Did you mean: bacteroidetes
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World Journal of Gastroenterology Aug 2015Relation between the gut microbiota and human health is being increasingly recognised. It is now well established that a healthy gut flora is largely responsible for... (Review)
Review
Relation between the gut microbiota and human health is being increasingly recognised. It is now well established that a healthy gut flora is largely responsible for overall health of the host. The normal human gut microbiota comprises of two major phyla, namely Bacteroidetes and Firmicutes. Though the gut microbiota in an infant appears haphazard, it starts resembling the adult flora by the age of 3 years. Nevertheless, there exist temporal and spatial variations in the microbial distribution from esophagus to the rectum all along the individual's life span. Developments in genome sequencing technologies and bioinformatics have now enabled scientists to study these microorganisms and their function and microbe-host interactions in an elaborate manner both in health and disease. The normal gut microbiota imparts specific function in host nutrient metabolism, xenobiotic and drug metabolism, maintenance of structural integrity of the gut mucosal barrier, immunomodulation, and protection against pathogens. Several factors play a role in shaping the normal gut microbiota. They include (1) the mode of delivery (vaginal or caesarean); (2) diet during infancy (breast milk or formula feeds) and adulthood (vegan based or meat based); and (3) use of antibiotics or antibiotic like molecules that are derived from the environment or the gut commensal community. A major concern of antibiotic use is the long-term alteration of the normal healthy gut microbiota and horizontal transfer of resistance genes that could result in reservoir of organisms with a multidrug resistant gene pool.
Topics: Age Factors; Anti-Bacterial Agents; Bacteriological Techniques; Bacteroidetes; Computational Biology; Diet; Firmicutes; Gastrointestinal Microbiome; Health Status; Homeostasis; Host-Pathogen Interactions; Humans; Intestines; Prebiotics; Probiotics; Synbiotics
PubMed: 26269668
DOI: 10.3748/wjg.v21.i29.8787 -
Scientific Reports Oct 2017Alzheimer's disease (AD) is the most common form of dementia. However, the etiopathogenesis of this devastating disease is not fully understood. Recent studies in...
Alzheimer's disease (AD) is the most common form of dementia. However, the etiopathogenesis of this devastating disease is not fully understood. Recent studies in rodents suggest that alterations in the gut microbiome may contribute to amyloid deposition, yet the microbial communities associated with AD have not been characterized in humans. Towards this end, we characterized the bacterial taxonomic composition of fecal samples from participants with and without a diagnosis of dementia due to AD. Our analyses revealed that the gut microbiome of AD participants has decreased microbial diversity and is compositionally distinct from control age- and sex-matched individuals. We identified phylum- through genus-wide differences in bacterial abundance including decreased Firmicutes, increased Bacteroidetes, and decreased Bifidobacterium in the microbiome of AD participants. Furthermore, we observed correlations between levels of differentially abundant genera and cerebrospinal fluid (CSF) biomarkers of AD. These findings add AD to the growing list of diseases associated with gut microbial alterations, as well as suggest that gut bacterial communities may be a target for therapeutic intervention.
Topics: Aged; Alzheimer Disease; Bacteroidetes; Bifidobacterium; Biomarkers; Case-Control Studies; Feces; Female; Firmicutes; Gastrointestinal Microbiome; Humans; Male; tau Proteins
PubMed: 29051531
DOI: 10.1038/s41598-017-13601-y -
Frontiers in Immunology 2020is a relatively new genus of bacteria isolated primarily from medical clinical samples, although at a low rate compared to other genus members of the phylum, which are... (Review)
Review
is a relatively new genus of bacteria isolated primarily from medical clinical samples, although at a low rate compared to other genus members of the phylum, which are highly relevant in dysbiosis and disease. According to the taxonomy database at The National Center for Biotechnology Information, the genus consists of 13 species: , and and , and the subspecies subspecies vulgaris (vs. subsp.) are the newest strains featured outside that list. Although typically isolated from the human gut microbiome various species of this genus have been isolated from patients suffering from appendicitis, and abdominal and rectal abscess. It is possible that as spp. emerge, their identification in clinical samples may be underrepresented as novel MS-TOF methods may not be fully capable to discriminate distinct species as separate since it will require the upgrading of MS-TOF identification databases. In terms of pathogenicity, there is contrasting evidence indicating that may have protective effects against some diseases, including liver fibrosis, colitis, cancer immunotherapy, and cardiovascular disease. In contrast, other studies indicate is pathogenic in colorectal cancer and is associated with mental signs of depression. Gut dysbiosis seems to play a role in determining the compositional abundance of in the feces (., in non-alcoholic steatohepatitis, hepatic encephalopathy, and liver fibrosis). Since is a relatively recent sub-branch genus of the phylum, and since are commonly associated with chronic intestinal inflammation, this narrative review illustrates emerging immunological and mechanistic implications by which spp. correlate with human health.
