Gut metagenome
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ABSTRACT:
PROVIDER: PRJNA1064274 | ENA |
REPOSITORIES: ENA
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Project description:Gut microbiome research is rapidly moving towards the functional characterization of the microbiota by means of shotgun meta-omics. Here, we selected a cohort of healthy subjects from an indigenous and monitored Sardinian population to analyze their gut microbiota using both shotgun metagenomics and shotgun metaproteomics. We found a considerable divergence between genetic potential and functional activity of the human healthy gut microbiota, in spite of a quite comparable taxonomic structure revealed by the two approaches. Investigation of inter-individual variability of taxonomic features revealed Bacteroides and Akkermansia as remarkably conserved and variable in abundance within the population, respectively. Firmicutes-driven butyrogenesis (mainly due to Faecalibacterium spp.) was shown to be the functional activity with the higher expression rate and the lower inter-individual variability in the study cohort, highlighting the key importance of the biosynthesis of this microbial by-product for the gut homeostasis. The taxon-specific contribution to functional activities and metabolic tasks was also examined, giving insights into the peculiar role of several gut microbiota members in carbohydrate metabolism (including polysaccharide degradation, glycan transport, glycolysis and short-chain fatty acid production). In conclusion, our results provide useful indications regarding the main functions actively exerted by the gut microbiota members of a healthy human cohort, and support metaproteomics as a valuable approach to investigate the functional role of the gut microbiota in health and disease.
2017-07-19 | PXD005780 | Pride
Project description:Despite accepted health benefits of dietary fiber, little is known about the mechanisms by which fiber deprivation impacts the gut microbiota and alters disease risk. Using a gnotobiotic model, in which mice were colonized with a synthetic human gut microbiota, we elucidated the functional interactions between dietary fiber, the gut microbiota and the colonic mucus barrier, which serves as a primary defence against pathogens. We show that during chronic or intermittent dietary fiber deficiency, the gut microbiota resorts to host-secreted mucus glycoproteins as a nutrient source, leading to erosion of the colonic mucus barrier. Dietary fiber deprivation promoted greater epithelial access and lethal colitis by the mucosal pathogen, Citrobacter rodentium, but only in the presence of a fiber-deprived microbiota that is pushed to degrade the mucus layer. Our work reveals intricate pathways linking diet, gut microbiome and intestinal barrier dysfunction, which could be exploited to improve health using dietary therapeutics. Germ-free mice (Swiss Webster) were colonized with synthetic human gut microbiota comprising of 14 species belonging to five different phyla (names of bacterial species: Bacteroides thetaiotaomicron, Bacteroides ovatus, Bacteroides caccae, Bacteroides uniformis, Barnesiella intestinihominis, Eubacterium rectale, Marvinbryantia formatexigens, Collinsella aerofaciens, Escherichia coli HS, Clostridium symbiosum, Desulfovibrio piger, Akkermansia muciniphila, Faecalibacterium prausnitzii and Roseburia intestinalis). These mice were fed either a fiber-rich diet or a fiber-free diet for about 6 weeks. The mice were then sacrificed and their cecal tissues were immediately flash frozen for RNA extraction. The extracted RNA was subjected to microarray analysis based on Mouse Gene ST 2.1 strips using the Affy Plus kit. Expression values for each gene were calculated using robust multi-array average (RMA) method.
