Probiotics as a Complementary Therapy for Management of Obesity: A Systematic Review

Background Considering the observed role of probiotics in modulating gut microbiome, probiotics are discussed to be one potential complementary therapy for obesity management in recent years. The aim of the present study was to systematically review the meta-analyses of controlled trials and investigate the effects of probiotics on obesity. Methods A comprehensive search was conducted on PubMed, Web of Science, and Cochrane Library web databases up to May 2020. Inclusion criteria were meta-analyses of controlled trials which evaluated the impact of probiotics on obesity in English language. Meta-analyses done on pregnant women, children, animal studies, or the effect of prebiotics on anthropometric indices were excluded. Results Within 325 recorded studies, 20 studies met the inclusion criteria consisting of 16676 overweight/obese adults with different underlying disorders such as nonalcoholic fatty liver disease (NAFLD), or polycystic ovary syndrome (PCOS). The length of intervention varied from 2 to 26 weeks. Results of meta-analyses have shown a moderate effect of probiotics on body weight in overweight/obese adults: from -0.526 kg/m2 (95% CI: -0.810, -0.247) to -0.25 kg/m2 (95% CI: -0.33, -0.17). Body mass index (BMI) was changed from -1.46 kg/m2 (95% CI: -2.44, -0.48) to -1.08 kg/m2 (95% CI: -2.05, -0.11) in NAFLD. Probiotics could reduce BMI from -0.36 kg/m2 (95% CI: -0.74, 0.02) to -0.29 kg/m2 (95% CI: -0.54, -0.03) in patients with PCOS. Conclusion It seems that the probiotic products could have beneficial effects as an adjunct therapy for care and management of obesity when used in high dose. However, due to heterogeneity of included studies, it is required to confirm our results by more meta-analyses of clinical trials.