression are susceptible even in the low concentration of chronic antibiotic existing environments. This study provides the importance of the appropriate use of antibiotics dose to maintain the sustainable and healthy aquaculture industry and water ecosystem.
ARTICLE | doi:10.20944/preprints202206.0298.v1
Subject: Biology, Ecology Keywords: cyanosphere; cyanobacteria; Cyanocohniella; Llayta; macrocolonies; metagenomic-assembled genome; microbiome
Online: 21 June 2022 (16:11:44 CEST)
Cyanobacterial macrocolonies known as Llayta are found at Andean wetlands and consumed since pre-Columbian times in South America. Macrocolonies of filamentous cyanobacteria are niches for colonization by other microorganisms; however, the microbiome of edible Llayta has not been explored. Based on a culture-independent approach, we report the presence, identification and metagenomic genome reconstruction of Cyanocohniella sp. LLY associated to Llayta trichomes. The assembled genome of strain LLY is now available for further inquiries, and may be instrumental for taxonomic advances on this genus. All known members of the Cyanocohniella genus have been isolated from salty European habitats. A biogeographic gap for the Cyanocohniella genus is partially filled by the existence of strain LLY at Andes Mountains wetlands in South America as a new habitat. This is the first genome available for members of this genus. Genes involved in primary and secondary metabolism are described providing new insights on the putative metabolic capabilities of Cyanocohniella sp. LLY. The reconstructed genome of strain LLY is now available and instrumental for further inquiries and taxonomic advances on the genus Cyanocohniella.
ARTICLE | doi:10.20944/preprints202204.0265.v1
Subject: Life Sciences, Microbiology Keywords: Microbiome; Rhizosphere; Metabarcoding; 16S rDNA; Agriculture lands; Reclaimed lands
Online: 28 April 2022 (03:24:56 CEST)
Plants especially in their natural habitat are considered part of a rich ecosystem that includes many various microorganisms in the soil. The current study aimed to identify the bacterial profile of agriculture-related soil samples using the metabarcoding technique to compare and explore relevant rhizosphere bacteria associated with plant cultivations in newly reclaimed land and habitual cultivated ones. Total environmental DNA was extracted from rhizosphere and non-cultivated samples derived from three land types in Egypt. The bacterial 16S rDNA was amplified and sequenced by NGS technology to profile each sample. The microbial profile was characterized by statistical and literature-based methods. Among all samples, the most identified phyla were Actinobacteriota (28%), followed by Proteobacteriota (26%), Firmicutes (14%), Ac-idobacteriota and Chloroflexi (7%), Gemmatimonadota (5%), Bacteriodota and Crenarchaeota (3%), and Myxococcota (2%), in addition to 37 other phyla with <1% counts. A total of 74 OTU was unique to the plant rhizosphere area and classified as Bacteriodota (5.1%:0.3%), Firmicutes (2.4%:0.1%), and Proteobacteria (3.5%:2%) phyla in agriculture and reclaimed lands, respectively. Moreover, the rhizosphere profile included a large portion of uncultured and unidentified bac-terial species, which opened a window to further analysis. Our analysis provides a key Knowledge about the rhizosphere microbiome and highlights its possible use to create microbial-based bi-ofertilizers targeting plant performance in contrast to traditional fertilizers and their side effect on the agriculture sector.
ARTICLE | doi:10.20944/preprints202203.0399.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: microbiome; genetic algorithm; feature selection; human health; machine learning
Online: 31 March 2022 (08:00:03 CEST)
The relationship between the host and the microbiome, or the assemblage of microorganisms (including bacteria, archaea, fungi, and viruses), has been proven crucial for its health and disease development. The high dimensionality of microbiome datasets has often been addressed as a major difficulty for data analysis, such as the use of Machine Learning (ML) and Deep Learning (DL) models. Here we present BiGAMi, a bi-objective genetic algorithm fitness function for feature selection in microbial datasets to train high-performing phenotype classifiers. The proposed fitness function allowed us to build classifiers that outperformed the baseline performance estimated by the original studies by using as few as 0.04% to 2.32% features of the original dataset. In 19 out of 21 classification exercises, BiGAMi achieved its results by selecting 6-68% fewer features than the highest performance of a Sequential Forward Feature Selection algorithm. This study showed that the application of a bi-objective GA fitness function against microbiome datasets succeeded in selecting small subsets of bacteria whose contribution to understood diseases and the host state was already experimentally proven. Applying this feature selection approach to novel diseases is expected to quickly reveal the microbes most relevant to a specific condition.
REVIEW | doi:10.20944/preprints202112.0503.v1
Subject: Life Sciences, Other Keywords: Plant Pathogen; Biocontrol; Microbes; AMF; Bacteriophages; Microbiome; Sustainable strategies
Online: 31 December 2021 (10:45:32 CET)
Food security has become a major concern worldwide in recent years due to ever increasing population. Providing food for the growing billions without disturbing environmental balance is incessantly required in the current scenario. In view of this, sustainable modes of agricultural practices offer better promise and hence are gaining prominence recently. Moreover, these methods have taken precedence currently over chemical-based methods of pest restriction and pathogen control. Adoption of Biological Control is one such crucial technique that is currently in the forefront. Over a period of time, various biocontrol strategies have been experimented with and some have exhibited great success and promise. This review highlights the different methods of plant-pathogen control, types of plant pathogens, their modus operandi and various biocontrol approaches employing a range of microorganisms and their byproducts. The study lays emphasis on the use of upcoming methodologies like microbiome management and engineering, phage cocktails, genetically modified biocontrol agents and microbial volatilome as available strategies to sustainable agricultural practices. More importantly, a critical analysis of the various methods enumerated in the paper indicates the need to amalgamate these techniques in order to improve the degree of biocontrol offered by them.
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Microbiome; Diazotroph; Nitrogen fixation bacteria; Random Forest; Network; Trichomona
Online: 23 August 2021 (12:15:31 CEST)
Biofertilizer, an environment-friendly and renewable plant nutrient source, has been widely applied and studied to reduce dependency on chemical fertilizers. However, most studies focus on the effects of biofertilizer on the bacterial and fungal communities, and we still lack an understanding of biofertilizer on the protistan community. Here, the effects of biofertilizer application on the composition and interaction of the protistan community in the wheat rhizosphere were investigated based on a 4-year field experiment. Biofertilizer application altered soil physicochemical properties and the protistan community composition (ANOSIM, p < 0.001), and significantly induced an alpha diversity decline. Random forecast and redundancy analysis demonstrated that nitrogenase activity and available phosphorus were the main drivers. Trichomonas classified to the phylum Metamonada was enriched by biofertilizer, and was significantly positive connections with soil nitrogenase activity and some function genes involved in nitrogen-fixation and nitrogen-dissimilation. Biofertilization loosely connected biotic interactions, while did not affect the stability of the protistan community. Besides, biofertilizer promoted the connections of protists with fungi, bacteria, and archaea. Combined with the conjunct biotic network (protist, fungi, bacteria, and archaea) and interactions between protists and soil physicochemical properties/function genes, protists may act as keystone taxa potentially driving soil microbiome composition and function.
REVIEW | doi:10.20944/preprints202106.0529.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Oral microbiome; oral cavity; dysbiosis; oral diseases; systemic diseases
Online: 22 June 2021 (07:47:57 CEST)
The human oral microbiome refers to an ecological community of symbiotic and pathogenic microorganisms found in the oral cavity. The oral cavity is a suitable environment that provides various kinds of biological niches such as teeth, tongue, and oral mucosa. The oral cavity is the gateway between the external environment and the human body, maintaining oral homeostasis, protecting the mouth, and preventing disease. On the flip side, the oral microbiome plays an important role in triggering, development, and progression of oral and systemic diseases. Currently, disease diagnosis through the analysis of the human oral microbiome has been realized with the recent development of innovative detection technology, and is overwhelmingly promising compared to the previous era. It has been found that patients with oral diseases and systemic diseases have variations in the oral microbiome compared to normal subjects. This narrative review provides insight into the pathophysiological role that oral microbiome plays in influencing oral and systemic diseases, and updates the knowledge related to the oral microbiome over the past 30 years. A wide range of updates was provided with the latest knowledge of the oral microbiome to help researchers and clinicians in both academic and clinical aspects. The microbial community information can be utilized in non-invasive diagnosis and help develop a new paradigm in precision medicine, which will benefit human health in the era of post-metagenomics.
