REVIEW | doi:10.20944/preprints202211.0364.v1
Subject: Medicine & Pharmacology, Gastroenterology Keywords: leptospirosis; dysbiosis; Weil's disease
Online: 21 November 2022 (03:26:33 CET)
Leptospirosis is an important zoonotic disease, causing about 60,000 deaths annually. One of the reasons for the severe course of leptospirosis is a cytokine storm, which develops as a result of an excessive immune response. The gut microbiota that resides in the gastrointestinal tract provides essential health benefits to its host, particularly by regulating immune homeostasis and a bidirectional relationship with many internal organs. A change in the gut microbiota can be caused not only by antibiotics, but also by infectious agents such as the coronavirus or the flu virus. It is known that L. interrogans can change the microbiota of mice. Thus, gut dysbiosis in leptospirosis can affect the clinical course of the disease, through the gut–organ axis. Modulation of intestinal microbiota by probiotics and/or fecal microbiota transplantation in leptospirosis may become an important area of scientific research.
REVIEW | doi:10.20944/preprints202111.0157.v1
Subject: Life Sciences, Microbiology Keywords: Microbiome; Cattle; Johne’s disease; Dysbiosis; Mastitis
Online: 8 November 2021 (15:17:16 CET)
: Cattle farming is an ancient practice, with roots in the early Neolithic era that has retained its status in the food industry today, with global beef market revenue amounting to $385.7B, as of 2018. Hence, cattle maintenance is naturally essential to cater to nutritional requirements of modern civilization. This extensive review aims to provide a holistic overview of cattle microbiome, analysing the native microbial composition within respiratory tract, gastrointestinal tract, reproductive tract, and skin. The dysbiosis associated with various diseases such as bovine respiratory disease, bovine digital dermatitis, mastitis, Johne's disease, uterine diseases (metritis and endometritis) and metabolic disorders (ruminal acidosis and ketosis) has been discussed. Moreover, various non-antibiotic microbial therapies including phage therapy, prebiotics and probiotics have been examined as potential means to reduce disease-associated dysbiosis. In general, this review highlights the importance of the microbiome in maintenance of health in cattle and its potential in alleviating bovine diseases, with an aim to enhance cattle health and production.
ARTICLE | doi:10.20944/preprints202201.0371.v2
Subject: Medicine & Pharmacology, Nutrition Keywords: Chronic Kidney Disease; aminoacids; Dysbiosis; metabolic disorders
Online: 27 January 2022 (15:48:16 CET)
Background: A comparison of the amino acid (AA) plasma profile and markers of intestinal absorption-inflammation between healthy subjects aged 65-70 years and age-matched patients affected by stage 3b-4 chronic kidney disease (CKD3b-4) was performed. Methods: eleven healthy volunteers were compared with 12 CKD3b-4 patients at their first outpatient control (T0) and after 12-months (T12). Adherence to a low protein diet (LPD, 0.6±0.1 g/kg/day) was assessed by Urea Nitrogen Appearance. The following parameters were assessed: renal function, nutritional parameters, bioelectrical impedance analysis, plasma levels of 20 total aminoacids (TAAs), both essential (EAAs) including branched-chain amino acids (BCAAs) and non-essential (NEAAs). Zonulin and faecal Calprotectin markers were used to evaluate intestinal permeability/inflammation. Results: Four patients dropped out of the study; in the remaining 8 residual kidney function (RKF) remained stable, their LPD adherence had risen to 0.89g/kg/day, anaemia had worsened and extracellular body fluid had increased. In comparison to healthy subjects, TAA levels of histidine, arginine, asparagine, threonine, glycine, and glutamine had all increased. No variation in BCAAs was observed. A significant increase was detected in faecal calprotectin and zonulin levels in CKD patients as the disease progressed. Conclusions: This study confirms the finding in aged patients of an alteration in levels of several AAs secondary to uraemia. Intestinal markers provide confirmation of a relevant alteration to the intestinal function in CKD patients.
