Structural characterization of polysaccharides from 'Nanguo' pear and its protective effect against inflammatory...

Inflammatory bowel disease (IBD) is a chronic disease characterized by intestinal inflammation, intestinal barrier impairment, and gut microbiota dysfunction. This study aimed to investigate the effects of 'Nanguo' pear (Pyrus ussuriensis Maxim.) polysaccharides (NGP) in ameliorating dextran sulfate sodium (DSS)-induced IBD in mice. NGP was extracted and purified, and NGP-3, the dominant polysaccharides in 'Nanguo' pear, was found to consist of galacturonic acid, xylose, arabinose, and galactose in a molar ratio of 1.92:1:0.73:0.36. Supplementation with NGP and NGP-3 alleviated weight loss and reduced disease activity index scores. Histological staining showed that NGP and NGP-3 treatments reduced crypt damage and inflammatory cell infiltration, and promoted the expression of intestinal barrier proteins (MUC2, Occludin, and ZO-1). NGP and NGP-3 treatments significantly reduced the mRNA expression of TNF-α, IL-6, and IL-1β and promoted the production of short-chain fatty acids. Additionally, NGP and NGP-3 supplementation increased the abundance and diversity of gut microbiota. Specifically, NGP treatment increased the abundance of Akkermansia muciniphila_D, Lachnospiraceae, and Desulfovibrio spp. and NGP-3 treatment increased the abundances of Oscillospirales, Sporobacter, and Dorea A. In conclusion, NGP exerts protective effects against colitis.