REVIEW | doi:10.20944/preprints201903.0267.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: hepatocellular carcinoma, gut microbiota, gut-liver axis, intestinal dysbiosis
Online: 28 March 2019 (13:43:07 CET)
Hepatocellular carcinoma (HCC), one of the leading causes of death worldwide, has a causal nexus with liver injury, inflammation, and regeneration that accumulate over decades. Observations from recent studies have accounted for the involvement of the gut-liver axis in the pathophysiological mechanism responsible for HCC. The human intestine nurtures a diversified colony of microorganisms residing in the host ecosystem. The intestinal barrier is critical for conserving the normal physiology of the gut microbiome. Therefore, a rupture of this barrier or dysbiosis cause the intestinal microbiome to serve as the main source of portal-vein endotoxins such as lipopolysaccharide, in the progression of hepatic diseases. Indeed, increased bacterial translocation is a key sign of HCC. Considering the limited number of clinical studies on HCC with respect to the microbiome, we focus on the clinical as well as animal studies involving the gut microbiota with the current understandings of the mechanism by which the intestinal dysbiosis promotes hepatocarcinogenesis. Future research might offer mechanistic insights into the specific phyla targeting the leaky gut, as well as microbial dysbiosis, and their metabolites, as key pathways that drive HCC-promoting microbiome-mediated liver inflammation and fibrosis, thereby restoring the gut barrier function.
REVIEW | doi:10.20944/preprints201811.0171.v1
Subject: Medicine And Pharmacology, Endocrinology And Metabolism Keywords: Autism, ASD, microbiota, gut-brain-axis, microbiota-gut-brain-axis, therapy
Online: 7 November 2018 (14:45:10 CET)
New research points to a possible link between Autism Spectrum Disorder and the gut microbiota as many autistic children have co-occurring gastrointestinal problems. This review focuses on specific alterations of gut microbiota mostly observed in autistic patients. Particularly, the mechanisms through which such alterations may trigger the production of the bacterial metabolites or leaky gut in autistic people are described. Various altered metabolite levels were observed in autistic children, many of those were of bacterial origin such as short chain fatty acids (SCFAs), indoles and lipopolysaccharides. A less integrative gut-blood-barrier is abundant in autistic individuals. This explains the leakage of bacterial metabolites into the patients triggering new body responses or altered metabolism. Some other co-occurring symptoms such as mitochondrial dysfunction, oxidative stress in the cells, altered tight junctions in the blood brain barrier and structural changes in cortex, hippocampus, amygdala and cerebellum were detected. Moreover, this paper suggests that autism is associated with an unbalanced gut microbiota (dysbiosis). Although the cause-effect relationship between autism and gut microbiota is not yet well established, consumption of specific probiotics may represent a powerful tool to re-establish gut homeostasis and promote gut health. Diagnostic and therapeutic value of new biomarkers leading to the perturbation in the phenylalanine metabolism will be discussed.
REVIEW | doi:10.20944/preprints202309.1475.v1
Subject: Medicine And Pharmacology, Internal Medicine Keywords: complex regional pain syndrome, microbiota, boron-containing compounds, prebiotic boron, gut–brain axis, gut–musculoskeletal axis, gut–immune system axis
Online: 21 September 2023 (11:27:14 CEST)
The microbiota–gut–brain axis has garnered increasing attention in recent years for its role in various health conditions, including neuroinflammatory disorders like complex regional pain syndrome (CRPS). CRPS is a debilitating condition characterized by chronic neuropathic pain, and its etiology and pathophysiology remain elusive. Emerging research suggests that alterations in the gut microbiota composition and function could play a significant role in CRPS development and progression. Our paper explores the implications of microbiota in CRPS and the potential therapeutic role of boron (B). Studies have demonstrated that individuals with CRPS often exhibit dysbiosis, with imbalances in beneficial and pathogenic gut bacteria. Dysbiosis can lead to increased gut permeability and systemic inflammation, contributing to the chronic pain experienced in CRPS. B, an essential trace element, has shown promise in modulating the gut microbiome positively and exerting anti-inflammatory effects. Recent preclinical and clinical studies suggest that B supplementation may alleviate neuropathic pain and improve CRPS symptoms by restoring microbiota balance and reducing inflammation. Our review highlights the complex interplay between microbiota, inflammation, and neuropathic pain in CRPS and underscores the potential of B as a novel therapeutic approach to target the microbiota–gut–brain axis, offering hope for improved management of this challenging condition.
REVIEW | doi:10.20944/preprints202306.1251.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: mTOR; gut microbes; metabolites; therapy
Online: 16 June 2023 (14:02:23 CEST)
The mammalian or mechanistic target of rapamycin (mTOR) integrates multiple intracellular and extra-cellular upstream signals involved in the regulation of anabolic and catabolic processes in cells, and plays a key regulatory role in cell growth and metabolism. Activation of the mTOR signaling pathway has been reported to be associated with a wide range of human diseases. A growing number of in vivo and in vitro studies have demonstrated that the gut microbes and its complex metabolites can regulate host metabolic and immune responses through the mTOR pathway, and result in disorders of host phys-iological functions. In this review, we summarize the regulatory mechanisms of gut microbes and mTOR in different diseases, and discuss the crosstalk between gut microbes and their metabolites and mTOR in the disorders in gastrointestinal tract, liver, heart and other organs. We also discuss the promising appli-cation of multiple potential drugs that can adjust the gut microbiota and mTOR signal pathways. Despite the limited findings between gut microbes and mTOR, elucidating their relationship may provide new clues for the prevention and treatment of various diseases.
REVIEW | doi:10.20944/preprints202302.0067.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: fecal microbiota transplantation; horse; gut microbiota
Online: 3 February 2023 (09:50:36 CET)
Equine fecal microbiota transplantation (FMT) is an emerging therapy for restoring gut microbiome balance in horses. An imbalance in the gut microorganisms, known as dysbiosis, can cause inflammation and metabolic disruptions. FMT, which involves transferring gut bacteria from a healthy donor to a diseased recipient, has shown positive results in treating gastrointestinal diseases in horses, but is still largely limited to research purposes due to safety concerns and lack of understanding of its mechanisms. This paper aims to shed light on the possible mechanisms of FMT in horses and discuss future perspectives for its clinical application. Further research is needed to develop more effective and safer FMT techniques for horses.
REVIEW | doi:10.20944/preprints202011.0683.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: gut microbiota; early-life gut microbiota; gut dysbiosis; long-term health and disease; Developmental Origins of Health and Disease (DOHaD)
Online: 27 November 2020 (11:22:07 CET)
Abstract: Early life gut microbiota have been increasingly recognized as major contributors to short and/or long-term human health and diseases. Numerous studies have demonstrated that human gut microbial colonization begins at birth but continues to develop a succession of taxonomic abundances for two to three years until the gut microbiota reaches adult-like diversity and proportions. Several factors, including gestational age (GA), delivery mode, birth weight, feeding types, antibiotic exposure, maternal microbiome and diet influence the diversity, abundance and function of the early life gut microbiota. Gut microbial life is essential for assisting with the digestion of food substances to release nutrients, exerting control over pathogens, stimulating or modulating the immune system and influencing many systems such as the liver, brain, and endocrine system. Microbial metabolites play multiple roles in these interactions. Furthermore, studies provide evidence supporting that imbalances of the gut microbiota in early life, referred to as dysbiosis, are associated with specific childhood or adult disease outcomes, such as asthma, atopic dermatitis, diabetes, allergic diseases, obesity, cardiovascular diseases (CVD) and neurological disorders. These findings support that the human gut microbiota may play a fundamental role in the risk of acquiring diseases that may be programmed during the early life stage. In fact, it is critical to explore the role of the human gut microbiota in early life. In this review, we summarize the general understanding of the colonization and development of the gut microbiota in early life, highlighting the recent findings regarding the relationship between the gut microbiota composition and their metabolites, and immune functions, which could significantly influence long-term health and disease. We then review known pathophysiological interactions of the early gut microbiome with a number of well characterized diseases and pose potential etiological mechanisms.
REVIEW | doi:10.20944/preprints202210.0465.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Gut-bone axis; Gut-brain axis; Microbiome; Probiotics; Osteoporosis
Online: 31 October 2022 (06:16:35 CET)
The gut microbiome is a collection of microorganisms and parasites that reside in the gastrointestinal tract. There are many factors that can affect the composition of this community, such as age, sex, medications, and environmental triggers. The relationship between the human host and the gut microbiota is very important for both the survival and development of the organism. The disruption of this relationship can lead to the development of various inflammatory diseases. CBD and THC are used to treat muscle spasticity associated with multiple sclerosis. It is now clear these compounds also benefit patients with neuroinflammation. A study that investigated the role of gut microbiota in treating the inflammation and paralysis in a mouse model demonstrated that treatment with CBD and THC produced significant decrease in the inflammation levels. They also exhibited a significant increase in the number of anti-inflammatory cytokines. The presence of certain cannabinoids can suppress neuroinflammation and prevent microbial dysbiosis. Several studies have revealed the role of the gut microbiota in the development and maintenance of skeletal integrity and bone mineral density. The gut is a major source of nutrients, including vitamins B and K. It can also influence the development and maintenance of bone matrix. The presence of the gut microbiota can influence the actions of certain T regulatory cells, which can lead to the development of bone formation and proliferation. In addition, its metabolites can prevent bone loss. The gut microbiota can help maintain the bone's equilibrium and prevent the development of metabolic diseases, such as osteoporosis. In this review, the dual functions gut microbiota plays in the regulation of gut-bone axis and gut-brain axis and the impact of CBD on these roles are discussed in detail.
REVIEW | doi:10.20944/preprints202308.1970.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: cardiovascular health; gut microbiota; microbiome; dysbiosis; atherosclerosis
Online: 30 August 2023 (03:54:51 CEST)
Cardiovascular disease (CVD), comprising heart and blood vessel disorders, persists as the foremost contributor to global morbidity and mortality. In modern times, the intricate composition of gut microbiota has garnered significant focus, particularly for its varying impact on diverse ailments. Perturbations in gut microbiota and consequent dysbiosis have demonstrated connections with the advancement and origin of CVD, including conditions like atherosclerosis, hypertension, and heart failure. This comprehensive review delves into the pivotal role of gut microbiota in maintaining cardiovascular well-being.
ARTICLE | doi:10.20944/preprints202309.1073.v1
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: dyslipidemia; gut microbiota; mendelian randomization
Online: 18 September 2023 (05:54:09 CEST)
The determination of a causal relationship between gut microbiota and a range of dyslipidemia remains uncertain. To clarify these associations, we employed a two-sample mendelian randomization (MR) analysis utilizing the inverse-variance weighted (IVW) method. This comprehensive analysis investigated the genetic variants that exhibited a significant association (p<1e-5) with 129 distinct gut microbiota genera, and their potential link to diverse forms of dyslipidemia. The results indicated a potential causal relationship between 22 gut microbiota genera and dyslipidemia in humans. Furthermore, these findings suggested that the impact of gut microbiota on dyslipidemia regulation is dependent on the specific phylum, family, and genus. Bacillota phylum demonstrated the greatest diversity, with 15 distinct genera distributed among 8 families. Notably, gut microbiota derived from the Lachnospiraceae and Lactobacillaceae families exhibit statistically significant associations with lipid levels that contribute to overall health (p<0.05). The sensitivity analysis indicated that our findings possess robustness (p>0.05). The findings of our investigation provide compelling evidence that supports a causal relationship between the gut microbiota and dyslipidemia in the human body. It is noteworthy to highlight the significant influence of the Bacillota phylum as a pivotal regulator of lipid levels, and the families Lachnospiraceae and Lactobacillaceae should be acknowledged as probiotics that make substantial contributions to this metabolic process.
ARTICLE | doi:10.20944/preprints202310.0525.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: Age-related macular degeneration; Glaucoma; Gut microbiota; Mendelian randomization; Gut-retina axis
Online: 9 October 2023 (14:55:25 CEST)
Purpose The objective of this study was to eliminate any ambiguity by examining the correlation between gut microbiota and both AMD and glaucoma. Methods Mendelian randomization studies were conducted utilizing the data sourced from the GWAS database for the gut microbiome, AMD, and glaucoma. SNP estimates were summarized through five MR methods. We utilized Cochran's Q statistic to evaluate the heterogeneity of the instrumental variables. Additionally, we employed a "leave-one-out" approach to verify the stability of our findings. Results IVW suggests that Eubacterium (oxidoreducens group) and Parabacteroides had a protective effect on AMD. Both weighted median and IVW suggests that Lachnospiraceae (NK4A136 group) and Ruminococcaceae (UCG009) had a protective effect on AMD. However, both weighted median and IVW suggests that Dorea had a risk effect on AMD. Similarly, The IVW of Eubacterium (ventriosum group) showed a risk effect on AMD. The weighted median of Eubacterium (nodatum group), Lachnospiraceae (NC2004 group), and Roseburia had a risk effect on glaucoma. IVW suggested that Ruminococcaceae (UCG004) had a risk effect on glaucoma. Reverse MR analysis found a causal link between Eubacterium (nodatum group) and glaucoma. No causal relationships were found between AMD or glaucoma and the other mentioned bacterial groups. No significant heterogeneity or evidence of horizontal pleiotropy was detected. Conclusions This study found that certain gut bacteria had protective effects on AMD, while others may be risk factors for AMD or glaucoma. Besides, reverse MR found that glaucoma led to increased abundance of certain gut bacteria. Further trials are needed to clarify the specific mechanisms involved.
REVIEW | doi:10.20944/preprints202304.0767.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: COVID-19; SARS-CoV-2; Gut microbiota; Variants; Probiotics; gut microbiota metabolites
Online: 23 April 2023 (04:34:31 CEST)
Natural herbs and functional foods contain bioactive molecules capable of augmenting the immune system and mediating anti-viral functions. Functional foods, such as prebiotics, probiotics, and dietary fibers, have been shown to have positive effects on gut microbiota diversity and immune function. The use of functional foods has been linked with en-hanced immunity, regeneration, improved cognitive function, maintenance of gut mi-crobiota, and significant improvement in overall health. The gut microbiota plays a critical role in maintaining overall health and immune function, and disruptions to its balance have been linked to various health problems. SARS-CoV-2 infection has been shown to affect gut microbiota diversity, and the emergence of variants poses new challenges to combat the virus. SARS-CoV-2 recognizes and infects human cells through ACE2 receptors prevalent in lung and gut epithelial cells. Humans are prone to SARS-CoV-2 infection because the respiratory and gastrointestinal tracts are rich in microbial diversity and contain high ACE2 and TMPRSS2. This review article explores the potential use of functional foods in mitigating the impact of SARS-CoV-2 variants on gut microbiota diversity and the potential use of functional foods as a strategy to combat these effects.
REVIEW | doi:10.20944/preprints202307.0759.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: fetal development; gut-brain axis (GBA); maternal gut bacteria; placenta
Online: 12 July 2023 (03:58:47 CEST)
Gut microbiota plays a critical role in physiological regulation throughout life and is specifically modified to meet the demands of individual life stages and during pregnancy. Maternal gut microbiota is uniquely adapted to the pregnancy demands of the mother and the developing fetus. Both animal studies in pregnant germ-free rodents and human studies have supported a critical association between the composition of maternal microbiota during pregnancy and fetal development. Gut microbiota may also contribute to the development of the fetal gut-brain axis (GBA), which is increasingly recognized for its critical role in health and disease. Most studies consider birth as the time of GBA activation and focus on postnatal GBA development. This review focuses on GBA development during the prenatal period and the impact of maternal gut microbiota on fetal GBA development. It is hypothesized that adaptation of maternal gut microbiota to pregnancy is critical for the GBA prenatal development and maturation of GBA postnatally. Consequently, factors affecting maternal gut microbiota during pregnancy, such as maternal obesity, diet, stress and depression, infection, and medication, also affect fetal GBA development and are critical for GBA activity postnatally. Altered maternal gut microbiota during gestation has been shown to have long-term impact postnatally and multigenerational effects. Thus, understanding the impact of maternal gut microbiota during pregnancy on fetal GBA development is crucial for managing fetal, neonatal, and adult health, and should be included among public health priorities.