REVIEW | doi:10.20944/preprints202001.0228.v1
Subject: Medicine & Pharmacology, Other Keywords: autoimmune disease; autoimmunity; dysbiosis; Mediterranean diet; microbiome
Online: 21 January 2020 (02:58:57 CET)
The nutritional habits regulate the gut microbiota and may provoke and/or prevent autoimmune disease. Western diet is rich in sugars, meat and poly-unsaturated fatty acids, which lead to dysbiosis of intestinal microbiota, disruption of gut epithelial barrier and chronic mucosal inflammation. On the other hand, Mediterranean Diet (MedDiet) is rich in ω3 fatty acids, fruits and vegetables and has anti-inflammatory properties, which can restore gut eubiosis. The effect of MedDiet and its components in health and disease states have been thoroughly analyzed in several studies. Moreover, several studies have specifically investigated the association between MedDiet, microbiota and risk for autoimmune diseases. Furthermore, the MedDiet has been associated with lower risk of cardiovascular diseases, which plays a critical role in reducing mortality in patients suffering from autoimmune diseases with comorbidities. The aim of the present review is to specifically highlight current knowledge regarding possible interactions of MedDiet with the patterns of intestinal microbiota focusing on autoimmunity and a blueprint through dietary modulations for the prevention and management of diseases’s activity and progression.
ARTICLE | doi:10.20944/preprints202202.0208.v1
Subject: Biology, Physiology Keywords: aging; intestinal microbiota; dysbiosis; probiotics; microbial co-occurrences
Online: 17 February 2022 (10:59:55 CET)
Age-related alterations in the gut microbiome composition and its impacts on the host’s health have been well described; however, detailed analyses of the gut microbial structure defining ecological microbe-microbe interactions is limited. One of the ways to determine these interactions is by understanding microbial co-occurrence patterns. We previously showed promising abilities of Lactobacillus acidophilus DDS-1 on the aging gut microbiome and immune system. However, the potential of the DDS-1 strain to modulate microbial co-occurrence patterns is unknown. Hence, we aimed to investigate the ability of L. acidophilus DDS-1 to modulate the fecal, mucosal and cecal-related microbial co-occurrence networks in young and aging C57BL/6J mice. Our Kendall’s tau correlation measures of co-occurrence revealed age-related changes in the gut microbiome, which were characterized by reduced number of nodes and associations across sample types when compared to younger mice. After four-week supplementation, L. acidophilus DDS-1 differentially modulated the overall microbial community structure in fecal and mucosal samples as compared to cecal samples. Beneficial bacteria such as Lactobacillus and Akkermansia acted as connectors in aging networks in response to L. acidophilus DDS-1 supplementation. Our findings provided the first evidence of the DDS-1-induced gut microbial ecological interactions revealing the complex structure of microbial ecosystems with age.
ARTICLE | doi:10.20944/preprints202106.0493.v1
Subject: Medicine & Pharmacology, Veterinary Medicine Keywords: Chronic diarrhea, idiopathic inflammatory bowel disease, microbiota, dysbiosis
Online: 21 June 2021 (08:56:30 CEST)
The long-term impact of treatment of dogs with steroid-responsive enteropathy (SRE) on the fe-cal microbiome and metabolome has not been investigated. Therefore, this study aimed to evaluate the fecal microbiome and metabolome of dogs with SRE before, during, and following treatment with standard immunosuppressive therapy and an elimination diet. We retrospec-tively selected samples from 9 dogs with SRE enrolled in a previous clinical trial, which received treatment for 8 weeks, and had achieved remission as indicated by the post-treatment clinical scores. Long-term (1 year) samples were obtained from a subset (5/9) of dogs. Samples from 13 healthy dogs were included as controls (HC). We evaluated the microbiome using 16S rRNA sequencing and qPCR. To evaluate the recovery of gut function, we measured fecal metabolites using an untargeted approach. While improvement was observed for some bacterial taxa after 8 weeks of treatment, several bacterial taxa remained significantly different from HC. Seven-ty-five metabolites were altered in dogs with SRE, including increased fecal amino acids and vitamins, suggesting malabsorption as a component of SRE. One year after treatment, however, all bacterial species evaluated by qPCR and 16S rRNA gene sequencing, and all but thirteen me-tabolites were no longer different from healthy controls.
