Comparative Efficacy of Probiotics for the Treatment of Obesity: A Systematic Review and Network Meta-analysis

CONTEXT: Probiotics have been proposed as a potential intervention for obesity, yet the optimal probiotic formulation remains unclear. OBJECTIVE: To evaluate the comparative efficacy of probiotics on body shape and serum lipid profiles in patients with obesity. DATA SOURCES: PubMed, Web of Science, Cochrane Library, and Embase from database inception to May 1, 2024, were searched. DATA EXTRACTION: From each randomized controlled trial, we extracted information on publication year, first author, country, inclusion criteria, sample size, probiotic formulation and genera, treatment duration, dosage, physical activity, dietary interventions, and changes in body composition and lipid metabolism outcomes from baseline to the end of follow-up. DATA ANALYSIS: Data were pooled using a random-effects model. The certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation framework for network meta-analysis. All data were pooled to obtain the change in body weight and lipid metabolism using mean differences (MDs) with 95% CIs. A total of 47 studies with 3555 participants were included in the analysis. Twenty-six probiotic interventions, including 8 single-genus and 18 multiple-genus probiotic interventions, were identified. All estimates refer to the comparison with placebo. Within the network meta-analysis framework, Mix10 (a combination of Bifidobacterium, Lacticaseibacillus, Lactobacillus, and Streptococcus) (MD: -2.83 kg; 95% CI: -4.33 to -1.32) and Mix12 (a combination of Bifidobacterium, Lactiplantibacillus, and Lactobacillus) (MD: -2.14 kg; 95% CI: -3.13 to -1.15) ranked highest for weight reduction compared with placebo. Mix10 was also ranked higher for increasing high-density-lipoprotein cholesterol (MD: 0.20 mmol/L; 95% CI: 0.12 to 0.29). CONCLUSION: Mix10 and Mix12 ranked highest for weight reduction, with Mix10 also ranking higher for lipid metabolism. These findings are based on low to moderate certainty and should be confirmed in future well-designed trials. SYSTEMATIC REVIEW REGISTRATION: This study was registered on INPLASY (Registration no. INPLASY202440090, https://inplasy.com/inplasy-2024-4-0090/).