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: renal diets; fiber; renal nutrition; chronic kidney disease; gut microbiota
Online: 26 August 2019 (12:23:22 CEST)
Nutrition is crucial for the management of patients affected by chronic kidney disease (CKD) to slow down disease progression and to correct symptoms. The mainstay of the nutritional approach to renal patients is protein restriction coupled with adequate energy supply to prevent malnutrition. However, other aspects of renal diets, including fiber content, can be beneficial. This paper summarizes the latest literature on the role of different types of dietary fiber in CKD, with special attention to intestinal microbiota and the potential protective role of renal diets. Fibers have been identified based on aqueous solubility, but other features, such as viscosity, fermentability, and bulking effect in the colon should be considered. A proper amount of fiber should be recommended not only in the general population but also in CKD patients, to achieve an adequate composition and metabolism of intestinal microbiota and to reduce the risks connected with obesity, diabetes, and dyslipidemia.
REVIEW | doi:10.20944/preprints202112.0045.v1
Online: 3 December 2021 (09:57:35 CET)
Rotavirus (RV) and norovirus (NoV) are the leading cause of acute gastroenteritis (AGE) worldwide. Several studies have demonstrated that histo-blood group antigens (HBGAs) have a role in NoV and RV infections, since their presence on the gut epithelial surfaces is essential for the susceptibility to many NoV and RV genotypes. Polymorphisms in genes that code for enzymes required for HBGAs synthesis lead to secretor or non-secretor and Lewis positive and Lewis negative individuals. While secretor individuals appear to be more susceptible to RV infections, regarding NoVs infections there are too many discrepancies that prevent drawing conclusions. A second factor that influences enteric viral infections is the gut microbiota of the host. In vitro and animal studies have determined that the gut microbiota limits, but in some cases enhances, enteric viral infection. The ways microbiota can enhance NoV or RV infection include virion stabilization and promotion of virus attachment to host cells, whereas experiments with microbiota-depleted and germ-free animals point to immunoregulation as the mechanism by which the microbiota restricts infection. Human trials with live, attenuated RV vaccines and analysis of the microbiota in responders and non-responders individuals also allowed the identification of bacterial taxa linked to vaccine efficacy. As more information is gained on the complex relationships that are established between the host (glycobiology and immune system), the gut microbiota and the intestinal viruses, new avenues will be open for the development of novel anti-NoV and anti-RV therapies.
REVIEW | doi:10.20944/preprints202210.0210.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: Obesity; gut microbiota; placenta; brain development; fatal development
Online: 14 October 2022 (10:15:21 CEST)
Obesity in pregnancy induces metabolic syndrome, low-grade inflammation, altered endocrine factors, placental function, and the maternal gut microbiome. All these factors impact fetal growth and development, including brain development. The lipid metabolic transporters of the maternal-fetal-placental unit are dysregulated in obesity. Consequently, the transport of essential long-chain PUFAs for fetal brain development is disturbed. The mother’s gut microbiota is vital in maintaining postnatal energy homeostasis and maternal-fetal immune competence. Obesity during pregnancy changes the gut microbiota, affecting fetal brain development. Obesity and a high-fat diet in pregnancy can induce placental and intrauterine inflammation and thus influence the neurodevelopmental outcomes of the offspring. Several epidemiological studies observed an association between maternal obesity and adverse neurodevelopment. This review discusses the effects of maternal obesity and gut microbiota on fetal neurodevelopment outcomes. In addition, the possible mechanisms of the impacts of obesity and gut microbiota on fetal brain development are discussed.
ARTICLE | doi:10.20944/preprints202003.0388.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: celiac disease; gut microbiota; mendelian randomization
Online: 26 March 2020 (14:08:31 CET)
Celiac disease (CeD) is a complex immune-mediated inflammatory condition triggered by ingestion of gluten in genetically predisposed individuals. Literature suggests that alterations in gut microbiota composition and function precede the onset of CeD. Considering that microbiota is partly determined by host genetics, we speculate that the genetic makeup of CeD patients could elicit disease development through alterations in the intestinal microbiota. To evaluate potential causal relationships between gut microbiota and CeD, we performed a Two-Sample Mendelian Randomization analysis (2SMR). Exposure data were obtained from the raw results of a previous Genome Wide Association Study (GWAS) of gut microbiota, and outcome data from summary statistics of CeD GWAS and Immunochip studies. We have identified a number of putative associations between gut microbiota SNPs associated with CeD. Regarding bacterial composition, most of the associated SNPs are related to Firmicutes phylum, whose relative abundance has been previously reported to be altered in CeD patients. In terms of functional units, we have linked a number of SNPs to several bacterial metabolic pathways that seem to be related to CeD. Overall, this study represents the first 2SMR approach to elucidate the relationship between microbiome and CeD.
REVIEW | doi:10.20944/preprints202308.1394.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Gut microbiota; gastrointestinal illnesses; probiotics
Online: 21 August 2023 (09:46:46 CEST)
Modulating the gut microbiota with probiotics has been identified as a promising therapeutic method for the management of gastrointestinal illnesses. The effectiveness of probiotics in the treatment of gastrointestinal disorders can only be determined by delving into their underlying mechanisms of action. Through an analysis of the underlying processes, this study hopes to provide light on the potential benefits of probiotics for treating a variety of gastrointestinal conditions. The study covers a wide variety of gastrointestinal conditions, such as IBS, IBD, and antibiotic-associated diarrhea. Modifying the gut microbiota composition, strengthening the gut barrier function, modulating the immune system, and producing beneficial metabolites are among mechanisms of action that have been investigated. The strain- and dose-specific variables essential to getting the best treatment results are also highlighted. This review, which synthesizes the current information, gives a thorough overview of the effectiveness of probiotics in treating a variety of gastrointestinal illnesses and illuminates potential avenues for further study and therapeutic use.
REVIEW | doi:10.20944/preprints202002.0084.v1
Subject: Medicine And Pharmacology, Psychiatry And Mental Health Keywords: depression; leaky gut; microbiota; cytokines; neuroimmunomodulation; oxidative stress
Online: 6 February 2020 (10:30:36 CET)
There is robust evidence that major depression (MDD) is accompanied by a low-grade activation of the immune-inflammatory response system, which is involved in the pathophysiology of this disorder. It is also becoming apparent that glia cells are in reciprocal communication with neurons and orchestrate various neuromodulatory, homeostatic, metabolic, and immune mechanisms and have a crucial role in neuroinflammatory mechanisms in MDD. Those cells mediate the central nervous system (CNS) response to systemic inflammation and psychological stress, but at the same time, they may be an origin of the inflammatory response in the CNS. The sources of activation of the inflammatory response in MDD are immense, however, in recent years, it is becoming increasingly evident that the gastrointestinal tract with gut-associated lymphoid tissue (GALT) and increased intestinal permeability to bacterial LPS and food-derived antigens contribute to activation of low-grade inflammatory response with subsequent psychiatric manifestations. Furthermore, an excessive permeability to gut-derived antigenic material may lead to subsequent autoimmunities which are also known to be comorbid with MDD. In this chapter, we discuss fascinating interactions between the gastrointestinal tract, increased intestinal permeability, intestinal microbiota, and glia-neuron crosstalk, and their roles in the pathogenesis of the inflammatory hypothesis of MDD. To emphasize those crucial intercommunications for the brain functions, we propose the term of microbiota-gut-immune-glia (MGIG) axis.
REVIEW | doi:10.20944/preprints202310.0234.v1
Subject: Medicine And Pharmacology, Clinical Medicine Keywords: endometriosis; the endocannabinoid system; CB1; CB2; gut microbiota
Online: 4 October 2023 (10:52:24 CEST)
There is a growing interest in the endocannabinoid system and the gut microbiota. Both areas have been suggested to play a role in endometriosis, however this is yet to be studied comprehensively. The purpose of this narrative review is to identify the gaps in endometriosis research in the context of these two areas. It underscores the limited knowledge regarding the involvement of the endocannabinoid system and gut microbiota in endometriosis. Further research in these areas is essential to unlock the therapeutic potential of cannabis and enhance the understanding of endometriosis pathogenesis.
REVIEW | doi:10.20944/preprints201709.0040.v2
Subject: Biology And Life Sciences, Endocrinology And Metabolism Keywords: Gut microbiota; obesity; insulin resistance, NAFLD; probiotic; prebiotic; symbiotic
Online: 6 October 2017 (16:15:42 CEST)
Gut microbiota play critical roles in development of obese-related metabolic diseases such as nonalcoholic fatty liver disease (NAFLD), type 2 diabetes, and insulin resistance, which highlighted the potential of gut microbiota-targeted therapies on these diseases. There are various ways that can manipulate gut microbiota including probiotics, prebiotics, synbiotics, antibiotics and some active components from herbal medicines. In this review, we first reviewed the main roles of gut microbiota in mediating the development of NAFLD, and the advances in gut microbiota-targeted therapies on NAFLD in both the experimental and clinical studies, as well as the conclusions on the prospect of gut microbiota-targeted therapies in the future.
REVIEW | doi:10.20944/preprints202307.1326.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: COVID-19; Gut Microbiota; Microbiome; Dysbiosis
Online: 19 July 2023 (10:06:33 CEST)
The COVID-19 pandemic caused by the SARS-CoV-2 virus has led to significant global health implications. Although the respiratory manifestations of COVID-19 are widely recognized, emerging evidence suggests that the disease may also significantly affect the gut microbiota, the intricate community of bacteria that lives within the gastrointestinal system. This extensive article intends to investigate the impact of COVID-19 on the gut microbiota, examining the underlying mechanisms, clinical implications, and potential therapeutic interventions. Understanding the complex interactions between COVID-19 and the gut microbiota will help us to gain valuable insights into the broader consequences of this viral infection on human health.
REVIEW | doi:10.20944/preprints202306.2222.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Gut microbiota; Cardiovascular diseases; Trimethylamine N-Oxide; Heart failure; Atherosclerosis
Online: 30 June 2023 (11:58:11 CEST)
Much evidence reveals an important link between gut microbiota and the heart. In particular, the gut microbiota plays a key role in the onset of cardiovascular (CV) disease, including heart failure (HF). In HF, splanchnic hypoperfusion causes intestinal ischemia resulting in the translocation of bacteria and their metabolites into the blood circulation. Among these, the most important is the Trimethylamine N-Oxide (TMAO), which is responsible through various mechanisms for pathological processes in different organs and tissues. In this review, we summarise the complex interaction between gut microbiota and CV disease, particularly with HF, and the possible strategies to influence its composition and function. Finally, we highlight the potential role of TMAO as a novel prognostic marker and new therapeutic target of HF.
ARTICLE | doi:10.20944/preprints202308.0183.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: bacterial diversity; gut microbiota; prolactin receptor; lactation; weaning
Online: 2 August 2023 (08:46:06 CEST)
Maternal milk supports offspring development by providing microbiota, macronutrients, micronutrients, immune factors, and hormones. The hormone prolactin (PRL) is an important component of milk with protective effects against chronic non-communicable diseases (NCDs). Because maternal milk regulates microbiota composition and microbiota protect against NCDs, we aimed to investigate whether PRL regulates gut microbiota in newborn mice. 16SrRNA sequencing of feces and bioinformatics analysis were performed to evaluate gut microbiota in mice null for the PRL receptor (Prlr-KO) at the onset of weaning (postnatal day 21). The normalized colon and cecal weights were higher and lower, respectively, in Prlr-KO mice relative to wild-type mice (Prlr-WT). Relative abundance (Simpson Evenness Index), phylogenetic diversity, and bacterial concentration in gut contents were lower in the absence of the PRL receptor. Eleven bacteria species, out of 470, differed between Prlr-KO and Prlr-WT mice with two bacterial genera (Anaerotruncus and Lachnospiraceae) related to NCD development being the most common in Prlr-KO. Furthermore, a higher metabolism of terpenoids and polyketides was predicted in Prlr-KO mice compared to Prlr-WT mice; these metabolites have antimicrobial properties and are present in microbe-associated pathogenicity. In summary, the absence of the PRL receptor changes intestinal microbiota composition, resulting in lower microbiota abundance and richness, which could contribute to NCD development.
ARTICLE | doi:10.20944/preprints202310.1242.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: dietary iron; pregnancy; mother; Neonate; gut microbiota
Online: 19 October 2023 (10:34:35 CEST)
The aim of the study was to investigate the association between maternal dietary iron intake during pregnancy and the gut microbiota characteristics of both the mother and neonate in a well-characterized cohort. A total of 95 mother-neonate dyads were included in our study, with basic information collected through questionnaires. A semi-quantitative Food Frequency Questionnaire (FFQ) was used to assess maternal dietary intake during pregnancy, and maternal dietary iron intake was categorized into <20 mg/d and ≥20 mg/d groups. Fecal samples were collected from the mother in the third trimester and the neonate, allowing for assessment of the community profile and diversity of gut microbiota via 16S rRNA amplicon sequencing. Then, a comparison between different maternal dietary iron intake groups was conducted, adjusting for delivery mode (VD, vaginal delivery; CS, cesarean section) and other potential confounding factors. No significant differences in community profile and diversity were observed for the maternal gut microbiota in different dietary iron intake groups. In neonate fecal samples, the Shannon (P = 0.044) and Simpson (P = 0.010) diversity indices of the gut microbiota were higher in the maternal dietary iron intake ≥20 mg/d group, while Simpson diversity presented the same tendency in vaginal delivery (P = 0.041) after stratification. The relative abundance of the core genus Bifidobacterium showed a significant difference between groups (4.69 [1.19–12.77] vs. 13.98 [3.44–27.28]; P = 0.044). The abundance of Lactobacillus was different in the ≥20 mg/d group under both delivery modes (VD: beta = 2.9, w = 4.13; CS: beta = 2.77, w = 3.8). Our findings suggest that adequate dietary iron intake during pregnancy may promote beneficial bacterial colonization and increase the biodiversity of the neonate gut microbiota.
ARTICLE | doi:10.20944/preprints202002.0082.v1
Subject: Medicine And Pharmacology, Psychiatry And Mental Health Keywords: gut microbiota; ADHD; 16S rRNA gene; Inattention
Online: 6 February 2020 (10:25:29 CET)
Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder. Given the growing evidence of gut microbiota being involved in psychiatric (including neurodevelopmental) disorders, we aimed to identify differences in gut microbiota composition between participants with ADHD and controls and to investigate the role of the microbiota in inattention and hyperactivity/impulsivity. Fecal samples were collected from 107 participants (NADHD=42; Ncontrols=50; NsubthreholdADHD=15; range age: 13-29 years). The relative quantification of bacterial taxa was done using 16S ribosomal RNA gene amplicon sequencing. Beta-diversity revealed significant differences in bacterial composition between participants with ADHD and healthy controls, which was also significant for inattention, but showing a trend in case of hyperactivity/impulsivity only. Ten genera showed nominal differences (P < 0.05) between both groups, of which seven genera were tested for their association with ADHD symptom scores (adjusting for age, sex, body mass index, time delay between feces collection and symptoms assessment, medication use and family relatedness). Our results show that variation of a genus from the Ruminococcaceae family (Ruminococcaceae_UCG_004) is associated (after multiple testing correction) with inattention symptoms, and suggest a role of gut microbiota in ADHD pathophysiology.
ARTICLE | doi:10.20944/preprints201912.0315.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Lactobacillus; piglet; weaning; gut microbiota; growth enhancement.
Online: 24 December 2019 (10:59:14 CET)
The composition of bacteria in the gastrointestinal tract of piglets is easily affected by environmental changes, particularly during the weaning period. Compound strains of Lactobacillus reuteri and Lactobacillus salivarius were supplemented to piglets during pre- and post-weaning to determine their effects in improving the growth performance and ameliorating the diarrhea rate and stress caused by antioxidation in piglets. A larger number of L. reuteri and L. salivarius colonized the distal segment of the ileum and the total numbers of Lactobacillus spp. and Bifidobacterium were higher in the ileal mucous membrane and cecal lumen with probiotics supplementation. The numbers of antioxidative and immune molecules were increased in the plasma following compound bacteria (CL) supplementation, whereas cortisol and endotoxin levels were lower and growth hormone and insulin-like growth factor 1 were higher. Spearman’s and KEGG analysis of the bacterial operational taxonomic unit and antioxidative and immune indices and metabolic genes indicated that the body growth modulation by CL supplementation could be attributed to optimization of the intestinal bacterial composition. Collectively, these results suggest that supplementation with CL could reduce stress and improve the growth performance of piglets during weaning by optimizing the intestinal bacterial composition.