Subject: Life Sciences, Biochemistry Keywords: Gut-Brain Axis; Nutrition; Microbiome; SCFA; Gut dysbiosis
Online: 13 May 2021 (13:30:00 CEST)
Diet plays a pivotal role in the overall health of an individual. Not only does it help carry out and regulate certain physiological functions, but it also can determine the composition of the gut microbiome. While the relative number of microorganisms that make up the gut microbiome vary between individuals and can be dependent on different environmental factors, there is evidence to suggest that composition of the microbiome can correlate with overall health or disease. When the GI microbiome is disturbed or suddenly changes it results in microbiome dysbiosis, a condition that correlates with the presence of certain diseases. Diseases linked to microbiome dysbiosis range from metabolic disorders, inflammatory bowel diseases to disorders of the brain. Many of these diseases are linked to the connection between the brain and the gut, known as the brain-gut axis. This bidirectional communication is important to maintain normal intestinal function, but is also responsible for the GI response to emotions as well as the emotional response to GI disturbances. By exploiting the interaction between microbiome health and nutrition, diet can be used to alleviate disease symptoms, protect against the development of certain conditions, and better maintain overall health. This review will examine the effects of nutrition on the microbiome, diseases linked to disruption of the normal microbiome, and the way that altering the diet can mitigate symptoms or prevent disease.
REVIEW | doi:10.20944/preprints202103.0424.v1
Subject: Medicine & Pharmacology, Allergology Keywords: vaginal probiotics; reproductive dysbiosis; bacterial vaginosis; VVC; IVF
Online: 16 March 2021 (12:28:32 CET)
The use of probiotics in reproductive-related dysbiosis is an area of continuous progress due to the growing interest from clinicians and patients suffering recurrent reproductive microbiota disorders. An imbalance in the natural colonization sites related to reproductive health: vaginal, cervicovaginal, endometrial and also pregnancy-related altered microbiota could play decisive role in reproductive outcomes. Oral and vaginal administrations are in continuous discussion regarding the clinical effect pursued, but probiotics as oral supplement therapy is the route administration better studied. To complement and summarise with qualitative and quantitative information of vaginal probiotics clinical studies, the main objective of this work was to retrieve the standardised protocols commonly used and their microbiota modulation capacities. The studies selected were related to treat bacterial vaginosis (BV) as the most commonly disorder, few studies on vulvovaginal candidiasis (VVC) and also administration to stabilise microbiota before in vitro fertilisation (IVF). Probiotic doses administered were similar to oral probiotics protocols, ranging from ≥ 107 CFU/day to 2.5 x 1010 CFU/day, and variable regarding posology duration from 1 day to 12 weeks, being 1 week commonly applied. Moderate modulation was achieved regarding the relative abundance decrease of abnormal microbiota, coinciding with parallel increase in Lactobacillus species.
REVIEW | doi:10.20944/preprints202112.0433.v1
Subject: Life Sciences, Microbiology Keywords: Lactobacillus spp, Bacillus spp., Anti-cancer, Probiotics, Gastrointestinal, Dysbiosis.
Online: 27 December 2021 (14:50:58 CET)
Malignant neoplasm is one of the most incurable diseases among inflammatory diseases. Researchers have been studying for decades to win over this lethal disease and provide the light of hope to humankind. The gastrointestinal bacteria of human hold a complex ecosystem and maintain homeostasis. One hundred trillion microbes are residing in the gastrointestinal tract of human. Disturbances in the microbiota of human’s gastrointestinal tract can create immune response against inflammation and also can develop diseases , including cancer. The bacteria of the gastrointestinal tract of human, can secrete a variety of metabolites and bioproducts which aid in the preservation of homeostasis in the host and gut. During pathogenic dysbiosis, on the other hand, numerous microbiota subpopulations may increase and create excessive levels of toxins, which can cause inflammation and cancer. Furthermore, the immune system of host and the epithelium cell can be influenced by gut microbiota. Probiotics, which are bacteria that live in the gut, have been protected against tumor formation. Probiotics are now studied to see if they can help fight dysbiosis in cancer patients undergoing chemotherapy or radiotherapy because of their capacity to maintain gut homeostasis. Countless numbers of gut bacteria have demonstrated anti-cancer efficiency in cancer treatment, prevention, and boosting the efficiency of immunotherapy. The review article has briefly explained the anti-cancer immunity of gut microbes and their application in treating a variety of cancer. This review paper also highlights the pre-clinical studies of probiotics against cancer and the completed and ongoing clinical trials on cancers with the two most common and highly effective probiotics Lactobacillus and Bacillus spp.
