If you have ever had a ‘gut feeling’ about something, you’ve sensed a connection that science is proving true: your gut communicates with the rest of your body. Specifically, research shows that the gut microbiome, or the collection of bacteria that live in the digestive tract, influences a host of bodily functions, including cholesterol metabolism, inflammation, blood pressure, and more. Recent studies suggest that an imbalance in the number and diversity of gut bacteria may even contribute to the development of cardiovascular disease (CVD), a group of conditions that includes atherosclerosis, heart attack, heart failure and stroke.  As we learn more about the important role the gut microbiome plays in preserving health and triggering disease, a whole new box of tools for treating and preventing CVD may result.

The Gut Microbiome

Our bodies host trillions of bacteria that live on and within us, with the largest concentration of bacteria found in the lower digestive tract. These tiny organisms maintain the health of the lining of gut, produce important nutrients, regulate the immune system, and can trigger or reduce inflammation throughout the body. Research suggests that the number, diversity, and balance of different families of bacteria have a direct influence on cardiovascular health. Phillip Tran, DO, Cardiologist at Dignity Health, Yavapai Regional Medical Group, is enthusiastic about these discoveries. “We know there are several known and common risk factors for CVD, including smoking, obesity, diabetes, and inactivity.  Abnormal gut flora is now being considered another major risk factor. This may open up exciting new modalities for treating and preventing CVD.”


Inflammation results from a complex series of immune reactions in the body that can be triggered by a host of conditions.  Dr. Tran states, “Chronic inflammation is a root cause of cardiovascular disease. An important factor in reducing inflammation in the body appears to be maintaining a healthy population of the bacteria that protect and feed the lining of the gut.”

When bacterial populations are healthy and diverse, the lining of the gut, which prevents pro-inflammatory, disease-causing substances from entering the body, remains intact.  However, when bacterial populations shift, either through dietary changes, stress, medications, or other causes, the gut lining itself can become damaged and inflamed, thus allowing disease-causing substances to enter the blood stream. This condition, often called leaky gut, may lead to an increased risk of cardiovascular disease.

Cholesterol, Blood Pressure and TMAO

Some of the most interesting medical research done in the last few years relates to the discovery of a potential link between gut bacteria, diet, increased CVD risk, and a chemical called trimethylamine N-oxide, or TMAO. Dr. Tran describes the connection. “TMA, or trimethylamine, is produced by certain gut bacteria when people regularly consume red meats. TMA is converted to TMAO in the liver, and research suggests that TMAO may increase inflammation in atherosclerotic plaque, decrease the elimination of cholesterol from the body, and indirectly promote increased cholesterol production.  Foam cells, which are the cholesterol-filled cells found in plaque, may also increase in number and size under the influence of TMAO.”

Several studies from the U.S. and Europe have demonstrated that blood levels of TMAO are often linked to an increased risk of heart attack and stroke. Higher levels of TMAO have also been measured in people suffering from heart failure.  Keeping in mind that these correlations do not prove that TMAO causes cardiovascular disease, researchers continue to study this intriguing connection.

Prebiotics and Probiotics

Several studies have shown that food and supplement-based pre and probiotics may reduce total cholesterol, LDL-cholesterol and inflammation.

Prebiotics are plant fibers that feed the health-promoting bacteria living in the gut. These fibers may be one of the reasons why a high fiber, plant-based diet is strongly linked with better blood cholesterol levels, reduced inflammation, and reduced CVD risk.

Probiotics include beneficial bacteria, yeasts and fungi, many of which are produced from the fermentation of a variety of foods. Probiotics can be taken as supplements or eaten as a natural part of fermented foods. Some common, probiotic-rich fermented foods include yogurt (dairy or plant based), sauerkraut, kimchi (a spicy Korean condiment), kefir, and kombucha (a type of fermented tea).

Dr. Tran thinks we need more research to clarify and prove the benefits of taking probiotic supplements to prevent or treat CVD. He states, “Although many studies suggest that probiotics can favorably alter serum lipids, some human studies examining the benefits of probiotics on serum lipids have shown conflicting results.” Many researchers concur, stating that the science is new and will take time to determine what types and blends of probiotics might be therapeutic for certain conditions, and in what form probiotic supplements should be consumed for the best outcomes.

Steps to Improve Gut and Cardiovascular Health

Dr. Tran suggests the following steps to improve the health of your gut and possibly reduce your risk of CVD.

  1. Maintain healthy intestinal flora by eating a diet rich in high fiber, plant based foods, and by regularly consuming healthy fermented foods.
  2. Take antibiotics with caution and care as they kill all bacteria and can promote the growth of unhealthy bacteria in the gut. Supplement with prebiotics and probiotics whenever you take antibiotics.
  3. If you have cardiovascular disease, talk to your cardiologist about the potential benefits of pre and probiotics. While the science is not yet clear, boosting a healthy population of gut bacteria may reduce inflammatory processes that trigger cardiovascular conditions.

For more information about heart health and healthy living, subscribe to YRMC HealthConnect. To schedule an appointment with Dr. Tran, contact YRMG Cardiology in Prescott at (928) 445-6025.