Eating probiotics regularly may modestly improve your blood pressure, according to new research in the American Heart Association journal Hypertension.

Probiotics are live microorganisms (naturally occurring bacteria in the gut) thought to have beneficial effects; common sources are yogurt or dietary supplements.

“The small collection of studies we looked at suggest regular consumption of probiotics can be part of a healthy lifestyle to help reduce high blood pressure, as well as maintain healthy blood pressure levels,” said Jing Sun, Ph.D., lead author and senior lecturer at the Griffith Health Institute and School of Medicine, Griffith University, Gold Coast, Queensland, Australia. “This includes probiotics in yogurt, fermented and sour milk and cheese, and probiotic supplements.”

Analyzing results of nine high-quality studies examining blood pressure and probiotic consumption in 543 adults with normal and elevated blood pressure, researchers found:

--Probiotic consumption lowered systolic blood pressure (the top number) by an average 3.56 millimeters of mercury (mm Hg) and diastolic blood pressure (the lower number) by an average 2.38 mm Hg, compared to adults who didn’t consume probiotics

--The positive effects from probiotics on diastolic blood pressure were greatest in people whose blood pressure was equal to or greater than 130/85, which is considered elevated

--Consuming probiotics for less than eight weeks didn’t lower systolic or diastolic blood pressure

--Probiotic consumption with a daily bacteria volume of 10⁹-10 ¹² colony-forming units (CFU) may improve blood pressure. Consumption with less than 10⁹ CFU didn’t lower blood pressure. CFU is the amount of bacteria or the dose of probiotics in a product.

--Probiotics with multiple bacteria lowered blood pressure more than those with a single bacteria.

“We believe probiotics might help lower blood pressure by having other positive effects on health, including improving total cholesterol and low-density lipoprotein, or LDL, cholesterol; reducing blood glucose and insulin resistance; and by helping to regulate the hormone system that regulates blood pressure and fluid balance,” Sun said.

“The studies looking at probiotics and blood pressure tend to be small,” Sun said. “Moreover, two studies had a short duration of three to four weeks of probiotic consumption, which might have affected the overall results of the analysis.

Additional studies are needed before doctors can confidently recommend probiotics for high blood pressure control and prevention, she said.