Evidence suggests that the gut microbiome may influence certain aspects of cardiovascular health. The bidirectional relationship between the gut microbiome and the heart has been referred to as the “gut-heart axis.” Compositional differences in gut microbiota have been observed in individuals with certain cardiovascular illnesses when compared to healthy populations. Emerging research has suggested that probiotics may help support some factors associated with certain cardiovascular pathologies. Specific probiotics may help support microbial homeostasis, modulate pro-inflammatory cytokines, and the production of certain microbial metabolites, including short-chain fatty acids (SCFAs). 

The inflammatory response has been associated with the pathogenesis of several cardiovascular illnesses. SCFAs have been shown to help support the inflammatory response through the modulation of regulatory T cells, interleukin (IL)-1ꞵ, and IL-6. Butyrate, an SCFA, has been shown to help decrease tumor necrosis factor-alpha (TNF-α) levels and help increase plasma levels of IL-10, a cytokine associated with anti-inflammatory actions. SCFAs have been associated with the inhibition of histone deacetylase, an enzyme that has been associated with changes to blood pressure and inflammatory status. 

Clinical studies have correlated the role of probiotic supplementation in support of certain atherogenic changes and other cardiovascular functions. A randomized, placebo-controlled 12-week trial involving species from the Bifidobacterium, Lactobacillus, Lactococcus, Streptococcus, and Enterococcus genera reported reductions in TNF-α, systolic blood pressure, and IL-6 with greater effect at the higher amount of 10 billion colony-forming units (CFUs) daily. 

Dysbiosis among certain gut microbiota may also influence parameters related to hypertension. A recently published review article aggregated information on more than 15 bacteria, including those from the Methanobrevibacter, Oxalobacter, Klebsiella, and Salmonella genera. The authors reported that dysbiosis in the gut associated with these genera may be linked to the presence of hypertension. Other microbes have been associated with the presence of normal blood pressure, including Bifidobacterium, Butyrivibrio, and Coprococcus. 

Atherogenic changes and dysbiosis in the gut microbiome may be linked to cardiovascular illnesses, such as acute myocardial infarction. In clinical studies involving individuals with acute myocardial infarction, gut microbial compositional differences were observed in 14 types of bacteria and more than 30 microbial metabolites. Spirochaetes, Lachnospiraceae, Synergistetes, and Syntrophomonadaceae have been shown to be significantly more abundant after acute myocardial infarction, alongside decreased secretions of certain metabolites, including SCFAs. However, more research is needed before clinical conclusions can be made, particularly clinical research that is replicable and addresses a primary outcome with statistically significant biometrics. 

Although more evidence is needed, recent research suggests that there may be a link between gut microbial composition and cardiovascular function. Studies indicate that probiotics may help support gut microbial integrity, microbial metabolite production, and certain aspects of cardiovascular health. 

By Dr. C Ambrose, ND, MAT