Oral betaine ameliorates high-fat diet-induced hepatic steatosis in mice by inducing miR-96-5p targeting IGF1R

Metabolic dysfunction–associated steatotic liver disease (MASLD) is a growing health concern with limited treatment options. Here we show that oral betaine attenuates high-fat diet (HFD)–induced steatosis in mice and oleic acid–induced lipid accumulation in HepG2 cells. Betaine reduced body-weight gain, hepatic triglyceride content and Oil Red O staining, while restoring expression of miR-96-5p and lowering insulin-like growth factor 1 receptor (IGF1R). Gain-of-function of miR-96-5p decreased triglycerides and lipid droplets, and reporter assays confirmed direct targeting of IGF1R. Immunoblotting and immunofluorescence further showed reduced IGF1R expression in HFD-fed livers treated with betaine. These findings identify a betaine–miR-96-5p–IGF1R axis that mitigates hepatic steatosis and highlight betaine as a potential therapeutic strategy for MASLD. • Betaine lowers body weight and HFD-induced hepatic steatosis in mice. • In HepG2 cells, betaine prevents OA-induced lipid droplets and restores lipid genes. • Betaine restores miR-96-5p suppressed by HFD and OA and lowers triglycerides. • miR-96-5p targets IGF1R and this was validated by luciferase and blots.