Gut microbial fermentation promotes the intestinal anti-inflammatory activity of Chinese yam polysaccharides

Plant polysaccharides possess many health-promoting properties, which are closely related to the digestion, absorption and utilization of polysaccharides in the host. The characteristic changes in Chinese yam polysaccharide (CYP) during simulated gastrointestinal digestion and faecal fermentation, as well as the intestinal anti-inflammatory effects of CYP and fermented CYP, were studied. The molecular weight of CYP remained unchanged during gastrointestinal digestion. After 24 h of faecal fermentation, free glucose and mannose released from CYP were utilized by gut microbiota, and the production of short-chain fatty acids increased. Simultaneously, CYP improved the growth of Bifidobacterium and Megasphaera. Compared with CYP, faecal fermented CYP exhibited greater suppression of anti-inflammatory mediators and increased intestinal tight junction expression in LPS-stimulated coculture Caco-2/Raw264.7 cells. The obtained results reveal that the role of CYP in promoting gut health is closely related to the interactions between CYP and gut microbes, and CYP has potential as an anti-inflammatory adjuvant in enteritis therapy.