AIM:To investigate the effects of Balanophora involucrata Hook.f.(BIH)extracts on bile acid metabolism and liver injury in mice with metabolic dysfunction-associated fatty liver disease(MAFLD)through the gut mi-crobiota-farnesoid X receptor(FXR)axis,and to explore the underlying mechanisms.METHODS:Forty C57BL mice were randomly divided into control group,MAFLD model group,medium-dose BIH group,and high-dose BIH group.The mice in control group received a regular diet,while those in other groups were fed with high-fat diet for 12 weeks to induce MAFLD.The mice in medium-and high-dose BIH groups received 0.598 and 0.299 g/kg BIH solution,respectively,while those in control and MAFLD groups received an equivalent volume of normal saline.Serum levels of total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C)and high-density lipoprotein cholesterol(HDL-C)were measured using an automatic biochemical analyzer.Liver morphology,steatosis and fibrosis were assessed by HE,oil red O and Masson staining.Levels of TC,tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)in liver tissues,and bile acids in serum and ileum tissues were measured by ELISA.Protein expression of FXR and fibroblast growth factor 15(FGF15)in ileum tissues,and FXR,small heterodimer partner(SHP)and cholesterol 7α-hydroxylase(CYP7A1)in liver tissues were analyzed by Western blot.Intestinal microbiota changes were assessed by 16S rRNA gene sequencing.RESULTS:(1)The MAFLD mice exhibited increased serum TC,TG,LDL-C and bile acid levels,liver TC,TNF-α and IL-6 levels,and lipid deposition.However,BIH intervention improved these factors and increased FXR and SHP pro-teins,but decreased CYP7A1 expression in the liver.The protein levels FXR and FGF15 in the ileum were also elevated.(2)Intestinal flora analysis demonstrated that BIH intervention improved the abundance and diversity of intestinal flora in MAFLD mice.Specifically,there was an increase in Bacteroidetes/Firmicutes ratio and a decrease in Proteobacteria and Verrucomicrobia.At the genus level,abundance of Duncaniella,Muribaculum and Paramuribaculum increased,while He-licobacter decreased.CONCLUSION:Treatment with BIH regulates intestinal flora,decreases FXR levels,enhances CYP7A1 expression,promotes bile acid synthesis,reduces hepatic cholesterol accumulation,and attenuates liver steato-sis and inflammation in MAFLD mice,indicating potential therapeutic effects.