Heart disease is the number one cause of death worldwide, claiming nearly 20 million lives each year. Most people know that genetics, diet, exercise, and smoking all affect heart health.
But now, researchers are paying more attention to something else: the trillions of tiny bacteria living in our digestive system, known as the gut microbiome.
Scientists have suspected for a while that these gut microbes may be linked to coronary artery disease (CAD), a serious condition where the blood vessels around the heart become clogged or narrowed. But until recently, it wasn’t clear exactly which bacteria were involved or how they influenced heart disease.
A team of researchers in South Korea is beginning to answer these questions. In a study published in the journal mSystems, Dr. Han-Na Kim and her colleagues at the Samsung Advanced Institute for Health Sciences and Technology looked at the gut bacteria of people with CAD.
Their goal was to understand not just which bacteria were present, but also what those bacteria were doing.
The researchers studied stool samples from 14 people with coronary artery disease and 28 healthy individuals. They used a method called metagenomic sequencing, which helps scientists examine all the DNA in a sample.
This allowed them to identify 15 specific bacterial species linked to CAD and map out the biological pathways that might connect them to the disease.
What they found was striking. People with heart disease had major changes in their gut microbiome. There was more activity in pathways linked to inflammation and metabolism problems.
At the same time, there was a loss of bacteria that normally produce short-chain fatty acids, which help protect the gut and reduce inflammation. One of these protective bacteria is Faecalibacterium prausnitzii, and its levels were much lower in the people with CAD.
Another interesting discovery was that some bacteria usually seen as “good” can act differently depending on the health of the person.
For example, Akkermansia muciniphila and F. prausnitzii are often considered helpful, but in people with CAD, they may actually contribute to disease. This shows that even beneficial bacteria can turn harmful under certain conditions.
The researchers also looked at a group of bacteria called Lachnospiraceae. Some studies said these bacteria are less common in people with heart disease. But Kim’s team found that while some Lachnospiraceae species decrease, others increase.
This means that different strains within the same bacterial family can have opposite effects—some helping, some harming. Dr. Kim described them as the “Dr. Jekyll and Mr. Hyde” of the gut microbiome.
This research highlights just how complex the relationship between gut bacteria and heart disease really is. It’s not enough to look at one type of bacteria and assume it’s good or bad. Instead, scientists need to study the specific strains and how they behave in different environments.
Looking ahead, the team wants to combine bacterial data with information about a person’s genes and metabolism. The hope is to develop personalized treatments that use gut bacteria to prevent or reduce heart disease.
For example, future therapies could include special diets, probiotics, or even screening tests that analyze a person’s gut bacteria to predict their heart disease risk.
Dr. Kim believes that focusing on prevention is key. If doctors can use gut bacteria to spot problems early—or even stop them from happening—this could greatly reduce the number of people affected by heart disease.
In short, your gut bacteria may play a bigger role in your heart health than anyone thought. As researchers learn more, they’re getting closer to turning this knowledge into real treatments that could help millions of people stay healthier, longer.
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.
The study is published in mSystems.
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