S774 The Effect of Gut Microbiome-Modulating Therapies on Anthropometric Parameters and Blood Pressure in Metabolic Syndrome: A Systematic Review, Meta-Analysis and Meta-Regression

Introduction: Metabolic syndrome (MetS) affects more than 2 in 5 U.S. adults and increases the risk of all-cause mortality. Central obesity, characterized by increased waist circumference (WC) >94 cm in men and >80 cm in women, and hypertension, defined as a systolic (SBP) >130 mmHg and/or diastolic blood pressure (DBP) >85 mmHg, are 2 key features of MetS. We aimed to critically evaluate the effect of gut microbiome-modulating therapies—including probiotics, prebiotics, synbiotics, and fecal microbiota transplantation (FMT)—on anthropometric and blood pressure parameters in individuals with MetS. Methods: We performed a systematic review, random-effects meta-analysis and univariate meta-regression of clinical trials published through April 2023, to assess the impact of these microbiome therapies on biomarkers of weight, WC, body mass index (BMI), SBP and DBP in adult patients diagnosed with MetS using ATP III, IDF or WHO criteria. Meta-analysis results were highlighted as mean differences (MDs) with 95% confidence intervals (CIs), and heterogeneity was quantified using I² statistics. Further univariate linear meta-regressions were conducted with age, BMI, dosage, intervention duration, and region. Risk of bias was assessed using Cochrane RoB 2 tool. Results: This study included 17 clinical trial comparisons including 754 metabolic syndrome participants (386 intervention, 368 control/placebo). Our analysis showed that these adjunct therapies did not exert significant influences on DBP (MD: 0.27 mmHg, 95% CI: -1.82; 2.35, P = 0.80, I2 = 67.4), SBP (MD: 0.17 mmHg, 95% CI: -2.81; 3.15, P = 0.91, I2 = 52.6), or BMI (0.39 kg/m2, 95% CI: -0.17; 0.94, P = 0.17, I2 = 97.4). However, statistically significant changes were observed in WC (MD: -1.62 cm, 95% CI: -2.08; -1.17, P < 0.01, I2 = 0.0) and weight (MD: -1.50 kg, 95% CI: -2.00; -1.00, P < 0.01, I2 = 3.5). Age, baseline BMI, initial biomarker levels, dosage of pro/synbiotics, trial duration, type of nutraceutical, and geographic region were confounders. Conclusion: These findings indicate a potential role for microbiome-modulating therapies in ameliorating anthropometric parameters such as WC and weight in MetS, although their efficacy to influence blood pressure is limited. Further rigorous large-scale clinical trials with standard formulations, is needed to clarify the precise mechanisms at play, identify the most effective formulations and appropriate patient groups, and better understand sources of variability.