REVIEW | doi:10.20944/preprints202106.0526.v1
Subject: Life Sciences, Biochemistry Keywords: virome; microbiome; next generation sequencing; mycoviruses; plant pathogenic viruses
Online: 21 June 2021 (16:23:44 CEST)
Forest health is dependent on the variability of microorganisms interacting with the host tree/holobiont. Symbiotic microbiota and pathogens engage in a permanent interplay, which influences the host. Thanks to the development of NGS technologies, a vast amount of genetic information on the virosphere of temperate forests has been gained the last seven years. To estimate the qualitative/quantitative impact of NGS in forest virology, we have summarized viruses affecting major tree/shrub species and their fungal associates, including fungal plant pathogens, mutualists and saprotrophs. The contribution of NGS methods is extremely significant for forest virology. Reviewed data about viral presence in holobionts, allowed us to address the role of the virome in the holobionts. Genetic variation is a crucial aspect in hologenome, significantly reinforced by horizontal gene transfer among all interacting actors. Through virus-virus interplays synergistic or antagonistic relations may evolve, which may drastically affect the health of the holobiont. Novel insights of these interplays may allow practical applications for forest plant protection based on endophytes and mycovirus biocontrol agents. The current analysis is conceived in light of the prospect that novel viruses may initiate an emergent infectious disease and that measures for avoidance of future outbreaks in forests should be considered.
REVIEW | doi:10.20944/preprints202012.0041.v1
Subject: Medicine & Pharmacology, Allergology Keywords: liver cirrhosis; liver fibrosis; gut microbiome' gut-liver axis
Online: 1 December 2020 (18:19:00 CET)
Liver cirrhosis is one of the most prevalent chronic liver diseases worldwide. In addition to viral hepatitis, genetic conditions such as steatohepatitis, autoimmune hepatitis, sclerosing cholangitis, and Wilson’s disease can also lead to cirrhosis. Moreover, alcohol can cause cirrhosis on its own and exacerbate chronic liver disease from other causes. The treatment of cirrhosis can be divided into addressing the cause of cirrhosis and reversing liver fibrosis. To this date, there is still no clear consensus on the treatment of cirrhosis. Recently, there has been a lot of interest in potential treatments that modulate the gut microbiota and gut-liver axis for the treatment of cirrhosis. According to recent studies, modulation of the gut microbiome by probiotics ameliorates the progression of liver disease. The precise mechanism for relieving cirrhosis via gut microbial modulation has not been identified. This paper summarizes the role and effects of the gut microbiome in cirrhosis based on experimental and clinical studies on absorbable antibiotics, probiotics, prebiotics, and synbiotics. Moreover, it provides evidence of a relationship between the gut microbiome and liver cirrhosis.
Subject: Earth Sciences, Atmospheric Science Keywords: Atacama microbiome; function prediction; extremophiles; osmotic stress; salt amendments
Online: 14 October 2020 (10:26:02 CEST)
Over the past 150 million years, the Chilean Atacama Desert has been transformed into one of the most inhospitable landscapes by geophysical changes, which makes it an ideal Mars analog that has been explored for decades. However, two heavy rainfalls that occurred in the Atacama in 2015 and 2017 provide a unique opportunity to study the response of resident extremophiles to rapid environmental change associated with excessive water and salt shock. Here we combine mineral/ salt composition measurements, amendment cell culture experiments, and next-generation sequencing analyses to study the variations in salts and microbial communities along a latitudinal aridity gradient of the Atacama Desert. In addition, we examine the reshuffling of Atacama microbiomes after the two rainfall events by comparing with previous researches. Analysis of microbial community composition revealed that soils within the southern arid desert were consistently dominated by Actinobacteria, Proteobacteria, Acidobacteria, Planctomycetes, Chloroflexi, Bacteroidetes, Gemmatimonadetes, and Verrucomicrobia. Intriguingly, the hyperarid microbial consortia exhibited a similar pattern to the more southern desert. Salts at the shallow subsurface were dissolved and leached down to a deeper layer, challenging indigenous microorganisms with the increasing osmotic stress. Microbial viability was found to change with aridity and rainfall events. This study sheds light on the structure of xerophilic, halophilic, and radioresistant microbiomes from the hyperarid northern desert to the less arid southern transition region, as well as their response to changes in water availability. Our findings may infer similar events that happened on the wetter early Mars.
CONCEPT PAPER | doi:10.20944/preprints202004.0358.v1
Subject: Life Sciences, Microbiology Keywords: MDR typhoid; metal resistant genes; water toxicity; gut microbiome
Online: 20 April 2020 (02:27:07 CEST)
AMR and drug void have caused huge panic today with few thousand death per year. MDR Typhoid was a serious old disease and caused serious health hazard in humen and animals demanding an update on molecular biology of the status on transferable genetic elements. R-plasmids combined in F’-plasmid and the new MDR conjugative plasmids were shown abundant in Sanmonella ranging 70-440kb with similarities. BlaTEM, blaCTX-M, blaOXA, blaNDM mdr genes were abundant in >50 plasmids analyzed and metal resistant gene clusters are predominant in most large plasmids. Among the acetyltransferase all catA1, aacA1 and aac-1b-cr genes were located. Abundant streptomycin phosphotransferases (StrAB) and rarely colistin resistant Mcr-5/9 phosphoethanolamine–lipid A transferase were detected. Altered isomeric dihydropterote synthases (Sul1/2/3) were present giving sulfamethoxazole resistance and dhfr gene frequently associated giving trimethoprim resistance. Metal resistant gene clusters like SilABC (CusABC), PcoAB, RcnA, terABC, and merABCXT etc were found in many Salmonella enterica plasmids. Toxin genes like HipA and virulence genes like spvABD were located in few plasmids increasing virulence and pathogenesis. Drug efflux genes tetA or tetB and OqxB, floR, CmlA were frequent where as QepA and EamA genes were rarely seen. Thus, Salmonella metal resistant genes combined with antibiotic resistant genes has tried to overcome the both toxic antibiotics and metalions causing Typhoid AMR. Such acquisition spreads salmoniasis in the live stocks (pig, cow, chicken) where toxic soil and water dominate increasing chance of MDR typhoid in human.
ARTICLE | doi:10.20944/preprints202002.0227.v1
Subject: Biology, Ecology Keywords: peatland management; microbiome; methanogens; dissolved organic matter; Methylococcaceae; sulfate
Online: 16 February 2020 (16:22:46 CET)
Drained peatlands are significant sources of the greenhouse gas (GHG) carbon dioxide. Rewetting is a proven strategy to protect carbon stocks; however, it can lead to increased emissions of the potent GHG methane. The response to rewetting of soil microbiomes as drivers of these processes is poorly understood, as are biotic and abiotic factors that control community composition. We analyzed the pro- and eukaryotic microbiomes of three contrasting pairs of minerotrophic fens subject to decade-long drainage and subsequent rewetting. Also, abiotic soil properties including moisture, dissolved organic matter, methane fluxes and ecosystem respiration rates. The composition of the microbiomes was fen-type-specific, but all rewetted sites showed higher abundance of anaerobic taxa compared to drained sites. Based on multi-variate statistics and network analyses we identified soil moisture as major driver of community composition. Furthermore, salinity drove the separation between coastal and freshwater fen communities. Methanogens were more than tenfold more abundant in rewetted than in drained sites, while their abundance was lowest in the coastal fen, likely due to competition with sulfate reducers. The microbiome compositions were reflected in methane fluxes from the sites. Our results shed light on the factors that structure fen microbiomes via environmental filtering.
