In most countries, cardiovascular disease (CVD) causes more deaths than any other disease. And those numbers are growing as commonly implicated risk factors such as obesity and metabolic syndrome continue to soar.
Search for alternate strategies in microbes
Our microbiota is linked to these risk factors also as well as diabetes, hypertension, high cholesterol and more. Yet the direct relationship between gut microbiota and cardiovascular disease remains murky.
Plaque contains bacteria; individuals have shown the very same taxa matched in their gut and oral cavities as their plaque. These sites then may be sources that impact the stability of plaque and CVD development.
In addition, microbial composition is altered in patients with unstable versus stable plaques; more microbes with pro-inflammatory molecule production were present.
Furthermore, products of metabolism by gut microbes may contribute to CVD. For example, trimethylamine (TMA) is an organic compound that is generated by the gut microbiota. TMA-N-oxide (TMAO), a product of the microbial metabolite TMA, may promote atherosclerosis and cardiometabolic diseases. Clinical studies of more than 1,800 stable cardiac patients showed that all TMAO-associated metabolites—choline, betaine, and L-carnitine—had a positive association with prevalent CVDs and incident cardiovascular events.
Microbes and plaque instability
One new study investigated the contribution of the microbiota to the instability of coronary plaques. The study enrolled 30 patients with acute coronary syndrome and ten patients with stable angina. The researchers isolated gut bacteria from feces samples. Coronary plaque bacteria were extracted from angioplasty balloons.
- Fecal bacteria had a pronounced presence of Bacteroidetes and Firmicutes.
- Coronary plaques primarily contained microbes with pro-inflammatory phenotypes belonging to Proteobacteria and Actinobacteria.
- Those with acute coronary syndrome had more Firmicutes, Fusobacteria and Actinobacteria
- Those with stable angina had more abundance of Bacteroidetes and Proteobacteria.
Microbes may play a role in heart attack onset was presented at European Society of Cardiology Congress 2019 together with the World Congress of Cardiology.
The study found that unlike gut bacteria, the bacteria in coronary plaques were pro-inflammatory. In addition, patients with acute coronary syndrome (heart attack) had different bacteria in their guts compared to patients with stable angina.
First author Eugenia Pisano, of the Catholic University of the Sacred Heart, Rome, Italy concluded: “Microbiota in the gut and coronary plaque could have a pathogenetic function in the process of plaque destabilisation and might become a potential therapeutic target.”
Thus, infectious triggers might play a direct role in plaque destabilisation. Maintaining a healthy microbiota and avoiding dysbiosis may present a role for probiotic therapy in CVD in the future.