REVIEW | doi:10.20944/preprints202106.0529.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Oral microbiome; oral cavity; dysbiosis; oral diseases; systemic diseases
Online: 22 June 2021 (07:47:57 CEST)
The human oral microbiome refers to an ecological community of symbiotic and pathogenic microorganisms found in the oral cavity. The oral cavity is a suitable environment that provides various kinds of biological niches such as teeth, tongue, and oral mucosa. The oral cavity is the gateway between the external environment and the human body, maintaining oral homeostasis, protecting the mouth, and preventing disease. On the flip side, the oral microbiome plays an important role in triggering, development, and progression of oral and systemic diseases. Currently, disease diagnosis through the analysis of the human oral microbiome has been realized with the recent development of innovative detection technology, and is overwhelmingly promising compared to the previous era. It has been found that patients with oral diseases and systemic diseases have variations in the oral microbiome compared to normal subjects. This narrative review provides insight into the pathophysiological role that oral microbiome plays in influencing oral and systemic diseases, and updates the knowledge related to the oral microbiome over the past 30 years. A wide range of updates was provided with the latest knowledge of the oral microbiome to help researchers and clinicians in both academic and clinical aspects. The microbial community information can be utilized in non-invasive diagnosis and help develop a new paradigm in precision medicine, which will benefit human health in the era of post-metagenomics.
ARTICLE | doi:10.20944/preprints201910.0359.v1
Subject: Biology, Physiology Keywords: adiposity; dysbiosis; hops; menopause; microbiota; 8-prenylnaringenin; obesity; ovariectomy
Online: 31 October 2019 (02:22:34 CET)
Estrogen decline during menopause is associated with altered metabolism, weight gain and increased risk for cardiometabolic diseases. The gut microbiota also plays a role in the development of cardiometabolic dysfunction and is also subject to changes associated with age-related hormone changes. Phytoestrogens are plant-based estrogen mimics that have gained popularity as dietary supplements for treatment or prevention of menopause-related symptoms. These compounds have the potential to both modulate and to be metabolized by the gut microbiota. Hops (Humulus lupulus L.) contain potent phytoestrogen precursors, which rely on microbial biotransformation in the gut to estrogenic forms. We supplemented ovariectomized (OVX) or sham-operated (SHAM) C57BL/6 mice, with oral estradiol (E2), a flavonoid-rich extract from hops, or a placebo carrier oil to observe effects on adiposity, inflammation, and gut bacteria composition. Hops extract and E2 protected against increased visceral adiposity and liver triglyceride accumulation in OVX animals. Surprisingly, we found no evidence of OVX having a significant impact on the overall gut bacterial community structure. We did find differences in abundance of Akkermansia muciniphila, which was lower with HE treatment relative to the OVX E2 treatment and to placebo in the SHAM group.
REVIEW | doi:10.20944/preprints201903.0267.v1
Subject: Medicine & Pharmacology, Gastroenterology 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/preprints201809.0215.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: gut microbiota; skin microbiota; inflammation; psoriasis; psoriatic arthritis; dysbiosis
Online: 12 September 2018 (07:49:33 CEST)
Psoriasis is a chronic inflammatory disease characterized by skin lesions. Psoriasis development has been associated both with genetic and environmental factors. Though skin and gut microbiota has been implicated in number of pathologies including atopic dermatitis, inflammatory bowel disease, Crohn’s disease, allergy, obesity, its role has been poorly studied in psoriatic disease, which incorporates both psoriasis and psoriatic arthritis. This literature review summarizes the most recent and major findings on microbiota features in psoriatic disease as well as gives immune system role in the given condition. Despite conflicting findings, psoriasis patients were frequently found to have distinct microbial composition in both skin and guts especially in the major bacterial phyla, Firmicutes, Bacteroidetes, and Akkermansia. Furthermore, bacterial DNA has been found in psoriatic patients both locally and systemically, and altogether suggesting role of bacteria in the chronic disease and future studies in this field.
