Understanding How the Gut Microbiome Affects Heart Health

Scientists are learning that keeping your heart healthy may also depend on the health of your stomach. Your gut is home to trillions of bacteria, viruses, and fungi that play a role in a wide array of health conditions, including cardiovascular diseases.

The population of microbes living in the human intestinal tract and their genetic influence, known as the gut microbiome, go beyond simply digesting and processing your food. These microbes play a vital role in processing nutrients and some vitamins, but scientists have also learned that the gut microbiome also influences the development of medical conditions throughout the body.

Investigators have reported links between changes in the relative abundance of specific microbial types or gut bacteria richness and cardiovascular diseases. Early studies have found bacterial DNA in plaque buildup in arteries that match gut microbes tied to disease states. Changes in the composition of the gut microbiome have been found in patients with cardiovascular risk factors, including hypertension, dyslipidemia and insulin resistance.

While associations have been found, there is no solid evidence to determine whether changes in the microbiome cause cardiovascular diseases or are merely associated with them. Researchers are continuing to dive deeper into this topic to determine if the gut could be a useful treatment target for preventing heart diseases.

Exploring the Gut-Cardiac Axis

The gut has been found to have two-way communication with the brain, an idea referred to as the gut-brain axis.

An emerging area of research is determining the relationships involved in a similar gut-cardiac axis and the impact of gut health and cardiovascular function. The gut microbiota, its metabolites, and gut-related inflammation are seen as factors affecting heart structure and function. The gut-cardiac axis signals a shift in the cardiology field. This line of research holds promise in terms of integrating gut health into cardiovascular risk assessment and treatment programs.

Gut Microbiome Mechanisms of Interest

A substance known as trimethylamine N-oxide (TMAO) is of particular interest to cardiovascular researchers. When microbes in the gut break down nutrients in red meat, fish, poultry, and eggs, a metabolite called trimethylamine is formed. This metabolite is converted into TMAO, which is connected to the formation of plaque in arteries.

Research has shown that people with high TMAO levels in their blood are more likely to suffer a heart attack or stroke than those with lower levels. Since red meat is a main source of TMAO, cutting back can stop the gut from creating too much TMAO.

A September 2022 study in Arteriosclerosis, Thrombosis, and Vascular Biology found that among nearly 4,000 people ages 65 and older, those who averaged a single serving of red meat per day had a 22% higher risk of heart disease.

Bile acids are another gut microbiome byproduct of interest to researchers. These acids are involved in metabolic disease, inflammatory bowel disease, and cardiovascular conditions. Research has shown that bile acids can lead to cardiac remodeling and changes in the electrical system of the heart.

Researchers studied stool samples from 1,400 people and identified several types of gut-dwelling bacteria whose levels were associated with blood markers of cardiovascular disease, including cholesterol, triglyceride, and blood glucose levels. Bacteria known as Oscillibacter were linked with reduced cholesterol levels. Finding ways to influence the presence of this bacterium could lead to future preventative treatment options.

Options to Maintain Your Gut Health

Though it remains unclear how exactly your gut microbiome interacts with your cardiovascular system, taking good care of the billions of microbes that live within your gut is probably a safe bet. Two particular substances found in food play a role in what types of microbes develop in your gut. Probiotics and prebiotics are live bacteria, found in an array of foods, that can influence the makeup of your gut microbiome.

Foods that contain probiotics, such as yogurt, have been tied to healthier blood pressure. Probiotics are microorganisms found in foods, including yogurt and cheese.

Prebiotics are substances you can eat that contain the precursor materials that bacteria need to make chemicals that are then absorbed by our bodies. Garlic, onions, whole wheat pasta, and sweet potatoes are among the foods that can provide you with prebiotics.

Visit the Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI) website to keep up with the latest in heart research and treatment options.