Polysaccharides from Tetrastigma Hemsleyanum Diels et Gilg ameliorated inflammatory bowel disease by rebuilding the intestinal mucosal barrier and inhibiting inflammation through the SCFA-GPR41/43 signaling pathway

In this study, the therapeutic effects of Tetrastigma hemsleyanum polysaccharide (THP) on inflammatory bowel disease (IBD) and its possible mechanisms were investigated based on the IBD mouse model induced by dextran sodium sulfate (DSS) and the lipopolysaccharide (LPS)-stimulated Caco-2 cell model. THP significantly alleviated the signs and symptoms of DSS-induced IBD mice, including the reduced weight, shortened colonic length, and increased colitis disease activity index. In vivo, THP significantly reduced inflammatory cell infiltration and oxidative damage, promoted intestinal mucus secretion, and restored the integrity of the intestinal epithelial barrier and mucus barrier. Furthermore, THP reversed the changes in the intestinal flora of colonized mice and restored the levels of short-chain fatty acids (SCFAs) by increasing the abundance of potentially beneficial bacteria and increasing the abundance of butyrate-producing bacteria. In addition, THP upregulated the expression of G-protein-coupled receptors (GPR41 and GPR43) both in vivo and in vitro. In summary, the current investigation showed that THP effectively protected against intestinal inflammation and impairment in the intestinal barrier in the setting of DSS-induced IBD, possibly by regulating gut microbiota structure and corresponding SCFA metabolites, and the pathway of SCFAs action may be related to SCFA-GPR41/43 signaling pathway.