ARTICLE | doi:10.20944/preprints202111.0540.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: Probiotics; Dysbiosis; Obesity; High Fat Diet; Lactobacillus plantarum; Enterococcus faecium
Online: 29 November 2021 (12:59:43 CET)
Fat reduction and anti-inflammation are commonly claimed properties of probiotics. Lactobacillus plantarum and Enterococcus faecium were tested in high fat-induced obesity mice and in vitro experiments. After 16 weeks of probiotics, L. plantarum outperforms E. faecium on the anti-obesity property as indicated by body weight, regional fat accumulation, serum cholesterol, inflammatory cytokines (in blood and colon tissue), and gut barrier defect (FITC-dextran assay). With fecal microbiome analysis, L. plantarum but not E. faecium reduced fecal abundance of pathogenic Proteobacteria without an alteration in total Gram-negative bacteria when compared with non-probiotics obese mice. With palmitic acid induction, the condition media from both probiotics similarly attenuated supernatant IL-8, improved enterocyte integrity and down-regulated cholesterol absorption-associated genes in Caco-2 cell (an enterocyte cell line) and reduced supernatant cytokines (TNF-α and IL-6) with normalization of cell energy status (extracellular flux analysis) in bone-marrow-derived macrophages. Because the anti-inflammatory effect of the condition media of both probiotics on palmitic acid-activated enterocytes was neutralized by amylase, the active anti-inflammatory molecules might, partly, be exopolysaccharides. As L. plantarum out-performed E. faecium in anti-obesity property, possibly through the reduced fecal Proteobacteria, with a similar anti-inflammatory exopolysaccharide; L. plantarum is a potentially better option for anti-obesity than E. faecium.
ARTICLE | doi:10.20944/preprints202110.0076.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: coronary artery disease; gut microbiome; dysbiosis; obesity; Bacteroidetes; LPS; indoxyl sulfate
Online: 5 October 2021 (10:33:24 CEST)
Gut dysbiosis, alongside with high-fat diet and cigarette smoking, is considered one of the factors promoting coronary arterial disease (CAD) development. The present study aimed to research whether gut dysbiosis can increase bacterial metabolites concentration in the blood of CAD patients and what impact these metabolites can exert on endothelial cells. The gut microbiome of 15 CAD patients and age-matched 15 healthy controls was analyzed by metagenome sequencing. The in vitro impact of LPS and indoxyl sulfate at concentrations present in patients sera on endothelial cells was investigated. A metagenome sequencing analysis revealed gut dysbiosis in CAD patients, further confirmed by elevated levels of LPS and indoxyl sulfate in patients sera. CAD was associated with depletion of Bacteroidetes and Alistipes. LPS and indoxyl sulfate in meager concentrations demonstrated co-toxicity to endothelial cells inducing reactive oxygen species, E-selectin, and monocyte chemoattractant protein-1 (MCP-1) production and promoting thrombogenicity of endothelial cells confirmed by monocyte adherence. The co-toxicity of LPS and indoxyl sulfate was associated with harmful effects on endothelial cells, strongly suggesting that gut dysbiosis-associated increased intestinal permeability can initiate or promote endothelial inflammation and atherosclerosis progression.
