Gut Microbiota Mediates the Protective Effects of Dietary methionine restriction against blood lipid and gut redox state Associated Obesity Induced by High-Fat Diet

• 1、School of Food Science and Technology, Jiangnan University, Wuxi 214122
• 2、The State Key Laboratory of Food Science and Technology, Wuxi 214122

Abstract：To investigate the effects of dietary methionine restriction (MR) on serum lipid and intestinal antioxidative function in high-fat diet mice, sixty three male C57BL/6 mice were randomly equally divided into control group(C), high-fat diet group(HM), high-fat with MR group (LM). Body weight was recorded weekly. After 12 weeks, 9 mice were choosed randomly to obtain blood plasma, cecum, ileum and colon. Plasma total cholesterol (TC), triglyceride (TG), lowdensity lipoprotein (LDL), highdensity lipoprotein (HDL) were examined. The total antioxidant capacity (T-AOC), glutathione-peroxidase activity (GSH-Px), and malondialdehyde content (MDA) in ileum and colon were determined. DNA was extracted from cecal contents, and analysis microbiota by Terminal restriction fragment length polymorphism. The results showed that MR significantly decreased the body weight, the concentrations serum lipid, and improved intestinal redox status and gut microbiota. The remaining mice were kept feeding until the 30th week. To verify whether these regarding healthy changes via MR worked through gut microbita. Fecal samples were collected from group C, group HM and group LM. The remaining mice of group HM and group LM were were randomly divided into2 groups respectively, high–fat diet with fecal microbiota in group C mice (HM-C), high–fat diet with fecal microbiota in group LM mice (HM-LM), methionine restriction diet with fecal microbiota in group C mice (LM-C), methionine restriction diet with fecal microbiota in group HM mice (LM-HM). Fecal microbiota transplantation by gavage lasted for the first week at the beginning of the experiment. Body weight was recorded daily. Then the mice were sacrificed on 33th days and blood plasma ,ileum and colon were obtained. Plasma total cholesterol (TC), triglyceride (TG), lowdensity lipoprotein (LDL), highdensity lipoprotein (HDL) were examined. The total antioxidant capacity (T-AOC), glutathione-peroxidase activity (GSH-Px), malondialdehyde content (MDA), and catalase capacity (CAT) in ileum and colon were determined. The morphological structures of ileum and colon were observed using Hematoxylin and Eosin staining method. The results showed that the fecal microbiota of high-diet mice destroyed the gut redox state and morphological structures of ileum and colon in MR mice and the fecal microbiota of MR mice controlled the body weight gain and improved serum lipid and the gut redox state in high-diet mice.

Keywords： methionine restriction high-fat-diet serum lipid gut