Topics: Animals; Bacteroidetes; Dysbiosis; Gastrointestinal Microbiome; Host-Pathogen Interactions; Humans; Inflammation; Intestines; Mental Disorders; Mental Health; Neoplasms
PubMed: 32582143
DOI: 10.3389/fimmu.2020.00906 -
Gut Microbes 2021Hypothalamic regulations of food intake are altered during obesity. The dopaminergic mesocorticolimbic system, responsible for the hedonic response to food intake, is... (Review)
Review
Hypothalamic regulations of food intake are altered during obesity. The dopaminergic mesocorticolimbic system, responsible for the hedonic response to food intake, is also affected. Gut microbes are other key players involved in obesity. Therefore, we investigated whether the gut microbiota plays a causal role in hedonic food intake alterations contributing to obesity. We transferred fecal material from lean or diet-induced obese mice into recipient mice and evaluated the hedonic food intake using a food preference test comparing the intake of control and palatable diets (HFHS, High-Fat High-Sucrose) in donor and recipient mice. Obese mice ate 58% less HFHS during the food preference test ( < 0.0001) than the lean donors, suggesting a dysregulation of the hedonic food intake during obesity. Strikingly, the reduction of the pleasure induced by eating during obesity was transferable through gut microbiota transplantation since obese gut microbiota recipient mice exhibited similar reduction in HFHS intake during the food preference test (40% reduction as compared to lean gut microbiota recipient mice, < 0.01). This effect was associated with a consistent trend in modifications of dopaminergic markers expression in the striatum. We also pinpointed a highly positive correlation between HFHS intake and ( < 0.0001), which could represent a potential actor involved in hedonic feeding probably through the gut-to-brain axis. We further demonstrated the key roles played by gut microbes in this paradigm since depletion of gut microbiota using broad-spectrum antibiotics also altered HFHS intake during food preference test in lean mice. In conclusion, we discovered that gut microbes regulate hedonic aspects of food intake. Our data demonstrate that gut microbiota modifications associated with obesity participate in dysregulations of the reward and hedonic components of the food intake. These data provide evidence that gut microbes could be an interesting therapeutic target to tackle hedonic disorders related to obesity.
Topics: Animals; Bacteroidetes; Brain-Gut Axis; Corpus Striatum; Diet, High-Fat; Fecal Microbiota Transplantation; Feeding Behavior; Food Preferences; Gastrointestinal Microbiome; Hyperphagia; Male; Mice; Mice, Inbred C57BL; Obesity; Reward
PubMed: 34424831
DOI: 10.1080/19490976.2021.1959242 -
Frontiers in Cellular and Infection... 2023The real causal relationship between human gut microbiota and T1D remains unclear and difficult to establish. Herein, we adopted a two-sample bidirectional mendelian...
OBJECTIVE
The real causal relationship between human gut microbiota and T1D remains unclear and difficult to establish. Herein, we adopted a two-sample bidirectional mendelian randomization (MR) study to evaluate the causality between gut microbiota and T1D.
METHODS
We leveraged publicly available genome-wide association study (GWAS) summary data to perform MR analysis. The gut microbiota-related GWAS data from 18,340 individuals from the international consortium MiBioGen were used. The summary statistic data for T1D (n = 264,137) were obtained from the latest release from the FinnGen consortium as the outcome of interest. The selection of instrumental variables conformed strictly to a series of preset inclusion and exclusion criteria. MR-Egger, weighted median, inverse variance weighted (IVW), and weighted mode methods were used to assess the causal association. The Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis were conducted to identify heterogeneity and pleiotropy.
