Exopolysaccharides from Lactobacillus plantarum YW11 improve immune response and ameliorate inflammatory bowel disease symptoms.

Exopolysaccharides (EPSs) possess many bioactivities such as immune regulation, antioxidant, anti-tumor and modulation of intestinal microbial balance but their direct effect on inflammatory bowel disease (IBD) response has not been studied. The purpose of this study was to evaluate the anti-inflammatory effect of EPS produced by L. plantarum YW11 administered at different dosages in IBD mouse model induced with 5% dextran sulphate sodium (DSS). The DSS-induced colitis, accompanied by body weight loss, reduction of colon coefficient and histological colon injury was considerably ameliorated in mice fed the EPS (10 mg/kg). The middle dose of the EPS (25 mg/kg) could effectively recover the intestinal microbial diversity and increase the abundance of Roseburia, Ruminococcus and Blautia with increased content of butyric acid. Moreover, EPS also reduced the production of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IFN-γ, IL-12 and IL-18) and enhanced the anti-inflammatory cytokine IL-10. This study showed that EPS might help in modulation of gut microbiota and improve the immunity of the host to reduce the risk of IBD symptoms.