• Posted July 14, 2023

Could the Bacteria in Your Gut Play a Part in How Clogged Your Arteries Are?

Your gut bacteria could affect your risk for the fatty deposits in heart arteries -- and future heart attacks, researchers say.

A new study finds a link between the levels of certain microbes in the gut and these coronary atherosclerotic plaques.

Led by researchers from Uppsala and Lund Universities in Sweden, the study analyzed gut bacteria and cardiac images from nearly 9,000 Swedish patients ages 50 to 65 with no known heart disease.

“We found that oral bacteria, especially species from the Streptococcus genus, are associated with increased occurrence of atherosclerotic plaques in the small arteries of the heart when present in the gut flora," said researcher Tove Fall, a professor of molecular epidemiology at Uppsala University.

"Species from the Streptococcus genus are common causes of pneumonia and infections of the throat, skin and heart valves," she said in a university news release. "We now need to understand whether these bacteria are contributing to atherosclerosis development.”

The authors said advanced technology that allows for sequencing and comparing DNA content in biological samples aided the analysis. At the same time, improved imaging techniques enable researchers to detect and measure early changes in the small vessels of the heart.

“The large number of samples with high-quality data from cardiac imaging and gut flora allowed us to identify novel associations,” said lead author Sergi Sayols-Baixeras, a postdoctoral researcher at Uppsala University. "Among our most significant findings, Streptococcus anginosus and S. oralis subsp. oralis were the two strongest ones."

These bacteria were associated with inflammation markers in the blood. Some species linked to fatty deposits in arteries were also linked to the levels of the same species in the mouth.

“We have just started to understand how the human host and the bacterial community in the different compartments of the body affect each other,” said senior author Marju Orho-Melander, a professor in genetic epidemiology at Lund University. "Our study shows worse cardiovascular health in carriers of streptococci in their gut. We now need to investigate if these bacteria are important players in atherosclerosis development."

The findings were published July 12 in the journal Circulation.

More information

The U.S. National Institutes of Health has more on atherosclerosis.

SOURCE: Uppsala University, news release, July 12, 2023