Glucomannan from <i>Dendrobium officinale</i> Alleviates Colitis via Modulating Gut Microbiota and Upregulating Deoxycholic Acid Production

ABSTRACT Dietary fiber is a bioactive substance that can modulate gut microbiota and exert a relieving effect on inflammatory bowel disease (IBD). Dendrobium officinale polysaccharide (DOP) is a type of bioactive dietary fiber that has been proven to have various biological activities on intestinal function. However, the key mechanism underlying DOP‐mediated protection against colitis is unclear. In this study, we proved that DOP alleviates colitis induced by dextran sulfate sodium (DSS), and its beneficial effects depend on the gut microbiota. Specifically, DOP supplementation significantly increased the abundance of Clostridium and Ruminococcus in mice, leading to the upregulated secondary bile acid synthesis pathway and increased deoxycholic acid (DCA) production. Notably, DCA administration alleviated colitis manifestations in DSS‐treated mice. Collectively, these results indicate that DOP exerts its mechanism of improving colitis by modulating gut microbiota and promoting the synthesis of DCA.