Gum Disease Bacterium Linked to Heart Rhythm Disorders

A groundbreaking study from Hiroshima University has uncovered a surprising connection between oral health and heart rhythm conditions. Researchers have found that the bacterium Porphyromonas gingivalis, commonly associated with gum disease (periodontitis), can enter the bloodstream and reach the heart, where it promotes scar tissue formation and disrupts normal electrical activity. This infiltration increases the likelihood of atrial fibrillation (AFib), a serious arrhythmia that raises the risk of stroke and heart failure.

Clinicians have long observed that individuals with gum disease are more prone to cardiovascular problems. Meta-analyses reveal that periodontitis can elevate the risk of developing AFib by about 30%. The global incidence of AFib has surged in recent years, nearly doubling from 33.5 million cases in 2010 to around 60 million in 2019, prompting investigations into potential causes including the role of oral bacteria.

Inflammation from gum infections can lead immune cells to release chemical signals into the bloodstream, causing systemic inflammation that harms various organs. Notably, DNA from bacteria like P. gingivalis has been detected in heart tissues, vascular plaques, and even brain tissue, implicating it in multiple systemic diseases.

This new research provides direct evidence of P. gingivalis migrating from the gums to the heart’s left atrium in both animal models and humans. Using a mouse model infected with the bacterium, scientists observed that the bacteria could invade the heart tissue, leading to increased fibrosis and abnormal heart rhythms over time. The bacteria's presence correlated with more significant scar tissue formation, which impairs electrical conduction.

In human samples, P. gingivalis DNA was identified in the left atrial tissue of patients with AFib, especially those with severe gum disease. The bacteria’s ability to hide inside cells and evade immune defenses may contribute to persistent inflammation and tissue damage.

The findings suggest that maintaining good oral hygiene through regular brushing, flossing, and dental checkups might help prevent bacteria from entering the bloodstream and affecting the heart. Preventive dental care could thus be a crucial strategy in reducing AFib risk.

Dr. Miyauchi emphasized that periodontal treatment might play an important role in preventing and managing AFib by blocking the pathway for bacterial translocation into the heart. Moving forward, the team aims to deepen the understanding of how P. gingivalis impacts cardiac cells and to foster collaboration between dental and medical professionals to improve cardiovascular health.

Source: https://medicalxpress.com/news/2025-05-heart-rhythm-disorder-bacterium-lurking.html