Subject: Life Sciences, Microbiology Keywords: cananbis sativa; marijuana; hemp; microbiome; endophytes; secondary metabolites; Cannabinoids
Online: 15 January 2020 (07:04:25 CET)
Plants, including Cannabis (Cannabis sativa subsp. sativa) host distinct beneficial microbial communities on and inside their tissues, designated the plant microbiota from the moment that they are planted into the soil as seed. They contribute to plant growth promotion, facilitating mineral nutrient uptake, inducing defense resistance against pathogens, higher yield and modulating plant secondary metabolites. Understanding the microbial partnerships with Cannabis has the potential to affect agricultural practices by improving plant fitness and the production yield of cannabinoids. Much less is known about this beneficial Cannabis-microbe partnership, and the complex relationship between the endogenous microbes associated with various tissues of the plant, particularly, the role that cannabis may play in supporting or enhancing them. This review will focus on Cannabis microbiota studies and the effect of endophytes on the elicitation of secondary metabolites production in Cannabis plants. The aim of this review is to shed light on the importance of Cannabis microbiome and how cannabinoid compounds concentration can be stimulated through symbiotic and or mutualistic relationships with endophytes.
REVIEW | doi:10.20944/preprints201806.0152.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: protein; skeletal muscle; sarcopenia; gut microbiome; metabolome; diet; supplementation
Online: 11 June 2018 (11:05:04 CEST)
Muscle mass, strength and physical function are known to decline with age. This is associated with the development of geriatric syndromes including sarcopenia and frailty. These conditions are associated with disability, falls, longer hospital stay, higher readmission rates, institutionalisation, osteoporosis, and death. Moreover, they are associated with reduced quality of life, as well as substantial costs to health services around the world. Dietary protein is essential for skeletal muscle function. Older adults have shown evidence of anabolic resistance, where greater amounts of protein are required to stimulate muscle protein synthesis and therefore require higher daily amounts of dietary protein. Research shows that resistance exercise has the most beneficial effect on preserving skeletal muscle. A synergistic effect has been noted when this is combined with dietary protein, yet studies in this area lack consistency. This is due, in part, to the variation that exists within dietary protein, in terms of dose, quality, source, amino acid composition and timing. Research has targeted participants that are replete in dietary protein with negative results. Inconsistent measures of muscle mass, muscle function, physical activity and diet are used. This review attempts to summarise these issues, as well as introduce the possible role of the gut microbiome and its metabolome in this area.
ARTICLE | doi:10.20944/preprints201802.0090.v1
Subject: Life Sciences, Microbiology Keywords: antibiotics; geomicrobiology; Illumina sequencing; microbiome diversity; Streptomyces; Cave microbiology
Online: 12 February 2018 (16:30:42 CET)
Moonmilk are cave carbonate deposits that host a rich microbiome including antibiotic-producing Actinobacteria making these speleothems appealing for bioprospecting. Here we investigated the taxonomic profile of the actinobacterial community of three moonmilk deposits of the cave “Grotte des Collemboles” via high-throughput sequencing of 16S rRNA amplicons. Actinobacteria was the most common phylum after Proteobacteria, ranging from 9 to 23% of the total bacterial population. Next to actinobacterial OTUs attributed to uncultured organisms at the genus level (~44%), we identified 47 actinobacterial genera with Rhodoccocus (4 OTUs, 17%) and Pseudonocardia (9 OTUs, ~16%) as the most abundant in terms of absolute number of sequences. Streptomycetes presented the highest diversity (19 OTUs, 3%), with most of OTUs unlinked to the culturable Streptomyces strains previously isolated from the same deposits. 43% of OTUs were shared between the three studied collection points while 34% were exclusive to one deposit indicating that distinct speleothems host their own population despite their nearby localization. This important spatial diversity suggests that prospecting within different moonmilk deposits should result in the isolation of unique and novel Actinobacteria. These speleothems also host a wide range of non-streptomycetes antibiotic-producing genera, and should therefore be subjected to methodologies for isolating rare Actinobacteria.
ARTICLE | doi:10.20944/preprints202209.0177.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: non-target action; soil microbiome; pesticide contamination; fungicide; soil quality
Online: 13 September 2022 (11:00:07 CEST)
Pesticides are widely used in agriculture as a pest control strategy. Despite the benefits of pesticides on crop yields, the persistence of chemical residues in soil have an unintended impact on non-targeted microorganisms. In this study, we evaluated the impact of the combined fungicide (difenoconazole, epoxiconazole, and kresoxim-methyl) on fungal and bacterial communities of Phaeozem. In the fungicide-treated soil, the Shannon index of both fungal and bacterial communities was decreased, while Chao1 index did not differ compared to the control soil. Among bacterial taxa, the relative abundance of Athrobacter, Sphingomicrobium, and Sphingomonas increased in fungicide-treated soil due to their ability to utilize fungicides and other toxic compounds. Rhizopus and plant-beneficial Chaetomium were the dominant fungal genera, which increased 2-4 times in the fungicide-treated soil, while the relative abundance of Mortierella and Talaromyces decreased. Fusarium acuminatum was the most abundant phytopathogenic fungus that causes root rot disease of wheat, but applied fungicide treatment decreased their diversity in the soil 2 times, which is consistent on the observed plants.
ARTICLE | doi:10.20944/preprints202209.0098.v1
Subject: Life Sciences, Microbiology Keywords: MALDI-TOF; DNA Sequencing; environment; bacteria; Microbiome; bioinformatics; Dominican Republic
Online: 7 September 2022 (04:26:40 CEST)
Our research team compared the performance of matrix-assisted laser desorption/ionization followed by a time of flight (MALDI-TOF) mass spectrometry and genomic DNA extraction followed by sequencing, assembly and alignment for phylogenetic assessment. We performed these comparisons to determine our methodology’s overall efficacy and accuracy for environmental bacteria. In addition, we collected samples from various contaminated rivers in the Dominican Republic. For both methods, we analyzed these results and reported the main differences between each method.
ARTICLE | doi:10.20944/preprints201912.0383.v1
Subject: Biology, Ecology Keywords: terraformation; Mars; evolution; microbiome; synthetic biology; drylands; hypercycles; restoration ecology
Online: 29 December 2019 (13:23:07 CET)
What is the potential for synthetic biology as a way of engineering, on a large scale, complex ecosystems? Can it be used to change endangered ecological communities and rescue them to prevent their collapse? What are the best strategies for such ecological engineering paths to succeed? Is it possible to create stable, diverse synthetic ecosystems capable of persisting in closed environments? Can synthetic communities be created to thrive on planets different from ours? These and other questions pervade major future developments within synthetic biology. The goal of engineering ecosystems is plagued with all kinds of technological, scientific and ethic problems. In this paper we consider the requirements for Terraformation, i. e. for changing a given environment to make it hospitable to some given class of life forms. Although the standard use of this term involved strategies for planetary terraformation, it has been recently suggested that this approach could be applied to a very different context: ecological communities within our own planet. As discussed here, this includes multiple scales, from the gut microbiome to the entire biosphere.
REVIEW | doi:10.20944/preprints201910.0189.v1
Subject: Life Sciences, Microbiology Keywords: microbiome; microbiota-gut-brain axis; ADHD; attention-deficit-hyperactive-disorder
Online: 17 October 2019 (09:04:10 CEST)
The latest research cumulates staggering information about the correlation between the microbiota-gut-brain axis and neurodevelopmental disorders. This review aims to shed light on the potential influence of the microbiome on the development of the most prevalent neurodevelopmental disease, attention-deficit-hyperactive disorder (ADHD). As the etiology and pathophysiology of ADHD are still unclear, finding viable biomarkers and effective treatment still represent a challenge. Therefore, we focused on factors that have been associated with a higher risk of developing ADHD while simultaneously influencing the microbial composition. We reviewed the effect of a differing microbial composition on neurotransmitter concentrations important in the pathophysiology of ADHD. Additionally, we deduced factors that correlate with a high prevalence of ADHD while simultaneously affecting the gut microbiome such as emergency c-sections, and premature birth as the former leads to a decrease of the gut microbial diversity and the latter causes neuroprotective Lactobacillus levels to be reduced. Also, we assessed nutritional influences such as breastfeeding, ingestion of short-chain fatty acids (SCFAs) and polyunsaturated fatty acids (PUFAs) on the host’s microbiome and development of ADHD. Finally, we discussed the potential significance of Bifidobacterium as a biomarker for ADHD, the importance of preventing premature birth as prophylaxis and nutrition as a prospective therapeutic measurement against ADHD.
