Arabinoxylan combined with different glucans improve lipid metabolism disorder by regulating bile acid and gut microbiota in mice fed with high-fat diet

The effect of arabinoxylan (AX) combined with β-glucan and xyloglucan on lipid metabolism by regulating bile acids and gut microbiota was investigated in mice fed with high-fat diet. Fifty male ICR/KM mice were randomly divided into five groups: control diet (CON) group, high-fat diet (HFD) group, high-fat diet with AX (HFAX) group, high-fat diet with AX and β-glucan (HFAB) group, and high-fat diet with AX and xyloglucan (HFAG) group. After 8 weeks of feeding, the mice were sacrificed and samples were collected. In contrast to CON, HFD disturbed lipid metabolism, bile acids, and gut microbiota in mice. Mice in HFD group had increase in weight, blood lipids and liver fat, and circulating bile acid as well as abnormal liver tissue morphology and disordered gut microbiota. Compared with HFD, HFAB and HFAG mice had reduced body weight and cholesterol and triglyceride levels; Fxr was activated, Cyp7a1 was inhibited to reduce bile acids, the microbial species diversity increased, the number of beneficial bacteria increased, and the number of conditional pathogenic bacteria decreased. HFAG uniquely activated intestinal bile acid receptors (Fxr and Tgr5) and increased the abundance of Bacteroidetes and Akkermansia. In summary, the effect of AX compounded glucans (β-glucan or xyloglucan) on lipid metabolism was better than that of single AX by regulating bile acid metabolism and gut microbiota possibly due to the more complex chemical structure of combined polysaccharides.