Study Identifies Distinct Microbial Signatures Associated with CAD

Cardiovascular diseases claim nearly 20 million lives each year, making them the leading cause of death worldwide. While genetics and environmental factors affect risk, growing evidence points to the gut microbiota as an important player, particularly in coronary artery disease (CAD). Scientists in Seoul have now advanced understanding of how gut bacteria contribute to CAD progression by revealing specific microbial species and pathways linked to disease mechanisms.

In a study published in mSystems, Han-Na Kim and her colleagues at Sungkyunkwan University explored how microbes in the gut relate to the development of CAD. “We’ve gone beyond identifying ‘which bacteria live there’ to uncovering what they actually do in the heart-gut connection,” said Kim.

The researchers compared fecal samples from 14 people diagnosed with CAD and 28 healthy individuals using metagenomic sequencing—a technique that reconstructs the full genomes of microorganisms from the DNA present in a sample. Through this approach, they identified 15 bacterial species associated with CAD and mapped pathways connecting those microbes to metabolic and inflammatory processes involved in the disease.

“Our high-resolution metagenomic map shows a dramatic functional shift toward inflammation and metabolic imbalance, a loss of protective short-chain fatty acid producers, such as Faecalibacterium prausnitzii, and an overactivation of pathways, such as the urea cycle, linked to disease severity,” Kim explained. The results suggest that certain bacterial functions, rather than the presence or absence of specific microbes, drive the imbalance seen in CAD. 

The study also challenges simple categorizations of “good” and “bad” bacteria. Genome-level analysis indicated that microbes typically viewed as beneficial—such as Akkermansia muciniphila and F. prausnitzii—may act differently depending on whether they inhabit healthy or diseased guts. “The big unanswered question now is which strains are the healers, and which are the troublemakers,” Kim said.

The findings underscore the complexity of linking microbial composition to disease. For instance, species of Lachnospiraceae have been reported as reduced in CAD, yet the new study found some types increased. As Kim noted, Lachnospiraceae “may be the Dr. Jekyll and Mr. Hyde of the gut.”

Looking ahead, Kim’s team aims to integrate microbial, genetic, and metabolomic data to pinpoint causal pathways in heart disease. Ultimately, they hope to design precision-based interventions—such as stool-based screening and nutritional strategies—to prevent cardiovascular disease. “Prevention,” Kim said, “is the most promising frontier for reducing the global burden of heart disease.”