Heart disease is the number one cause of death around the world, taking nearly 20 million lives each year.
While most people know that genetics, diet, and exercise all affect heart health, scientists are now learning that tiny microbes living in our gut may also play a key role.
These microbes, which help digest food and support the immune system, may also influence the development of coronary artery disease (CAD). But until recently, it was unclear exactly which bacteria were involved and how they contributed to heart problems.
Now, new research from South Korea is beginning to solve this mystery. A study led by Dr. Han-Na Kim at the Samsung Advanced Institute for Health Sciences and Technology looked at how gut bacteria are connected to the heart.
The findings were published in the scientific journal mSystems. The team didn’t just look at which bacteria were present. They studied what those bacteria were actually doing inside the body, especially how they affect the link between the gut and the heart.
The researchers used a powerful technique called metagenomic sequencing to study stool samples from people with and without coronary artery disease. They examined samples from 14 people with CAD and 28 healthy individuals. This allowed them to map out the genetic information of the microbes and see how they interact with the body.
They found 15 types of bacteria that were linked to CAD. People with the disease had more of some bacteria and fewer of others. In particular, they noticed that helpful bacteria like Faecalibacterium prausnitzii, which usually reduce inflammation, were missing or low in number.
At the same time, pathways that cause inflammation and metabolic problems—such as the urea cycle—were overactive. These changes suggest that the gut becomes unbalanced in people with CAD, which may make the disease worse.
One surprising finding was that even bacteria we normally think of as “good” can behave badly in the wrong environment. Akkermansia muciniphila and F. prausnitzii are usually seen as helpful.
But in people with CAD, these same bacteria might act differently and actually add to the disease. This shows that the behavior of microbes depends a lot on the health of the person they live in.
The study also revealed that bacteria from the same family can have opposite effects. For example, earlier research suggested that members of the Lachnospiraceae family decrease in people with CAD. But in this study, some Lachnospiraceae actually increased.
This means some strains might be helpful, while others might be harmful. Dr. Kim compared them to Dr. Jekyll and Mr. Hyde—showing two very different sides depending on the situation.
Going forward, the research team hopes to combine microbial data with genetic and metabolic information to understand exactly how gut bacteria affect heart disease.
Their goal is to create new ways to prevent heart disease before it starts. This could include using gut bacteria to help diagnose problems early or changing diets to improve the balance of microbes in the gut.
Dr. Kim believes prevention is the best strategy. If scientists can figure out which bacteria protect the heart and which ones harm it, they could create personalized treatments that use this knowledge. Restoring the right balance of microbes could become a powerful way to keep our hearts healthy.
In reviewing this study, it’s clear that the gut plays a much bigger role in heart disease than we once thought. The more we understand about the bacteria living inside us, the closer we get to new tools that can help people live longer and healthier lives.
If you care about heart health, please read studies about top foods to love for a stronger heart, and why oranges may help fight obesity, diabetes, and heart disease.
For more health information, please see recent studies about simple guide to a 7-day diabetes meal plan, and why you should add black beans to your plate.
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