2016-11-21 | GSE79067 | GEO
Project description:Cancer cachexia and the associated skeletal muscle wasting are considered poor prognostic factors, although effective treatment has not yet been established. Recent studies have indicated that the pathogenesis of skeletal muscle loss may involve dysbiosis of the gut microbiota and the accompanying chronic inflammation or altered metabolism. In this study, we evaluated the possible effects of modifying the gut microenvironment with partially hydrolyzed guar gum (PHGG), a soluble dietary fiber, on cancer-related muscle wasting and its mechanism using a colon-26 murine cachexia model. Compared to a fiber-free (FF) diet, PHGG contained fiber-rich (FR) diet attenuated skeletal muscle loss in cachectic mice by suppressing the elevation of the major muscle-specific ubiquitin ligases Atrogin-1 and MuRF1, as well as the autophagy markers LC3 and Bnip3. Although tight junction markers were partially reduced in both FR and FF diet-fed cachectic mice, the abundance of Bifidobacterium, Akkermansia, and unclassified S24-7 family increased by FR diet, contributing to the retention of the colonic mucus layer. The reinforcement of the gut barrier function resulted in the controlled entry of pathogens into the host system and reduced circulating levels of lipopolysaccharide-binding protein (LBP) and IL-6, which in turn led to the suppression of proteolysis by downregulating the ubiquitin-proteasome system and autophagy pathway. These results suggest that dietary fiber may have the potential to alleviate skeletal muscle loss in cancer cachexia, providing new insights for developing effective strategies in the future.
2021-11-23 | E-MTAB-11094 | biostudies-arrayexpress
Project description:The diets of industrialized countries reflect the increasing use of processed foods, often with the inclusion of novel food additives. Xanthan gum is a complex polysaccharide with unique rheological properties that have established its use as a widespread stabilizer and thickening agent. Xanthan gum’s chemical structure is distinct from the host and dietary polysaccharides that are more commonly expected to transit the gastrointestinal tract, and little is known about its direct interaction with the gut microbiota, which plays a central role in digestion of other dietary fiber polysaccharides. Here, we show that the ability to digest xanthan gum is surprisingly common in industrialized human gut microbiomes and appears contingent on a single uncultured bacterium in the family Ruminococcaceae. Our data reveal that this primary degrader cleaves the xanthan gum backbone before processing the released oligosaccharides using additional enzymes. Surprisingly, some individuals harbor a Bacteroides intestinalis that is incapable of consuming polymeric xanthan gum but grows on oligosaccharide products generated by the Ruminococcaceae. Feeding xanthan gum to germfree mice colonized with a human microbiota containing the uncultured Ruminococcaceae supports the idea that this additive can drive expansion of this primary degrader along with exogenously introduced Bacteroides intestinalis. Our work demonstrates the existence of a potential xanthan gum food chain involving at least two members of different phyla of gut bacteria and provides an initial framework to understand how widespread consumption of a recently introduced food additive influences human microbiomes.
2022-02-28 | PXD031522 | Pride
Project description:Dietary fiber can suppress excess adipose tissue and weight gain in rodents and humans when fed high fat diets. The gut microbiome is thought to have a key role, although exactly how remains unclear. In a tightly controlled murine study, we explored how different types of dietary fiber and doses affect the gut microbiota and gut epithelial gene expression. We show that 10% pectin and 10% FOS suppress high fat diet (HFD)-induced weight gain, effects not seen at 2% doses. Furthermore, 2 and 10% mixtures of dietary fiber were also without effect. Distinct gut microbiota profiles were stimulated at the family and operational taxonomic unit (OTU) level by the different fiber treatments. Plasma levels of the gut hormone PYY were elevated by 10% pectin and FOS, but not 10% mixed fibers, and similarly RNA seq revealed some distinct effects of the 10% single fibers on gut epithelial gene expression. These data show how the ability of dietary fiber to suppress HFD-induced weight gain is dependent upon both fiber type and dose. It also shows that the microbial response to dietary fiber is distinct and that there is not a single microbial response associated with the inhibition of adiposity and weight gain. PYY seems key to the latter response, although the role of other factors such as Reg3g and CCK needs to be explored.
2025-02-05 | GSE288466 | GEO
Project description:This dataset provides a comprehensive proteomic characterization of a defined five-strain human gut bacterial consortium, including Bifidobacterium and Roseburia species. The consortium was grown on different carbohydrate sources, human milk oligosaccharides, dietary fibers, or a combination of both, to investigate how substrate availability influences microbial protein expression and metabolic activity. The resulting data captures functional responses and interactions within the community, offering insights into carbohydrate utilization, cross-feeding dynamics, and gut microbial ecology. This resource can support studies of microbiome function, microbial interactions, and dietary modulation of gut microbiota.
