Dendrobium officinale Polysaccharide Alleviates Type 2 Diabetes Mellitus by Restoring Gut Microbiota and Repairing Intestinal Barrier via the LPS/TLR4/TRIF/NF-kB Axis

Dendrobium officinale polysaccharide(DOP), the main active component, has a variety of bioactivities.In this study, a type 2 diabetes mellitus (T2DM) and antibiotic-inducedpseudo-germ-free mouse models were used to investigate the hypoglycemicmechanisms of DOP. The findings showed that DOP ameliorated dysfunctionalglucolipid metabolism, lipopolysaccharide (LPS) leakage, and metabolicinflammation levels in T2DM mice. Furthermore, DOP significantly upregulatedthe mRNA expression of tight junction proteins Claudin-1, Occludin, and ZO-1 and reducedintestinal inflammation and oxidative stress damage through the LPS/TLR4/TRIF/NF-& kappa;Baxis to repair the intestinal barrier. Interestingly, pseudo-germ-freemouse experiments confirmed that the above beneficial effects of DOPwere dependent on gut microbiota. 16S rRNA analysis showed that DOPstrongly inhibited the harmful bacterium Helicobacter by 94.57% and facilitated the proliferation of probiotics Allobaculum, Bifidobacterium, and Lactobacillus by 34.96, 139.41,and 88.95%, respectively. Therefore, DOP is capable of rebuildingcertain specific intestinal microbiota to restore intestinal barrierinjury, which supports the utilization of DOP as a new type of prebioticin functional foods for T2DM.