Inulin and Lycium barbarum polysaccharides ameliorate diabetes by enhancing gut barrier via modulating gut microbiota and activating gut mucosal TLR2+ intraepithelial γδ T cells in rats

Previously we demonstrated the anti-diabetic effect of dietary inulin (INU), but the underling mechanism still remains unclear. In this study, 8 weeks treatment of INU with or without Lycium barbarum polysaccharides (LBP) decreased blood glucose, plasma lipopolysaccharide (LPS) and inflammation in diabetic rats. Moreover, altered gut microbial community and short-chain fatty acids (SCFAs) were found after the intervention. Intriguingly, these changes in gut microbiota were closely correlated with improved mucosal Toll-like receptor (TLR) 2+γδ intraepithelial lymphocytes (IELs) and tight-junction proteins (including ZO-1 and occludin) in gut barrier. Taken together, our results highlighted that dietary INU combined with LBP possessed the ability to modify gut microbiota and improve diabetes-related biochemical abnormalities through improving gut barrier by activating gut mucosal γδ IELs via TLR2, which may potentially contribute to the control of the disease.