ARTICLE | doi:10.20944/preprints202310.1351.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: Stroke; gut microbiota; butyric acid; microglia; astrocytes; NLRP3
Online: 20 October 2023 (11:53:16 CEST)
Ischemic stroke (IS) is a group of vascular disease concomitant with high morbidity and mortality. Berberine is a bioactive substance and it has known to improve stroke, but the mechanism is yet to be proven. Mice were fed with BBR for 14 days. Then, mice were made into MCAO/R models. Neurological score, infarct volume, neuronal damage and markers associated with inflammation were detected. We tested the changes of intestinal flora in model mice after BBR administration by 16SrRNA sequencing. Chromatography-mass spectrometry was used to detect butyrate chemically. Tissue immunofluorescence was used to detect the changes of microglia and astroglia in mice brain. Our findings suggest that berberine improves stroke outcomes by modulating gut microbiota. Specifically, after MCAO/R mice were given berberine, beneficial bacteria producing butyric acid increased significantly, and the mice also had significantly higher levels of butyric acid. Administration of butyric acid and an inhibitor of butyric acid synthesis, heptyl-coA, showed that butyric acid improved stroke outcomes in model mice. In addition, butyric acid could inhibit the activation of microglia and astrocytes in the brain of model mice, thereby inhibiting the release of inflammatory cytokines IL-6, IL-1β, TNF-α and improving stroke outcomes. Our results suggest that berberine may improve stroke outcomes by modulating the gut flora to increase the abundance of butyric acid. These findings elucidate the mechanisms by which berberine improves stroke outcomes and provide some basis for clinical treatment.
REVIEW | doi:10.20944/preprints202211.0303.v1
Subject: Medicine And Pharmacology, Psychiatry And Mental Health Keywords: gut-brain-axis; BDNF; bacteria; neuron; neurotrophin; hippocampus
Online: 16 November 2022 (09:54:53 CET)
Growing evidence suggests a possible involvement of the intestinal microbiota in generating new neurons, but a detailed breakdown of the microbiota composition is lacking. In this report, we systematically reviewed preclinical rodent reports addressing the connection between the composition of the intestinal microbiota and neurogenesis and neurogenesis-affecting neurotrophins in the hippocampus. Various changes in bacterial composition from low taxonomic resolution at the phylum level to high taxonomic resolution at the species level were identified. As for neurogenesis, studies predominantly used doublecortin (DCX) as a marker of newly formed neurons or bromodeoxyuridine (BrdU) as a marker of proliferation. Brain-derived neurotrophic factor (BDNF) was the only neurotrophin found researched in relation to the intestinal microbiota. Phylum Actinobacteria, genus Bifidobacterium and genus Lactobacillus found the strongest positive while phylum Firmicutes, phylum Bacteroidetes and family Enterobacteriaceae as well as germ-free status, showed the strongest negative correlation towards neurogenesis or BDNF mRNA expression. Age, short-chain fatty acids (SCFA), obesity and chronic stress were recurring topics in all studies identified. Overall, these findings add to the existing evidence of a connection between microbiota and processes in the brain. To better understand this interaction, further investigation based on analyses of higher taxonomic resolution and clinical studies would be a gain to the matter.
ARTICLE | doi:10.20944/preprints202105.0710.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Gut microbiota; Mycobiota; Bacteria; Fungi; Malaria; Plasmodium falciparum; 16S metagenomics; ITS metagenomics; Children; Cohort; Mali; Dogon country
Online: 31 May 2021 (08:25:57 CEST)
The gut microbiota has recently been associated with susceptibility/resistance to malaria in animal models and humans, yet the impact of the gut microbiota on the risk of a malaria attack remains to be assessed. This study aims at assessing the influence of the gut microbiota on malaria attacks and Plasmodium parasitæmia in children living in a malaria-endemic area in Mali. Three hundred healthy children were included in a 16-months cohort study in Bandiagara. Their gut bacteria and fungi community structures were characterised via 16S and ITS metabarcoding from stool samples collected at inclusion. Clinician team monitored the occurrence of malaria attacks. Asymptomatic carriage of Plasmodium was assessed by qPCR. Over the 16-month period, 107 (36%) children experienced at least one occurrence of malaria attacks, and 82 (27%) at least one asymptomatic Plasmodium parasitæmia episode. A higher gut bacteria richness was independently associated with susceptibility to asymptomatic parasitæmia episodes and malaria attacks; while the Shannon H diversity and Chao-1 richness index of gut fungi community structure was relatively homogeneous in children who were and were not infected with P. falciparum. Using a linear discriminant effect size analysis of operational taxonomic units assigned to the species level, 17 bacteria, including Clostridiaceae, Eubacteriaceae, Senegalimassilia sp., Atopobiaceae and Lachnosipraceae, and seven fungi, including Dioszegia fristigensis, Ogataea polymorpha and Cutaneotrichosporon cyanovorans, were associated with susceptibility; whereas eight bacteria, including, Bifidobacterium spp., Weissela confusa and Peptostreptococcacea, and 3 fungi, Malassezia sp., Niesslia exosporoides, and Didymocrea leucaenae, were associated with resistance to malaria. Moreover, 15 bacteria, including Coproccus eutactus, Terrisporobacter petrolearius, Klebsiella pneumoniae and Ruminococcaceae, and 13 fungi, including Wallemia mellicola, were associated with susceptibility, whereas 19 bacteria, including Bifidobacterium spp., Bacteroides fragilis, Peptostreptococcacea, and Lactobacillus ruminis, and three fungi, including Cryptococcus neoformans, were associated with resistance to asymptomatic Plasmodium parasitæmia episodes. Further studies are needed to confirm these findings that point the way towards strategies aiming to reduce the risk of malaria by modulating gut microbiota components in at-risk populations.
REVIEW | doi:10.20944/preprints201805.0404.v2
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: microbiota; kynurenine pathway; serotonin; inflammation; gut motility
Online: 22 June 2018 (06:29:42 CEST)
The human gastrointestinal tract is inhabited by trillions of commensal bacteria collectively known as the gut microbiota. Our recognition of the significance of the complex interaction between the microbiota, and its host has grown dramatically over the past years. A balanced microbial community is a key regulator of the immune response, and metabolism of dietary components, which in turn, modulates several brain processes impacting mood and behavior. Consequently, it is likely that disruptions within the composition of the microbiota would remotely affect the mental state of the host. Here, we discuss how intestinal bacteria and their metabolites can orchestrate gut-associated neuroimmune mechanisms that influence mood and behavior leading to depression. In particular, we focus on microbiota-triggered gut inflammation and its implications in shifting the tryptophan metabolism towards kynurenine biosynthesis while disrupting the serotonergic signaling. We further investigate the gaps to be bridged in this exciting field of research in order to clarify our understanding of the multifaceted crosstalk in the microbiota-gut-brain interphase, bringing about a novel microbiota-targeted therapeutics for mental illnesses.
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: gut microbiota; Entamoeba histolytica; resistance to oxidative stress; resistance to nitrosative stress; virulence
Online: 24 February 2021 (16:26:55 CET)
Amebiasis is a disease caused by the unicellular parasite Entamoeba histolytica. In most cases, the infection is asymptomatic but when symptomatic, the infection can cause dysentery and invasive extraintestinal complications. In the gut, E.histolytica feeds on bacteria. Increasing evidences support the role of the gut microbiota in the development of the disease. In this review we will discuss the consequences of E.histolytica infection on the gut microbiota. We will also discuss new evidences about the role of the gut microbiota in regulating the resistance of the parasite to oxi-dative stress and its virulence.
REVIEW | doi:10.20944/preprints202304.0753.v2
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: Lead Toxicity; Autism Spectrum Disorder; Microbiota; Gut-Brain Axis; Probiotics
Online: 12 September 2023 (02:53:37 CEST)
Autism Spectrum Disorder (ASD), a neurodevelopmental disorder characterized by persistent deficits in social interaction and communication manifests in early childhood and is followed by restricted and stereotyped behaviors, interests or activities in adolescence and adulthood (DSM-V). Although genetics and environmental factors have been implicated, the exact causes of ASD have yet to be fully characterized. New evidence suggests that dysbiosis or perturbation in gut microbiota (GM) and exposure to lead (Pb) may play important roles in ASD etiology. Pb is a toxic heavy metal that has been linked to a wide range of negative health outcomes including anemia, encephalopathy, gastroenteric diseases and more importantly cognitive and behavioral problems inherent to ASD. Pb exposure can disrupt GM, which is essential for maintaining overall health. GM, consisting of trillions of microorganisms, has been shown to play a crucial role in the development of various physiological and psychological functions. GM interacts with the brain in a bidirectional manner referred to as “Gut-Brain Axis (GBA).” In this review, following a general overview of ASD and GM, the interaction of Pb with GM in the context of ASD is emphasized. Potential exploitation of this interaction for therapeutic purposes is also touched upon.
ARTICLE | doi:10.20944/preprints202303.0049.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: ASVs; diet habit; Gekko japonicus; gut microbiota; sex
Online: 3 March 2023 (01:31:32 CET)
Numerous studies have demonstrated that multiple intrinsic and extrinsic factors shape the structure and composition of gut microbiota in a host. The disorder of gut microbiota may trigger various host diseases. Here, we collected fecal samples from wild-caught Japanese geckos (Gekko japonicus) and captive conspecifics fed with mealworms (mealworm-fed geckos) and fruit flies (fly-fed geckos), aiming to examine dietary and sexual correlates of gut microbiota. We used the 16S rRNA gene sequencing technology to determine the composition of gut microbiota. The dominant phyla with a mean relative abundance higher than 10% were Verrucomicrobiota, Bacteroidota and Firmicutes. Gut microbial community richness was higher in mealworm-fed geckos than in fly-fed and wild geckos, and community diversity was higher in mealworm-fed geckos than in wild geckos. Neither alpha nor beta diversity of gut microbiota differed among wild, mealworm-fed and fly-fed geckos. The beta rather than alpha diversity of gut microbiota was sex-dependent. Based on the relative abundance of gut bacteria and its gene functions, we concluded that gut microbiota contributed more significantly to the host’s metabolic and immune functions. Higher diversity of gut microbiota in mealworm-fed geckos could result from higher chitin contents of insects of the order Coleoptera. This study not only provides basic information about the gut microbiota of G. japonicus, but also shows that gut microbiota correlates with dietary habit and sex in the species.
ARTICLE | doi:10.20944/preprints202307.1458.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: alkylresorcinols; olivetol; gut microbiota; fecal microbiota transplantation; endocannabinoid system
Online: 21 July 2023 (13:59:22 CEST)
Background: Alkylresorcinols (ARs) are polyphenolic compounds with a wide spectrum of biological activities and potentially implicated in the regulation of host metabolism. The present study is aimed to establish whether ARs can be produced by human gut microbiota and to evaluate alterations in the content of ARs in stool samples of C57BL and db/db and LDLR (-/-) mice in dependence on diet specifications and olivetol (5-n-pentylresorcinol) supplementation in order to estimate a regulatory potential of ARs. Methods: The quantita-tive analysis of ARs levels in mice stool samples was performed using gas chromatography with mass spectrometric detection; fecal microbiota transplantation (FMT) from human donor to germ-free mice was performed to explore whether the intestinal microbiota could produce ARs molecules. Results: A significant increase in the amounts of individual mem-bers of ARs homologues in stool samples was revealed in 14 days after FMT. 5-n-Pentylresorcinol supplementation to a regular-chow diet influences the amounts of sev-eral ARs in stool of C57BL/6 and LDLR (-/-), but not db/db mice. Conclusions: For the first time, we have shown that several ARs can be produced by the intestinal microbiota. Taking into account, that AR concentrations in human serum are correlated with LPS levels and with microbiota diversity indexes in human stool samples, it can be assumed that ARs may serve as quorum-sensing molecules, influencing gut microbiota composition and host me-tabolism as well.
ARTICLE | doi:10.20944/preprints202312.0392.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: gut microbiome; methotrexate; microbiota; periodontitis; rheumatoid arthritis; mouth
Online: 6 December 2023 (10:28:22 CET)
This study evaluated the influence of methotrexate (MTX) and non-surgical periodontal treatment (NSPT) on the composition of the oral-gut microbiota in patients with rheumatoid arthritis (RA). Assessments were performed at baseline (T0), 6 months after MTX treatment (T1), and 45 days after NSPT (T2). The composition of the oral and gut microbiota was assessed by amplifying the V4 region of the 16S gene from subgingival plaques and stools. The results of the analysis of continuous variables were presented descriptively and non-parametric tests were adopted. Thirty-seven patients (27 with periodontitis) were evaluated at T0; 32 patients (24 with periodontitis) at T1; and 28 patients (17 with periodontitis) at T2. Nine individuals were lost to follow-up. MTX tended to reduce the alpha diversity of the oral-gut microbiota, while NSPT appeared to increase the number of different species of oral microbiota. MTX and NSPT influenced beta diversity in the oral microbiota. The relative abundance of oral microbiota was directly influenced by periodontal status. MTX did not affect the periodontal condition but modified the interactions between clinical parameters and the oral-gut microbiota. MTX and NSPT directly affected the composition and richness of the oral-gut microbiota. However, MTX did not influence periodontal clinical parameters.
ARTICLE | doi:10.20944/preprints202007.0338.v1
Subject: Biology And Life Sciences, Food Science And Technology 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/preprints202109.0288.v1
Subject: Medicine And Pharmacology, Endocrinology And Metabolism Keywords: Diet; Obesity; Gut microbes; High-fiber diet; High fat diet
Online: 16 September 2021 (13:50:36 CEST)
With the ever-increasing rate, obesity has become an epidemiological problem throughout the globe comprising about 39% of the world population as of now. Among several reasons, disruption of the gut microbial ecosystem might contribute to the pathogenesis of metabolic disorders, including obesity, metabolic syndrome, type 2 diabetes, and other associated comorbidities. Though the mechanisms related to dysbiosis are unclear, diet might play a modulating role where different dietary approaches manipulate microbial richness and abundance as well as stability. For instance, shifting of Firmicutes and Bacteroidetes ratio in the gut might have a role in association with the dietary approaches and ingestion duration. Along with altered gut microbial composition, microbial metabolites such as short-chain fatty acids (SCFA) after ingestion of non-digestible dietary starches may have an impact on host metabolism by regulating lipogenesis, gluconeogenesis, and inflammation with potential associations to health and obesity. The dietary approaches like carbohydrates, fibre, protein, and/or fat diet at various arrangements can make a shift in the composition of gut microbiota if introduced for a short period. However, the unique pattern of the gut microbes usually remains the same along with the longer period of habitual diet. Though the short-term dietary intervention or circadian rhythm influences a transient change in gut microbes, other than habitual diet, the understanding related to long-term dietary change-induced permanent alterations is minimum. Alternatively, the usage of prebiotics, probiotics as well as postbiotics could be beneficial to overcome dysbiosis. This review highlights the current knowledge and the interaction between the human intestinal microbiota and diet as a modifying factor, in obesity allowing the scientists to uncover novel targets and tools to use as customized therapy.
