The effect of Lactobacillus plantarum NCU116 on liver function, oxidative stress and lipid metabolism in rats with high fat diet induced non-alcoholic fatty liver disease (NAFLD) was studied. The rats were divided into four groups: the normal diet (ND) group; the high fat diet (HFD) group; and HFD plus L. plantarum NCU116 as two doses (NCU116-L, 10(8) CFU mL(-1); NCU116-H, 10(9) CFU mL(-1)) groups. Treatment of L. plantarum NCU116 for 5 weeks was found to restore liver function and oxidative stress in rats with NAFLD, and decrease the levels of fat accumulation in the liver. In addition, the bacterium significantly reduced endotoxin and proinflammatory cytokines, and regulated bacterial flora in the colon and the expression of lipid metabolism in the liver. These results suggest that possible underlying mechanisms for the beneficial effect of L. plantarum NCU116 on NAFLD may include two pathways of downregulating lipogenesis and upregulating lipolysis and fatty acid oxidation related gene expression.