REVIEW | doi:10.20944/preprints201808.0093.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Triticum durum, cropping systems, microbiome, fertilization, tillage, breeding, environmental footprint
Online: 5 August 2018 (12:04:57 CEST)
The global demands for various grains including durum wheat (Triticum durum Desf.) are expected to increase substantially in the coming years due to ever-growing human population’s needs for food, feed and fuel. Thus, providing consistent or increased durum grain to the world market is one of the priorities for policy-makers, researchers, and farmers. What are the major achievements in agronomic advancement for durum wheat cultivation in recent decades? How might the current cropping systems be improved to increase crop yield and quality and improve resource use efficiencies while minimizing input costs and decreasing negative impact on the environment? Canada is one of the major durum wheat producers in the world, as Canada contributes about 50% to global trade of durum grain. Canada’s research achievements in durum wheat might serve as a guide for advancing the cultivation of the crop in other regions/countries on the planet. This review summarizes the major Canadian research findings in the aspects of durum wheat agronomics during the period 2001 to 2017 years. It highlights the main advancements in seeding and tillage, crop rotation and diversification, and use of pulse-induced microbiomes to improve soil health and feedback mechanism. The genetic gain and breeding for resistance against abiotic and biotic stresses are discussed. Finally, we identified main constraints and suggested some near-term research priorities. The research findings highlighted in this review will be of use for other areas on the planet to increase durum wheat productivity, improve soil fertility and health, and enhance long-term sustainability.
REVIEW | doi:10.20944/preprints201804.0370.v1
Subject: Life Sciences, Microbiology Keywords: Parkinson’s disease; gut microbiome; neurodegenerative diseases; microbiota-gut-brain-axis
Online: 28 April 2018 (12:09:20 CEST)
In the last years evidence has emerged that neurodegenerative diseases (NDs) are strongly associated with the microbiome composition in the gut. Parkinson’s disease (PD) is the most intensively studied neurodegenerative disease in this context. In this review, we performed a systematic evaluation of published literature comparing changes in colonic microbiome in PD to the ones observed in other NDs including Alzheimer’s Disease (AD), Multiple system atrophy (MSA), Multiple sclerosis (MS), Neuromyelitis optica (NMO) and Amyotrophic lateral sclerosis (ALS). To warrant comparability of different studies, only human case-control studies were included. Several studies showed an increase of Lactobacillus, Bifidobacterium, Verrucomicrobiaceae and Akkermansia in PD. A decrease in PD was observed of Faecalibacterium spp., Coprococcus spp., Blautia spp., Prevotella spp. and Prevotellaceae. On low taxonomic resolution, like phylum level, the changes are not disease specific and inconsistent. However, on higher taxonomic resolution like genus or species level, a minor overlap was observed between PD and MSA, both alpha synucleinopathies. We show that a methodical standardization of sample collection and analysis is necessary for ensuring the reproducibility and comparability of data. We also provide the evidence, that assessing the microbiota composition at high taxonomic resolution, reveals changes in relative abundance, that may be specific or characteristic for one disease, or a disease-group and might evolve discriminative power. The interactions between bacterial species and strains and moreover the co-abundances must be more deeply investigated before assumptions of the effects of specific bacteria on the host can be made with certainty.
REVIEW | doi:10.20944/preprints202206.0030.v1
Subject: Life Sciences, Biochemistry Keywords: naturally organic boron containing compounds; prebiotic candidate; microbiome; intestinal microflora; symbiosis
Online: 2 June 2022 (09:04:15 CEST)
Boron (B) is considered a prebiotic chemical element with a role in both the origin and evolution of life, as well as an essential micronutrient for plants, some bacteria, fungi, and algae. B has beneficial effects on the biological functions of humans and animals, such as reproduction, growth, calcium metabolism, bone formation, energy metabolism, immunity, brain function, and steroid hormones. In the future, naturally organic B (NOB) species may become promising novel prebiotic candidates. We included the most relevant works about NOB species, starting from our 30-year research experience. NOB-containing compounds have been shown essential for the symbiosis between different kingdoms. New insights into the essentiality of NOB species for healthy symbiosis between the human/animal host and the microbiota will determine the use of natural B-based nutraceuticals to target the colon (colonic foods). The mechanism of action (MoA) of NOB species is related to both the B signaling molecule [autoinducer-2–borate (AI-2B)], as well as the fortification of the colonic mucous gel layer with NOB species from the specific prebiotic boron-rich diet. Therefore, both microbiota and the mucous gel layer of the colon become the NOB species’ target. This paper reviews the evidence supporting the essentiality of the NOB species on the symbiosis between the microbiota and the human/animal host with the stated aim of highlighting the MoA and target of these species.
ARTICLE | doi:10.20944/preprints202110.0076.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: coronary artery disease; gut microbiome; dysbiosis; obesity; Bacteroidetes; LPS; indoxyl sulfate
Online: 5 October 2021 (10:33:24 CEST)
Gut dysbiosis, alongside with high-fat diet and cigarette smoking, is considered one of the factors promoting coronary arterial disease (CAD) development. The present study aimed to research whether gut dysbiosis can increase bacterial metabolites concentration in the blood of CAD patients and what impact these metabolites can exert on endothelial cells. The gut microbiome of 15 CAD patients and age-matched 15 healthy controls was analyzed by metagenome sequencing. The in vitro impact of LPS and indoxyl sulfate at concentrations present in patients sera on endothelial cells was investigated. A metagenome sequencing analysis revealed gut dysbiosis in CAD patients, further confirmed by elevated levels of LPS and indoxyl sulfate in patients sera. CAD was associated with depletion of Bacteroidetes and Alistipes. LPS and indoxyl sulfate in meager concentrations demonstrated co-toxicity to endothelial cells inducing reactive oxygen species, E-selectin, and monocyte chemoattractant protein-1 (MCP-1) production and promoting thrombogenicity of endothelial cells confirmed by monocyte adherence. The co-toxicity of LPS and indoxyl sulfate was associated with harmful effects on endothelial cells, strongly suggesting that gut dysbiosis-associated increased intestinal permeability can initiate or promote endothelial inflammation and atherosclerosis progression.
Subject: Earth Sciences, Atmospheric Science Keywords: vertical farming; controlled environment agriculture; plant factories; biostimulant; microbiome; hydroponics; aeroponics
Online: 28 May 2021 (11:07:33 CEST)
Vertical farming (VF) is a potential solution for the production of high-quality, accessible, and climate-friendly nutrition for growing urban populations. However, to realize VF’s potential as a sustainable food source, innovative technologies are required to ensure that VF can be industrialized on a massive scale and extended beyond leafy greens and fruits into the production of food staples or row crops. A major obstacle to the economic and environmental sustainability of VF is the lighting energy consumed. While technological advances have improved the energy efficiency of VF lighting systems, there has been insufficient research into biostimulation as an approach to reduce energy needs. We conducted a controlled trial to investigate the application of a phycocyanin-rich Spirulina extract (PRSE) as a biostimulant in hydroponically grown, vertically farmed lettuce (Lactuca sativa and Salanova®). PRSE application reduced the time from seeding to harvest by 6 days, increased yield by 12.5%, and improved quality including color, taste, texture, antioxidant flavonoid levels and shelf life. Metagenomic analysis of the microbial community of the nutrient solution indicated that PRSE increased the overall bacterial diversity including raising the abundance of Actinobacteria and Firmicutes and reducing the abundance of potentially pathogenic bacteria. This preliminary study demonstrates that microalgae-derived biostimulants may play an important role in improving the economic and environmental sustainability of VF.