REVIEW | doi:10.20944/preprints201803.0170.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: oral dysbiosis; human oral microbiome; yet-un cultivable organisms; systemic diseases
Online: 20 March 2018 (07:06:45 CET)
The human body supports the growth of a wide array of microbial communities in various niches, such as the oral cavity, gastro-intestinal and urogenital tracts and on the surface of the skin. These host associated microbial communities include yet-un-cultivable bacteria and are influenced by various factors. Together, these communities of bacteria are referred to as the human microbiome. Human oral microbiome consists of both symbionts and pathobionts. Deviation from symbiosis among the bacterial community leads to “dysbiosis”—a state of community disturbance. Dysbiosis occurs due to many confounding factors that predispose to a shift in the composition and relative abundance of microbial communities. Dysbiotic communities have been a major cause for many microbiomes related systemic infections. Such dysbiosis is directed by certain important pathogens called the “keystone pathogens” that could modulate community microbiome variations. One such persistent infection is oral infection, mainly periodontitis, where a wide array of causal organisms has been implied to systemic infections such as cardio vascular disease, diabetes mellitus, rheumatoid arthritis and Alzheimer’s disease. The keystone pathogens co-occur with many yet-cultivable bacteria and their interactions lead to dysbiosis. This has been the focus of recent research. While immune evasion is one of the major modes that lead to dysbiosis, new processes and new virulence factors of bacteria have been shown to be involved in this important process of that determine disease or health state. This review focuses on such dysbiotic communities, their interactions and their virulence factors that predispose the host to other systemic implications.
ARTICLE | doi:10.20944/preprints202201.0032.v1
Subject: Medicine & Pharmacology, Pathology & 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.
ARTICLE | doi:10.20944/preprints202012.0416.v1
Subject: Medicine & Pharmacology, Allergology 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.
REVIEW | doi:10.20944/preprints202007.0305.v1
Subject: Life Sciences, Immunology Keywords: spondyloarthritis; HLA-B27; pathogenesis; inflammation; arthritogenic peptides; unfolded protein response; ERAP1; gut dysbiosis
Online: 14 July 2020 (11:39:13 CEST)
Spondyloarthritis comprises of a group of inflammatory diseases of the joints and spine with various clinical manifestations. The group includes ankylosing spondylitis, reactive arthritis, psoriatic arthritis, arthritis associated with inflammatory bowel disease, and undifferentiated spondyloarthritis. The exact etiology and pathogenesis of spondyloarthritis are still unknown, but five hypotheses explaining the pathogenesis exist. These hypotheses suggest that spondyloarthritis is caused by arthritogenic peptides, an unfolded protein response, HLA-B27 homodimer formation, malfunctioning endoplasmic reticulum aminopeptidases, and, last but not least, gut inflammation and dysbiosis. Here we discuss the five hypotheses and the evidence supporting each. In all of these hypotheses, HLA-B27 plays a central role. It is likely that a combination of these hypotheses, with HLA-B27 taking center stage, will eventually explain the development of spondyloarthritis in predisposed individuals.
REVIEW | doi:10.20944/preprints202111.0175.v1
Subject: Biology, Other 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/preprints202112.0088.v1
Subject: Medicine & Pharmacology, Obstetrics & Gynaecology Keywords: polycystic ovary syndrome; evolution; insulin resistance; infertility; environment; toxins; endocrine disrupting chemicals; dysbiosis; lifestyle; diet
Online: 6 December 2021 (15:34:25 CET)
Polycystic ovary syndrome (PCOS) is increasingly recognized as a complex metabolic disorder that manifests in genetically susceptible women following a range of negative exposures to nutritional and environmental factors related to contemporary lifestyle. The hypothesis that PCOS phenotypes are derived from a mismatch between ancient genetic survival mechanisms and modern lifestyle practices is supported by a diversity of research findings. The proposed evolutionary model of the pathogenesis of PCOS incorporates evidence related to evolutionary theory, genetic studies, in-utero developmental epigenetic programming, transgenerational inheritance, metabolic features including insulin resistance, obesity and the apparent paradox of lean phenotypes, reproductive effects and subfertility, the impact of the microbiome and dysbiosis, endocrine disrupting chemical exposure, and the influence of lifestyle factors such as poor quality diet and physical inactivity. Based on these premises, the diverse lines of research are synthesized into a composite evolutionary model of the pathogenesis of PCOS. It is hoped that this model will assist clinicians and patients to understand the importance of lifestyle interventions in the prevention and management of PCOS and provide a conceptual framework for future research. It is appreciated that this theory represents a synthesis of the current evidence and that it is expected to evolve and change over time.
