What effect does probiotic consumption have on blood pressure?
This was the question that a systematic review in Hypertension set out to answer. Several databases were analysed, and publications were included if they met established criteria previously determined by the reviewers, such as (1) human randomized, control trials; (2) adults ≥ 18 year-old with or without hypertension, (3) use of probiotics with live bacteria, and (4) had accessible full articles in English. Finally, 9 trials with 543 participants were included; the majority of trials (7) used fermented dairy products.
Using this meta-analysis, the authors found that consumption of probiotics significantly changed systolic blood pressure by −3.56 mm Hg and diastolic blood pressure by −2.38 mm Hg compared to control groups. Although the species of live bacteria varied from trial to trial, a greater reduction in blood pressure was found with multiple species than with a single species of probiotics, for both systolic and diastolic blood pressure. Interventions that lasted less than 8 weeks or that gave subjects fewer than 1011 colony-forming units did not result in a significant reduction of blood pressure.
Thus, the authors concluded that probiotics may result in a modest improvement in blood pressure, and may have a greater effect when baseline blood pressure is elevated.
Khalesi S et al. (2014) Effect of Probiotics on Blood Pressure: A Systematic Review and Meta-Analysis of Randomized, Controlled Trials Hypertension 64(4) pp. 897-903. doi:10.1161/HYPERTENSIONAHA.114.03469