AimsThis study investigated the antiobesity effect of lactic acid bacteria (Lactobacillus plantarum LG42) isolated from gajami sik-hae. Methods and ResultsMale C57BL/6J mice were divided into four groups (n=10); NDC (normal diet & DW), HDC (high-fat diet & DW), LGLAB (high-fat diet & Lactobacillus plantarum LG42, 1x10(7)CFU per mouse), HGLAB (high-fat diet & L.plantarum LG42, 1x10(9)CFU per mouse). After 12weeks, GLAB supplemented groups showed lower body weight, with a significant reduction in epididymal and back fat. Serum and hepatic triglyceride, serum insulin and leptin levels were significantly lowered in GLAB supplemented groups. The hepatic mRNA expression of PPAR and CPT-I were significantly increased in GLAB groups, whereas the level of ACC, SREBP-1 and LXR were significantly decreased in GLAB groups compared with HDC group. Additionally, GLAB reduces the expression of PPAR in the epididymal adipose tissue resulting in inhibition of genes regulated by PPAR. ConclusionThese results suggest that the Lactobacillus plantarum LG42 has antiobesity effects in high-fat-diet-induced obese mice. Significance and Impact of the StudyThese results may contribute to nutraceutical and food industries in developing functional food and probiotics based therapies for the treatment and prevention of obesity.