ARTICLE | doi:10.20944/preprints202112.0053.v1
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: diabetes type-1; T1D; diabetes type-2; T2D; antibiotics; antibiotic classes; microbiome; dysbiosis; prevalence; concordance
Online: 3 December 2021 (12:45:23 CET)
Abstract: Several publications have raised the issue that the development of diabetes is preceded by alteration of the microbiome (dysbiosis) and hence, the role of environmental factors, triggering dysbiosis, should be considered. Antibiotics are powerful agents inducing dysbiosis and the authors wanted to explore the possible relationship between the consumption of different major classes of antibiotics and the prevalence of diabetes (type-1, /T1D/, type-2 /T2D/) in thirty European countries. According to our hypothesis, if such association exists, the dominant use of certain major antibiotic classes might be reflected in the prevalence of T1D and T2D in different countries. Comparisons were performed between the prevalence of diabetes (T1D and T2D) estimated for 2019 and featured in the Diabetes Atlas with the average yearly consumption of major antibiotic classes of the previous 10 years (2010-19) extracted from the ECDC yearly reports on antibiotic consumption in Europe. Pearson correlation and variance analysis were used to estimate the possible relationship. Strong, positive (enhancer) associations were found between the prevalence of T1D and the consumption of tetracycline (J01A /p: 0.001/) and the narrow spectrum penicillin (J01CE /p: 0,006/, CF /p: 0.018/). Strong negative (inhibitor) association was observed with broad-spectrum, beta-lactamase resistant penicillin (J01CR /p: 0.003/), macrolide (J01F /p: 0.008/) and quinolone (J01M /p: 0.001/). T2D showed significant positive associations with cephalosporin (J01D /p: 0.048/) and quinolone (J01M /p: 0.025/), and a non-significant negative association was detected with broad-spectrum, beta-lactamase-sensitive penicillin (J01CA /p: 0.67/). Countries with the highest prevalence of diabetes (first 10 positions) showed concordance with the higher consumption of “enhancer” and the lower consumption of “inhibitor” antibiotics (first 10 positions) as indicated by variance analysis. Countries with high prevalence of T1D showed high consumption of tetracycline (p: 0.015), and narrow spectrum, beta-lactamase sensitive penicillin (p: 0.008), and low consumption of “inhibitor” antibiotics (broad-spectrum, beta-lactamase resistant, combination penicillin (p: 0.005), cephalosporin (p: 0.036), and quinolone (p: 0.003). Countries with a high prevalence of T2D consumed more cephalosporin (p: 0.084), quinolone (p: 0.54), and less broad-spectrum, beta-lactamase sensitive penicillin (p: 0.012) than other countries. Conclusion/Interpretation: The development of diabetes-related dysbiosis might be attached to higher consumption of specific classes of antibiotics, showing positive (enhancer) associations with the prevalence of diabetes, and the low consumption of other classes of antibiotics shoving negative (inhibitory) associations. Those groups of antibiotics are different in T1D and T2D
REVIEW | doi:10.20944/preprints201808.0438.v1
Subject: Life Sciences, Virology Keywords: Enteric Virus, Non-Human Primate, Virome, Macaque, Dysbiosis, Enteritis, Diarrhea, Animal Model, Rotavirus, Calicivirus, Gut Microbiome
Online: 27 August 2018 (00:17:27 CEST)
There is an important role non-human primates (NHP) play in biomedical research. Phylogenetic proximity of any of the NHP species to Homo sapiens assures that much better translatability of research outcomes from model studies involving human diseases can be achieved than from those generated with other pre-clinical systems. Our group and others used during past two decades NHPs in research directed towards viral and autoimmune disorders of the gastrointestinal tract. This review summarizes progress made in the area of enteric viral infections and its applicability to human disease.