RESULTS
At the phylum level, only Bacteroidetes was indicated to have causality on T1D (OR = 1.24, 95% CI = 1.01-1.53, = 0.044) in the IVW analysis. When it comes to their subcategories, Bacteroidia class (OR = 1.28, 95% CI = 1.06-1.53, = 0.009, = 0.085), Bacteroidales order (OR = 1.28, 95% CI = 1.06-1.53, = 0.009, = 0.085), and group genus (OR = 0.64, 95% CI = 0.50-0.81, = 2.84×10, = 0.031) were observed to have a causal relationship with T1D in the IVW analysis. No heterogeneity and pleiotropy were detected.
CONCLUSIONS
The present study reports that Bacteroidetes phylum, Bacteroidia class, and Bacteroidales order causally increase T1D risk, whereas group genus, which belongs to the Firmicutes phylum, causally decreases T1D risk. Nevertheless, future studies are warranted to dissect the underlying mechanisms of specific bacterial taxa's role in the pathophysiology of T1D.
Topics: Humans; Gastrointestinal Microbiome; Diabetes Mellitus, Type 1; Genome-Wide Association Study; Mendelian Randomization Analysis; Bacteroidetes
PubMed: 37313342
DOI: 10.3389/fcimb.2023.1163898 -
Gut Microbes 2021is the type strain for the genus , a group of gram-negative anaerobic bacteria that commonly colonize the gastrointestinal tract of numerous species. First isolated in... (Review)
Review
is the type strain for the genus , a group of gram-negative anaerobic bacteria that commonly colonize the gastrointestinal tract of numerous species. First isolated in the 1930s from a clinical specimen as , the strain was re-classified to form the new genus in 2006. Currently, the genus consists of 15 species, 10 of which are listed as 'validly named' (, and ) and 5 'not validly named' (, and ) by the List of Prokaryotic names with Standing in Nomenclature. The genus has been associated with reports of both beneficial and pathogenic effects in human health. Herein, we review the literature on the history, ecology, diseases, antimicrobial resistance, and genetics of this bacterium, illustrating the effects of on human and animal health.
Topics: Animals; Anti-Bacterial Agents; Bacteroidetes; Drug Resistance, Bacterial; Gastrointestinal Microbiome; Gram-Negative Bacterial Infections; Humans; Phylogeny; Probiotics
PubMed: 34196581
DOI: 10.1080/19490976.2021.1922241 -
Science (New York, N.Y.) Aug 2022The microbiome contributes to the development and maturation of the immune system. In response to commensal bacteria, intestinal CD4 T lymphocytes differentiate into...
The microbiome contributes to the development and maturation of the immune system. In response to commensal bacteria, intestinal CD4 T lymphocytes differentiate into functional subtypes with regulatory or effector functions. The development of small intestine intraepithelial lymphocytes that coexpress CD4 and CD8αα homodimers (CD4IELs) depends on the microbiota. However, the identity of the microbial antigens recognized by CD4 T cells that can differentiate into CD4IELs remains unknown. We identified β-hexosaminidase, a conserved enzyme across commensals of the Bacteroidetes phylum, as a driver of CD4IEL differentiation. In a mouse model of colitis, β-hexosaminidase-specific lymphocytes protected against intestinal inflammation. Thus, T cells of a single specificity can recognize a variety of abundant commensals and elicit a regulatory immune response at the intestinal mucosa.
Topics: Animals; Bacteroidetes; CD4-Positive T-Lymphocytes; CD8 Antigens; Colitis; Disease Models, Animal; Intestinal Mucosa; Mice; Mice, Inbred C57BL; beta-N-Acetylhexosaminidases
PubMed: 35926021
DOI: 10.1126/science.abg5645 -
Cell Feb 2022The human gut microbiota resides within a diverse chemical environment challenging our ability to understand the forces shaping this ecosystem. Here, we reveal that...
The human gut microbiota resides within a diverse chemical environment challenging our ability to understand the forces shaping this ecosystem. Here, we reveal that fitness of the Bacteroidales, the dominant order of bacteria in the human gut, is an emergent property of glycans and one specific metabolite, butyrate. Distinct sugars serve as strain-variable fitness switches activating context-dependent inhibitory functions of butyrate. Differential fitness effects of butyrate within the Bacteroides are mediated by species-level variation in Acyl-CoA thioesterase activity and nucleotide polymorphisms regulating an Acyl-CoA transferase. Using in vivo multi-omic profiles, we demonstrate Bacteroides fitness in the human gut is associated together, but not independently, with Acyl-CoA transferase expression and butyrate. Our data reveal that each strain of the Bacteroides exists within a unique fitness landscape based on the interaction of chemical components unpredictable by the effect of each part alone mediated by flexibility in the core genome.
