Postbiotics as a novel intervention for obesity management and improving metabolic parameters: a systematic review and meta-analysis of animal studies

Recently, it has been reported that consuming specific postbiotics may be effective in managing obesity. Therefore, the present study aimed to systematically assess the effect of postbiotics consumption on weight management, dietary intake, and metabolic indices in animal models of obesity. The search was conducted using the PubMed, Scopus, Web of Science, and Google Scholar databases for relevant articles published in English up to May 2025. The risk of bias for included studies was evaluated by the OHAT tool. The STATA 17 software, using the random-effect model, was employed to combine the results. The heterogeneity of included studies was evaluated using Cochrane's Q and I-square tests. The subgroup and sensitivity analyses were also performed. Forty animal studies were included in this meta-analysis. Accordingly, supplementation with different forms of postbiotics was accompanied by a significant decrease in the body weight, body fat, and serum levels of LDL-C, TG, TC, FBG, insulin, and HOMA-IR (P = 0.001, 0.040, < 0.001, < 0.001, < 0.001, < 0.001, < 0.001, 0.014 respectively) and significant increase of serum HDL-C level (P = 0.011). However, no significant change was observed in food intake (P = 0.497). Upon the subgroup analyses, SCFAs as a postbiotic supplement, the treatment dose of ≥ 100 mg/kg, and intervention duration ≥ 8 weeks were more effective in improving body weight and fat mass and FBG, HOMA-IR, and HDL-C levels; reducing FBG and HOMA-IR levels; and lowering serum FBG levels, respectively. Overall, the intake of postbiotics demonstrated potential anti-obesity effects and metabolic improvements through gut microbiota modulations, decreasing obesity-related inflammation, reducing adipogenesis, and improving lipid metabolism. However, future well-designed clinical trials are required to determine their safety, efficacy, and health benefits on humans and confirm this preliminary evidence.