Can Probiotics Help Lower High Blood Pressure?

Increasing evidence shows that changes in the gut microbiome may be associated with hypertension. But does it mean balancing gut bacteria composition can help manage high blood pressure?

The gut microbiome is home to about 39 trillion microbial cells, including bacteria and fungi, which protect against harmful microorganisms and help digest dietary fiber.

When the balance of the gut microbiome is disrupted, beneficial bacteria are lost due to antibiotic use or chronic alcohol consumption; gut dysbiosis may occur.

Such imbalance can play a role in developing digestive disorders, but its impact is not limited to the gastrointestinal tract. Gut dysbiosis has been associated with type 2 diabetes, cancer, cardiovascular disease, and even neurological disorders like Alzheimer's disease.

Gut microbiome disruption may also contribute to the development of hypertension, or high blood pressure, affecting nearly half (48%) of Americans.

Only about one-fifth of people with hypertension have their blood pressure effectively controlled. The condition doesn't always respond to treatment, even when it combines multiple medications and lifestyle changes.

So, could balancing the gut microbiome with probiotics be a way to manage chronically high blood pressure?

How are gut bacteria associated with hypertension?

According to a 2020 meta-analysis, four potential mechanisms may explain the relationship between gut microbiome and high blood pressure.

• The first mechanism may be the brain-gut-kidney axis, which refers to the physical and chemical connections between these three organs. Animal studies have shown that physiological changes in the gut, such as a decrease in protective goblet cells, occur before the onset of hypertension.

When dysbiotic fecal microbiota were transferred from people with hypertension to mice, they experienced increased blood pressure. Similarly, when feces from hypertensive stroke-prone rats were transplanted to those with normal blood pressure, the recipient animals had their blood pressure increased.

• Another explanation may be inflammation, the immune system's response to injury or infection. The gut microbiome is one of the key regulators of the immune and inflammatory response, both of which play important roles in the development of hypertension.

When gut dysbiosis occurs, including the increases of bacteria like Bilophila wadsworthia and Clostridium cocleatum, it results in an increased production of inflammation-causing compounds called lipopolysaccharides and permeability of the intestine. Both of these factors were shown to contribute to increased blood pressure.

• Production of short-chain fatty acids (SCFAs), by-products of bacterial fermentation of fiber in the gut, is a potential link between gut dysbiosis and hypertension. A 2019 study found that individuals with hypertension have higher stool levels of SCFAs acetate, butyrate, and propionate which proposed that these could be related

• The hazardous metabolite trimethylamine N-oxide (TMAO), whose increased levels of which are associated with dysbiosis, may also be involved in hypertension. Treating rats with the beneficial bacteria Lactobacillus rhamnosus GG strain was shown to prevent the worsening of hypertension by reducing blood TMAO levels, according to a 2019 study.

Probiotics for hypertension management

Understanding the impact of the gut microbiome on blood pressure may open the door to new approaches to managing it. Scientists have been investigating whether probiotics — live beneficial bacteria and yeasts — may help with hypertension.

A 2024 meta-analysis of nine trials found that probiotic consumption reduced systolic blood pressure (SBP) by 3.56 mm Hg and diastolic blood pressure (DBP) by 2.38 mm Hg. Individuals who consumed multiple probiotic species saw greater blood pressure reductions than those who took single species.

A meta-analysis analyzing data from 653 individuals indicates that supplementation with Lactobacillus plantarum may help reduce both SBP and DBP by 1.58 mmHg and 0.92 mmHg, respectively.

Hypertension is common in type 2 diabetes, affecting 70% to 80% of people with the condition. A meta-analysis looking into the potential benefits of probiotics in individuals with both type 2 diabetes and high blood pressure found that supplementation with good bacteria may reduce SBP by 5.04 mm Hg and DBP by 0.39 mm Hg.

A 2020 meta-analysis that included data from 846 participants with hypertension found that supplementation with probiotics reduced SBP by 2.05 mmHg and DBP by 1.26 mmHg. The effect of probiotics was more pronounced in participants with diabetes. The benefits depended on the duration of supplementation, dosage, and a participant's age rather than the use of single or multiple probiotic strains.

Choose fiber instead, an expert says

Francine Marques, Ph.D., professor at the Monash University School of Biological Sciences, says the evidence that reduced blood pressure is not very robust. While there are studies showing that certain probiotics may lower blood pressure, they are small in size.

Speaking of meta-analyses, large studies reviewing existing evidence, Marques says the key issue is that each individual study used different types of probiotics containing different combinations of bacteria and at different concentrations.

An alternative would be the intake of dietary fiber that has prebiotic effects such as it feeds gut bacteria. Fiber intake and its capacity to lower blood pressure are well-established.

Marques

Women with hypertension should consume at least 28 g of fiber a day. For men, the minimum daily intake is at least 38 g. Each extra 5 g of fiber a day is estimated to reduce systolic blood pressure by 2.8 mm Hg and diastolic blood pressure by 2.1 mm Hg.

Some fiber-rich foods are fresh fruits and vegetables, whole grains, nuts, seeds, and legumes.

It may be too early to recommend probiotics for hypertension management. Moreover, probiotics definitely shouldn't replace prescribed medications and lifestyle interventions. Make sure to consult a doctor if you are experiencing hypertension for a possible treatment plan.