Effect of embryo-remaining oat rice on the lipid profile and intestinal microbiota in high-fat diet fed rats

Embryo-remaining oat rice (EROR), as a newly developed oat product, is popular in China for its good taste, but little is known about its healthy functions. In this study, the effects of EROR on lipid metabolism regulation were investigated in in vitro and in vivo models. The results showed that the oat ethanol extracts significantly alleviated lipid accumulation, total cholesterol and triglyceride levels in HepG2 cells. EROR supplementation dramatically improved the lipid profile in the serum and liver and downregulated the expression levels of HMGCR, SREBP-1C and FAS, which are related to lipid metabolic disorder in high-fat diet (HFD) fed rats. A HFD decreases the production of short-chain fatty acids (SCFAs) in the cecum, which are related to intestinal microbiota dysbiosis. The intake of EROR significantly increased the total SCFAs, acetate and propionate and promoted the abundance of SCFA-producing bacteria. Furthermore, the intake of EROR led to abundant increases in Bifidobacterium and Akkermansia and decreases of Rombutsia , Fusicatenibacter , Holdemanella and Turicibacter , which were negatively and positively correlated with the lipid metabolism-related indices. These results provide evidence that EROR is a good functional food candidate to ameliorate lipid metabolic disorder and hyperlipidemia.