ARTICLE | doi:10.20944/preprints202002.0306.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Egyptian mongoose; Gut microbiota; Microbial profiling; Bio-ecology; Mediterranean Wild Carnivores
Online: 21 February 2020 (08:02:59 CET)
Egyptian mongoose (Herpestes ichneumon) is a medium-size carnivore that in Europe is restricted to Iberia. The bio-ecology of this species remains to be elucidated in several dimensions, including gut microbiota that is nowadays recognized as a fundamental component of mammals. In this work, we investigated the gut microbiota of this herpestid by single-molecule real-time sequencing of twenty paired male (n=10) and female (n=10) intestinal samples. This culture-independent approach enabled microbial profiling based on 16S rDNA and investigation of taxonomical and functional features. The core gut microbiome of the adult subpopulation was dominated by Firmicutes, Fusobacteria, Actinobacteria, and Proteobacteria. Eight genera were uniquely found in adults and five in non-adults. When comparing gut bacterial communities across sex, four genera were exclusive of females and six uniquely found in males. Despite these compositional distinctions, alpha- and beta-diversity analyses showed no statistically significant differences across sex or between adult and non-adult specimens. However, males presented a significantly higher abundance of amino acid and citrate cycle metabolic pathways, compared to the significant overrepresentation in females of galactose’ metabolic pathways. Adults showed a significantly higher abundance of cationic antimicrobial peptide resistance pathways, while non-adults bared a significant overrepresentation of two-component systems associated with antibiotic synthesis, flagellin production and chemotaxis control. This study adds new insights into mongoose bio-ecology palette, highlighting taxonomical and functional microbiome dissimilarities across sex and age classes, possibly related to primary production resources and life-history traits that impact on behavior, diet and gut ecosystem.
ARTICLE | doi:10.20944/preprints202311.0543.v1
Subject: Biology And Life Sciences, Aquatic Science Keywords: protein sources; gut health; microbiome; Oreochromis niloticus; amino acid intake
Online: 8 November 2023 (11:36:54 CET)
Dietary protein quality plays a key role in maintaining intestinal mucosal integrity, but also modulates the growth of luminal microorganisms. This work assessed the effect of dietary protein sources on the performance, gut morphology, and microbiome in Nile tilapia. Four isonitrogenous and isolipidic diets comprising equivalent amounts of the protein supply derived from either PLANT, ANIMAL, INSECT, or MICROBIAL (bacterial biomass) sources were fed to triplicate groups of fish (IBW: 12 g) during 46 days. Fish fed ANIMAL and MICROBIAL diets showed significantly higher growth than those fed the PLANT and INSECT diets (P < 0.05). Relative abundance at the phylum level shows Bacteroidetes, Fusobacteria and Proteobacteria as more abundant phyla in tilapia’s intestine, while Cetobacterium is the most representative genera in all treatments. Interesting patterns were observed in the correlation between amino acid intake and genus and species abundance. Metabolism prediction analysis showed that microbial amine and polyamine degradation pathways are modulated depending on diets. In conclusion, different protein sources interfere directly with the cross-talk of bacteria pathways and amino acid intake.
REVIEW | doi:10.20944/preprints201612.0119.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: antibiotic; bacteroidetes; dietary emulsifier; firmicutes; food additive; gut microbiota; non-nutritive sweetener; proteobacteria
Online: 23 December 2016 (11:21:40 CET)
Gut bacteria play an important role in several metabolic processes and human diseases, such as obesity and its co-morbidities, like fatty liver disease, insulin resistance/diabetes and cardiovascular events. Among several factors, dietary patterns, probiotics, prebiotics, synbiotics, antimicrobials and non-dietary factors, such as stress, age, exercise and climatic conditions, can dramatically impact the human gut microbiota diversity and equilibrium. However, the effect of minor food constituents, including food additives and trace contaminants, on human gut microbiota has received less attention. Consequently, the present review aimed to provide an objective perspective of the current knowledge regarding the impacts of minor food constituents on human gut microbiota and consequently, on human health.
REVIEW | doi:10.20944/preprints202311.1505.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: Gut microbiota; enteric nervous system; mental health
Online: 23 November 2023 (10:33:09 CET)
Bacteria in the gut microbiome play an intrinsic part in immune activation, intestinal permeability, enteric reflex, and entero-endocrine signaling. Gut microbiota communicates with the central nervous system (CNS) through the production of bile acids, short-chain fatty acids (SCFAs), glutamate (Glu), γ-aminobutyric acid (GABA), dopamine (DA), norepinephrine (NE), serotonin (5-HT) and histamine. A vast number of signals generated in the gastrointestinal tract (GIT) reaches the brain via afferent fibers of the vagus nerve (VN). Signals from the CNS are returned to entero-epithelial cells (EES) via efferent VN fibers and communicate with 100 to 500 million neurons in the submucosa and myenteric plexus of the gut wall, which is referred to as the enteric nervous system (ENS). Intercommunications between the gut and CNS regulate mood, cognitive behavior, and neuropsychiatric disorders such as autism, depression, and schizophrenia. The modulation, development, and renewal of nerves in the ENS, and changes in the gut microbiome alter the synthesis and degradation of neurotransmitters, which ultimately influence our mental health. The more we decipher the gut microbiome and understand its effect on neurotransmission, the closer we may get to the developing of novel therapeutic and psychobiotic compounds to improve cognitive functions and prevent mental disorders. In this review, the intricate control of entero-endocrine signaling and immune responses that keep the gut microbiome in a balanced state, and the influence that changing gut bacteria have on neuropsychiatric disorders are discussed.
ARTICLE | doi:10.20944/preprints202307.0687.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Shexiang Baoxin Pill; Atherosclerosis; Gut microbiota; Fecal metabolites; Correlation
Online: 11 July 2023 (10:25:05 CEST)
Background: Atherosclerosis (AS), a key pathological contributor of cardiovascular diseases (CVDs), was characterized by formation of atherosclerotic plaque in aortic wall and caused high mortality and morbidity worldwide. Factors contributing to the initiation and progression of AS included vascular endothelial dysfunction, dyslipidemia, inflammation, and oxidative stress. Shexiang Baoxin Pill (SBP) was a traditional Chinese medicine that had been widely applied in clinic and proved to be effective for patients with CVDs. However, the mechanisms underlying its anti-atherosclerotic effects have not been completely elucidated. The study aimed to investigate the protective effects of SBP on AS and its potential mechanisms. Methods: Different dose of SBP was orally administered in apolipoprotein E-deficient (ApoE-/-) mice treated with a high-fat diet (HFD). Histopathological and immunohistochemical analysis, ELISA, untargeted metabolomics analysis, 16S rRNA sequence analysis, and spearman analysis were applied to identify the protective effects and mechanisms of SBP in HFD-induced AS. Results: SBP significantly alleviated HFD-induced atherosclerotic lesion both in aorta and aortic sinus with a reduction in serum levels of total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C), as well as interleukin-6 (IL-6) and interleukin-1β (IL-1β), and increased high-density lipoprotein cholesterol (HFD-C) level with no significant change of body weight in HFD-induced ApoE-/- mice. Mechanismly, SBP markedly reshaped the gut microbiota composition and associated metabolomic characteristics. 2 differential intestinal floras at phylum level and 8 differential microbes at genus level, 5 metabolic pathways and 9 differential fecal metabolites related to CVDs were figured out. Besides, intensive correlation between 8 differential microbes and 9 fecal metabolites was observed. Conclusions: Our results showed that SBP could improve HFD-triggered serum lipid disorder, systematic inflammation, and contribute to the alleviation of atherosclerotic lesion. The antiatherogenic properties of SBP might partly result from the reshaping of the gut microbiota and fecal metabolic profile.
ARTICLE | doi:10.20944/preprints202310.1970.v1
Subject: Biology And Life Sciences, Aging Keywords: Alzheimer’s disease; Dementia; Twendee X; microbiome; gut microbiota; Oxidative stress; Quality of life; antioxidant
Online: 31 October 2023 (05:16:08 CET)
The human gut microbiota (GM) is a complex and dynamic ecosystem that hosts trillions of commensal and potentially pathogenic microorganisms. It is crucial in protecting humans from pathogens and in maintaining immune and metabolic homeostasis. Numerous studies have demonstrated that GM has a significant impact on health and disease, including Alzheimer’s disease (AD). AD is a progressive neurodegenerative disorder characterized by impaired short-term memory and cognitive deficits. Patients with AD have been reported to exhibit abnormalities in GM density and species composition. Oxidative stress (OS) has been implicated in the onset and progression of AD, however, the relationship between OS and gut microbiota in AD onset and progression is not clear. Twendee X®︎ (TwX), an oral supplement consisting of 8 active ingredients, has been shown to prevent dementia in mild cognitive impairment (MCI) in humans and substantially improve cognitive impairment in mouse models of AD. This positive effect is achieved through the potency of the combined antioxidants that regulate OS and therefore similar results cannot be achieved by a single antioxidant ingredient. To examine the impact of long-term OS elevation as seen in AD on the body and GM, we examined GM alterations during the initial OS elevation using a rat 2-week OS loading model, and examined the effects of TwX on OS and GM. Furthermore, using a questionnaire survey and fecal samples, we analyzed the impact of TwX on healthy individuals' gut bacteria and the associated effect on their quality of life (QOL). TwX was found to increase the number of bacteria species and their diversity in GM, as well as butyrate-producing bacteria, which tend to be reduced in AD patients. Additionally, TwX improved defecation condition and QOL. The gut bacteria function as part of the homeostatic function during OS elevation, and prophylactic administration of TwX strengthened this function. The results suggests that the preventative effect of TwX on dementia may involve the GM in addition to the other effects previously demonstrated.
REVIEW | doi:10.20944/preprints202307.2005.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: ncRNA; lncRNA; miRNA; cardiac arrhythmia; atrial fibrillation; gut microbiota; APRO family protein
Online: 31 July 2023 (02:24:36 CEST)
The non-coding RNAs (ncRNAs) are indispensable for controlling genes and genetic programming during development, as well as for health and cardiovascular diseases. Cardiac arrhythmia is a frequent cardiovascular disease, which has a complex pathology. Recent studies have shown that ncRNAs are also associated with cardiac arrhythmias. Many non-coding RNAs and/or genomes have been reported as a genetic background for cardiac arrhythmias. Arrhythmias may be affected by several functional and structural changes in the myocardium. Therefore, ncRNAs might be indispensable regulators of gene expression in cardiomyocytes, which could play a dynamic role in regulating the stability of cardiac conduction and/or in the remodeling process. Although it remains almost unclear how ncRNAs regulate the expression of molecules for controlling the cardiac conduction and/or in the remodeling process, gut microbiota and immune system within the intricate networks might be involved in the regulatory mechanisms. This study would discuss them and provide a research basis for ncRNAs modulation, which might support the development of emerging innovative therapies against cardiac arrhythmias.
ARTICLE | doi:10.20944/preprints202305.2093.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: NAFLD; Gut Microbiota; Inflammation; Metagenomics; Live Biotherapeutic Product
Online: 30 May 2023 (08:59:14 CEST)
Non-alcoholic fatty liver disease (NAFLD) affects about 20–40% of the adult population in high-income countries and is now a leading indication for liver transplantation and can drive to hepatocellular carcinoma. The link between gut microbiota dysbiosis and NAFLD is now clearly established. Through analyses of the gut microbiota with shotgun metagenomics, we observed that compared to healthy controls, Adlercreutzia equolifaciens is depleted in patients with liver diseases such as NAFLD. Its abundance also decreases as the disease progresses and eventually disappears in the last stages indicating a strong association with disease severity. Moreover, we show that A. equolifaciens possesses anti-inflammatory properties, both in vitro and in vivo in a humanized mouse model of NAFLD. Therefore, our results demonstrate a link between NAFLD and the severity of liver disease and the presence of A. equolifaciens and its anti-inflammatory actions. Counterbalancing dysbiosis with this bacterium may be a promising live biotherapeutic strategy of liver diseases..
REVIEW | doi:10.20944/preprints201810.0369.v1
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: Age-Related Macular Degeneration, Gut-retina axis, Gut microbiota, Dietary habits, Micronutrients, Fish oil, omega-3 Polyunsaturated fatty acids, Personalised medicine
Online: 16 October 2018 (17:39:27 CEST)
Age-related macular degeneration (AMD) is a complex multifactorial disease and the primary cause of legal and irreversible blindness among individuals aged >=65 years in developed countries. Globally, it affects 30-50 million individuals, with an estimated increase of approximately 200 million by 2020 and approximately 300 million by 2040. Currently, the neovascular form may be able to be treated with the use of anti-VEGF drugs, while no effective treatments are available for the dry form. Many observational studies, such as AREDS-1 and AREDS 2, have shown a potential role of micronutrient supplementation in lowering the risk of progression of the early stages of AMD. Recently, low-grade inflammation, sustained by dysbiosis and a leaky gut, has been shown to contribute to the development of AMD. Given the ascertained influence of the gut microbiota in systemic low-grade inflammation and its potential modulation by macro- and micro-nutrients, a potential role of diet in AMD has been proposed. This review discusses the role of the gut microbiota in the development of AMD. Using PubMed, Web of Science and Scopus, we searched for recent scientific evidence discussing the impact of dietary habits (high fat and high glucose or fructose diets), micronutrients (vitamins C, E, and D, zinc, beta-carotene, lutein and zeaxanthin) and omega-3 fatty acids on the modulation of the gut microbiota and their relationship with AMD risk and progression.
COMMUNICATION | doi:10.20944/preprints202304.1127.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: COVID-19; gut microbiota; diversity; diabetes; metformin
Online: 28 April 2023 (07:06:36 CEST)
The gut microbiota plays a crucial role in maintaining host health and has a significant impact on human health and disease. In this study, we investigated the alpha diversity of gut microbiota in COVID-19 patients and analyzed the impact of COVID-19 variants, antibiotic treatment, type 2 diabetes (T2D), and metformin therapy on gut microbiota composition and diversity. We used a culture-based method to analyze the gut microbiota and calculated alpha-diversity using the Shannon H' and Simpson 1/D indices. We collected clinical data, such as length of hospital stay (LoS), C-reactive protein (CRP) levels, and neutrophil-to-lymphocyte ratio (NLR). We found that patients with T2D had significantly lower alpha-diversity than those without T2D. Antibiotic use was associated with a reduction in alpha-diversity, while metformin therapy was associated with an increase. We did not find significant differences in alpha-diversity between the Delta and Omicron groups. Length of hospital stay, CRP levels, and NLR showed weak to moderate correlations with alpha diversity. Our findings suggest that maintaining a diverse gut microbiota may benefit COVID-19 patients with T2D. Interventions aimed at preserving or restoring gut microbiota diversity, such as avoiding unnecessary antibiotic use and promoting metformin therapy, may improve patient outcomes.
ARTICLE | doi:10.20944/preprints202007.0147.v1
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: gut microbiota; obesity; weight-loss; Mediterranean diet; 16S rRNA; High-throughput sequencing
Online: 8 July 2020 (11:07:10 CEST)
Although it is known that the gut microbiota (GM) can be modulated by diet, the efficacy of specific dietary interventions in determining its composition and diversity in obese patients remains to be ascertained. The present work aims to evaluate the impact of a moderately hypocaloric Mediterranean diet on the GM of obese and overweight patients (OB). The GM of 23 OB patients (F/M= 20/3) was compared before (T0) and after 3 months (T3) of the nutritional intervention (NI). Fecal samples were analyzed by Illumina MiSeq sequencing of the 16S rRNA gene. At baseline, the GM characterization confirmed the typical obesity-associated dysbiosis. After 3 months of NI, patients presented a statistically significant reduction of the body weight and fat mass, along with changes in the relative abundance of many microbial patterns. In fact, we observed an increased abundance in several Bacteroidetes taxa (i.e. Sphingobacteriaceae, Sphingobacterium, Bacteroides spp., Prevotella stercorea) and depletion of many Firmicutes taxa (i.e. Lachnospiraceae members, Ruminococcaceae and Ruminococcus, Veillonellaceae, Catenibacterium, Megamonas). In addition, the phylum Proteobacteria showed an increased abundance, while the genus Sutterella, within the same phylum, decreased after the intervention. Metabolic pathways, predicted by bioinformatic analyses, showed a decrease in membrane transport and cell motility after NI. The present study extends our knowledge of the GM profiles in OB, highlighting the potential benefit of a moderate caloric restriction in counteracting the gut dysbiosis.
