Probiotics May Be a Useful Adjunctive Treatment for Reducing Blood Pressure

Through a metaanalysis, researchers in Australia have confirmed a slight antihypertensive effect with use of probiotics that was consistent through 9 studies.

According to researchers in Australia, use of probiotics may promote improved control of blood pressure. Sun et al at the Griffith University in Australia searched several databases, including PubMed, Scopus, the Cochrane Library, and the Physiotherapy Evidence Database, to identify relevant articles for inclusion in a metaanalysis of trials evaluating probiotics for blood pressure reduction.¹

A total of 9 trials qualified for inclusion in the analysis, and data from trials were combined for metaanalysis using a random effects model. Investigators found that systolic blood pressure was significantly lowered by consumption of probiotics by an average of 3.56 mm Hg, and diastolic blood pressure was lower by 2.38 mm Hg versus control patients.¹

In a subgroup analysis of study data, investigators found that probiotics may be more effective in patients with higher initial blood pressure levels (≥130/85 mm Hg). Evidence suggests that treatment with probiotic cultures containing at least 10¹¹ colony-forming units of beneficial bacteria for a minimum of 8 weeks was necessary to elicit a treatment effect. Treatment with smaller doses of probiotics for durations shorter than 8 weeks, according to investigators, was not associated with any significant effect on blood pressure.¹

Although trials under analysis did not always track the influence of other dietary factors, and used different doses of probiotics, study authors believe the results suggest beneficial cardiovascular effects attributable to probiotics. In a press release, authors suggested that probiotic supplements may be, “part of a healthy lifestyle to help reduce high blood pressure…[and to] maintain healthy blood pressure levels.”^1,2

Previous studies suggest that milk peptides have an antihypertensive effect, including antihypertensive effects through inhibition of angiotensin-converting enzyme.³ For instance, a study in rats showed that a probiotic supplement helped to reduce endothelial dysfunction by potentiating effects on the angiotensin system. Increased expression of endothelial nitric oxide synthase and a reduction in proinflammatory cytokines, and reductions on oxidative stress markers, were observed after 7 weeks of treatment with 50 billion bacteria per kg of body weight for 7 weeks.⁴

A metaanalysis published in 2013 in the British Journal of Nutrition is consistent with the findings of the Griffith University researchers. The 2013 metaanalysis, which included 14 qualifying randomized controlled trials, estimated average reductions of 3.10 mm Hg in systolic blood pressure and 1.09 mm Hg in diastolic blood pressure with use of probiotic fermented milk products.⁵

The finding that probiotics contain blood pressure—modulating substances suggests that probiotics could be a source of compounds for drug discovery. In addition, for some patients, probiotics may be a useful adjunct to other treatments for blood pressure reduction.

References

• Khalesi S, Sun J, Buys N, Jayasinghe R. Effect of probiotics on blood pressure: a systematic review and meta-analysis of randomized, controlled trials [published online July 21, 2014]. Hypertension. 2014.
• Preidt R. Could probiotics help tame high blood pressure? www.nlm.nih.gov/medlineplus/news/fullstory_147424.html. Accessed July 2014.
• Jauhiainen T, Korpela R. Milk peptides and blood pressure. J Nutr. 2007;137(3 suppl 2):825S-829S.
• Rashid SK, Khodja NI, Auger C, et al. Probiotics (VSL#3) prevent endothelial dysfunction in rats with portal hypertension: role of the angiotensin system. PLoS One. 2014;9(5):e97458.
• Dong JY, Szeto IM, Makinen K, et al. Effect of probiotic fermented milk on blood pressure: a meta-analysis of randomised controlled trials. Br J Nutr. 2013;110(7):1188-1194.