Could Probiotic Supplements Be an Effective Intervention to Reduce Hypertension? A Systematic Literature Review

Introduction Pathogenesis of high blood pressure or hypertension is associated with microbial imbalance or dysbiosis of the gut microbiome. Previous research suggests probiotic consumption may reduce elevated blood pressure, possibly through manipulation of the gut microbiome, and may offer a future potential therapy for hypertension.
The aim of this research was to critically evaluate current research evidence to assess whether probiotic supplements may reduce high blood pressure and formulate recommendations regarding their use as an intervention to support hypertensive clients in a Nutritional Therapy context. The objectives were to outline the possible association between gut dysbiosis and hypertension, and to explore possible mechanisms by which probiotics may influence blood pressure.
Methods A systematic review of the literature based upon PRISMA protocol was conducted. Four databases were searched: Cochrane Library (Central), CINAHL, Medline and TRIP from January 2014 until July 2020. Five eligible randomised controlled trials, including 453 participants, were identified and critically appraised to assess the quality of their evidence.
Results Of the three highest quality studies, two supported probiotic supplements to be effective in reducing blood pressure, one study reported no effect. The remaining two studies were appraised to be of lesser methodological quality so were given less weighting for quality of evidence. This research study found moderate evidence that probiotic supplementation can significantly reduce blood pressure in individuals with borderline hypertension. No effect was reported in normotensives.
Conclusion Probiotic supplementation may offer a convenient and effective adjunct for hypertensives to reduce high blood pressure alongside other dietary/lifestyle/medical interventions.
Recommendation Further large-scale trials of longer duration on hypertensives are recommended to establish functional pathways, bacterial strain, dosage and required timescale.