Previous researchers have documented that probiotic bacteria can have anti-obesity effects on mice fed a high fat diet (HFD) and improve metabolic syndrome. The beneficial effects of the probiotic bacteria are suggested to be strain dependent. In this study, two candidate lactobacteria strains, Lactobacillus casei IBS041, Lactobacillus acidophilus AD031 and two bifidobacteria strains, Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI, were individually administered to HFD-fed mice for 8 weeks. B. longum BORI significantly suppressed mouse weight gain without affecting food intake. L. acidophilus and B. bifidum BGN4 significantly decreased triglyceride levels in mouse liver while B. longum BORI significantly lowered total cholesterol levels in liver. L acidophilus and B. bifidum BGN4 significantly inhibited serum activities of aspartate transaminase and alanine transaminase. Diet supplementation with L. acidophilus, B. bifidum BGN4 and B. longum BORI efficiently improved hepatocyte hydropic degeneration and hepatic steatosis. Of the four probiotic candidates, the bifidobacteria B. longum BORI and B. bifidum BGN4, developed in our laboratory, and L. acidophilus AD031showed excellent anti-obesity effects and suppressed lipid deposition in liver. (C) 2016 Published by Elsevier Inc.