Ontology highlight
ABSTRACT:
PROVIDER: PRJNA774891 | ENA |
REPOSITORIES: ENA
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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: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:Gut microbiota has profound effects on obesity and associated metabolic disorders. Targeting and shaping the gut microbiota via dietary intervention using probiotics, prebiotics and synbiotics can be effective in obesity management. Despite the well-known association between gut microbiota and obesity, the microbial alternations by synbiotics intervention, especially at the functional level, are still not characterized. In this study, we investigated the effects of synbiotics on high fat diet (HFD)-induced metabolic disorders, and systematically profiled the microbial profile at both the phylogenetic and functional levels. Synbiotics significantly reversed the HFD-induced change of microbial populations at the levels of richness, taxa and OTUs. Potentially important species Faecalibaculum rodentium and Alistipes putredinis that might mediate the beneficial effects of synbiotics were identified. At the functional level, short chain fatty acid and bile acid profiles revealed that interventions significantly restored cecal levels of acetate, propionate, and butyrate, and synbiotics reduced the elevated total bile acid level. Metaproteomics revealed the effect of synbiotics might be mediated through pathways involved in carbohydrate, amino acid, and energy metabolisms, replication and repair, etc. These results suggested that dietary intervention using our novel synbiotics alleviated HFD-induced weight gain and restored microbial ecosystem homeostasis phylogenetically and functionally.
2022-02-22 | PXD009564 | Pride
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:A diet rich in dietary fiber and polyphenols supports the normal intestinal barrier function crucial for intestinal and overall health. Birch wood-derived fiber containing glucuronoxylans (GX)- and polyphenols have the potential in multiple food technological applications and have favorable effects on gut microbiota and colonic metabolism. However, their impact on intestinal barrier function is unknown. To elucidate their potential as new intestinal health-supporting food ingredients, we investigated the effect of GX- and polyphenol-rich extract (GXpoly ) and highly purified GX-rich extract (pureGX) on the gene expression of the colon mucosa.
2023-12-01 | GSE230139 | GEO
Project description:Analysis of breast cancer survivors' gut microbiota after lifestyle intervention, during the COVID-19 lockdown, by 16S sequencing of fecal samples.
2023-01-13 | E-MTAB-12486 | biostudies-arrayexpress
Project description:Gut microbiota after dietary intervention
| PRJNA202975 | ENA
Project description:The gut microbiota influences host epigenetics by fermenting dietary fiber into butyrate. Although butyrate could promote histone acetylation by inhibiting histone deacetylases, it may also undergo oxidation to acetyl-CoA, a necessary cofactor for histone acetyltransferases. Here, we find that epithelial cells from germ-free mice harbor a loss of histone H4 acetylation across the genome except at promoter regions. Using stable isotope tracing in vivo with 13C-labeled fiber, we demonstrate that the microbiota supplies carbon for histone acetylation. Subsequent metabolomic profiling revealed hundreds of labeled molecules and supported a microbial contribution to host fatty acid metabolism, which declined in response to colitis and correlated with reduced expression of genes involved in fatty acid oxidation. These results illuminate the flow of carbon from the diet to the host via the microbiota, disruptions to which may affect energy homeostasis in the distal gut and contribute to the development of colitis.
2022-12-11 | PXD026959 | Pride
Project description:The human gut microbiota is crucial for degrading dietary fibres from the diet. However, some of these bacteria can also degrade host glycans, such as mucins, the main component of the protective gut mucus layer. Specific microbiota species and mucin degradation patterns are associated with inflammatory processes in the colon. Yet, it remains unclear how the utilization of mucin glycans affects the degradation of dietary fibres by the human microbiota. Here, we used three dietary fibres (apple pectin, β-glucan and xylan) to study in vitro the dynamics of colon mucin and dietary fibre degradation by the human faecal microbiota. The dietary fibres showed clearly distinguishing modulatory effects on faecal microbiota composition. The utilization of colon mucin in cultures led to alterations in microbiota composition and metabolites. Metaproteome analysis showed the central role of the Bacteroides in degradation of complex fibres while Akkermansia muciniphila was the main degrader of colonic mucin. This work demonstrates the intricacy of complex glycan metabolism by the gut microbiota and how the utilization of host glycans leads to alterations in the metabolism of dietary fibres. Metaproteomics analysis of this data reveals the functional activities of the bacteria in consortia, by this contributing to a better understanding of the complex metabolic pathways within the human microbiota that can be manipulated to maximise beneficial microbiota-host interactions.
2024-06-13 | PXD035981 | Pride
Project description:<p>Findings from recent studies suggest that the community of microbes residing in the human body is important in disease etiology; however, it remains unclear whether personal factors modulate human microbial composition. Studies based on animal models indicate that differences in composition might be attributed to sex-mediated effects. We analyzed the relationship of sex, adiposity, and dietary fiber intake with gut microbial composition using fecal samples from human subjects. We explored the associations of these factors with metrics of community composition and specific taxon abundances. We found that men and women had significantly different microbial community composition and that women had reduced abundance of a major phylum. Adiposity was associated with gut microbiome composition and specifically in women but not in men. Fiber from fruits and vegetables and fiber from beans were each associated with increased abundance of specific bacterial taxa. These findings provide initial indications that sex, adiposity, and dietary fiber might play important roles in influencing the human gut microbiome. Better understanding of these factors may have significant implications for gastrointestinal health and disease prevention.</p>
| phs000884 | dbGaP