REVIEW | doi:10.20944/preprints202010.0437.v1
Subject: Life Sciences, Biochemistry Keywords: breast cancer; microbiota; bacteria; dysbiosis; pro-carcinogenic; anti-carcinogenic; genetics; next-generation sequencing; cancer treatments; cancer prevention
Online: 21 October 2020 (12:51:23 CEST)
One in eight women will be diagnosed with breast cancer (BC) in their lifetime, resulting in over 2 million cases annually. BC is the most common cancer among women. Unfortunately, the etiology of majority of cases remains unknown. Recently, evidence has shown that the human microbiota plays an important role in health and disease. Intriguingly, studies have revealed the presence of microorganisms in human breast tissue, which was previously presumed to be sterile. Next-generation sequencing technologies have paved way for the investigation of breast microbiota, uncovering bacterial signatures that are associated with BC. Some of the bacterial species were found to possess pro-carcinogenic and/or anti-carcinogenic properties, suggesting that the breast microbiota has potentially crucial roles in maintenance of breast health. In this review, we summarize the recent findings on breast tissue microbiota and its interplay with BC. Bacterial signatures identified via next-generation sequencing as well as their impact on breast carcinogenesis and cancer therapies are reviewed. Correlation of breast tissue microbiota and other factors, such as geographical and racial differences, in BC is discussed. Additionally, we discuss the future directions of research on breast microbiota as well as its potential role in prevention, diagnosis and treatment of BC.
REVIEW | doi:10.20944/preprints202011.0683.v1
Subject: Medicine & Pharmacology, Allergology 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.
Subject: Medicine & Pharmacology, Gastroenterology Keywords: ulcerative colitis; inflammatory bowel disease; pediatrics; FMT; probiotics; synbiotics; antibiotics; prebiotics; fecal microbiota transplant; colitis-associated cancer; colorectal cancer; CAC; CRC; dysbiosis
Online: 20 September 2021 (14:20:39 CEST)
Ulcerative colitis (UC) is a chronic autoimmune disorder affecting the colonic mucosa. UC is a subtype of inflammatory bowel disease along with Crohn’s disease and presents with varying extraintestinal manifestations. No single etiology for UC has been found, but a combination of genetic and environmental factors is suspected. Research has focused on the role of intestinal dysbiosis in the pathogenesis of UC, including the effects of dysbiosis on the integrity of the colonic mucosal barrier, priming and regulation of the host immune system, chronic inflammation, and progression to tumorigenesis. Characterization of key microbial taxa and their implications in the pathogenesis of UC and colitis-associated cancer (CAC) may present opportunities for modulating intestinal inflammation through microbial-targeted therapies. In this review, we will discuss the microbiota-immune crosstalk in UC and CAC, as well as the evolution of microbiota-based therapies.
REVIEW | doi:10.20944/preprints202111.0116.v1
Subject: Life Sciences, Other Keywords: microglia and astrocytes phenotypes; intercellular crosstalk; lesion microenvironment; neuroinflammation; in vivo glia-to neuron reprogramming; subpial delivery; gut dysbiosis; electrostimulation; rehabilitation; neuroprotective strategies
Online: 5 November 2021 (11:14:51 CET)
Traumatic spinal cord injury (SCI) elicits an acute inflammatory response which comprises numerous cell populations. It is driven by the immediate response of macro-phages and reactive M1 microglia, which triggers activation of genes responsible for the dysregulated microenvironment within the lesion site and in the spinal cord parenchyma immediately adjacent to the lesion. Recently published data indicate that microglia induces astrocyte activation and determines the fate of astrocytes. Conversely, astrocytes have the potency to trigger microglial activation and control their cellular functions. Here we review current information about the release of diverse signaling molecules (pro-inflammatory vs anti-inflammatory) in individual cell phenotypes (microglia, astrocytes, blood inflammatory cells) in acute and subacute SCI stages, and how they contribute to delayed neuronal death in a the surrounding spinal cord tissue which is spared and functional but reactive. In addition, temporal correlation in progressive degeneration of neurons and astrocytes and their functional interactions after SCI are discussed. Finally, the review highlight the time-dependent transformation of reactive mi-croglia (M1) and astrocytes (A1) into their neuroprotective phenotypes (M2a, M2c and A2) which are crucial for spontaneous post-SCI locomotor recovery. We also provide sug-gestions on how to increase functional outcome after SCI and discuss key therapeutic approaches.