Tartary buckwheat leaf pectic polysaccharides with distinct molecular weights and degrees of esterification differentially ameliorate ulcerative colitis in mice
The intestinal barrier consists of mechanical barrier, chemical barrier, immune barrier and biological barrier that collaborate to uphold the protective role of the intestinal mucosal barrier. Pectic polysaccharide is essential for preserving the integrity of the intestinal mucosal barrier through many processes. Tartary buckwheat leaves pectic polysaccharide (TBP) and its modified products (TBP-LDE and TBP-LMW) had been proved to have immunomodulatory effects in our study. This study further found that TBP, TBP-LDE and TBP-LMW had ameliorate effects on intestinal mucosal barrier damage induced by dextran sodium sulfate. TBP, TBP-LDE, and TBP-LMW could reduce weight loss, colon atrophy, tissue damage and goblet cell loss, increase tight junction protein, restore intestinal barrier function, and inhibit inflammation. The improvement effect of low esterification degree TBP-LDE and low molecular weight TBP-LMW was better than that of TBP. In addition, TBP, TBP-LDE, and TBP-LMW promoted SCFAs while reducing intestinal mucosal barrier damage in a manner that was dependent on the gut microbiome by promoting beneficial bacteria, and inhibiting harmful bacteria. The results provided a scientific basis for TBP, especially the low esterification degree and low molecular weight part, as a natural anti-inflammatory food to restore the imbalance of inflammatory intestinal flora, promote intestinal health and improve intestinal mucosal barrier damage.