Effects of cholesterol-lowering probiotics on the metabolism of bile acid in a rat model of non-alcoholic fatty liver disease and the possible mechanism / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the effects of two cholesterol-lowering probiotics, DM9054 (Lac-tobacillus Rhamnosus GG, LGG) in combination with 86066 (Lactobacillus plantarum WCFS1, LP), on the metabolism of bile acid via a rat model of non-alcoholic fatty liver disease (NAFLD) and the possible mecha-nism. Methods Twenty-one SD male rats were randomly divided into three groups including control group, NAFLD model group and probiotics intervention group. Rats in the control group received normal diet. The rat model of NAFLD was established by feeding rats with chronic high fat diet (45% of calories derived from fat di-et) for 20 weeks. Rats in the probiotics intervention group were given high fat diet together with cholesterol-low-ering probiotics through oral gavage. General indexes of each group including body weight and the levels of tri-glyceride, cholesterol and CK18-M30 in serums samples were detected. The expression of cholesterol 7-alpha hydroxy-lase (CYP7A1), fibroblast growth factor receptor 4 (FGFR4), farnesoid X receptor (FXR), fibroblast grwoth factor 15 (FGF15) and apical sodium-dependent bile acid transparter(ASBT) at mRNA level were de-tected by using real-time polymerase chain reaction (real-time PCR). Western blot assay was used to detect the protein expression of CYP7A1, FXR in liver tissues and ASBT in ileum tissues. The expression of FXR in liver and ileum tissues were analyzed by immunohistochemistry. Results Rats with NAFLD showed loss of body weight and decreased levels of the serological markers after treating with the probiotics (P0. 05). Conclusion Probiotics intervention might up-regulate the expression of CYP7A1 by suppressing the FXR path-way in liver tissues and inhibiting the expression of ASBT in ileum tissues. Treating NAFLD rats with cholester-ol-lowering probiotics could activate the FXR-FGF15 pathway in ileum tissues and enhance the metabolism of bile acid, which contributed to the alleviation of NAFLD.