Effects of dietary supplementation with green lentil (Lens culinaris) hulls on NAFLD: Focus on intestinal and hepatic metabolism

Lentil hulls, a by-product of lentil processing, are rich in polyphenols and dietary fiber. In this study, a mouse model of nonalcoholic fatty liver disease (NAFLD) induced by dextran sulfate sodium (DSS) and high-fat diet (HFD) was used to investigate the intervention effect of green lentil hulls (GLH) from the perspective of intestinal and hepatic metabolism. Results suggest that DSS-induced gut inflammation and barrier disruption aggravate NAFLD; GLH intervention lowered body weight, liver weight gain and lipid deposition. It also inhibited liver fat accumulation and inflammation as well as intestinal inflammation. In addition, it enhanced liver antioxidant capacity, glucose tolerance and intestinal barrier integrity. Analysis of intestinal flora indicated that GLH advanced the abundance of Akkermansia-muciniphila and Verrucomicrobiaceae, which led to increased content of short-chain fatty acids (SCFAs) and inhibited the Firmicutes and Proteobacteria. Moreover, GLH intervention regulated taurine and hypotaurine metabolism, as well as the biosynthesis of unsaturated and saturated fatty acids in the liver. The relief by GLH on NAFLD may be a comprehensive effect of its rich dietary fiber and polyphenols on intestinal and hepatic metabolism via the gut-liver axis. This research also suggests that the low-value lentil hulls can serve as a valuable food supplement for enhanced gut health and reduced risk of NAFLD.