Numerous studies have suggested a link between gum disease and heart disease. Now, new research clarifies how bacteria in our mouths can lead to cardiovascular health problems. (You might want to go brush and floss before you continue reading.)

Porphyromonas gingivalis is an oral bacteria that causes periodontitis, a more advanced stage of the common gum disease gingivitis. Oral bacteria can break free during chewing or toothbrushing and enter the bloodstream, binding to blood cells and making their way to blood vessels. This is particularly likely to occur in people with serious gum infections.

Scientists have previously identified P. gingivalis in the arterial plaque of heart attack patients, and animal studies show that P. gingivalis can both cause and accelerate the buildup of plaque inside the coronary and aortic arteries, a condition known as atherosclerosis. The accumulation of plaque provokes inflammation, which is thought to be a crucial component of atherosclerosis.

But exactly how P. gingivalis participates in that process has remained mysterious—until now. A team of researchers led by Torbjörn Bengtsson of Örebro University in Sweden infected aortic smooth muscle cells with P. gingivalis. They observed that the bacteria altered gene expression in a way that dramatically increased inflammationThis is the first time the chemical process has been observed at a molecular level. Their findings were recently published in the journal Infection and Immunity.

In addition to identifying the mechanism by which P. gingivalis provoked inflammation, the researchers discovered that the combination of the bacteria and stress may amplify the risk of a heart attack. “P. gingivalis markedly increases the sensitivity of platelets … to adrenaline, which means that a combination of periodontitis and stress increases the risk for [blood clot and heart attack],” said Bengtsson.

Now that they better understand the mechanism linking periodontitis to heart disease, the researchers will continue searching for biomarkers that could help diagnose and treat the disease more quickly. Nearly half of adults over age 30 in the United States suffer from periodontal disease, according to the Centers for Disease Control and Prevention.

After controlling for factors such as high blood pressure, diabetes, obesity, alcohol consumption and smoking, the prevalence of cardiovascular diseases in patients with periodontitis is still 25–50 percent higher than in people who don’t have the gum disease, said Bengtsson, who also emphasized the importance of good oral hygiene.

“Taking care of your teeth by careful brushing and flossing and going to the dentist regularly is of course basic and very important,” he said, adding that removal of plaque through regular dental cleanings to prevent periodontitis is still the general treatment.

However, his team is also testing new methods of controlling oral bacteria before they cause serious gum disease. It turns out that a protein in some lactobacillus—the so-called “good” bacteria that help the body fight a multitude of ailments from diarrhea to yeast infections—may also hold promise for preventing and treating periodontitis.