Lactobacillus plantarum 17-1 Ameliorates DSS-Induced Colitis by Modulating the Colonic Microbiota Composition and Metabolome in Mice

<b>Background/Objectives</b>: <i>Lactobacillus</i> strains are widely used as probiotics in the functional food industry and show potential for treating inflammatory bowel disease (IBD). However, the strain specificity and limited stress resistance of <i>Lactobacillus</i> restricts its therapeutic effectiveness. The aim of this study was to investigate the effects of dietary supplementation with microencapsulated <i>Lactobacillus plantarum</i> 17-1 on the intestinal immune responses, gut microbiota composition, and metabolic characteristics in colitis mice. <b>Methods</b>: Mice were pre-fed a diet containing microencapsulated <i>Lactobacillus plantarum</i> 17-1 for 3 weeks and then treated with 2.5% dextran sulfate sodium (DSS) in drinking water for 8 days to induce colitis. <b>Results</b>: The results showed that microencapsulated <i>Lactobacillus plantarum</i> 17-1 effectively alleviated clinical symptoms and histopathological features of colitis mice and suppressed the up-regulation of pro-inflammatory cytokines IL-6 and IL-17 in the colon of colitis mice. Additionally, <i>Lactobacillus plantarum</i> 17-1 significantly increased the relative abundance of several beneficial bacterial taxa, including <i>Ruminococcaceae</i>_UCG_014, <i>Bacteroides</i>, <i>Prevotellaceae</i>_UCG_001, <i>Lactococcus</i>, <i>Weissella</i>, <i>Pediococcus</i>, and so on. Moreover, it regulated the levels of multiple inflammation-related metabolites involved in linolenic acid metabolism, arachidonic acid metabolism, primary bile acid biosynthesis, and tyrosine metabolism. <b>Conclusions</b>: These results suggest that dietary supplementation with microencapsulated <i>Lactobacillus plantarum</i> 17-1 reduced colitis inflammation in mice by modulating the intestinal microbiota composition and metabolic characteristics, which may serve as a potential therapeutic strategy for IBD.