Kattimani, Vivekanand Sabanna

Background: Hypertension is a major contributor to global cardiovascular morbidity and mortality. Despite a wide range of pharmacologic treatments, many patients continue to have uncontrolled blood pressure. Recent research highlights the gut microbiota as a modifiable factor in blood pressure regulation through mechanisms involving systemic inflammation, microbial metabolites such as short-chain fatty acids, and angiotensin-converting enzyme modulation. Probiotic and prebiotic supplementation has gained interest as an adjunct strategy, yet existing reviews are limited in scope and often lack robust subgroup analysis. Objective: To systematically evaluate the effect of probiotic and prebiotic supplementation on blood pressure in adults with hypertension or elevated blood pressure, with an emphasis on gut microbiota modulation. Methods: We conducted a systematic search of PubMed, Scopus, Cochrane CENTRAL, and ScienceDirect for articles published from May 1, 2015, to April 30, 2025. ClinicalTrials.gov and PROSPERO were also searched. Eligible studies were randomized controlled trials in English involving adults 19-44 years with hypertension or pre-hypertension, comparing probiotic or prebiotic interventions with placebo, no treatment, or standard care. The primary outcome were changes in systolic and diastolic blood pressure; secondary outcomes included gut microbiota composition, inflammatory markers, endothelial function, and adverse effects. Two independent reviewers screened studies and assessed quality using the Cochrane Risk of Bias Tool 2.0. Results: Of 601 records screened, 23 trials met inclusion criteria. Most studies showed modest reductions in systolic and diastolic blood pressure with probiotic or prebiotic use. Mechanistic insights included improved gut barrier integrity, reduced inflammation, and increased beneficial metabolites. Subgroup analyses suggested efficacy varied by strain type, dosage, duration, and delivery method. Secondary outcomes showed improvements in lipid profiles, insulin resistance, and abundance of Bifidobacterium. Conclusion: Modulation of gut microbiota shows potential as an adjunct approach in managing hypertension.. While short-term benefits are observed, variability across studies limits generalizability. Larger trials with standardized methods are needed to confirm long-term clinical relevance. Keywords: Hypertension, Blood Pressure, Gut Microbiota, Probiotics, Prebiotics, Randomized Controlled Trials, Systematic Review