Regulatory Function of Buckwheat-Resistant Starch Supplementation on Lipid Profile and Gut Microbiota in Mice Fed with a High-Fat Diet.

Buckwheat-resistant starch (BRS) has shown to be a nutrient capable of lowering cholesterol and reducing obesity. In this study, the regulatory effects of tartary buckwheat starch on blood lipid level and gut microbiota (Lactobacillus, Bifidobacterium, Enterococcus, and Escherichia coli) in mice fed with a high-fat diet was investigated. Male C57BL/6 mice were separately fed with a normal diet (CON), a high-fat diet (HFD), and high-fat diet supplemented with buckwheat-resistant starch (HFD+BRS) for 6 weeks. After the feedings, lipid profile, blood glucose, plasma levels of cytokines, short-chain fatty acid content in the colon and intestinal flora of fecal were measured. Furthermore, the antioxidant indices of the liver and duodenum tissues were measured to evaluate the antioxidant capacity of mice. Significantly reduced plasma levels of total cholesterol (TC), triglyceride (TG), glucose, and cytokines were observed in the HFD+BRS group, accompanied by an increased antioxidant capacity in the liver and duodenum. In addition, supplementation with BRS significantly inhibited the increase in plasma lipopolysaccharide, tumor necrosis factor-α, and interleukin-6 levels. Gut microbiota composition was regulated by the supplement of BRS, which promoted the growth of Lactobacillus, Bifidobacterium, and Enterococcus, as well as inhibited the growth of Escherichia coli. In contrast to the HFD group, the content of short-chain fatty acids in mice colon increased in the BRS group. In conclusion, BRS benefited the cholesterol and glucose metabolism, as well as optimized gut microbiota composition in mice fed with a high-fat diet. PRACTICAL APPLICATION: This study identified the beneficial effects of tartary buckwheat-resistant starch on the regulation of blood lipids and intestinal flora in mice fed a high-fat diet. The result of this study will provide a basis for the development of probiotic products supplemented with tartary buckwheat-resistant starch and direction for further research.