ARTICLE | doi:10.20944/preprints202308.0855.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Canaries; Serinus canaria; gut bacterial microbiota; bacterial communities; reproduction; reproductive cycle; 16S rRNA gene sequencing
Online: 10 August 2023 (11:14:53 CEST)
Investigation of bacterial communities is on the rise both in human and veterinary medicine. Their role in health maintenance and pathogenic mechanisms is in the limelight of infectious, metabolic, and cancer research. Among the most considered, gut bacterial communities takes the cake. Their part in animals was assessed mainly to improve animal production, public health, and pet management. In this regard, canaries deserve attention, being a popular pet and source of economic income for bird-keepers, for whom breeding represents a pivotal point. Thus, the aim of the present work was to follow gut bacterial communities’ evolution along on whole reproductive cycle of 12 healthy female canaries. Feces were collected during parental care, molting, and resting phase, and submitted for 16S rRNA sequencing. Data analysis a substantial presence of Lactobacillus aviarius along all the phases, and a relevant shift of microbiota during molting and rest due to an abrupt decrease of Vermiphilaceae family. Although the meaning of such change is not clear, future research may highlight unforeseen scenarios. Moreover, Lactobacillus aviarius may be deemed for normal bacteria flora restoration in debilitated birds, perhaps improving their health and productivity.
REVIEW | doi:10.20944/preprints202210.0362.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: gut microbiome; time-restricted feeding; intermittent fasting; targeted approach; hormonal signaling; metabolic regulators
Online: 24 October 2022 (12:00:48 CEST)
Each individual has a unique gut microbiota; therefore the genes in our microbiome outnumber the genes in our genome by about 150 to 1. Perturbation in host nutritional status influences gut microbiome composition and vice versa. The gut microbiome can help in producing vitamins, hormones, and other active metabolites that support the immune system; harvest energy from food; aid in digestion; protect against pathogens; improve gut transit and function; send signals to the brain and other organs, oscillating the circadian rhythm and coordinate with host metabolism through multiple cellular pathways. Gut microbiota can be influenced by host genetics, medications, diet, and lifestyle factors from preterm to aging. So before prescribing a customized treatment, it is crucial to monitor and count the gut flora as a focused biomarker. Many nutritional approaches that have been developed help in maintaining and restoring an optimal microbiome such as specific diet therapy, nutrition interventions and customized eating patterns. One of these approaches is time-restricted feeding/eating (TRF/E), a type of intermittent fasting (IF) in which a subject abstains from food intake for a specific time window. Such a dietary modification might alter and restore the gut microbiome for proper alignment of cellular and molecular pathways throughout the lifespan. In this review, we have highlighted that gut microbiota would be a targeted biomarker and TRF/E would be a targeted approach for restoring the gut microbiome associated molecular pathways like hormonal signaling, the circadian system, metabolic regulators, neural responses, and immune-inflammatory pathways. Consequently, modulation of gut microbiota through TRF/E could contribute in proper utilization and availability of the nutrients and in this way confer protection against diseases for harnessing personalized nutrition approaches to improve human health.
ARTICLE | doi:10.20944/preprints202310.1357.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Holstein calf; Growth; Gut microbiota; Saccharomyces cerevisiae fermentation products
Online: 20 October 2023 (12:36:34 CEST)
Saccharomyces cerevisiae fermentation products (SCFP) can potentially promote gastrointestinal growth and immunity in young livestock. However, reports within the existing literature on the effects of SCFP supplements on calves have been inconsistent; therefore, we perform the following experiments to resolve the inconsistencies. A total of 22 Holstein calves [10 d after birth, BW = 48.93 ± 3.99 kg (mean ± SD)] were assigned randomly into two groups, namely the control group (CON) and SCFP group, each having 11 replicas. The calves in the CON were fed a basal diet, while the SCFP group was fed the basal diet supplemented with 5g/head/d SCFP (NutriTek, Diamond V, Cedar Rapids, IA52404, United States) incorporated into feed. All the calves were regularly fed thrice daily at 08:00, 14:30, and 21:00 and had free access to water. A 5-day adaptation phase was followed by a 45-day experimental period. The results showed that compared to the CON, at the end of the d-45 trial, the body weight was significantly greater in the SCFP group (p < 0.05), and during the 1-45 days, the ADG was higher (p < 0.05). The FCR in the 30-45 days SCFP group was higher (p < 0.05). Furthermore, the apparent digestibility of DM, CP, EE, ADF, Ca, and P were significantly increased in the SCFP group, except for NDF (p < 0.05). The concentration of GH and IGF-1 in serum showed a tremendous increase (p < 0.05) with SCFP supplementation on d 15 and d 45. On d 15, SCFP supplementation significantly increased the serum IgA contents (p < 0.05). Notably, on d 15 and d 45, the serum concentrations of IL-1β, IL-6, and TNF-α reduced (p < 0.001). Moreover, the Actinobacteriota in the SCFP group were significantly lower than those in the CON group (p = 0.034). SCFP significantly increased the abundance of Butyricimonas, Parabacteroides, and Ruminococcus. The differences among sob, Chao1, and PD-tree groups were statistically significant (p < 0.05). In conclusion, these results demonstrate that SCFP supplementation improved ADG, apparent digestibility and serum hormone, enhanced immunity, and regulated gut microbiota, thereby jointly promoting the growth of pre-weaning calves.
REVIEW | doi:10.20944/preprints202201.0320.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Butyrate; Colorectal cancer; Gut microbiota; Diet; omega-3 PUFAs
Online: 21 January 2022 (11:33:23 CET)
Knowledge regarding the influence of the microbial community in cancer promotion or protection has expanded even more through the study of bacterial metabolic products and how they can modulate cancer risk, which represents an extremely challenging approach for the relationship between intestinal microbiota and colorectal cancer (CRC). This review discusses research pro-gresses in the effect of bacterial dysbiosis from a metabolic point of view, particularly on the bio-chemical mechanisms of butyrate, one of the main short chain fatty acids (SCFAs) with an-ti-inflammatory and anti-tumor properties in CRC. Increased daily intake of omega-3 polyun-saturated fatty acids (PUFAs) significantly increases the density of bacteria that are known to produce butyrate. Omega-3 PUFAs have been proposed as a treatment to prevent gut microbiota dysregulation and lower the risk or progression of CRC.
ARTICLE | doi:10.20944/preprints202303.0205.v1
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: dietary fiber; childhood obesity; gut microbiota; metabolite; high-meat diet
Online: 13 March 2023 (02:18:52 CET)
The gut microbiota plays a crucial role in childhood obesity, and diet is a dominating driver. The effects of fructo-oligosaccharides (FOS), as a dietary fiber, on the composition and metabolism of gut microbiota in healthy children was investigated by vitro fermentation system with a reformative YCFA medium (rich in tryptic hydrolysates of meat). The 16S rRNA sequencing technology was utilized to analyze the varieties of gut microbiota. Measurement of short chain fatty acids (SCFAs) and gases were used by the gas chromatograph. Majorbio Cloud Platform and MetOrigin, as the interactive cloud server, perform the microbiota analysis, the metabolic pathway enrichment analysis, the statistical correlations, and biological relationships using network visualization. We found that the FOS group significantly regulated the composition and metabolism of gut microbiota. The co-metabolism network showed that 3 metabolites were related to 6 differential bacteria and 8 metabolism pathways. These findings suggest that dietary fiber could regulate the composition of gut microbiota and its metabolites in a better direction, but when dietary fiber participates in precision nutrition formula, it may be relevant for precision obesity, may help identify windows of opportunity for the dietary intervention of childhood obesity.
ARTICLE | doi:10.20944/preprints202109.0351.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: oral microbiota; gut microbiota; networks analysis; ecological niche; newborns
Online: 21 September 2021 (09:13:34 CEST)
The onset and progression of the salivary and gut microbiota, the transmission and the impact of the salivary microbiota on the development of early fecal microbial communities was herein explored. We characterized the microbiota of 82 faecal and 80 salivary samples, collected from 82 healty newborns at birth, 7, 15, 30, 90 and 180 days of life, by 16S rRNA targeted-metagenomics approach. Correlation heat-maps and co-occurrence networks were used to investigate microbial taxa relationship in saliva, gut and between the two ecosystems. In saliva microbiota, Streptococcus and Staphylococcus appeared as early commensals, dominating this ecosystem through the time, while Fusobacterium, Prevotella, Porphyromonas, Granulicatella and Veillonella were late colonizers. anaerobes as Enterobacteriace, Staphylococcus and Streptococcus, were gut microbiota pioneers, followed by the anaerobic Bifidobacterium, Veillonella, Eggerthella and Bacteroides. Streptococcus, Staphylococcus and Veillonella were shared by gut and saliva ecosystems (core microbiota). Early saliva and gut microbiota seem to evolve independently driven by local adaptation strategies, with the only exception for the oral Streptococcus and Veillonella genera, involved in gut microbiota development as seeding species. A more comprehensive knowledge of how oral microbiota may impact pathophysiological conditions of gut microbiota may open new avenues on the design of postbiotics.
ARTICLE | doi:10.20944/preprints202312.0172.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: sex differences; testosterone; gut microbiota; microbiome; fecal microbiota transplantation; metabolic disease; cross-sex
Online: 4 December 2023 (10:13:20 CET)
Increasing evidence of sexual dimorphism in pathophysiology of metabolic complications caused by sex steroids is under investigation. The gut microbiota represents a complex microbial ecosystem involved in energy metabolism, immune response, nutrition acquisition, and health of host organisms. Gender-specific differences in composition are present between females and males. The purpose of this study was to use cross-sex fecal microbiota transplantation (FMT) for the detection of sex-dependent metabolic, hormonal, and gut microbiota changes in female and male recipients. Healthy non-obese female and male Wistar rats were divided into donor, same-sex, and cross-sex recipient groups. After a 30-day period of FMT administration, biochemical markers (glucose and lipid metabolism) and sex hormones were measured and gut microbiota was analyzed. Cross-sex male recipients displayed significantly lower testosterone concentration compared to males that received same-sex FMT. Sex-dependent changes caused by cross-sex FMT were detected, while several bacterial taxa correlated with plasma testosterone levels. This study represents the first to study the effect of cross-sex changes in the gut microbiome concerning metabolic and hormonal changes/status in adult non-obese Wistar rats. Herein, we present the cross-sex FMT as a potential tool to modify sex-specific pathologies.
REVIEW | doi:10.20944/preprints202103.0598.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Camellia sinensis; tea polyphenols; gut microbiota; gastrointestinal bacteria; systematic review
Online: 24 March 2021 (16:18:03 CET)
A diet high in polyphenols is associated with a diversified gut microbiome. Tea is the second most consumed beverage in the world, after water. The health benefits of tea might be attributed to the presence of polyphenol compounds such as catechins, theaflavins, tannins, and flavonoids. Although many studies are on tea, little is known of its effects on trillions of gut microbiota. Hence, this review is aimed at systematically studying the effect of tea polyphenols on the stimulation or suppression of gut microbiota in humans and animals. It was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Articles were retrieved from PubMed and Scopus databases, and data were extracted from 6 human trials and 15 animal studies. Overall, huge variations were observed in terms of microbiota composition between humans and animals. A more consistent pattern of diversified microbiota was observed in animal studies. Tea alleviated the gut microbiota imbalance caused by high-fat diet-induced obesity, diabetes, and ultraviolet-induced damage. Overall changes in microbiota composition measured by beta diversity analysis showed that tea had shifted the microbiota from the pattern seen in animals that received tea-free intervention. In humans, the prebiotic-like effect was observed towards gut microbiota, but these results appear in lower-quality studies. Beta diversity in human microbiota remains intact despite tea intervention; supplementation with different teas affected different types of bacterial taxa in the gut. These studies suggest that tea polyphenols may have a prebiotic effect in disease-induced animals and in a limited number of human interventions. Further intervention is needed to identify the mechanisms of action underlying the effects of tea on gut microbiota.
ARTICLE | doi:10.20944/preprints202010.0138.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Mass drug administration; Azithromycin; Gut microbiota; V4-16S rRNA sequencing
Online: 6 October 2020 (15:55:40 CEST)
Community-level mass treatment with azithromycin has been associated with a mortality benefit in children. However, antibiotic exposures result in disruption of the gut microbiota and repeated exposures may reduce recovery of the gut flora. We conducted a nested cohort study to examine associations between mass drug administration (MDA) with azithromycin and the gut microbiota of rural Malawian children aged between 1-59 months. Fecal samples were collected from the children prior to treatment and 6 months after two or four biannual rounds of azithromycin treatment. DNA was extracted from fecal samples and V4-16S rRNA sequencing used to characterize the gut microbiota. Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria were the dominant phyla while Faecalibacterium and Bifidobacterium were the most prevalent genera. There were no associations between azithromycin treatment and changes in alpha diversity, however, four biannual rounds of treatment were associated with increased abundance of Prevotella. The lack of significant changes in gut microbiota after four biannual treatments supports the use of mass azithromycin treatment to reduce mortality in children living in low- and middle-income settings.
ARTICLE | doi:10.20944/preprints202306.1404.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: 16S rRNA sequencing; diet; popped amaranth; gut microbiota, short-chain fatty acids
Online: 20 June 2023 (08:19:25 CEST)
Popped amaranth is a nutritious food consumed since pre-Hispanic times, currently its consumption has been associated with recovery of malnourished children. However, there is no information on the impact that popped amaranth consumption has on gut microbiota composition. A non-randomized pilot trial was conducted to evaluate the changes on composition, structure, and function of gut microbiota of stunted children who received four grams of popped amaranth daily for three months. Stool and serum were collected at the beginning and at the end of the trial. Short-chain-fatty acids were quantified and gut bacterial composition was analyzed by 16S rRNA gene sequencing. Biome-try and hematology results showed that children have no other pathology more than to be low-height-for age. Increase of total SCFAs levels in feces was ob-served as well as a decrease in relative abundance of Alistipes putredinis, Bac-teroides coprocola, and Bacteroides stercoris, bacteria related with inflammation and colitis. On the contrary, an increase in relative abundance of Akkermansia muciniphila and Streptococcus thermophiles, bacteria associated with health and longevity, was observed. Results have proven that popped amaranth, a nutri-tious food, help to combat children malnutrition through gut microbiota modu-lation.
ARTICLE | doi:10.20944/preprints201903.0005.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: oleic acid; acorn feed ham; gut microbiota; ulcerative colitis
Online: 1 March 2019 (08:42:26 CET)
Background: Diets based on meat products are not recommended in the case of ulcerative colitis (UC). However, some foods, as those containing high oleic acid and a low omega-6/omega-3 ratio show anti-inflammatory properties. The objective here is to test if some traditional cured meat products, as acorn-fed ham (high levels of oleic acid), may be useful for controlling inflammatory diseases as UC in animal models. Methods: 3 rat cohorts have been used: vegetable rat feed, control ham and acorn-fed ham (a traditional ham where high oleic acid concentration from acorns is storage in the muscle fat). UC was induced with DSS in drinking water ad libitum for one week. Short-chain fatty acids (SCFAs) and 16S rRNA from bacterial populations were analyzed in cecum samples. Colon samples were analyzed for histological parameters (inflammatory cell density, mucosa damages, myeloperoxidase). Results: In the acorn-fed ham cohort, a protective effect was observed with respect to UC disease activity index, inflammatory cells density, colon mucosa alterations, myeloperoxidase levels, blood total antioxidant capacity and lower levels of pro-inflammatory cytokines, in comparison with feed cohort. Both ham diets caused a reduction in Firmicutes and an increase in Actinobacteria, Bacteroidetes and Proteobacteria in comparison with rat feed diet. Also, acorn-fed ham diet induced changes in gut microbiota composition, with pronounced enrichments in anti-inflammatory bacterial genera such as Alistipes, Bacteroides, Blautia, Butyricimonas and Parabacteroides. Conclusions: In the acorn-fed ham cohort, as a result of the dietary intake of oleic acid and low intake of omega-6 fatty acids, a strong preventive effect against UC symptoms was observed, indicating a valuable effect of this traditional Mediterranean cured meat product.
