Effects of probiotic supplementation on anthropometric and metabolic characteristics in adults with metabolic syndrome: A systematic review and meta-analysis of randomized clinical trials.

AIMS: We conducted a systematic review and meta-analysis to evaluate evidence from randomized controlled trials (RCTs) documenting the effectiveness of supplementation with pro-/synbiotics versus placebo controls on anthropometric and metabolic (glucoregulatory status, lipid profile) indices in adults with metabolic syndrome (MetS). METHODS Databases of MEDLINE, Scopus, Embase, Web of Science, and Cochrane Library were searched through March 2020 to identify eligible RCTs evaluating the effects of pro-/synbiotic consumption in adults (≥18 years) with MetS. Mean differences (MDs) and 95% confidence intervals (CIs) were pooled using random-effects models. RESULTS Ten eligible publications (9 RCTs, n = 344 participants) were included. Supplementation with pro-/synbiotics reduced total cholesterol (TC) in adults with MetS versus placebo (MD: -6.66 mg/dL, 95% CI: -13.25 to -0.07, P = 0.04, I2 = 28.8%, n = 7), without affecting weight, body mass index, waist circumference, fasting blood sugar, homeostasis model assessment for insulin resistance, insulin, triglyceride, low-density lipoprotein cholesterol, or high-density lipoprotein cholesterol (P > 0.05). CONCLUSIONS Pro-/synbiotic consumption may be beneficial in reducing TC levels in adults with MetS. However, our observations do not support the effectiveness of pro-/synbiotics consumption on other anthropometric or metabolic outcomes of MetS. Further investigations with larger sample sizes are required to confirm these findings.