Subject: Keywords: pandemics; contagious diseases; human race extinction; viruses; microbiome; COVID-19; blindness
Online: 14 April 2021 (17:53:49 CEST)
The recent SARS-CoV-2 pandemic, which is causing COVID 19 disease, has taught us unexpected lessons about the dangers of human extinction through highly contagious and lethal diseases. As the COVID 19 pandemic is now being controlled by various isolation measures, therapeutics and vaccines, it became clear that our current lifestyle and societal functions may not be sustainable in the long term. We now have to start thinking and planning on how to face the next dangerous pandemic, not just overcoming the one that is upon us now. Is there any evidence that even worse pandemics could strike us in the near future and threaten the existence of the human race? The answer is unequivocally yes. It is not necessary to get infected by viruses of bats, pangolins and other exotic animals that live in remote forests in order to be in danger. Creditable scientific evidence indicates that the human gut microbiota harbor billions of viruses which are capable of affecting the function of vital human organs such as the immune system, lung, brain, liver, kidney, heart etc. It is possible that the development of pathogenic variants in the gut can lead to contagious viruses which can cause pandemics, leading to destruction of vital organs, causing death or various debilitating diseases such as blindness, respiratory, liver, heart and kidney failures. These diseases could result n the complete shutdown of our civilization and probably the extinction of human race. In this essay, I will first provide a few independent pieces of scientific facts and then combine this information to come up with some (but certainly not all) hypothetical scenarios that could cause human race misery, even extinction. I hope that these scary scenarios will trigger preventative measures that could reverse or delay the projected adverse outcomes.
REVIEW | doi:10.20944/preprints202102.0119.v2
Subject: Life Sciences, Biochemistry Keywords: Multiple sclerosis (MS); microbiome; bacteria; virus; immunity; central nervous system (CNS)
Online: 24 March 2021 (13:34:39 CET)
Multiple sclerosis (MS) is a chronic inflammatory neurodegenerative autoimmune disease characterized by aberrant infiltration of immune cells into the central nervous system (CNS) and by the loss of myelin. Sclerotic lesions and various inhibitory factors hamper remyelination processes within the CNS. MS patients typically experience gradual cognitive and physical disabilities as the disease progresses. The etiology of MS is still unclear and emerging evidence suggests that microbiome composition could play a much more significant role in disease pathogenesis than was initially thought. Initially believed to be isolated to the gut microenvironment, we now know that the microbiome plays a much broader role in various tissues and is essential in the development of the immune system. Here, we present some of the unexpected roles that the microbiome plays in MS and discuss approaches for the development of next-generation treatment strategies.
REVIEW | doi:10.20944/preprints202011.0276.v2
Subject: Medicine & Pharmacology, Gastroenterology Keywords: Vitamin D; VDR; inflammation; microbiome; metabolites; nuclear receptor; probiotics; tight junctions
Online: 24 December 2020 (09:55:13 CET)
Inflammatory bowel disease (IBD) is a chronic inflammation of the gastrointestinal0 tract (GIT), including Crohn’s disease (CD) and ulcerative colitis (UC), which differ in the location and lesion extensions. Both diseases are associated with microbiota dysbiosis, with a reduced population of butyrate-producing species, abnormal inflammatory response, and micronutrient deficiency (e. g. vitamin D hypovitaminosis). Vitamin D (VitD) is involved in immune cell differentiation, gut microbiota modulation, gene transcription, and barrier integrity. Vitamin D receptor (VDR) regulates the biological actions of the active VitD (1α, 25-dihydroxyvitamin D3), and is involved in the genetic, environmental, immune, and microbial aspects of IBD. VitD deficiency is correlated with disease activity and its administration targeting a concentration of 30 ng/mL may have the potential to reduce disease activity. Moreover, VDR regulates functions of T cells and Paneth cells and modulates release of antimicrobial peptides in gut microbiota-host interactions. Meanwhile, beneficial microbial metabolites, e.g. butyrate, upregulate the VDR signaling. In this review, we summarize the clinical progress and mechanism studies on VitD /VDR related to gut microbiota modulation in IBD. We also discuss epigenetics in IBD and the probiotic regulation of VDR. Furthermore, we discuss the existing challenges and future directions. There is a lack of well-designed clinical trials exploring the appropriate dose and the influence of gender, age, ethnicity, genetics, microbiome, and metabolic disorders in IBD subtypes. To move forward, we need well-designed therapeutic studies to examine whether enhanced vitamin D will restore functions of VDR and microbiome in inhibiting chronic inflammation.
ARTICLE | doi:10.20944/preprints201903.0099.v1
Subject: Biology, Entomology Keywords: genetically modified insects; symbiosis; microbiome; transgenic; self-limiting; insect rearing; mutualism
Online: 7 March 2019 (14:00:12 CET)
Mass insect rearing can have a range of applications, for example in biological control of insects. Since the performance of released biological control agents determines efficacy, the competitive fitness of insects post release is a key variable. Here, we tested whether inoculation with a gut symbiont, Enterobacter cloacae, and gnotobiotic rearing of larvae could improve insect growth and male competitive fitness of a transgenic diamondback moth, which has shown variation in fitness when reared in different insectaries. All larvae were readily infected with the focal symbiont. Under gnotobiotic rearing pupal weights were reduced and there was a marginal reduction in larval survival. However, gnotobiotic rearing substantially improved the fitness of transgenic males. In addition, in gnotobiotic conditions, inoculation with the gut symbiont increased pupal weights and male fitness, increasing the proportion of transgenic progeny from 20 to 30% relative to symbiont-free insects. Gnotobiotic conditions may improve the fitness of transgenic males by excluding microbial contaminants, while symbiont inoculation could further improve fitness by providing additional protection against infections, or by normalizing insect physiology. The simple innovation of incorporating antibiotic into diet, and inoculating insects with symbiotic bacteria that are resistant to that antibiotic, could provide a readily transferable tool for other insect rearing systems.
ARTICLE | doi:10.20944/preprints201806.0193.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: aronia; ginseng; mushroom; pancreatectomy; type 2 diabetes; gut microbiome; insulin secretion
Online: 12 June 2018 (13:01:30 CEST)
The combination of freeze-dried aronia, red ginseng, ultraviolet-irradiated shiitake mushroom and natokinase (AGM; 3.4: 4.1: 2.4: 0.1) was examined to evaluate its effects on insulin resistance, insulin secretion and gut microbiome in a non-obese type 2 diabetic animal model. Pancreatectomized (Px) rats were provided high fat diets supplemented with either of 1) 0.5 g AGM (AGM-L), 2) 1 g AGM (AGM-H), 3) 1 g dextrin (control), or 4) 1g dextrin with 120 mg metformin (positive-control) per kg body weight for 12 weeks. AGM (1 g) contained 6.22 mg cyanidin-3-galactose, 2.5 mg ginsenoside Rg3 and 0.6 mg β-glucan. Px rats had decreased bone mineral density in the lumbar spine and femur and lean body mass in the hip and leg compared to the normal-control and AGM-L and AGM-H prevented the decrease. Visceral fat mass was lower in the control group than the normal-control group and its decrease was smaller by AGM-L and AGM-H. HOMA-IR was lower in descending order of the control, positive-control, AGM-L, AGM-H and normal-control groups. Glucose tolerance was deteriorated in the control group and it was improved by AGM-L and AGM-H more than in the positive-control group. Glucose tolerance is associated with insulin resistance and insulin secretion. Insulin tolerance indicated insulin resistance was highly impaired in diabetic rats, but it was improved in the ascending order of the positive-control, AGM-L and AGM-H. Insulin secretion capacity, measured by hyperglycemic clamp, was much lower in the control group than the normal-control group and it was improved in the ascending order of the positive-control, AGM-L and AGM-H. Diabetes modulated the composition of gut microbiome and AMG prevented the modulation of gut microbiome. In conclusion, AGM improved glucose metabolism by potentiating insulin secretion and reducing insulin resistance in insulin deficient type 2 diabetic rats. The improvement of diabetic status alleviated body composition changes and prevented changes of gut microbiome composition.
