Obesity is a chronic, relapsing, progressive disease which is associated with a wide range of fatal diseases in the world. This review article evaluated the efficacy of Lactobacillus gasseri in the management of obesity. The information was extracted from electronic resources (PubMed, Science Direct, Wiley, and Google). The results of the research showed that the efficacy of L. gasseri on weight loss is strain-sensitive. There are two well-known strains, BNR17 and SBT2055, which come from different sources and are used in many animal and clinical studies. More evidence on the efficacy of L. gasseri SBT2055 than on BNR17 is present in the literature. The daily dose of L. gasseri SBT2055 in clinical trials is higher than BNR17 at the dose of 1011. It seems that the use of a high dose of L. gasseri BNR17 in clinical trials is associated with more pleasant results on weight loss.