Project description:Gut microbiota is an unignored target in maintaining intestinal homeostasis due to its regulatory effects on intestinal health through multiple mechanisms, including enhancing intestinal barriers, modulating microbial diversity, secreting various metabolites, etc. Bacteriocins produced by probiotics have been gradually proved vital for intestinal diseases intervention, however, the corresponding mechanisms have received less attention and the whole story of their regulative activities are hard to be fully uncovered. The two-peptide Plantaricin NC8 (PLNC8), coded by gene plnc8, is a bacteriocin ubiquitously produced by Lactobacillus plantarum, has been regarded as the potential vital bacteriocin for the anti-inflammatory effects of Lactobacillus plantarum. This study exploited CRISPR-cas9 and prokaryotic gene overexpression techniques to construct the plnc8 strains for the anti-inflammatory mechanism investigation. Based on the metagenomics, transcriptomics and metabolomics analysis, the anti-enteritis mechanism of PLNC8 systematically in DSS-induced enteritis models were comprehensively revealed. PLNC8 induced alterations in the composition of gut microbiota composition, promoting the alterations of multiple probiotics such as Eubacterium plexicaudatum, Doreasp.5-2, Enterococcus cecorum and Prevotella oulorum. Besides, various metabolites produced by the gut microbiota were influenced, and the key metabolites of xanthine, hypoxanthine, and L-histidine were regulated via purine and histidine metabolic pathways. These metabolites further inhibited p38 MAPK phosphorylation of enterocytes induced by DSS. Ultimately, the intestinal barrier repairment and anti- enteritis were achieved, proving the anti-enteritis effects of PLNC8 via microbe-metabolites-enterocyte axis.
Project description:Host-microbiome communication is frequently perturbed in gut pathologies due to microbiome dysbiosis, leading to altered production of bacterial metabolites. Among these, 7a-dehydroxylated bile acids are notably diminished in inflammatory bowel disease patients. Herein, we investigated whether restoration of 7a-dehydroxylated bile acids levels by Clostridium scindens, a human-derived 7a-dehydroxylating bacterium, can reestablish intestinal epithelium homeostasis following colon injury. Gnotobiotic and conventional mice were subjected to chemically-induced experimental colitis following administration of Clostridium scindens. Colonization enhanced the production of 7a-dehydroxylated bile acids and conferred prophylactic and therapeutic protection against colon injury through epithelial regeneration and specification. Computational analysis of human datasets confirmed defects in intestinal cell renewal and differentiation in ulcerative colitis patients while expression of genes involved in those pathways showed a robust positive correlation with 7a-dehydroxylated bile acid levels. Clostridium scindens administration could therefore be a promising biotherapeutic strategy to foster mucosal healing following colon injury by restoring bile acid homeostasis.
