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ABSTRACT:
PROVIDER: PRJNA1095916 | ENA |
REPOSITORIES: ENA
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Project description:Background and Aims: Many inflammatory diseases are associated with microbial dysbiosis, which may considerably alter the production of short-chain fatty acids (SCFAs). SCFAs are produced in the large bowel through bacterial fermentation of dietary fiber and play an important role in maintaining gut homeostasis. SCFAs, particularly acetate and butyrate, show beneficial immunomodulatory effects contributing to the prevention of inflammatory and allergic reactions. Thus, reduced production of SCFAs may impact on the mucosal immune responses critical to fighting pathogens. This study aims to determine the influence of SCFAs on a murine model of colonic bacterial infection. Methods: In the present study, we used acetate- (HAMSA) or butyrate- (HAMSB) yielding diets to deliver high concentrations of individual SCFAs to the large bowel of mice infected with C. rodentium. We assessed the effects of these SCFAs on clinical burden and gut pathogenicity in correlation with changes in bacteria growth, fecal microbiota composition, function and changes in the immunological profile. Results: Here we show in vitro that acetate and butyrate directly inhibited growth of the attaching and effacing (A/E) pathogen C. rodentium in a bacteriostatic manner. This correlated with reduced expression of Tir, a gene responsible for bacterial adherence and pathogenicity. Interestingly, HAMSA-fed mice presented reduced clinical scores during C. rodentium infection associated with high concentrations of fecal acetate. This was linked with compositional and functional changes in the microbiota when examining 16s sequencing and proteomics analysis. The HAMSA mediated is protection involved increased expression IL-22 and Muc-2 in the colon and increased numbers of CD8αα+ TCRγδ T cells in the colonic epithelium. These effects were dependent on GPR43, a metabolite-sensing GPCR that binds acetate. Conclusions: We established a promising new approach to moderate bacterial gut infections by manipulating the gut microbiota and mucosal immune tolerance through diets that yield the SCFA acetate.
2022-02-15 | PXD008149 | Pride
Project description:Intracerebral hemorrhage (ICH) induces alterations in the gut microbiota composition, significantly impacting neuroinflammation post-ICH. However, the impact of gut microbiota absence on neuroinflammation following ICH-induced brain injury remain unexplored. Here, we observed that the gut microbiota absence was associated with reduced neuroinflammation, alleviated neurological dysfunction, and mitigated gut barrier dysfunction post-ICH. In contrast, recolonization of microbiota from ICH-induced SPF mice by transplantation of fecal microbiota (FMT) exacerbated brain injury and gut impairment post-ICH. Additionally, microglia with transcriptional changes mediated the protective effects of gut microbiota absence on brain injury, with Apoe emerging as a hub gene. Subsequently, Apoe deficiency in peri-hematomal microglia was associated with improved brain injury. Finally, we revealed that gut microbiota influence brain injury and gut impairment via gut-derived short-chain fatty acids (SCFA).
2024-05-13 | GSE266602 | GEO
Project description:Gut dysbiosis is closely involved in the pathogenesis of inflammatory bowel disease (IBD). However, it remains unclear whether IBD-associated gut dysbiosis plays a primary role in disease manifestation or is merely secondary to intestinal inflammation. Here, we established a humanized gnotobiotic (hGB) mouse system to assess the functional role of gut dysbiosis associated with two types of IBD - Crohn's disease (CD) and ulcerative colitis (UC). In order to explore the functional impact of dysbiotic microbiota in IBD patients on host immune responses, we analyzed gene expression profiles in colonic mucosa of hGB mice colonized with healty (HC), CD, and UC microbiota.
2015-10-10 | GSE73882 | GEO
Project description:It has been shown in vitro that only specific dietary-fibers contribute to immunity but studies in vivo are not conclusive. Here we investigated degree of polymerization (DP) dependent effects of β2→1-fructans on immunity via microbiota-dependent and -independent effects. To this end, conventional or germ-free mice received short- or long-chain β2→1-fructan for 5 days. Immune cell populations in the spleen, mesenteric lymph nodes (MLN), and Peyer's patches (PPs) were analyzed with flow cytometry, genome-wide gene expression in the ileum was measured with microarray, and gut microbiota composition was analyzed with 16S rRNA sequencing of fecal samples. We found that β2→1-fructans modulated immunity by both microbiota and microbiota-independent effects. Moreover, effects were dependent on the chain-length of the β2→1-fructans type polymer. Both short- and long-chain β2→1-fructans enhanced T-helper 1 cells in Peyer's patches, whereas only short-chain β2→1-fructans increased regulatory T cells and CD11b-CD103- DCs in the MLN. A common feature after short- and long-chain β2→1-fructan treatment was enhanced Fut2 expression and other IL-22-dependent genes in the ileum of conventional mice. These effects were not associated with shifts in gut microbiota composition, or altered production of short-chain fatty acids. Both short- and long-chain β2→1-fructans also induced immune effects in germ-free animals, demonstrating direct effect independent from the gut microbiota. Also, these effects were dependent on the chain-length of the β2→1-fructans. Short-chain β2→1-fructan induced lower CD80 expression by CD11b-CD103- DCs in PPs, whereas long-chain β2→1-fructan specifically modulated B cell responses in germ-free mice. In conclusion, support of immunity is determined by the chemical structure of β2→1-fructans and is partially microbiota-independent.