Topics: Acyl Coenzyme A; Amino Acid Sequence; Amino Acids, Branched-Chain; Bacteroidetes; Butyrates; Coenzyme A-Transferases; Gastrointestinal Microbiome; Genetic Variation; Hydrogen-Ion Concentration; Metabolome; Polymorphism, Single Nucleotide; Polysaccharides; Promoter Regions, Genetic; Species Specificity; Stress, Physiological; Transcription, Genetic
PubMed: 35120663
DOI: 10.1016/j.cell.2022.01.002 -
Microbiome Feb 2019Bacteria within family S24-7 (phylum Bacteroidetes) are dominant in the mouse gut microbiota and detected in the intestine of other animals. Because they had not been...
BACKGROUND
Bacteria within family S24-7 (phylum Bacteroidetes) are dominant in the mouse gut microbiota and detected in the intestine of other animals. Because they had not been cultured until recently and the family classification is still ambiguous, interaction with their host was difficult to study and confusion still exists regarding sequence data annotation.
METHODS
We investigated family S24-7 by combining data from large-scale 16S rRNA gene analysis and from functional and taxonomic studies of metagenomic and cultured species.
RESULTS
A total of 685 species was inferred by full-length 16S rRNA gene sequence clustering. While many species could not be assigned ecological habitats (93,045 samples analyzed), the mouse was the most commonly identified host (average of 20% relative abundance and nine co-occurring species). Shotgun metagenomics allowed reconstruction of 59 molecular species, of which 34 were representative of the 16S rRNA gene-derived species clusters. In addition, cultivation efforts allowed isolating five strains representing three species, including two novel taxa. Genome analysis revealed that S24-7 spp. are functionally distinct from neighboring families and versatile with respect to complex carbohydrate degradation.
CONCLUSIONS
We provide novel data on the diversity, ecology, and description of bacterial family S24-7, for which the name Muribaculaceae is proposed.
Topics: Animals; Bacteriological Techniques; Bacteroides; Biodiversity; DNA, Bacterial; DNA, Ribosomal; Gastrointestinal Microbiome; Metagenomics; Mice; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Species Specificity
PubMed: 30782206
DOI: 10.1186/s40168-019-0637-2 -
Nutrients Mar 2018Nutritional supplements are popular among athletes to improve performance and physical recovery. Protein supplements fulfill this function by improving performance and... (Randomized Controlled Trial)
Randomized Controlled Trial
Nutritional supplements are popular among athletes to improve performance and physical recovery. Protein supplements fulfill this function by improving performance and increasing muscle mass; however, their effect on other organs or systems is less well known. Diet alterations can induce gut microbiota imbalance, with beneficial or deleterious consequences for the host. To test this, we performed a randomized pilot study in cross-country runners whose diets were complemented with a protein supplement (whey isolate and beef hydrolysate) ( = 12) or maltodextrin (control) ( = 12) for 10 weeks. Microbiota, water content, pH, ammonia, and short-chain fatty acids (SCFAs) were analyzed in fecal samples, whereas malondialdehyde levels (oxidative stress marker) were determined in plasma and urine. Fecal pH, water content, ammonia, and SCFA concentrations did not change, indicating that protein supplementation did not increase the presence of these fermentation-derived metabolites. Similarly, it had no impact on plasma or urine malondialdehyde levels; however, it increased the abundance of the phylum and decreased the presence of health-related taxa including , , and . Thus, long-term protein supplementation may have a negative impact on gut microbiota. Further research is needed to establish the impact of protein supplements on gut microbiota.
Topics: Adult; Animals; Athletes; Bacteroidetes; Bifidobacterium longum; Biomarkers; Cattle; Clostridiales; Dietary Proteins; Dietary Supplements; Double-Blind Method; Dysbiosis; Feces; Gastrointestinal Microbiome; Humans; Male; Molecular Typing; Physical Conditioning, Human; Physical Endurance; Pilot Projects; Protein Hydrolysates; Spain; Sports Nutritional Physiological Phenomena; Whey Proteins
PubMed: 29534465
DOI: 10.3390/nu10030337