Effects of probiotics supplementation on blood pressure: An umbrella meta-analysis of randomized controlled trials

Aims Several meta-analyses have revealed that probiotics could lower blood pressure, but the findings were inconsistent. In this regard, an umbrella meta-analysis was carried out to provide a more accurate estimate of the overall impacts of probiotics supplementation on blood pressure. Data synthesis We searched the following international databases till November 2021: PubMed, Scopus, EMBASE, Web of Science, and Google Scholar. A random-effects model was applied to evaluate the effects of probiotics on blood pressure. Sensitivity analysis was performed by using the leave-one-out method. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to evaluate the certainty of evidence. Pooled effect size of 14 meta-analyses with 15,494 participants indicated significant decreases in both systolic (Weighted mean difference (WMD)= -1.96 mmHg; 95% confidence interval (CI): -2.78, -1.14, p< 0.001, and standardized mean difference (SMD)= -2.62; 95% CI: -4.96, -0.28, p< 0.001) and diastolic blood pressure (WMD= -1.28 mmHg; 95% CI: -1.76, -0.79, p <0.001, and SMD= -0.60 mmHg; 95% CI: -1.08, -0.12, p = 0.014) following probiotics supplementation. Greater effects on SBP were revealed in trials with a mean age of >50years, and duration of intervention ≤10 weeks. DBP was also more reduced in studies with a dosage of ≥1010 colony-forming unit (CFU) and SBP was decreased in patients with hypertension or diabetes analyzing WMD. Conclusion The present umbrella of meta-analyses suggests probiotics supplementation can improve blood pressure and claims that probiotics could be used as a complementary therapy for controlling high blood pressure. PROSPERO ID CRD42022306560.