Diversity of the intestinal microbiota and arterial stiffness in women
Involvement of the intestinal microbiota in arterial stiffness, one of the most recently identified cardiovascular risk factors, has been analyzed in an exclusively female population by a British team.
Systemic inflammation, insulin sensitivity and hyperglycemia–strongly linked to the composition of the intestinal microbiota–contribute to arterial stiffness (AS), a major marker of cardiovascular risk independent of the classic risk factors. This observation encouraged researchers to study the impact in this process of the composition of the intestinal microbiota and serum metabolites in 617 women.
A link between the intestinal microbiota and arterial stiffness
The first major result was that arterial stiffness is inversely correlated with microbial diversity, itself strongly influenced by diet–mainly by the consumption of fibers. In other words, the greater the bacterial richness, the lower the level of arterial stiffness. Moreover, there was an inverse correlation between AS and seven taxonomic units, two of which belonged to the Ruminococcaceae family. It should be noted that the influence of the microbiota was independent of insulin resistance, visceral fat or the consumption of tobacco or alcohol. The authors believe that the intestinal microbiota acts on the arterial walls by triggering inflammation, which would only be partially measured by C-reactive protein (CRP) level, insulin resistance and the other cardiovascular risk factors.
Two metabolites to blame
Bacterial metabolites such as phenylacetylglutamine, TMAO(Trimethylamine N-Oxide), and IPA (indole-3-propionic acid) were also associated with an increase in AS. The results show that only phenylacetylglutamine and IPA concentrations are likely to play a role in the action of the microbiota on the arterial wall. These two metabolites are known for their association with cardiovascular mortality and metabolic syndrome, respectively. For the first time, the data show that the composition of the intestinal microbiota is strongly correlated with arterial stiffness in women, independently of visceral fat and the other characteristics linked to obesity. The researchers conclude that modulating the microbiota by diet and/or by using probiotics could be a therapeutic option to reduce arterial stiffness, thus lowering cardiovascular risk.
Menni, C. et al. Gut microbial diversity is associated with lower arterial stiffness in women. Eur Heart J doi: 10.1093/eurheartj/ehy226