Ulcerative colitis (UC) is a non-specific chronic inflammatory disease with lesions located in the colon and rectum. The aim of this study was to evaluate the anti-inflammatory effects of exopolysaccharide-1 (EPS-1) isolated by L. helveticus KLDS1.8701 on UC. The anti-inflammatory effects of EPS-1 were studied using dextran sulphate sodium (DSS)-induced UC model. In vivo results showed that EPS-1 administration significantly ameliorated weight loss, colon shortening, disease activity index (DAI) score, myeloperoxidase (MPO) activity, and colon tissue damage. In addition, EPS-1 administration significantly decreased the levels of pro-inflammatory cytokines and increased levels of anti-inflammatory cytokines. Meanwhile, EPS-1 administration significantly up-regulated the expression of tight junction proteins and mucin. Furthermore, EPS-1 administration modulated gut microbiota composition caused by DSS and increased the short-chain fatty acids (SCFAs) levels. Collectively, our study showed the alleviative effects of EPS- isolated by L. helveticus KLDS1.8701 on DSS-induced UC via alleviating intestinal inflammation, improving mucosal barrier function, and modulating gut microbiota composition.

This study aimed to elucidate the underlying mechanisms for the protective effect of Lactobacillus on hypercholesterolemia. Firstly, twenty Lactobacillus strains were screened for potential probiotics with high bile salt hydrolase (BSH) activity using in vitro methods. Secondly, hypercholesterolemic mice induced by a cholesterol-enriched diet were administrated by the probiotic candidate strain L. plantarum Y15, identified from the screen. Results in vitro showed that L. plantarum Y15 possessed high BSH activity. In vivo, L. plantarum Y15 supplementation decreased total cholesterol and triglyceride in serum and liver, increased total cholesterol and total bile acid in feces, and alleviated histopathological changes in the liver. Furthermore, L. plantarum Y15 supplementation modulated the gut microbiota to the control group’s pattern, leading to increase BSH activity, which further influence FXR and SHP signaling pathway to upregulate the expression level of CYP7A1 to enhance the cholesterol catabolism.