ARTICLE | doi:10.20944/preprints202301.0467.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: antibiotic growth promoter; alternative; poultry production; next-generation sequencing; 16S rRNA; gut microbial diversity
Online: 26 January 2023 (04:06:59 CET)
Phage, which is often used therapeutically, has begun to receive interest as an alternative to antibiotic growth promoters (AGPs) to enhance chicken growth. Another option that has been extensively studied as a growth promoter in chicken is probiotics. However, there are no studies using phages and probiotics as prospective feed additives for broiler chickens. Therefore, this study demonstrated the effects of phage cocktail, probiotics and their combinations on growth performance and gut microbiota of broiler chickens. A total of 288 one-day-old male Cobb 500 broilers were randomly allotted to 1 of 6 treatments in a completely randomised design. The treatments were: (i) C (basal diet (BD) only), (ii) 1ɸ (BD + 0.1% phage cocktail), (iii) 2ɸ (BD + 0.2% phage cocktail), (iv) P (BD + 0.1% probiotic), (v) 1ɸP (BD + 0.1% phage cocktail + 0.1% probiotic), (vi) 2ɸP (BD + 0.2% phage cocktail + 0.1% probiotic). The 1ɸP treatment had significantly (P < 0.05) better BW (35 d), BWG (22 – 35 d, 1 – 35d), and FCR (1-21 d. 22-35 d, 1-35 d) compared to C. Unique gut microbiota diversity was also found between the ɸP (1ɸP and 2ɸP) and non-ɸP groups (C, 1ɸ, 2ɸ and P) in ilea, particularly in the 35 d chickens. Microorganisms associated with short-chain fatty acid (SCFA) producers were significantly (P <0.05) present in the ɸP group than in the non- ɸP group. The carbohydrate and amino acid metabolism predicted genes were significantly upregulated in ɸP groups compared to non- ɸP groups. These genes were involved in the digestion and absorption of nutrients as well as the production of energy. Our findings showed that 1ɸP treatment could be a potential alternative to AGPs for poultry where growth performance was enhanced, and gut microbiota was positively modulated.
REVIEW | doi:10.20944/preprints202310.1337.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: DISH; Gut microbiota; Skeletal Hyperostosis; Spondylitis; Irritable Bowel Syndrome; Inflammatory Bowel Disease; Intervertebral Disc Degeneration
Online: 20 October 2023 (12:28:17 CEST)
The interplay between Diffuse Idiopathic Skeletal Hyperostosis (DISH) and the gut microbiota represents a compelling area of research, offering insights into the relationship between spinal degenerative diseases and the gut's microbial inhabitants. This comprehensive review seeks to unravel the complex connection, shedding light on its implications for human health and potential therapeutic avenues. A crucial section dives into the world of gut microbiota (GM), exploring its impact on human health, featuring its defining characteristics, and highlighting its role in metabolism, immunomodulation, host interaction, and how its composition changes over time. The subsequent portion delves into the relationship between microbiome composition and pathological bone development, including the link between Intervertebral Disc Degeneration (IDD) and gut inflammation, emphasizing how gut inflammation and GM dysbiosis play pivotal roles. Further dissecting the interconnections, various axes of influence, including the gut-spine axis, gut-bone axis, gut-joint axis, gut-disc axis (specific to DISH), gut-ligament axis, and gut-muscle axis, are discussed. Of particular interest is the section on the impact of GM on DISH-derived pain, addressing a critical aspect of the condition's manifestation. The review discusses the potential of GM modulation as a treatment for DISH, providing hope for therapeutic advancements. Additionally, it highlights the positive impact of lifestyle interventions, such as dietary modifications, sleep optimization, and exercise regimens, in mitigating GM dysbiosis and potentially improving DISH outcomes. Lastly, the intriguing prospect of fecal microbiome transplant and its implications for DISH management is examined, opening new avenues for research and therapeutic interventions. In conclusion, this comprehensive review underscores the intricate interplay between DISH and the gut microbiota, offering a fresh perspective on the impact of GM on spinal degenerative diseases. It emphasizes the potential for innovative treatments, such as GM modulation and lifestyle interventions, and presents fecal microbiome transplant as an exciting area for future exploration.
ARTICLE | doi:10.20944/preprints202305.1372.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: weaned pig; gut microbiota; red beetroot; short chain fatty acids; bile acids
Online: 19 May 2023 (04:11:50 CEST)
Red beetroot, is a well-recognized and established source of bioactives (e.g., betalains and polyphenols) with anti-inflammatory and antimicrobial properties. It is proposed as a potential alternative to zinc oxide, with a focus on gut microbiota modulation and metabolite production. In this study, weaned pigs aged 28-days were fed either a control diet, diet supplemented with zinc oxide (3,000 mg/kg), or 2% and 4% pulverized whole red beetroot (CON, ZNO, RB2 and RB4; respectively) for 14 days. After the pigs were euthanized, blood and digesta samples were collected for microbial composition and metabolite analyses. Results showed, red beetroot supplemented diet at 2% improved the gut microbial richness relative to other diets, but marginally influenced the caecal microbial diversity compared to zinc oxide supplemented diet. Further increase in red beetroot levels (4% -RB4) lead to loss of caecal diversity, decreased short chain fatty acids and secondary bile acid concentrations. An increased Proteobacteria abundance, presumably due to increased lactate/lactic acid producing bacteria was also observed. Summarily, red beetroot contains several components conceived to improve the gut microbiota and metabolite output of weaned pigs. Future studies investigating individual components in red beetroot will better elucidate their contributions to gut microbiota modulation and pig health.
ARTICLE | doi:10.20944/preprints202303.0300.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: Health behaviors; gastrointestinal symptoms; gut microbiota; diet; exercise; cancer survivors
Online: 16 March 2023 (08:57:56 CET)
Background: Health behaviors, such as diet and exercise, are actions individuals take that can potentially impact gastrointestinal (GI) symptoms and the gut microbiota. Little is known about how health behaviours impact GI symptoms and the gut microbiota after anti-cancer therapies. Methods: This is a secondary analysis of a cross-sectional study that investigated relationships between GI symptoms, gut microbiota, and patient-reported outcomes in adult cancer survivors. Gut microbiota was assessed from stool samples using 16S rRNA gene sequencing. GI symptoms and health behaviors were measured via self-report. Descriptive statistics, linear regression, and correlation analyses are reported. Results: A total of 334 cancer survivors participated and a subsample of 17 provided stool samples. Most survivors rated their diet as moderately healthy (55.7%) and reported engaging in low intensity exercise (53.9%) for ≤5 hours/week (69.1%). Antibiotic use was associated with more belly pain, constipation, and diarrhea (p< .05). Survivors consuming a healthier diet had fewer symptoms of gas/bloating (p= 0.02). Better diet health was positively correlated with Lachnospiraceae abundance, and negatively with Bacteroides abundance (ps <.05). Greater exercise frequency positively correlated with abundance of Lachnospiraceae, Faecalibacterium, Bacteroides, Anaerostipes, Alistipes, and Subdoligranulum. (ps<.05). Conclusion: Results provide evidence for associations between dietary health behaviours and GI symptoms. Diet and exercise behaviours are related to certain types of bacteria, but the direction of causality is unknown. Dietary-based interventions may be optimally suited to address survivors’ GI symptoms by influencing the gut microbiota. Larger trials are needed.
ARTICLE | doi:10.20944/preprints202306.1726.v1
Subject: Medicine And Pharmacology, Dermatology Keywords: Gut Microbiota (GM); Psoriasis (Ps); Psoriatic Arthritis (PsA); Mendelian randomization(MR); Causal effect
Online: 25 June 2023 (08:26:05 CEST)
Background: Numerous investigations have shed light on the intriguing interplay between gut microbiota(GM) and psoriasis (Ps) as well as psoriatic arthritis (PsA). However, the precise nature of the causal relationship between them remains an area of active investigation. Methods: For the purpose of our investigation, we meticulously curated a collection of genetic variants (P < 1 × 10−5) associated with GM (n = 18,340) derived from the MiBioGen study. To explore the intricate relationship between GM and Ps as well as PsA, we harnessed the comprehensive resources of the FinnGen database, encompassing a vast cohort of individuals, including 4,510 Ps cases and 212,242 controls, and 1,637 PsA cases and 212,242 controls. Even complementary MR methods were implemented, including an inverse variance weighting method, followed by a sensitivity analysis to verify the robustness of the results. Results: In this study, we found that certain bacterial taxa, such as Lactococcus, Ruminiclostridium 5, and Eubacterium fissicatena, were identified as risk factors. Conversely, Alloprevotella and Odoribacter demonstrated a protective effect against Ps. In the case of PsA, our results revealed a distinct set of risk factors and protective factors among the gut bacterial taxa. Lactococcus, Verrucomicrobiales, Akkermansia, Coprococcus 1, Lachnospiraceae, and Verrucomicrobiaceae were identified as risk factors for PsA. On the other hand, Odoribacter, Rikenellaceae, Clostridium innocuum, and Marvinbryantia exhibited a protective effect against the development of PsA. Conclusion: Our findings shed light on the distinctive disease characteristics and onset features between Ps and PsA. Notably, certain intestinal flora were implicated in the pathogenesis of PsA, suggesting their potential role as early diagnostic indicators. Furthermore, we identified several bacterial flora that exhibit a potential protective effect against the occurrence of Ps and PsA. These discoveries lay a solid foundation for future endeavors in the prevention and treatment of these conditions.
ARTICLE | doi:10.20944/preprints202311.0691.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: faecal microbiota transplantation; autologous faecal microbiota transplantation; autologous haematopoietic stem cell transplantation; haematopoietic stem cell transplantation; HSCT; bone marrow transplantation, multiple myeloma, gut microbiome, gut microbiota; supportive care, supportive oncology
Online: 10 November 2023 (11:56:32 CET)
Haematopoietic stem cell transplantation (HSCT) is a curative approach for blood cancers, yet its efficacy is undermined by a range of acute and chronic complications. In light of mounting evidence to suggest that these complications are linked to a dysbiotic gut microbiome, we aimed to evaluate the feasibility of faecal microbiota transplantation (FMT) delivered during the acute phase after HSCT. Of note, this trial opted for FMT prepared using the individual’s own stool (autologous FMT) to mitigate risks of disease transmission from donor stool. Adults (>18 years) with multiple myeloma were recruited from a single centre. Stool was collected prior to starting first-line therapy. Patients that progressed to HSCT were offered FMT via 3 x re-tention enemas before day +5 (HSCT = day 0). Feasibility was determined by recruitment rate, number and volume of enemas administered, and retention time. Longitudinally collected stool samples were also col-lected to explore the influence of auto-FMT using 16S rRNA gene sequencing. N=4 (2F:2M) participants received auto-FMT in 12 months. Participants received an average of 2.25(1-3) enemas (43.67(25-50)mL total, retained for an average of 60.78(10-145)minutes). No AEs, attributed to the FMT, were identified. Although minimum requirements were met for the volume and retention of auto-FMT, recruitment was significantly impacted by the logistical challenges of pre-therapy stool collection. This ultimately under-mined the feasibility of this trial and suggests that third party (donor) FMT should be prioritised.
ARTICLE | doi:10.20944/preprints201805.0375.v1
Subject: Social Sciences, Behavior Sciences 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
ARTICLE | doi:10.20944/preprints202002.0109.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: dietary fiber; SCFA; growth period; chickens; gut microbiota; microbiotal diversity; age; cecum
Online: 9 February 2020 (16:24:29 CET)
Increasing numbers of researchers are interested in the importance of dietary fiber for the gut microbiota, microbiotal metabolite SCFA, energy metabolism and gut health of the host. However, studies have demonstrated that long-term and longitudinal observation may be needed to evaluate the effect of dietary fiber better, and few such works have been made in chickens. Therefore, we successively fed low-fiber, high--fiber and low-fiber diets to two breeds of chickens during different growth periods (1—8, 9—20 and 21—50 weeks), aiming to longitudinally observe the long-term effect of altered dietary fiber on the gut microbiota, SCFA and development of cecum of chickens with age. The results showed that the composition and function of the gut microbiota, SCFA and the development of the cecum were different during different periods, which was largly affected by dietary fiber. However, the causes of some effects were different during the different periods. For example, compared with that in low-fiber chickens at 8 weeks, dominant fiber-degradation bacteria such as Bacteroidetes, Alloprevotella and SCFA-producing bacteria such as Faecalibacterium increased due to a high-fiber diet at 20 weeks, while due to a high feed intake in 50 weeks. Moreover, the concentration of SCFA in 20 weeks was significantly higher than in 8 weeks and 50 weeks, but the causes of this difference were also distinct. It was proposed that a long-term observation was needed to evaluate the effect of dietary fiber better on chickens. The metabolite pathways of ATP-binding cassette (ABC) transporters encoded by Firmicutes were enriched in 8 weeks, while a two-component system and β–glucosidase encoded by Bacteroidetes were enriched in 20 and 50 weeks. The trend was the same in two breeds of chickens except for Alloprevotella. In addition, the total content of SCFA in the contents of cecum was also affected by the size of the cecum. Surprisingly, the length of the cecum shortened from 20—50 weeks, maybe due to reduced dietary fiber.
ARTICLE | doi:10.20944/preprints202012.0416.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: dysbiosis; familial adenomatous polyposis,; ulcerative colitis; 16S rRNA; gut microbiota; geo-graphic populations
Online: 16 December 2020 (18:05:43 CET)
Inflammatory bowel diseases, familial adenomatous polyposis (FAP) and colorectal cancer (CRC) are associated with alterations of the intestinal microbiota. However, few data are available on the perpetuation of FAP and ulcerative colitis (UC) in relation to microbial dysbiosis. This study evaluated the UC and genetically confirmed FAP patients’ gut microbial balance in concordance to clinical outcome. Fecal materials (average mass of 0.54 g) were collected from three FAP and five UC patients to compare with healthy individuals as control group. Genomic materials of micro-biota were isolated for next generation sequencing of 16S rRNA that was performed by using QIAseq 16S/ITS panel in Illumina Miseq Platform. Data processing and bioinformatics analysis were performed via CLC Genomic Workbench bioinformatics tool. The comparison between FAP, UC and control group revealed an alteration in the intestinal microbial composition. More in details, relative abundance of class levels showed statistical significance differences among FAP, UC and control groups. Our preliminary data focused on the explanation of how dysbiosis can lead to inflammation and drive processes together with host genetic profile that leads to colorectal carcinogenesis.
Subject: Medicine And Pharmacology, Endocrinology And Metabolism Keywords: Pueraria thomsonii Radix; type 2 diabetes mellitus; metabolomics; gut microbiota
Online: 6 March 2023 (04:55:17 CET)
Type 2 diabetes mellitus(T2DM) is an increasingly prevalent and serious health problem. Its onset is typically associated with metabolic disorders and disturbances in the gut microbiota. Previous studies have reported the anti-T2DM effects of Pueraria thomsonii Radix as a functional food. However, the mechanism of action is still unknown. In this study, the effects of Pueraria thomsonii Radix water extract(PTR) on db/db mice were evaluated by pharmacology, metabolomics, and 16S rRNA gene sequencing. The results showed that PTR could improve the body weight of mice, reduce fasting blood glucose(FBG), urinary glucose(UGLU), homeostasis model assessment insulin resistance(HOMA-IR), urinary albumin/creatinine ratio(UACR), and reduce pancreatic tissue damage. Metabolomics showed that the Model group produced 109 differential metabolites, of which 74 could be regulated by PTR. 16S rRNA sequencing was done in fecal samples and results showed that PTR could reduce the Firmicutes/Bacteroidetes ratio(F/B) associated with obesity and regulate 3 beneficial bacteria and 1 harmful bacteria. In conclusion, the results showed that PTR could ameliorate T2DM symptoms, metabolic disorder, and gut microbiota imbalance of db/db mice, and it was superior to metformin in some aspects. We suggested for the first time that γ-aminobutyric(GABA) may be involved in the regulation of the microbiota-gut-brain axis(MGB) and thus affect the metabolic disorders associated with T2DM. This study will provide a scientific basis for the development of functional food with PTR.
