Previous human clinical trials have shown that probiotic consumption may improve blood pressure (BP) control. The aim of the present systematic review was to clarify the effects of probiotics on BP using a meta-analysis of randomized, controlled trials.

PubMed, Scopus, Cochrane Library (Central), Physiotherapy Evidence Database, and databases were searched until January 2014 to identify eligible articles. Meta-analysis using a random-effects model was chosen to analyze the impact of combined trials. Nine trials were included.

Probiotic consumption significantly changed systolic BP by -3.56 mm Hg (95% confidence interval, -6.46 to -0.66) and diastolic BP by -2.38 mm Hg (95% confidence interval, -2.38 to -0.93) compared with control groups.

A greater reduction was found with multiple as compared with single species of probiotics, for both systolic and diastolic BP. Subgroup analysis of trials with baseline BP ≥130/85 mm Hg compared with <130/85 mm Hg found a more significant improvement in diastolic BP.

Duration of intervention <8 weeks did not result in a significant reduction in systolic or diastolic BP. Furthermore, subgroup analysis of trials with daily dose of probiotics <1011 colony-forming units did not result in a significant meta-analysis effect.

The present meta-analysis suggests that consuming probiotics may improve BP by a modest degree, with a potentially greater effect when baseline BP is elevated, multiple species of probiotics are consumed, the duration of intervention is ≥8 weeks, or daily consumption dose is ≥1011 colony-forming units.