The heart health of the future comes from the digestive tract. This is still a vision, but it will soon become reality. For a long time, microbes were considered solely responsible for digestion. In the meantime, microbiome researchers know better: an imbalance between healthy and disease-causing germs seems to be the starting signal for numerous diseases. Old-age diabetes, obesity, mental illnesses such as depression and anxiety disorders, and even heart disease could be the result of an incorrect colonization of our intestines. The research results still read like individual findings, but the puzzle is slowly coming together.
The fact is: The intestinal flora of sick people differs from that of healthy people. And in the blood of sick people there are more and more bacterial decomposition products floating around, which trigger pathological processes in the body. Risk factors such as smoking, obesity or stress could also have a fatal effect on the heart by altering the microbiome.
How intestinal bacteria damage
Obviously there is a direct connection between the quantity and variety of germs and a weakened heart. Currently, scientists suspect a simple mechanism: the intestinal microbes produce metabolic products, so-called metabolites, which have a positive or negative effect on heart health, depending on the type of bacteria. Every person has a different microbial intestinal flora that produces different amounts of metabolites. These pass into the bloodstream, act on the heart and influence health there.
The US-American Stanley Hazen from the Lerner Research Institute of the Cleveland Clinic discovered for example trimethyl-aminoxide, short TMAO. This protein indicates an increased risk of heart attack in the blood. It unfolds its fatal effect in a detour: it drives phagocytes in the blood to destroy cholesterol. They rustle up to form foam cells and settle on the walls of blood vessels. And the protein causes blood platelets to stick together more strongly. Both effects clog vessels in the brain and heart.
The substance TMAO not only indicates whether healthy people have an increased risk of falling ill. With its help, doctors can also predict how well patients recover from a heart attack.
Studies have shown that intestinal bacteria produce the precursor protein TMA from food components such as choline and carnitine, and the liver uses this to produce the heart-critical TMAO. Choline is found in eggs and milk, carnitine in beef, pork and lamb. The scientists’ assumption: People who eat a lot of red meat increase their TMAO level and thus their risk of getting heart disease and dying from the consequences of heart disease. How easily the TMAO mirror can be affected, shows the following investigation: With humans, who first vegetarian nourished themselves or eaten primarily chicken or turkey, but then changed to beef, lamb or pork, the TMAO mirror jumped upward.
How intestinal bacteria protect
But by no means everything is bad, what the intestinal bacteria secrete into our body. They can also excrete protective degradation products. An example of this are the short-chain fatty acids butyrate and propionate. In the large intestine native bacteria diminish indigestible ballast materials from our food to the short-chain fatty acids. Pulses, carrots or beet are considered to be particularly rich in these favorable fibers.
On average, our intestines are populated by about 20 butyrate-forming species. We can control their quantity through our diet: With a plant-based diet, they gain weight, we eat more meat, they disappear. Scientists suspect that there are several mechanisms at work behind butyrate that protect our heart: They strengthen the intestinal mucosa by controlling the immunological defenses of the intestine. And they regulate blood lipids by stimulating the body to excrete bile acids. The body needs them to digest fats. To build up supplies, it needs harmful cholesterol.
The intestinal bacteria with their excretions seem to be the missing piece of the puzzle that explains why food has a profound effect on our health. Take roughage to you! Eat more vegetables! Do without salt! Behind these tips, a wide field opens up with regard to the microbiome: It is not salt that increases blood pressure, but a protective shield of good germs in the intestine that becomes porous. Because salt kills bacteria that release protective substances that lower blood pressure.
All these findings point in one direction: heart failure, calcified coronary arteries and other heart diseases are not a fate. We can prevent them with a healthy diet. As long as there are no suitable therapies, we will only be able to multiply the protective microbes through targeted nutrition.