REVIEW | doi:10.20944/preprints201803.0170.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: oral dysbiosis; human oral microbiome; yet-un cultivable organisms; systemic diseases
Online: 20 March 2018 (07:06:45 CET)
The human body supports the growth of a wide array of microbial communities in various niches, such as the oral cavity, gastro-intestinal and urogenital tracts and on the surface of the skin. These host associated microbial communities include yet-un-cultivable bacteria and are influenced by various factors. Together, these communities of bacteria are referred to as the human microbiome. Human oral microbiome consists of both symbionts and pathobionts. Deviation from symbiosis among the bacterial community leads to “dysbiosis”—a state of community disturbance. Dysbiosis occurs due to many confounding factors that predispose to a shift in the composition and relative abundance of microbial communities. Dysbiotic communities have been a major cause for many microbiomes related systemic infections. Such dysbiosis is directed by certain important pathogens called the “keystone pathogens” that could modulate community microbiome variations. One such persistent infection is oral infection, mainly periodontitis, where a wide array of causal organisms has been implied to systemic infections such as cardio vascular disease, diabetes mellitus, rheumatoid arthritis and Alzheimer’s disease. The keystone pathogens co-occur with many yet-cultivable bacteria and their interactions lead to dysbiosis. This has been the focus of recent research. While immune evasion is one of the major modes that lead to dysbiosis, new processes and new virulence factors of bacteria have been shown to be involved in this important process of that determine disease or health state. This review focuses on such dysbiotic communities, their interactions and their virulence factors that predispose the host to other systemic implications.
ARTICLE | doi:10.20944/preprints201711.0199.v2
Subject: Life Sciences, Microbiology Keywords: human papillomavirus; HPV; cervical cancer; cancer screening; self-sampling; vaginal microbiome
Online: 1 December 2017 (07:19:13 CET)
In most industrialized countries, screening programs for cervical cancer have shifted from cytology (Pap smear or ThinPrep) alone on clinician-obtained samples to the addition of screening for human papillomavirus (HPV), its main causative agent. For HPV testing, self-sampling instead of clinician-sampling has proven to be equally accurate, in particular for assays that use nucleic acid amplification techniques. In addition, HPV testing of self-collected samples in combination with a follow-up Pap smear in case of a positive result is more effective in detecting precancerous lesions than a Pap smear alone. Self-sampling for HPV testing has already been adopted by some countries, while others have started trials to evaluate its incorporation into national cervical cancer screening programs. Self-sampling may result in more individuals willing to participate in cervical cancer screening, because it removes many of the barriers that prevent women, especially those in low socioeconomic and minority populations, from participating in regular screening programs. Several studies have shown that the majority of women who have been underscreened but who tested HPV-positive in a self-obtained sample, will visit a clinic for follow-up diagnosis and management. Additionally, a self-collected sample can also be used for vaginal microbiome analysis, which can provide additional information about HPV infection persistence as well as vaginal health in general.
REVIEW | doi:10.20944/preprints202006.0311.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: functional food; dietary supplement; phytochemicals; nutritional neuroscience; gut microbiome; personalized nutrition; Bangladesh
Online: 26 June 2020 (12:23:14 CEST)
Plants and plant-derived food products have been used for medicinal purposes since the ancient. Medicinal Plant-based functional foods or plant-based dietary compounds are a re-emerged interest for their therapeutic benefits and nutritive supports which has implicated in healthcare systems across the world. Neurological disorders are one of the greatest threats to public health and according to the World Health Organization, about 100 million people are affected globally by several neurological and mental ailments. In a traditional medication system, medicinal plants have been applied as both neuro-therapeutic purposes and micro-macro nutrients provider for the wellbeing of psychological states e.g. anti-depressant, anti-anxiety, anti-convulsions, anti-dementia, anti-psychotic, etc. Herein, it is a topic of great interest to present a conceptual aspect by reviewing relevant scientific literature about the plant-based functional foods or bioactive phytochemicals for the prevention and treatment of mental and neurological disorders. From the literature assessment, we have found that nutritional neuroscience is becoming an advanced research discipline and there has been a growing pile of evidence concerning the therapeutic use of plant-based functional foods and/or plant-derived food compounds for the management of neurologic health, evolving with promising impact over the time.
REVIEW | doi:10.20944/preprints201911.0300.v1
Subject: Biology, Entomology Keywords: artificial selection; biological control; genetics; genome assembly; genomics; insect breeding; microbiome; modelling
Online: 24 November 2019 (17:10:31 CET)
Biological control is widely successful for controlling pests, but effective biocontrol agents are now more difficult to obtain due to more restrictive international trade laws. Coupled with increasing demand, the efficacy of existing and new biocontrol agents needs to be improved with genetic and genomic approaches. Although they have been underutilised in the past, applying genetic and genomic techniques is becoming more feasible from both technological and economic perspectives. We review current methods and provide a framework for using them, incorporating evolutionary and ecological principles. First, it is necessary to identify which biocontrol trait to select and in what direction. Next, the genes or markers linked to these traits need be determined to better target their selection, followed by how to implement this information into a breeding program. Choosing a trait can be assisted by modelling to account for the proper agro-ecological context, and by knowing which traits have sufficiently high heritability values. We provide guidelines for designing genomic strategies in biocontrol programs, which depends on the organism, budget, and desired objective. Genomic approaches start with genome sequencing and assembly. We provide a guide for deciding the most successful sequencing strategy for biocontrol agents. Gene discovery involves quantitative trait loci (QTL) analyses, transcriptomic and proteomic studies, and gene editing. Improving biocontrol practices include marker-assisted selection, genomic selection and microbiome manipulation of biocontrol agents, and monitoring for genetic variation during rearing and post-release. We conclude by identifying the most promising applications of genetic and genomic methods to improve biological control efficacy.
ARTICLE | doi:10.20944/preprints201704.0105.v1
Subject: Mathematics & Computer Science, Other Keywords: symmetric nonnegative matrix factorization; similarity network fusion; human microbiome; multi-view clustering
Online: 18 April 2017 (03:31:04 CEST)
Integration of multi-view datasets which are comprised of heterogeneous sources or different representations is challenging to understand the subtle and complex relationship in data. Such data integration methods attempt to combine efficiently the complementary information of multiple data types to construct a comprehensive view of underlying data. Nonnegative matrix factorization (NMF), an approach that can be used for signal compression and noise reduction, has aroused widespread attention in the last two decades. The Kullback–Leibler divergence (or relative entropy) information distance can be used to measure the loss function of NMF. In this article, we propose a fast and robust framework (RSNMF) based on symmetric nonnegative matrix factorization (SNMF) and similarity network fusion (SNF) for clustering human microbiome data including functional, metabolic and phylogenetic profiles. Many existing methods typically utilize all the information provided by each view to create a consensus representation, which often suffers a lot from noise in data and cannot provide a precise representation of the latent data structures. In contrast, RSNMF combines the strength of SNMF and the advantage of SNF to form a robust clustering indicator matrix thus can reduce the noise influence. We conduct experiments on one synthetic and two real dataset (microbiome data, text data) and the results show that the proposed RSNMF has better performance over the baseline and the state-of-art methods, which demonstrates the potential application of RSNMF for microbiome data analysis.
ARTICLE | doi:10.20944/preprints201812.0177.v1
Subject: Life Sciences, Microbiology Keywords: skin allergy epidemic; skin microbiome; skin microbiome diversity; effect of synthetic cosmetics on skin; biodiversity; synthetic ingredients in modern cosmetics; skin health; healthy skin bacteria; damaged skin bacteria
Online: 17 December 2018 (07:27:34 CET)
As described in previous work, the use of synthetic chemical ingredients in modern cosmetics is postulated to be a cause of damage to the skin microbiome. The discovery that biodiversity on the human skin is currently the only reliable indicator of skin health, meant that for the first time, a mechanism to test for healthy skin was possible. Using this mechanism and in collaboration with The Medical University of Graz, who carried out the independent study, this work aimed to help answer whether modern day synthetic cosmetics are a main cause of long term damage to the skin microbiome. Thirty-two human participants tested three different face washes for their effect on the skin’s microbial diversity, along with skin pH, moisture and TEWL (trans-epidermal water loss), washing twice a day for four weeks. The upper volar forearm of the volunteers was swabbed at the beginning, two weeks in and end (four weeks). 16S rRNA sequencing was used. One leading ‘natural’ brand full of synthetic ingredients, a leading synthetic brand and a 100% natural face wash were used. Results give the first indications of a link between synthetic ingredients in a cosmetics product, and its effect on skin microbiome biodiversity. It paves the way for future studies on the topic with a larger sample group, longer test period and standardised methodology to create a universal standard for testing the health of skin using benchmark diversity values. This can be used in the future to test the effectiveness of cosmetics or ingredients on skin health, leading to the banning of products proven to harm the skin’s natural environment.
