Regular consumption of probiotics could help to reduce blood pressure and cut the risk of dying from a heart attack or stroke by one-fifth, according to a new study published in Hypertension. Whilst there is plenty of evidence to show that probiotics are good for the gut, this is the first indication that they may help the heart as well.

Probiotics are live microorganisms that occur naturally in the gut. These microorganisms are also present in some foods, such as live-cultured yoghurt, some fermented vegetables and aged cheeses. Past research has suggested that probiotics are good for our health by aiding digestion, intestinal function and protecting against harmful bacteria.

Research led by Jing Sun, PhD, of the Griffith Health Institute and School of Medicine at Griffith University in Australia, analysed nine research studies which involved more than 500 people. Those with elevated blood pressure saw a reduction when they consumed probiotics for more than eight weeks. The effect was similar to that seen in people who reduce their salt consumption from an average of six grams per day to four grams and may be enough to cut the risk of dying from a heart attack or stroke by one-fifth, the authors said.

The study found that probiotic products that contained a higher volume of bacteria and contained more than one type of bacteria were most effective.

“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.

Summary of results

• 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.