2018-03-22 | GSE94516 | GEO
Project description:Long-term dietary intake influences the structure and activity of the trillions of microorganisms residing in the human gut, but it remains unclear how rapidly and reproducibly the human gut microbiome responds to short-term macronutrient change. Here we show that the short-term consumption of diets composed entirely of animal or plant products alters microbial community structure and overwhelms inter-individual differences in microbial gene expression. The animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes, Bilophila and Bacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale and Ruminococcus bromii). Microbial activity mirrored differences between herbivorous and carnivorous mammals, reflecting trade-offs between carbohydrate and protein fermentation. Foodborne microbes from both diets transiently colonized the gut, including bacteria, fungi and even viruses. Finally, increases in the abundance and activity of Bilophila wadsworthia on the animal-based diet support a link between dietary fat, bile acids and the outgrowth of microorganisms capable of triggering inflammatory bowel disease. In concert, these results demonstrate that the gut microbiome can rapidly respond to altered diet, potentially facilitating the diversity of human dietary lifestyles. RNA-Seq analysis of the human gut microbiome during consumption of a plant- or animal-based diet.
2013-12-05 | E-GEOD-46761 | biostudies-arrayexpress
Project description:A high-sugar diet induces lifestyle-associated metabolic diseases, such as obesity and diabetes, which may underlie the pro-tumor effects of a high-sugar diet. We supplied GL261 syngeneic glioblastoma (GBM) model mice with a short-term high-glucose diet (HGD) and found an increased survival rate with no evidence of metabolic disease. Modulation of the gut microbiota by an HGD was critical for enhancing the anti-tumor immune response. Single-cell RNA sequencing showed that modulation of the gut microbiota by an HGD increased the T cell-mediated anti-tumor immune response in GBM mice. We found that the cytotoxic CD4+ T cell population in GBM mice increased due to synergy with anti-PD-1 immune checkpoint inhibitors, but this depended on an HGD. Thus, we determined that an HGD enhanced anti-tumor immune responses in GBM mice through changes in the gut microbiota and suggest that the role of an HGD in GBM should be re-examined.
2023-09-19 | GSE222192 | GEO
Project description:The gut microbiome is significantly altered in inflammatory bowel diseases, but the basis of these changes is not well understood. We have combined metagenomic and metatranscriptomic profiling of the gut microbiome to assess changes to both bacterial community structure and transcriptional activity in a mouse model of colitis. Gene families involved in microbial resistance to oxidative stress, including Dps/ferritin, Fe-dependent peroxidase and glutathione S-transferase, were transcriptionally up-regulated in colitis, implicating a role for increased oxygen tension in gut microbiota modulation. Transcriptional profiling of the host gut tissue and host RNA in the gut lumen revealed a marked increase in the transcription of genes with an activated macrophage and granulocyte signature, suggesting the involvement of these cell types in influencing microbial gene expression. Down-regulation of host glycosylation genes further supports a role for inflammation-driven changes to the gut niche that may impact the microbiome. We propose that members of the bacterial community react to inflammation-associated increased oxygen tension by inducing genes involved in oxidative stress resistance. Furthermore, correlated transcriptional responses between host glycosylation and bacterial glycan utilisation support a role for altered usage of host-derived carbohydrates in colitis. Complementary transcription profiling data from the mouse hosts have also been deposited at ArrayExpress under accession number E-MTAB-3590 ( http://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-3590/ ).
2015-05-22 | E-MTAB-3562 | biostudies-arrayexpress
Project description:Changes in microbiome composition have been associated with a wide array of human diseases, turning the human microbiota into an attractive target for therapeutic intervention. Yet clinical translation of these findings requires the establishment of causative connections between specific microbial taxa and their functional impact on host tissues. Here, we infused gut organ cultures with longitudinal microbiota samples collected from therapy-naïve irritable bowel syndrome (IBS) patients under low-FODMAP (fermentable Oligo-, Di-, Mono-saccharides and Polyols) diet. We show that post-diet microbiota regulates intestinal expression of inflammatory and neuro-muscular gene-sets. Specifically, we identify Bifidobacterium adolescentis as a diet-sensitive pathobiont that alters tight junction integrity and disrupts gut barrier functions. Collectively, we present a unique pathway discovery approach for mechanistic dissection and identification of functional diet-host-microbiota modules. Our data support the hypothesis that the gut microbiota mediates the beneficial effects of low-FODMAP diet and reinforce the potential feasibility of microbiome based-therapies in IBS.
2022-10-14 | GSE215048 | GEO
Project description:Changes in microbiome composition have been associated with a wide array of human diseases, turning the human microbiota into an attractive target for therapeutic intervention. Yet clinical translation of these findings requires the establishment of causative connections between specific microbial taxa and their functional impact on host tissues. Here, we infused gut organ cultures with longitudinal microbiota samples collected from therapy-naïve irritable bowel syndrome (IBS) patients under low-FODMAP (fermentable Oligo-, Di-, Mono-saccharides and Polyols) diet. We show that post-diet microbiota regulates intestinal expression of inflammatory and neuro-muscular gene-sets. Specifically, we identify Bifidobacterium adolescentis as a diet-sensitive pathobiont that alters tight junction integrity and disrupts gut barrier functions. Collectively, we present a unique pathway discovery approach for mechanistic dissection and identification of functional diet-host-microbiota modules. Our data support the hypothesis that the gut microbiota mediates the beneficial effects of low-FODMAP diet and reinforce the potential feasibility of microbiome based-therapies in IBS.
2022-10-14 | GSE215047 | GEO