REVIEW | doi:10.20944/preprints202305.0025.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: Parkinson's Disease; translational medicine; gut-brain axis; enteric nervous system; microbiota; rodent models; clinical evidence
Online: 1 May 2023 (11:04:20 CEST)
The enteric nervous system (ENS) is a neural network referred to as "the brain in the gut" because of its similarities to the central nervous system (CNS). The ENS consists of numerous types of neurons and glial cells distributed in two intramuscular plexuses that span the length of the intestine and control coordinated smooth muscle contractile activity and other intestinal functions. It is well-established that reciprocal communication exists between the brain and the gastrointestinal tract. Although the ENS can function independently, it is connected to the CNS through the afferent and efferent pathways of the parasympathetic and sympathetic nervous systems. In addition to regulating ENS function by the CNS, these connections are likely to be critically involved in the pathophysiology of Parkinson's disease (PD). PD is a common neurodegenerative disorder that presents with non-motor and motor symptoms. Surprisingly, ENS lesions have been shown to occur very early in the disease, even before CNS involvement. This has led to the postulation that the ENS may be central to the pathophysiology of PD. Autopsy studies have shown that α-synuclein (αS) aggregates in PD patients are found both in the substantia nigra (SN) and the ENS. Therefore, it has been hypothesized that the pathological process leading to PD may initially occur in the ENS years before the appearance of motor features. This process induces misfolding and aggregation of αS in specific subtypes of neurons in the CNS. Finally, it spreads retrogradely in the CNS through preganglionic vagal fibers to the dorsal motor nucleus of this nerve and to other central nervous structures. In addition to the presumed role in the spread of the disease process, it has also been suggested that pathological changes in the ENS might be involved in the gastrointestinal dysfunction frequently seen in Pd patients. Starting from the evidence in animal models and using a translational point of view, in this review, we aim to summarize the role of the ENS in the pathogenesis of PD and how this system could be modulated for a novel therapeutic approach. While acknowledging the presumed role of the microbiome in the gut-brain axis, we will shift the focus from this point of view to focus more on the neurons of the ENS.
ARTICLE | doi:10.20944/preprints202309.1988.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Clostridium perfringens; necrotic enteritis; broiler chickens; surface-exposed antigenic proteins; immune response; gut microbiota.
Online: 28 September 2023 (11:18:47 CEST)
Avian necrotic enteritis is an enteric disease of broiler chickens caused by certain pathogenic strains of Clostridium perfringens in combination with predisposing factors. A vaccine offering complete protection against the disease has not yet been commercialized. In a previous study, we produced five recombinant proteins predicted to be surface-exposed and unique to necrotic enteritis-causing C. perfringens and the immunogenicity of these potential vaccine candidates was assessed in broiler chickens. In the current work, the relative contribution of the antibodies raised by these putative antigens to protect broiler chickens was evaluated using an experimental necrotic enteritis induction model. Additionally, the link between the immune response elicited and the gut microbiota profiles in immunized birds subjected to infection with virulent C. perfringens was studied. ELISA results showed that the IgY antibody titers in vaccinated birds on days 21 and 33 were significantly higher than those on days 7 and 14 and those in birds receiving the adjuvant alone, while the relative contribution of the specific immunity attributed to these antibodies could not be precisely determined using this experimental NE induction model. Besides, 16S rRNA gene amplicon sequencing showed that immunization of birds with recombinant proteins had a low impact on the chicken caecal microbiota.
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Cordyceps militaris; crude polysaccharides; selenium-rich crude polysaccharides; high-fat diet (HFD); obesity; dyslipidemia; hypertriglyceridemia; gut microbiota
Online: 3 December 2020 (10:26:45 CET)
Administration of crude polysaccharides extract from natural product is a promising gut microbiota-targeted approach to preventing obesity and associated metabolic disorders. Dietary restrictions can change the type and number of gut bacteria, which is an important factor in delaying the onset and burden of diseases. This study aimed to investigate the effects of high-yield crude polysaccharides from Cordyceps militaris (CMP) on high-fat diet (HFD) mice model and the gut microbiota community assembly, and to identify whether selenium (Se) addition would improve CMP action mode during cultivation. We found that the CMP treatment ameliorated adipose and liver pathologic morphology and fat accumulation in obese mice, while, SeCMP intervention was not superior than CMP in body mass gain, but notably decreasing serum triglyceride level increased by HFD. The upregulated expression of gene Cyp7a1 in liver and protein UCP1 in brown adipose tissue (BAT) preliminary indicated that the effect might relate to bile acids (BAs) metabolism pathway and thermogenesis. In addition, CMP showed a drastic decrease in the gut microbes which positively correlated with dyslipidemia parameters. Our result reveals the potential of CMP to be used as functional food in the prevention of diet-induced adipose and liver steatosis, so does SeCMP has outstanding capacity of improving dyslipidemia.
ARTICLE | doi:10.20944/preprints202209.0488.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: carrot juice; human gut microbiota; fermentation; prebiotic; lactate; Lactobacillus fermentum; Lactobacillus salivarius; Lactobacillus mucosae; Bacteroides uniformis; Enterococcus faecium
Online: 30 September 2022 (11:19:07 CEST)
Carrot juice and its associated beverage products are well-known healthy drinks all over the world. However, what effect carrot juice has on the human gut microbiota and how it is fermented by the intestinal microbes have not been studied. Here, using an in vitro model of anaerobic fermentation, we demonstrated that carrot juice could be fermented into lactate and acetate by the human gut microbiota. 16S high-throughput sequencing and bioinformatic analyses indicated that fermentation of carrot juice could significantly change the composition of the human gut microbiome. Interestingly, carrot juice remarkably increased the abundances of beneficial bacteria, including Lactobacillus fermentum, Lactobacillus salivarius, Lactobacillus mucosae and Bacteroides uniformis and decreased the population of opportunistic pathogenic bacteria, such as Enterococcus faecium in the gut. Collectively, our study illustrates a favorable effect of carrot juice on the human gut microbiota and lays a foundation for the development of carrot juice as a novel prebiotic agent.
ARTICLE | doi:10.20944/preprints202310.0085.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: autism; gut dysfunction; gut motility; gut transit; mouse model; Neuroligin-3; video-imaging
Online: 3 October 2023 (08:57:54 CEST)
Individuals with autism often experience gastrointestinal issues but the cause is unknown. Many gene mutations that modify neuronal synapse function are associated with autism and therefore may impact the enteric nervous system that regulates gastrointestinal function. A missense mutation in the Nlgn3 gene encoding the cell adhesion protein, Neuroligin-3, was identified in two brothers with autism who both experienced severe gastrointestinal dysfunction. Mice expressing this mutation (Nlgn3R451C mice) are a well-studied preclinical model of autism and show autism-relevant characteristics, including impaired social interaction and communication, as well as repetitive behaviour. We previously showed colonic dysmotility in response to GABAergic inhibition and increased myenteric neuronal numbers in the small intestine in Nlgn3R451C mice bred on a mixed genetic background. Here we show that gut dysfunction is a persistent phenotype of the Nlgn3 R451C mutation in mice backcrossed onto a C57BL/6 background. We report that Nlgn3R451C mice show faster gastrointestinal transit in vivo and have longer small intestines compared to wild-types due to a reduction in smooth muscle tone. In Nlgn3R451C mice, we observed a decrease in resting jejunal diameter and neurally-regulated dysmotility as well as shorter durations of contractile complexes in the ileum. In Nlgn3R451C mouse colons, short contractions were inhibited to a greater extent by the GABAA antagonist, gabazine, compared to wild-type mice. Inhibition of nitric oxide synthesis decreased the frequency of contractile complexes in the jejunum, but not the ileum, in both wild-type and Nlgn3R451C mice. These findings demonstrate that changes in enteric nervous system function contribute to gastrointestinal dysmotility in mice expressing the autism-associated R451C missense mutation in the Neuroligin-3 protein.
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology 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.
REVIEW | doi:10.20944/preprints202012.0041.v1
Subject: Medicine And Pharmacology, Immunology And Allergy 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.
REVIEW | doi:10.20944/preprints201804.0370.v1
Subject: Biology And Life Sciences, Immunology And 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.
ARTICLE | doi:10.20944/preprints202306.2076.v1
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: sulforaphane; gut-organ axis; gut ecology; microbiome; chronic disease; nutrigenomics; nutritional medicine; food intolerance; epithelium, dysbiosis; gut barrier
Online: 29 June 2023 (08:06:36 CEST)
Given the accelerating scientific, clinical and consumer interest in highly-prevalent functional gastrointestinal disorders, appropriate therapeutic strategies are needed to address the many aspects of digestive dysfunction. Accumulating evidence for the crucifer-derived bioactive molecule, sulforaphane in upstream cellular defence mechanisms highlights its potential as a therapeutic candidate in targeting functional gastrointestinal conditions together with systemic disorders. This article catalogues the evolution of and rationale for a hypothesis that utilises multifunctional sulforaphane as the initial step in restoring the ecology of the gut ecosystem; it does this primarily by targeting the functions of intestinal epithelial cells. A growing body of work has identified the colonocyte as the driver of dysbiosis, so that targeting gut epithelial function could provide an alternative to targeting the microbes themselves for remediation of microbial dysbiosis. The hypothesis discussed herein has evolved over several years and is supported by case studies showing the application of sulforaphane in gastrointestinal disorders, related food intolerance and several systemic conditions. To our knowledge, this is the first time the effects of sulforaphane have been reported in a clinical environment where several of its key properties within the gut ecosystem appear to be related to its nutrigenomic effects on gene expression.
REVIEW | doi:10.20944/preprints202003.0293.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: skin; gut; microbiome; hormones
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.
REVIEW | doi:10.20944/preprints201807.0526.v1
Subject: Medicine And Pharmacology, Psychiatry And Mental Health 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/preprints202201.0032.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: antibiotic consumption; gut flora; dysbiosis; Alzheimer disease; dementia; gut-brain axis, mediator molecules
Online: 5 January 2022 (10:44:59 CET)
Background and objectives: Alzheimer's disease (AD) is a progressive neurodegenerative illness, responsible for 60-70% of all dementias, affecting over 50 million people worldwide, and nearly 11 million in European countries. Several putative factors are identified in the literature as causative agents or risk factors for the development of AD. The amyloid cascade hypothesis has been the main hypothesis about the pathophysiology of AD for decades. Recent studies raised the possible role of dysbiosis in the development of AD which prevents memory loss. The amyloid-β (Aβ) deposition might be considered as an inflammatory reaction to certain molecular products arising from the altered microbiome. Based on the above observations, it has been suspected, that antibiotic consumption patterns of different antibiotic classes might be associated with the prevalence of AD in European countries. Methods: Antibiotic consumption (ECDC) for 1997-2007, 2008-2018, and as the whole 1997-2018 period, have been compared to the AD prevalence for 2018 expressed in percentage of the population and statistically analyzed by Pearson calculation. Results: A significant positive correlation has been found between the AD prevalence (2018) and the average quinolone consumption for the year 1997-2007 (p: 0.044). A similar association was not observed for the entire 22 years (1997-2018) of the average quinolone consumption, and the years 2008-18, indicating 10-20 years of time-lapse between the antibiotic exposure and the development of AD. The ratio of broad-spectrum and narrow-spectrum antibiotics (B/N) estimated in the ECDC database for the years of 2008-2018 showed a strong positive association with AD prevalence (2018) (p: 0.026) and a positive correlation tendency for the entire 22 years 1997-2018 (p: 0.063), but none for the years 1997-2007 (p: 0.241). Broad-spectrum, beta-lactamase sensitive penicillin (J01CA) consumption showed a positive (non-significant) correlation with the prevalence of AD for the years 2008-2018 (p:0.080).Discussion: Our study indicated the possible sequential role of certain classes of antibiotics in the development of dysbiosis leading to amyloid deposits of AD, which strengthen the possible role of different mediator molecules (short-chain fatty acids, lipopolysaccharides, etc.) produced by the altered microbiome in the development of AD.
REVIEW | doi:10.20944/preprints202104.0175.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology 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.
ARTICLE | doi:10.20944/preprints202311.2001.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Gut-Liver Axis; Supplement; Dogs
Online: 1 December 2023 (07:03:06 CET)
The gut-liver axis plays a pivotal role in the development of liver diseases, necessitating exploration into substances capable of modulating the microbiota to prevent dysbiosis. Over the past decade, diverse therapeutic approaches have emerged to target pathogenic factors involved in the hepatic gut microbiota axis. This study investigated the impact of a supplement with hepatoprotective activity, containing extracts of Silybum marianum, prebiotics, probiotics, n-3 polyunsaturated fatty acids, minerals, and vitamins on hematological markers of liver functions and on the intestinal microbiota of 10 adult dogs with metabolic liver disease over a 35-day time span. Animals underwent clinical and laboratory evaluations every 7 days, before administration of the supplement (T0) and after 7, 14, 21, 28 and 35 days (T1, T2, T3, T4 and T5). In comparison to T0, a significant (P<0.05) decrease of AST activity was measured at T2, T3, T4 and T5. The activity of ALP, glucose and CRP significantly decreased (P<0.05) at T3, T4, and T5. The alpha diversity of the fecal microbiota significantly decreased (P<0.05) only at T1, a high variability was observed between dogs. The total short-chain fatty acid and lactic acid were also lower at T1 (P<0.05) in comparison to the other times of sampling. The beta diversity of fecal microbiota failed to find a clear pattern in relation to the sampling times. These results underscore the usefulness of the supplement on liver function and highlight high individual variability in its interaction with the fecal microbiome.
REVIEW | doi:10.20944/preprints202311.0440.v1
Online: 7 November 2023 (10:55:19 CET)
This mini-review examines the complex relationship between the gut microbiota and human health, with a special focus on its role in conditions such as inflammatory bowel disease (IBD) and cardiovascular disease (CVD). It explores how dietary patterns can affect the composition of the gut microbiota, thus contributing to the development of various diseases. The gut microbiota is crucial in the production of metabolites such as trimethylamine N-oxide (TMAO), which play a significant role in the development of both IBD and CVD. High levels of TMAO and other metabolites, such as phenylacetylglutamine, have been linked to an increased risk of CVD. The review highlights the potential of dietary interventions and therapies designed to modulate the gut microbiota in reducing these risks. Following a Mediterranean diet may offer cardiovascular protection, emphasizing the need for further research into the molecular mechanisms of diet-related changes in the microbiota.
REVIEW | doi:10.20944/preprints202308.0192.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: heart failure; gut; microbiome; relationship
Online: 2 August 2023 (10:05:19 CEST)
There is a bidirectional relationship between the heart and the gut. Gut microbiome is an excellent gut-homeostasis keeper since controls the growth of potentially harmful bacteria and protects the microbiota environment. There is evidence suggesting that diet rich in fatty acid can be metabolized and converted by gut microbiome and hepatic enzymes to trimethyl-amine N-oxide (TMAO) a product that is associated with atherogenesis, platelet dysfunction, thrombotic events, coronary artery disease, stroke, heart failure and ultimately death. Heart failure, by inducing gut ischemia and congestion and consequently gut barrier dysfunction promote an intestinal leak of microbes or even of their products, facilitating their entrance into the circulation and thus stimulating the low-grade inflammation and hence the immune response. Drugs used for heart failure may alter the gut microbiome, and conversely gut microbiome may modify the pharmacokinetic properties of the drugs. Modification of lifestyle based mainly on exercise and Mediterranean diet along with the use of pre- or probiotics may be beneficial to some extent for the gut microbiome environment. The potential role of gut microbiome in heart failure development and outcomes is a fruitful area of future research.