REVIEW | doi:10.20944/preprints202106.0504.v1
Subject: Biology, Anatomy & Morphology Keywords: Microbiota; Microbiome; Mosquitoes; Behavior; Oviposition; Larval habitat; Life History Traits; Nutrition; Development; Survival
Online: 21 June 2021 (11:22:15 CEST)
Mosquitoes are considered one of the most important threats worldwide due to their ability to vector pathogens. They are responsible for the transmission of major pathogens such as Malaria, dengue, Zika or Chikungunya. Due to the lack of treatments or prophylaxis against many of the transmitted pathogens and an increasing prevalence of mosquito resistance to insecticides and drugs available, alternative strategies are now being explored. Some of these involve the use of microorganisms as promising agent to limit the fitness of mosquitoes, attract or repel them and decrease the replication and transmission of pathogenic agents. In recent years, the importance of microorganisms colonizing the habitat of mosquitoes has particularly been investigated since they appeared to play major roles in their development and diseases transmission. In this issue we will synthesize researches investigating how microorganisms present within water habitats may influence breeding site selection and oviposition strategy of gravid mosquito females. We will also highlight the impact, effect of such microbes on the fate of females’ progeny during their immature stages with a specific focus on egg hatching, development rate and larvae of pupae survival.
REVIEW | doi:10.20944/preprints202104.0175.v1
Subject: Life Sciences, Biochemistry Keywords: Gut microbiome; Western and indigenous/traditional cultures; gut health; disease; lifestyle; novel microbials
Online: 6 April 2021 (12:40:04 CEST)
The mammalian gut ecosystem plays critical roles in multiple functions related to health and homeostasis. In many cases, disturbances in the gut ecosystem are associated with a large number of metabolic and chronic diseases and disorders such as diabetes, cancer, and obesity. A diverse community of microorganisms ranging from viruses to bacteria comprise the gut microbiota, which is often considered as an organ in itself. Recent studies have profiled the influence of lifestyles and dietary behavior by comparing the gut microbiome of populations with different cultural underpinnings. In this review, we provide an overview of the studies which report the influence on the gut microbial composition of dietary and lifestyle patterns in different contexts such as western industrialized countries and indigenous cultures (corresponding to different lifestyle gradients such as hunter-gatherers and pastoralists) and how this association may influence health and disease.
REVIEW | doi:10.20944/preprints202103.0231.v1
Subject: Biology, Anatomy & Morphology Keywords: Tryptophan metabolism; Kynurenine; Indoleamine 2,3-dioxygenase; Aryl hydrocarbon receptor; Microbiome; Indole; Colon cancer.
Online: 8 March 2021 (15:55:29 CET)
Tryptophan metabolism, via the kynurenine (Kyn) pathway, and microbial transformation of tryptophan to indolic compounds, are fundamental for host health; both of which are altered in colon carcinogenesis. Alterations in tryptophan metabolism begin early in colon carcinogenesis as an adaptive mechanism for the tumor to escape immune surveillance and metastasize. The microbial community is a key part of the tumor microenvironment and influences cancer initiation, promotion and treatment response. A growing awareness of the impact of the microbiome on tryptophan (Trp) metabolism in the context of carcinogenesis has prompted this review. We first compare the different metabolic pathways of Trp under normal cellular physiology to colon carcinogenesis, in both the host cells and the microbiome. Second, we review how the microbiome, specifically indoles, influence host tryptophan pathways under normal and oncogenic metabolism. We conclude by proposing several dietary, microbial and drug therapeutic modalities that can be utilized in combination to abrogate tumorigenesis.
ARTICLE | doi:10.20944/preprints202008.0643.v1
Subject: Keywords: ulcerative colitis; inflammatory bowel disease; immunotherapy; Bin1 monoclonal antibody; enteric neurons; microbiome; colon
Online: 28 August 2020 (11:45:28 CEST)
Ulcerative colitis (UC) is a common chronic disease of the large intestine. Current anti-inflammatory drugs prescribed to treat this disease have limited utility due to significant side-effects. Thus, immunotherapies for UC treatment are still sought. In the DSS mouse model of UC, we recently demonstrated that systemic administration of the Bin1 monoclonal antibody 99D (Bin1 mAb) developed in our laboratory was sufficient to reinforce intestinal barrier function and preserve an intact colonic mucosa, compared to control subjects which displayed severe mucosal lesions, high-level neutrophil and lymphocyte infiltration of mucosal and submucosal areas, and loss of crypts. Here we report effects of Bin1 mAb on colonic neurons and the gut microbiome that correlate with the benefits of treatment. In the DSS model, we found that induction of UC was associated with disintegration of enteric neurons and elevated levels of glial cells, which translocated to the muscularis at distinct sites. Further, we characterized an altered gut microbiome in DSS treated mice associated with pathogenic proinflammatory characters. Both of these features of UC induction were normalized by Bin1 mAb treatment. With regard to microbiome changes, we observed in particular that Firmicutes were eliminated by UC induction and that Bin1 mAb treatment restored this phylum including the genus Lactobacillus and Akkermansia as beneficial microorganisms. Overall, our findings suggest that the intestinal barrier function restored by Bin1 immunotherapy in the DSS model of UC is associated with a preservation of enteric neurons and an improvement in the gut microbiome, contributing overall to a healthy intestinal tract.
ARTICLE | doi:10.20944/preprints202007.0668.v1
Subject: Biology, Ecology Keywords: Intestinal microbiome; infant microbiota; diet; westernized; non-westernized; lifestyle; microbial diversity; human health
Online: 28 July 2020 (08:37:38 CEST)
The Human Gut Microbiome is an important host’s component defining its health. These microorganisms are mutualistic symbionts dependent on factors such as host’s age, subsistence models and sociocultural practices, among others. The conjunction of these factors define the microbial ecosystem dynamics. Using a fecal microbiome approach in children, a comparison of two Mexican communities with contrasting lifestyles: “westernized” (Mexico City) and “non-westernized” (Me’phaa indigenous group) was evaluated. The main differences between these two communities are in bacteria associated with different types of diets (high animal protein and refined sugars vs high fiber food, respectively). In addition, the gut microbiome of Me’phaa children showed higher total diversity and the presence of exclusive phyla, such as Deinococcus-Thermus, Chloroflexi, Elusimicrobia, Acidobacteria and Fibrobacteres. In contrast, Mexico City children had less diversity and the exclusive presence of Saccharibacteria phylum which is associated with the degradation of sugar compounds. This comparison allows further exploration of the selective pressures affecting microbial ecosystemic composition over the course of human evolution and the potential consequences of pathophysiological states correlated with westernization lifestyles.
ARTICLE | doi:10.20944/preprints201907.0247.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: opioid; microbiome-brain axis; DHA; anxiety; polyunsaturated fatty acids; intravenous self-administration; mice
Online: 23 July 2019 (04:09:40 CEST)
Opioids are highly addictive substances with a relapse rate of over 90%. While preclinical models of chronic opioid exposure exist for studying opioid dependence, none recapitulate the relapses observed in human opioid addiction. The mechanisms associated with opioid dependence, the accompanying withdrawal symptoms and the relapses that are often observed months or years after opioid dependence are poorly understood. Therefore, we developed a novel model of chronic opioid exposure whereby the level of administration is self-directed with periods of behavior acquisition, maintenance and then extinction alternating with reinstatement. This profile arguably mirrors that seen in humans, with initial opioid use followed by alternating periods of abstinence and relapse. Recent evidence suggests that dietary interventions that reduce inflammation, including omega-3 fatty acids such as docosahexaenoic acid (DHA), may reduce substance misuse liability. Using the self-directed intake model, we characterize the observed profile of opioid use and demonstrate that a diet enriched in polyunsaturated fat acids (PUFAs) ameliorates oxycodone-seeking behaviors in the absence of drug availability and reduces anxiety. Guided by the major role gut microbiota have on brain function, neuropathology, and anxiety, we profile the microbiome composition and the effects of chronic opioid exposure and DHA supplementation. We demonstrate that withdrawal of opioids led to a significant depletion in specific microbiota genera whereas DHA supplementation increased microbial richness, phylogenetic diversity, and evenness. Lastly, we examined the activation state of microglia in the striatum and found that DHA supplementation reduced the basal activation state of microglia. These preclinical data suggest that a diet enriched in PUFAs could be used as a treatment to alleviate anxiety induced opioid-seeking behavior and relapse in human opioid addiction.
