Do probiotics help with blood pressure? What the research does and doesn't show

The evidence doesn't support a probiotic as a treatment for high blood pressure. Pooled trials found averages about 2 mm Hg lower systolic and 1 mm Hg lower diastolic; one analysis found no significant effect under 8 weeks or under 100 billion CFU a day. The changes are small and the trials varied widely.

What the evidence doesn't support

It doesn't support a probiotic as a treatment for high blood pressure or as a replacement for anything a doctor has prescribed or advised. The average changes are small, and the trials pooled together used many different products and amounts, so they say little about any one probiotic. A review of 249 trials across probiotic uses found that effects are strain-specific and purpose-specific and that many products have no trial of their own; a product that lists species without strain codes can't borrow these results.

What the trials found

A 2014 meta-analysis of 9 randomized trials found systolic pressure 3.56 mm Hg lower (95% CI -6.46 to -0.66) and diastolic 2.38 mm Hg lower with probiotics than with control. The effect was not significant in trials shorter than 8 weeks, and not significant when the daily dose was below 10^11 CFU (100 billion). The authors saw larger changes with multiple species and when baseline pressure was 130/85 mm Hg or higher.

A 2023 meta-analysis of 26 trials in 1,624 people, all of 8 weeks or longer, found office systolic pressure 2.18 mm Hg lower (95% CI -3.41 to -0.94) and diastolic 1.07 mm Hg lower (95% CI -1.72 to -0.41). Three trials with ambulatory (24-hour) monitoring showed a similar fall, at borderline significance. Reductions were larger in people with diabetes or high blood pressure. Longer treatment did not add to the effect.

An umbrella meta-analysis of 14 earlier meta-analyses (15,494 participants) found systolic 1.96 mm Hg lower and diastolic 1.28 mm Hg lower. The diastolic effect was larger at doses of 10^10 CFU (10 billion) or more; the systolic effect was larger in people over 50 and in trials of 10 weeks or less.

Analysis	Size	Systolic	Diastolic
2014 meta-analysis	9 trials	-3.56 mm Hg	-2.38 mm Hg
2023 meta-analysis (8+ weeks)	26 trials, 1,624 people	-2.18 mm Hg	-1.07 mm Hg
Umbrella analysis	14 meta-analyses, 15,494 people	-1.96 mm Hg	-1.28 mm Hg

The analyses disagree on which doses and durations matter: one found nothing under 100 billion CFU or under 8 weeks, another found a stronger systolic effect in trials of 10 weeks or less. These are averages across trials that used many different products, not a prediction for any one person.

Probiotic effects are strain-specific, so a result for one named strain is not a result for "probiotics" in general, and a product that lists species without strain codes can't borrow it. See what the research shows across probiotics and how to choose a probiotic.

Questions people ask

Do probiotics lower blood pressure?

On average, trial groups taking probiotics had blood pressure about 2 mm Hg systolic and 1 mm Hg diastolic lower than control groups. That is a small average change, found with different products, and not evidence that a probiotic treats high blood pressure.

How much probiotic would I need?

The analyses disagree. A 2014 analysis found no significant effect below 100 billion CFU a day; the 2023 umbrella analysis found a larger diastolic effect from 10 billion CFU or more. Neither establishes a dose. See probiotics dosage.

Is it better in people who already have high blood pressure?

Reductions were larger in people with diabetes or high blood pressure in the 2023 analysis. That means trials in those groups showed larger average changes, not that a probiotic manages their condition.

When to talk to a doctor

High blood pressure usually has no symptoms, so it is found by measuring it. If you have been told yours is high, or you haven't had it checked, talk to a doctor. A probiotic is not a treatment for high blood pressure, and nothing above supports changing or skipping anything a doctor has recommended. If you take prescription medication, are pregnant or nursing, or have a weakened immune system, ask a doctor before adding any supplement (see who should not take probiotics).