REVIEW | doi:10.20944/preprints202307.0243.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Gut; probiotics; diseases; gastrointestinal system
Online: 4 July 2023 (13:55:45 CEST)
The stability of the gut barrier is very important for keeping the gut healthy and stopping dangerous substances from getting into the bloodstream. Several diseases, including cancer, have been linked to the gut barrier being broken. Live bacteria called probiotics that are good for the host have been shown to have the ability to improve the gut barrier and lower the risk of cancer in the gastrointestinal system. This review looks at how probiotics affect the health of the gut barrier and what that might mean for preventing cancer. Researchers have found that probiotics strengthen the connections between intestine cells, encourage the production of protective mucins, and change the make-up and balance of the gut bacteria. These processes help keep the gut barrier strong and stop harmful chemicals from getting into the bloodstream. Probiotics may help lower the chance of cancer by reducing inflammation throughout the body and protecting the GI tract from harmful substances. But more study is needed to fully understand the benefits of different probiotic strains, the best amounts to take, and how they affect the health of the gut barrier. Understanding how probiotics, the health of the gut barrier, and the risk of cancer all work together can help us come up with new ways to avoid and treat cancer.
ARTICLE | doi:10.20944/preprints202305.0726.v1
Subject: Physical Sciences, Particle And Field Physics Keywords: Unification, Geometry, Quantization, GUT, ToE
Online: 10 May 2023 (09:57:14 CEST)
As a first step a unification of the gravitational with the electromagnetic interaction within a classical framework is proposed. It is based on a V5-geometry, with x5 = q/m. The sole source term is mechanical stress energy, positioned along x5. The trajectories of test-bodies are placed in V4 (x5 = const)-slices. The resulting field equation couples a geometric G-tensor to mechanical stress energy, its momentum with respect to V5 and the change of this momentum with proper time τ. The following step proceeds to the quantization of space-time to enable the formalization of elementary particles und strong interaction. This is complimented by the inclusion of spin and the weak force, leading finally to a grand total equation, the stationary version of which corresponds to Schroedinger´s equation, the instationary version to the Einstein equation of General Relativity.
ARTICLE | doi:10.20944/preprints202202.0350.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: infant; breastfeeding; gut microbiome; Bifidobacterium
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.
ARTICLE | doi:10.3390/sci1030065
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: gut microbiota; liver; metabolism; inflammation
Online: 16 December 2019 (00:00:00 CET)
Toll-like receptor 5 ligand, flagellin, and Vascular Adhesion Protein-1 (VAP-1) are involved in non-alcoholic fatty liver disease (NAFLD). This study aimed to determine whether VAP-1 mediates flagellin-induced hepatic fat accumulation. The effects of flagellin on adipocyte VAP-1 expression were first studied in vitro. Then, flagellin (100 ng/mouse) or saline was intraperitoneally injected to C57BL/6J WT and C57BL/6-Aoc3-/- (VAP-1 KO) mice on high-fat diet twice a week every two weeks for 10-weeks. After that, the effects on inflammation, insulin signaling, and metabolism were studied in liver and adipose tissues. Hepatic fat was quantified histologically and biochemically. Because flagellin challenge increased VAP-1 expression in human adipocytes, we used VAP-1 KO mice to determine whether VAP-1 regulates the inflammatory and metabolic effects of flagellin in vivo. In mice, VAP-1 mediated flagellin-induced inflammation, leukocyte infiltration and lipolysis in visceral adipose tissue. Consequently, increased release of glycerol led to hepatic steatosis in WT but not KO mice. Flagellin-induced hepatic fibrosis was not mediated by VAP-1. VAP-1 KO mice harbored more inflammation-related microbes than WT, while flagellin did not affect the gut microbiota. Our results suggest that by acting on visceral adipose tissue, flagellin increased leukocyte infiltration that induced lipolysis. Further, the released glycerol participated in hepatic fat accumulation. In conclusion, the results describe that gut microbial flagellin through VAP-1 induced hepatic steatosis.
REVIEW | doi:10.20944/preprints202306.0421.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: OCd; obsessive-compulsive disorder; microbiota; gut; gut-brain axis; probiotics; fecal transplants; microbial reprogramming
Online: 6 June 2023 (08:53:21 CEST)
This review examines the evidence supporting the role of dysbiosis in the development of obses-sive-compulsive disorders (OCD). We review the molecular mechanisms and role of the microbiota in the microbiota-gut-brain axis, focusing on the endocrine, nervous, and immune pathways. We then propose a model that positions dysbiosis as the central unifying element in the neurochemi-cal, immunological, genetic, and environmental factors leading to OCD. Based on this, we review the animal and human clinical evidence for the use of microbial reprogramming strategies such as probiotic or fecal microbiota transplants to treat OCD. Finally, we discuss the unique challenges that must be addressed in future clinical interventions.
ARTICLE | doi:10.20944/preprints202209.0254.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: alcohol use disorder; gut-dysfunction; gut-thyroid axis; pro-inflammatory cytokines; thyroid-associated hormones
Online: 19 September 2022 (03:09:51 CEST)
(1) Background: Heavy and chronic alcohol intake causes altered gut-permeability and dysfunction; and exhibits a unique pro-inflammatory state. Thyroid-associated hormones and proteins may be dysregulated by alcohol administration; however, the impact of altered gut-derived changes on thyroid function is unclear. This study investigated the role of gut-dysfunction and pro-inflammatory activity on thyroid function in patients with alcohol use disorder (AUD). (2) Methods: Male and female AUD patients (n=44) were grouped as Gr.1 with normal thyroid stimulating hormone (TSH) levels (n=28, 0.8≤TSH≤3 mIU/L); and Gr.2 with clinically elevated TSH levels (n=16, TSH> 3 mIU/l). Demographics, drinking measures, comprehensive metabolic panel, and candidate thyroid markers (TSH, circulating triiodothyronine [T3] and free thyroxine [fT4]) were tested. Plasma-derived gut-dysfunction associated markers (lipopolysaccharide [LPS], LPS-binding protein [LBP], and LPS-induced pathogen-associated protein [CD14]), and cytokine profile (IL1-β, TNF-α, IL-6, IL-8, MCP-1, PAI-1) were analyzed and compared with the thyroid, demographic, and drinking markers. (3) Results: Both groups presented with a borderline overweight category of BMI. Gr.2 presented with numerically higher level of chronic and heavy drinking patterns vs Gr.1. fT4 levels were elevated while T3 was within normal limits in both the groups. Gut-dysfunction markers LBP and CD14 were numerically elevated in Gr.2 vs Gr.1 suggesting subtle ongoing changes; however, the difference was not statistically significant. All pro-inflammatory cytokines were significantly elevated in Gr.2 among IL1-, MCP-1, and PAI-1. Gr.2 showed a strong and statistically significant effect of gut-immune-pituitary response (r=0.896, p=0.002) on TSH levels in a multivariate regression model with LBP, CD14, and PAI-1 levels as upstream variables; this assessment was not significant in Gr.1. In addition, AUROC analysis demonstrated that many of the cytokines strongly predicted TSH in Gr.2, including IL-6 (area=0.774, p<0.001) and TNF- (area=0.708, p=0.017) among others. This was not observed in Gr.1. Gr.2 demonstrated elevated fT4 as well as TSH, which suggests that there was subclinical thyroiditis with underlying CNS dysfunction and lack of a negative feedback loop. (4) Conclusions: These findings reveal the toxic effects of heavy and chronic drinking that play a pathological role in thyroid gland dysregulation employing the gut-brain axis. These results also strongly emphasize potential directions to strongly consider thyroid dysregulation in the overall medical management of AUD.
REVIEW | doi:10.20944/preprints202111.0175.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: atherosclerotic cardiovascular disease (ACVD); atherosclerosis; gut dysbiosis; immune system; gut microbial metabolites; SCFAs; TMAO
Online: 9 November 2021 (13:45:20 CET)
Atherosclerosis is a leading cause of cardiovascular disease and mortality worldwide. Alterations in the gut microbiota composition, known as gut dysbiosis, have been shown to contribute to atherosclerotic cardiovascular disease (ACVD) development through several pathways. Disruptions in gut homeostasis are associated with activation of immune processes and systemic inflammation. The gut microbiota produces several metabolic products, namely trimethylamine (TMA), which is used to produce the proatherogenic metabolite trimethylamine-N-oxide (TMAO). Short chain fatty acids (SCFAs), including acetate, butyrate, and propionate, and certain bile acids (BAs) produced by the gut microbiota lead to inflammation resolution and decrease atherogenesis. Chronic low-grade inflammation is associated to common risk factors for atherosclerosis, including metabolic syndrome, type 2 diabetes mellitus (T2DM), and obesity. Novel strategies for reducing ACVD include the use of nutraceuticals such as resveratrol, modification of glucagon-like peptide 1 (GLP-1) levels, supplementation with probiotics, and administration of prebiotic SCFAs and BAs. Investigation into the relationship between the gut microbiota and its metabolites, and the host immune system could reveal promising insight into ACVD development, prognostic factors, and treatments.
REVIEW | doi:10.20944/preprints202304.0501.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: butyrate; inflammatory bowel disease; gut microbiota; microbial metabolites; nutrients; gut homeostasis; immune responses; T-cells
Online: 18 April 2023 (07:36:05 CEST)
Intestinal commensal microbes, called the gut microbiota, play a critical role in host immune homeostasis through active microbial metabolites and innate and adaptive immune responses. Dysbiosis or imbalance of the gut microbiota composition is associated with inflammatory bowel disease (IBD) which includes Crohn’s disease and ulcerative colitis. The incidence and prevalence rates of IBD have been increasing worldwide. It is well recognized that butyrate, a microbial metabolite of diet fibers, is a major energy source for colonocytes and plays a crucial role in regulating immune function and maintaining epithelial barrier function and intestinal homeostasis. Emerging evidence suggests that butyrate might be a potential therapeutic agent to treat IBD. In this review, we discuss about gut microbial metabolites, particularly butyrate, the synthesis and metabolism of butyrate, mechanisms of butyrate in immune and epithelial barrier function. Furthermore, we review the current research on various therapeutic implications of butyrate in IBD.
ARTICLE | doi:10.20944/preprints202307.1150.v1
Subject: Biology And Life Sciences, Aquatic Science Keywords: Macrobrachium rosenbergii; growth trait; gut microbiome
Online: 18 July 2023 (04:17:03 CEST)
In this study, we evaluated how gut microbes associated with hepatopancreatic and gonadal expression genes impact on growth traits in different sex of M. rosenbergii. By comparing the relative abundance of gut microbes between the male (high weight gain, HiWG) and female (low weight gain, LoWG) animals, we have shown that at the phyla, family and genera level, the abundance of microbes existed significantly difference between both group. At the genera level, the abundance of Candidatus Hepatoplasma and unidentified Chloroplast lower in the LoWG animals than in the HiWG animals, and Lactobacillus and Ligilactobacillus have opposed trend. The abundance of Candidatus Hepatoplasma and unclassfied Chloroplast was associated with the growth traits in the HiWG group. The Lolium perenne microbial species belong to unclassfied Chloroplast genera have tight association with Ralstonia pickettii, both might association on Geobacter anodirecteducens abundance, which correlation with the expression of glutathione peroxidase and collagen, which were highly expressed in the hepatopancreas and gonads of HiWG group animals of M. rosenbergii and might promote growth and development. These associations were not detected in the female LoWG group.
REVIEW | doi:10.20944/preprints202306.1578.v1
Subject: Medicine And Pharmacology, Endocrinology And Metabolism Keywords: Gut Microbiota; Dysbiosis; Endocrine; Diabetes; Therapeutic
Online: 21 June 2023 (16:02:04 CEST)
Gut microbiota is a complex and dynamic ecosystem that influences various aspects of human health. Unfortunately, there is a lack of literature highlighting the importance of gut microbiome especially in diabetes management. This paper performs bibliometric analysis to establish the rising interest of researchers in this area and the importance of gut microbiota in diabetes management. Subsequently, the study performs a narrative review to provide an overview of the gut microbiota consisting of bacteria, archaea, fungi, and viruses, and its diversity, composition, and variation among individuals. The paper further discusses the role of the gut microbiota in different diseases, including Clostridium difficile infection, behavioral disorders, cancer, obesity, diabetes, atherosclerosis, and inflammatory bowel disease, among others. It emphasizes the link between gut dysbiosis (imbalanced gut microbiota) and the development of chronic metabolic disorders. Additionally, the paper discusses the factor negatively impacting the gut microbiota. The paper concludes by explaining the mechanistic abnormalities that link dysbiosis to type 2 diabetes, including changes in short-chain fatty acid production, amino acid metabolism, bile acid regulation, and the production of specific bacterial products. Thus, the paper highlights the importance of understanding gut microbiota and related mechanisms for developing therapeutic interventions targeting the gut microbiota.
ARTICLE | doi:10.20944/preprints202211.0443.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: plastic; mealworms; insect; bacteria; gut microbiome
Online: 23 November 2022 (09:46:44 CET)
Polyurethane (PU) is a polymer widely used by humans whose recycling is highly complex due his chemical structure, being limited to incineration or accumulation in landfills. Biodegradation by enzymes and microorganisms has been studied for decades as an effective method of biological decomposition. In this study, Tenebrio molitor larvae (T. molitor) were fed with polyurethane foams, which gut enzymes and microorganisms were capable of degrading the polymer by 35% in 17 days of treatment, producing a weight loss of 14% in the mealworm. Changes in T. molitor gut bacterial community and diversity were observed, which may be due to colonization of species associated with PU degradation. Physical and structural biodegradation in PU by T. molitor compared to virgin PU, was demonstrated by Fourier Transform InfraRed spectroscopy (FTIR), Thermal Gravimetric Analysis (TGA) and Scanning Electron Microphotography (SEM).
REVIEW | doi:10.20944/preprints202207.0374.v1
Subject: Medicine And Pharmacology, Neuroscience And 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.
ARTICLE | doi:10.20944/preprints202107.0560.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: diversity index; multifractal; metagenome; gut mtagenome
Online: 26 July 2021 (10:04:41 CEST)
Species diversity in microbiome is a cutting-edge concept in metagenomic research. In this study, we propose a multifractal analysis for metagenomic research. From the chaos game representation (CGR) visualization of simulated and real metagenomes, we find that there exists self-similarity in the visualization of metagenomes. Then we compute the multifractal dimensions for simulated and real metagenomes. For simulated metagenomes, we also compute their diversity indices, such as species richness indices, Shannon’s diversity indices and Simpson’s diversity indices respectively for varying value of . Fom the Pearson correlation coefficients between their multifractal dimensions and traditional species diversity indices, we find that the correlation coefficients between the multifractal dimensions and species richness indices and Shannon diversity indices reach their maximums at respectively. The correlation coefficients between the multifractal dimensions and Simpson’s diversity indices reach their maximums at nearly. So the traditional diversity indices can be unified by the frame of multifractal analysis. These results coincided with the similar results in macrobial ecology. Finally, we apply our methods to real metagenomes of 100 infants’ gut microbiomes when they are newborn, 4 months and 12 months. Our results show that multifractal dimensions of infants’ gut microbiomes can discriminate the age difference.
ARTICLE | doi:10.20944/preprints202101.0455.v1
Subject: Medicine And Pharmacology, Immunology And Allergy 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.
REVIEW | doi:10.20944/preprints202005.0037.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: FFAR2; FFAR3; microbiota; gut; immune; SCFA
Online: 3 May 2020 (08:32:51 CEST)
Abstract: Role of gut microbiome in human health is becoming apparent. The major functional impact of gut microbiome is transmitted through the microbial metabolites that are produced in the gut and interact with host cells either in the local gut environment or get absorbed in the circulation to impact distant cells/organs. Short chain fatty acids (SCFAs) are the major microbial metabolites that are produced in the gut through fermentation of non-digestible fibers. SCFAs are known to function through various mechanism, however, their signaling through free-fatty acid receptor 2 and 3 (FFAR2/3; type of G-coupled protein receptors) is new therapeutic approach. FFAR2/3 are widely expression in diverse cell types in human and mice, and functions as sensors of SCFAs to change several physiological and cellular functions. FFAR2/3 modulates neurological signaling, energy metabolism, intestinal cellular homeostasis, immune response and hormone synthesis. FFAR2/3 functions through Gi and/or Gq signaling, that is mediated through specific structural features of SCFAs-FFAR2/3 bindings and modulating specific signaling pathway. In this review, we discussed the wide-spread expression and structural homologies between human and mice FFAR2/3, and their role in different human health conditions. This information can unlock opportunities to weigh the potential of FFAR2/3 as drug target to prevent human diseases.