ARTICLE | doi:10.20944/preprints201703.0216.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: 18S rRNA; fungi; mycobiome; carcinoma; High-Throughput Nucleotide Sequencing; microbiome; mouth; squamous cell
Online: 30 March 2017 (05:37:37 CEST)
Background: Studies employing next-generation sequencing (NGS) show that the oral fungal community (mycobiome) is far more complex than hitherto thought. However, the role of the oral mycobiome in health and disease, including oral carcinogenesis, has not been explored. Objective: To characterize the mycobiome associated with oral squamous cell carcinoma (OSCC). Methods: Tissue biopsies [cases: 25 OSCC; controls: 27 intra-oral fibro-epithelial polyp (FEP)] were collected from oral and maxillofacial units in Sri Lanka. Total DNA was extracted and subjected to sequencing of the fungal ITS2 region using Illumina’s 2x300 bp chemistry. High quality, non-chimeric merged reads were classified to species level using a BLASTN-algorithm with UNITE’s named species sequences as reference. Downstream analyses were performed using QIIME and LEfSe. Results: 364 species representing 160 genera and 2 phyla (Ascomycota and Basidiomycota) were identified, with Candida and Malassezia making up 48% and 11% of the average mycobiome, respectively. However, only 5 species and 4 genera were detected in ≥50% of the samples. The species richness and diversity were significantly lower in OSCC. At the genus level, Candida, Hannaella and Gibberella were overrepresented in OSCC while Alternaria and Trametes were more abundant in FEP. Species-wise, C. albicans, C. etchellsii and Hannaella luteola-like species were enriched in OSCC while Malassezia restricta, Aspergillus tamarii, Alternaria alternate, Cladosporium halotolerans, and Hanseniaspora uvarum-like species were the most significantly abundant in FEP. Conclusions: A dysbiotic mycobiome dominated by C. albicans was found in association with OSCC. Whether this dysbiosis plays a role in oral carcinogenesis warrants further investigation.
ARTICLE | doi:10.20944/preprints201703.0024.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: 16S rRNA; bacteria; bacteriome; carcinoma; High-Throughput Nucleotide Sequencing; microbiome; mouth; squamous cell
Online: 6 March 2017 (04:47:15 CET)
Studies on the possible association between bacteria and oral squamous cell carcinoma (OSCC) remain inconclusive, largely due to methodological variations/limitations. The objective of this study was to characterize the species composition as well as functional attributes of the bacteriome associated with OSCC. DNA obtained from 20 fresh OSCC biopsies (cases) and 20 deep-epithelium swabs (matched control subjects) were sequenced for the V1-V3 region using Illumina’s 2x300 bp chemistry. High quality, non-chimeric merged reads were classified to species level using a prioritized BLASTN-algorithm. Downstream analyses were performed using QIIME, PICRUSt, and LEfSe. Fusobacterium nucleatum subsp. polymorphum was the most significantly overrepresented species in the tumors followed by Pseudomonas aeruginosa and Campylobacter sp. Oral taxon 44, while Streptococcus mitis, Rothia mucilaginosa and Haemophilus parainfluenzae were the most significantly abundant in the controls. Functionally, genes involved in bacterial mobility, flagellar assembly, bacterial chemotaxis and LPS synthesis were enriched in the tumors while those responsible for DNA repair and combination, purine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, ribosome biogenesis and glycolysis/gluconeogenesis were significantly associated with the controls. This is the first epidemiological evidence for association of F. nucleatum and P. aeruginosa with OSCC. Functionally, an “inflammatory bacteriome” is enriched in OSSC.
REVIEW | doi:10.20944/preprints202107.0650.v1
Subject: Medicine & Pharmacology, Allergology Keywords: chronic disorders; inflammation; human superorganism; holobiont; microbiome; multimorbidity; microimmunosome; polypharmacy; drug safety; sustainable healthcare
Online: 29 July 2021 (11:37:20 CEST)
Microbiome First Medicine is a suggested 21st century healthcare paradigm that prioritizes the entire human, the human superorganism, beginning with the microbiome. To date, much of medicine has protected and treated patients as if they were a single species. This has resulted in unintended damage to the microbiome and an epidemic of chronic disorders [e.g., noncommunicable diseases and conditions (NCDs)]. Along with NCDs came loss of colonization re-sistance, increased susceptibility to infectious diseases, and increasing multimorbidity and polypharmacy over the life course. To move toward sustainable healthcare, the human micro-biome needs to be front and center. This paper presents microbiome-human physiology from the view of systems biology regulation. It also details the ongoing NCD epidemic including the role of existing drugs and other factors that damage the human microbiome. Examples are provided for two entryway NCDs, asthma and obesity, regarding their extensive network of comorbid NCDs. Finally, the challenges of ensuring safety for the microbiome are detailed. Under Microbiome First Medicine and considering the importance of keystone bacteria and critical windows of development, changes in even a few microbiota-prioritized medical decisions could make a significant difference in health across the life course.
REVIEW | doi:10.20944/preprints202012.0554.v1
Subject: Keywords: microbiome; vectorial capacity; density; competence; biting; extrinsic incubation period; longevity; mosquito; symbiosis; pathogen transmission
Online: 22 December 2020 (10:49:13 CET)
Microbiome research has gained considerable interest due to the emerging evidence of its impact on human and animal health. Similar to higher organisms, the gut-associated microbiota of mosquitoes affect host fitness and other phenotypes. It is now well established that microbes can alter pathogen transmission in mosquitoes, either positively or negatively, and avenues are being explored to exploit microbes for vector control. However, less attention has been paid to how microbiota affect phenotypes that impact vectorial capacity. Several mosquito and pathogen components, such as vector density, biting rate, survival, vector competence and pathogen extrinsic incubation period all influence pathogen transmission. Interestingly, the mosquito gut-associated microbes can impact each of these components, and therefore ultimately modulate vectorial capacity. Promisingly, this expands the options available to exploit microbes for vector control by also targeting parameters that affect vectorial capacity. However, there are still many knowledge gaps in the biology of the mosquito – microbe symbiosis that need to be addressed in order to understand these interactions more thoroughly and exploit them efficiently. Here, we review current evidence of the impacts of the microbiome on aspects of vectorial capacity highlighting opportunities for novel vector control strategies and areas where further studies are required.
ARTICLE | doi:10.20944/preprints201805.0375.v1
Subject: Behavioral Sciences, Other Keywords: autism phenome; gut microbiome; behaviour reversal; meta-analysis; 16srRNA sequencing; operational taxonomic units (OTUs)
Online: 25 May 2018 (16:15:27 CEST)
Background: Gut-Brain-Axis provides bidirectional communicational route; imbalance of which can have pathophysiological consequences. It is a frontier in autism research, affects 85% of autistic children (NIH report). Their microbiome has few overall microbes and smaller number of health promising microbes than their neurotypical peers. We hypothesize autism gut might play a role in manifestation of autism behaviours and on treatment, can revert back to normal behaviour considerably. The aim is to better understand to what degree gut microbiota of autism subjects differs from controls and identify bacterial species present exclusively in autism. Materials and Methods: 16s-rRNA-sequence of autism-subjects were retrieved from the American Gut Project Archive. Taxonomic assignment was inferred by similarity based methods using Quantitative Insights Into Microbial Ecology (QIIME). Species abundance was characterized and co-occurrence network was built to infer species interaction using measures of diversity. Statistical parameters were considered to validate the findings. Result: A total of 206 (1.8%) of American Gut Project datasets onstituted of autistic samples. Various bacteria such as Akkermansia sp., and Prevotella sp., were harboured in higher abundance in autistic children with statistical significance than in controls. Conclusion: These findings indicate connecting-link between gut-microbiome-brain-axis and autistic behaviour which can result in improved management