Dendrobium officinale polysaccharide attenuates type 2 diabetes in mice model by modulating gut microbiota and alleviating intestinal mucosal barrier damage

The purpose of this study was to investigate the hypoglycemic effect and mechanism of Dendrobium officinale polysaccharide (DOP) on type 2 diabetes mellitus (T2DM) mice established by high-fat diet and streptozotocin. The results showed that DOP improved glycolipid metabolism and serum inflammation levels, and inhibited intestinal-derived lipopolysaccharide (LPS) translocation, suggesting that inhibiting LPS-mediated intestinal barrier damage may be a key target for DOP to alleviate T2DM. Interestingly, the study found that DOP reduced intestinal inflammation and oxidative stress levels, significantly up-regulated the mRNA expression of tight junction proteins Claudin-1, Occludin and zonula occluden-1 (ZO-1), and ameliorated intestinal epithelial damage. In addition, DOP strongly inhibited the intestinal pathogenic bacteria and LPS-producing bacteria Helicobacter, Enterococcus and Desulfovibrio with a reduction rate of 95%, 73% and 9%, respectively, and promoted the proliferation of anti-inflammatory bacteria Bifidobacterium and Lactobacillus by 139% and 8%, respectively. Taken together, the hypoglycemic effect of DOP was related to the protection of intestinal mucosal barrier, and its underlying mechanism lied in its excellent anti-inflammatory and gut microbiota-modulatory effects, providing a theoretical basis for developing DOP as a novel prebiotic in functional food for diabetes.