Gum Disease⁣ Bacteria Linked to Increased Heart Rhythm Disorder Risk

⁤ ⁤ Updated June 07, 2025

A hiroshima university study reveals a potential link between gum disease and heart health. The research indicates that Porphyromonas gingivalis (P. gingivalis), a bacterium associated with periodontitis,‍ can travel to the heart and contribute to fibrosis, increasing the risk of atrial fibrillation (AFib).

afib,a heart rhythm disorder,has seen a global surge,nearly doubling between 2010 and ⁢2019. Scientists are investigating the ⁣role of gum disease in⁣ this increase. While previous research suggested inflammation as a factor, the new study published in Circulation, provides evidence of P. gingivalis presence in the left atrium of⁤ both animal models and ‍humans.

Shunsuke Miyauchi, assistant professor at ⁢HU’s Graduate School of Biomedical and Health Sciences, noted the study addresses whether P.gingivalis translocates to the left atrium and induces atrial fibrosis and⁣ AFib progression.

In a mouse ⁢model, researchers introduced the W83 ⁣strain of P. gingivalis into the tooth pulp of one group, while a control group remained uninfected. After 18 weeks,the infected mice showed a sixfold increase ‍in the likelihood of developing abnormal heart rhythms,with a 30% AFib inducibility rate compared to 5% in⁢ the control group.

The bacterium was detected in the ⁢left⁤ atrium of infected mice, where⁣ tissue had become stiff and fibrous. These mice also ⁢exhibited more heart scarring compared to⁤ the uninfected group. A separate human study found P. gingivalis in left atrial ⁣tissue from AFib patients, with⁢ higher amounts in those⁢ with severe gum disease.

P.gingivalis can invade host⁣ cells and evade destruction, potentially allowing it to bypass immune defenses and trigger harmful inflammation. infected mice showed elevated levels of galectin-3, a fibrosis biomarker, and increased expression of Tgfb1, a gene linked to inflammation and scarring.

“The causal relationship between periodontitis and⁤ atrial fibrillation is still unkown, but the spread of periodontal bacteria thru the bloodstream may connect these conditions,” said Miyauchi.

What’s next

The research team is now ‍focusing ⁣on the specific mechanisms by which P. gingivalis affects atrial cardiomyocytes ⁣and establishing a collaborative medical and dental system in Hiroshima Prefecture to improve cardiovascular care.