Project description:Dysbiosis is linked to the pathogenesis of inflammatory bowel disease. Although there is a lot of interest in restoring the balance, we do not understand the effects of dysbiosis, especially on epithelial cells. In addition, we know that epithelial cells from IBD patients maintain intrinsic defects. For that reason, we aimed to unravel if epithelial cells of UC patients are more sensitive towards microbiota stimulation, compared to non-IBD controls. In addition, we analyzed the effect of UC microbiota or microbiota of healthy donors towards epithelial cells. Confluent organoid derived monolayers of 8 UC patients and 8 non-IBD controls were co-cultured for 6 hours with microbiota (3.10^8 cells) , derived of a healthy donor (HD) or UC patients. If applicable, epithelial cells were first cultured for 24 hours with an inflammatory mix (100 ng/mL TNFα, 20 ng/mL IL1β, 1 µg/mL Flagellin). The inflammatory stimulation was continued in the 6 hours co-culture.Transcriptomic expression of epithelial cells was evaluated after 6 hours co-culture by Truseq for Illumina.
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.
Project description:The goal of this project is to find out whether human intestinal IgA1 and IgA2 secretion, transport and reactivity towards the microbiota might be involved in dysbiosis induction during Crohn’s disease and Ulcerative colitis. Mass spectrometry was used to characterize SIgA from Crohn’s disease patient and Ulcerative colitis patient, in term of O- and N-glycosylation in order to study their reverse transcytosis capacity and their role in intestinal inflammation.
Project description:ObjectiveThe bacterial intestinal microbiota plays major roles in human physiology and IBDs. Although some data suggest a role of the fungal microbiota in IBD pathogenesis, the available data are scarce. The aim of our study was to characterise the faecal fungal microbiota in patients with IBD.DesignBacterial and fungal composition of the faecal microbiota of 235 patients with IBD and 38 healthy subjects (HS) was determined using 16S and ITS2 sequencing, respectively. The obtained sequences were analysed using the Qiime pipeline to assess composition and diversity. Bacterial and fungal taxa associated with clinical parameters were identified using multivariate association with linear models. Correlation between bacterial and fungal microbiota was investigated using Spearman's test and distance correlation.ResultsWe observed that fungal microbiota is skewed in IBD, with an increased Basidiomycota/Ascomycota ratio, a decreased proportion of Saccharomyces cerevisiae and an increased proportion of Candida albicans compared with HS. We also identified disease-specific alterations in diversity, indicating that a Crohn's disease-specific gut environment may favour fungi at the expense of bacteria. The concomitant analysis of bacterial and fungal microbiota showed a dense and homogenous correlation network in HS but a dramatically unbalanced network in IBD, suggesting the existence of disease-specific inter-kingdom alterations.ConclusionsBesides bacterial dysbiosis, our study identifies a distinct fungal microbiota dysbiosis in IBD characterised by alterations in biodiversity and composition. Moreover, we unravel here disease-specific inter-kingdom network alterations in IBD, suggesting that, beyond bacteria, fungi might also play a role in IBD pathogenesis.
Project description:Gut microbiota and their metabolites influence host gene expression and physiological status through diverse mechanisms. Here we investigate how gut microbiota and their metabolites impact host′s mRNA m6A epitranscriptome in various antibiotic-induced microbiota dysbiosis models. With multi-omics analysis, we find that the imbalance of gut microbiota can rewire host mRNA m6A epitranscriptomic profiles in brain, liver and intestine. We further explore the underlying mechanisms regulating host mRNA m6A methylome by depleting the microbiota with ampicillin. Metabolomic profiling shows that cholic acids are the main down-regulated metabolites with Firmicutes as the most significantly reduced genus in ampicillin-treated mice comparing to untreated mice. Fecal microbiota transplantations in germ-free mice and metabolites supplementations in cells verify that cholic acids are associated with host mRNA m6A epitranscriptomic rewiring. Collectively, this study employs an integrative multi-omics analysis to demonstrate the impact of gut microbiota dysbiosis on host mRNA m6A epitranscriptomic landscape via cholic acid metabolism.
Project description:The period from birth to two years is the phase of the fastest growth and development in children, as well as an important window for the development of intestinal microbiota. Dysbiosis of the gut microbiome can lead to various adverse conditions in children, including malabsorption and immune abnormalities, ultimately resulting in a series of negative events related to growth and development. Lysine acetylation, as a significant post-translational modification, plays a complex and crucial role in the regulation of gut microbiota. This study aims to investigate the mechanism by which ABX-induced lysine acetylation affects the abnormal physiological state simulating gut microbiota dysbiosis in children. In this study, we identified a total of 16,579 acetylation sites from 5,218 proteins. We found that antibiotic-induced dysbiosis in young mice (3 weeks) can cause extensive changes in the lysine acetylation and proteomic profiles of cecal tissue. Differentially acetylated proteins are involved in various metabolic pathways, including the citrate cycle (TCA) cycle, butanoate metabolism, pyruvate metabolism, glycolysis/gluconeogenesis, and fatty acid biosynthesis. These differential acetylation sites are distributed across the cytoplasm, nucleus, and mitochondria, suggesting that multiple cellular functions are involved in regulation. Our findings suggest that early-life gut microbiota dysbiosis may lead to a series of metabolic disorders by regulating lysine acetylation in cecal tissue, resulting in delayed growth and development. This study aims to provide valuable insights into the molecular mechanisms underlying a series of pathophysiological processes caused by early-life gut microbiota dysbiosis. It contributes to a deeper understanding of the consequences of acetylation changes associated with early-life gut microbiota dysbiosis and its potential role in metabolic disorders.
Project description:DNA methylation profile of mouse sperm from conventionally-raised mice and gut dysbiosis experienced mice were characterized using whole-genome bisulfite sequencing. Genome-wide DNA methylation changes between control and dysbiotic male�s sperm were highly comparable, with no change in DNAme globally or at genomic features, only 21 differentially methylated regions (DMR) were identified, which did not overlap known regulatory elements. Epididymal sperm samples were harvested from 11 weeks old inbred male mice that were experiencing gut microbiota dysbiosis for 6-week (antibiotics treated, n=5), or drink sterilized water (control, n=5).