Project description:To elucidate whether Faecalibacterium prausnitzii has effects on intestinal toxicity induced by immune checkpoint inhibitors, we performed RNA-seq analysis of colon tissues of mice receiving DSS, DSS+ICB and DSS+ICB+F. prausnitzii gavage to compare the gene expression profiles.
Project description:A high-fat diet (HFD) was administered to C56BL/6 mice for 16 weeks. The intragastric injections of F. prausnitzii strains was administrated and changes in serum and liver metabolic indicators were then assessed. RNA-sequence (RNA-seq) was performed to identify differently expressed genes related to F. prausnitzii treatment.
Project description:We isolated immune cells from human blood of patients with IBD and non-inflamed controls. We stimulated them with F. prausnitzii EXL01 strain, Cadaverin or lipopolysaccharide (LPS) from Escherichia coli and performed Legendplex, ELISA, flow cytometry, RNA-sequencing (RNAseq), and Seahorse analysis. F. prausnitzii EXL01 strain induced the production of IL-10 in CD14+ monocytes from systemic circulation and intestinal tissue of IBD patients and non-inflamed controls in a direct and dose-dependent manner, without inducing a pro-inflammatory response as compared to LPS stimulation. RNAseq analysis confirmed these results and revealed that F. prausnitzii EXL01 strain differentially affects cell energy metabolism compared to LPS. The anti-inflammatory response induced by F. prausnitzii in monocytes was dependent on mitochondrial activity. F. prausnitzii induces an anti-inflammatory response and rewires energy metabolism in human monocytes, which might explain its beneficial impact on intestinal inflammation and human health in general. These results provide new insight into the mechanisms underlying the anti-inflammatory effects of F. prausnitzii and are crucial for a better understanding of its potential use in the treatment of IBD.
Project description:The human intestinal microbiota plays an essential role in host health. Modifications in its composition and diversity could induce pathologies such as inflammatory bowel diseases (IBD). These diseases are characterized by an unbalanced intestinal microbiota (a process known as dysbiosis) and an altered immune response. Faecalibacterium prausnitzii, the most abundant commensal bacterium in the human intestinal microbiota of healthy individuals (representing more than 5% of the total bacterial population), has been reported to be lower in feces and mucosa-associated microbiota of IBD patients. In addition, we have shown that both F. prausnitzii and its culture supernatant (SN) have anti-inflammatory and protective effects in both acute and chronic colitis models. However, the host molecular mechanisms involved in these anti-inflammatory effects remain unknown. In order to address this issue, we performed DNA chip-based transcriptomic analyses in HT-29 human intestinal epithelial cells stimulated with TNF-a and exposed to F. prausnitzii SN or to BHI (growth medium for F prausnitzii).
Project description:Faecalibacterium prausnitzii, a major commensal bacterium in the human gut, is well known for its anti-inflammatory effects, which improve host intestinal health. Although several studies have reported that inulin, a well-known prebiotic, increases the abundance of F. prausnitzii in the intestine, the mechanism underlying this effect remains unclear. In this study, we applied liquid chromatography tandem mass spectrometry (LC-MS/MS)-based multi-omics approaches to identify biological and enzymatic mechanisms of F. prausnitzii involved in the selective digestion of inulin. An LC-MS/MS-based intracellular proteomic and metabolic profiling was performed to determine the quantitative changes in specific proteins and metabolites of F. prausnitzii when grown on inulin. Interestingly, proteomic analysis revealed that the putative proteins involved in inulin-type fructan utilization by F. prausnitzii, particularly b-fructosidase and amylosucrase were upregulated in the presence of inulin. To investigate the function of these proteins, we overexpressed bfrA and ams, genes encoding beta-fructosidase and amylosucrase, respectively, in Escherichia coli, and observed their ability to degrade fructan. In addition, the enzyme activity assay demonstrated that intracellular fructan hydrolases degrade the inulin-type fructans taken up by fructan ATP-binding cassette transporters. Furthermore, we showed that the fructose uptake activity of F. prausnitzii was enhanced by the fructose phosphotransferase system transporter when inulin was used as a carbon source.