2026-04-23 | PXD074160 | Pride
Project description:Dietary lipids can affect metabolic health through gut microbiota-mediated mechanisms, but the influence of lipid-microbiota interaction on liver steatosis is unknown. We investigated the effect of dietary lipid composition on human microbiota in an observational study and combined diet experiments with microbiota transplants to study lipid-microbiota interactions and liver status in mice. In humans, low intake of saturated fatty acids (SFA) was associated with increased microbial diversity independent of fiber intake. In mice, cecum levels of SFA correlated negatively with microbial diversity and were associated with a shift in butyrate and propionate producers. Mice fed poorly absorbed SFA had improved metabolism and liver status. These features were transmitted by microbial transfer. Diets enriched in n-6- and/or n-3-polyunsaturated fatty acids were protective against steatosis but had minor influence on the microbiota. In summary, we find that unabsorbed SFA correlate with microbiota features that may be targeted to decrease liver steatosis.
2023-08-03 | GSE222060 | GEO
Project description:Background & Aims: The complex interactions between diet and the microbiota that influence mucosal inflammation and inflammatory bowel disease are poorly understood. Experimental colitis models provide the opportunity to control and systematically perturb diet and the microbiota in parallel to quantify the contributions between multiple dietary ingredients and the microbiota on host physiology and colitis. Methods: To examine the interplay of diet and the gut microbiota on host health and colitis, we fed over 40 different diets with varied macronutrient sources and concentrations to specific pathogen free or germ free mice either in the context of healthy, unchallenged animals or dextran sodium sulfate colitis model. Results: Diet influenced physiology in both health and colitis across all models, with the concentration of protein and psyllium fiber having the most profound effects. Increasing dietary protein elevated gut microbial density and worsened DSS colitis severity. Depleting gut microbial density by using germ-free animals or antibiotics negated the effect of a high protein diet. Psyllium fiber influenced host physiology and attenuated colitis severity through microbiota-dependent and microbiota-independent mechanisms. Combinatorial perturbations to dietary protein and psyllium fiber in parallel explain most variation in gut microbial density, intestinal permeability, and DSS colitis severity, and changes in one ingredient can be offset by changes in the other. Conclusions: Our results demonstrate the importance of examining complex mixtures of nutrients to understand the role of diet in intestinal inflammation. Keywords: IBD; Diet; Microbiota; Mouse Models; Systems Biology
2017-10-30 | GSE104461 | GEO
Project description:Background: Sleep is fundamental to growth, immune function, and overall health. We initiate our study to elucidate the impact of sleep fragmentation (SF) on the cardiac function, gut microbiome diversity, and the transcriptomic profile of inguinal white adipose tissue (iWAT) in mice, as well as the regulatory role of a high protein diet. Methods: We constructed chronic SF and high protein diet intervention mouse models for this research. Cardiac structure and function were evaluated by echocardiographic analyses. Gut microbiota composition was determined by 16s rDNA amplicon sequencing. Transcriptome alterations of iWAT were assessed by RNA-sequencing. Results: Our result revealed that SF interventions induced inflammatory changes in adipose tissue and perturbed the diversity and composition of the gut microbiota. Concurrently, 6-week SF intervention led to a significant decline in left ventricular systolic function in mice, manifested by a notable decrease in EF and FS. Masson staining revealed distinctions compared to the control group, suggesting an increase in myocardial collagen fiber content following SF intervention. High-protein diet intervention partially mitigated the damage to cardiac structure and function caused by SF. Meanwhile, high-protein diet coupled with improvements in the adipose tissue transcriptome changes induced by SF. Conclusions: In conclusion, chronic SF intervention induced cardiac damage, alters gut microbiota composition and induce adipose tissue inflammation. High-protein diet could partially mitigate the changes above.
2026-03-31 | GSE262679 | GEO