A recent study from Tokyo Medical and Dental University (TMDU) reveals that maintaining oral hygiene can protect not only your smile but also your heart. Researchers have discovered that the common oral pathogen Porphyromonas gingivalis (P. gingivalis) may inhibit heart muscle cells' ability to repair themselves after a heart attack, potentially worsening the damage.

Heart attacks occur when the coronary arteries are blocked, preventing adequate blood flow, nutrients, and oxygen from reaching the heart muscle, leading to the death of cardiac cells. These cells rely on a process called autophagy to remove damaged components and prevent cardiac dysfunction. However, the study shows that P. gingivalis, often found at the site of blockages in heart attacks, interferes with this protective process.

Researchers explored this by creating a mutant version of P. gingivalis that lacks gingipain, a virulence factor responsible for inhibiting autophagy. When cardiac cells and mice were infected with this mutant bacterium, their survival rate was significantly higher compared to those infected with the wild-type strain of P. gingivalis that still produces gingipain. The wild-type infection exacerbated the damage caused by a heart attack.

Further investigation revealed that gingipain disrupts the fusion of autophagosomes and lysosomes, essential for autophagy. This disruption causes an accumulation of damaged proteins in the cardiac muscle, leading to cell enlargement and ultimately cell death. In the mouse model, these effects significantly increased the severity of heart damage.

The findings suggest that treating infections caused by P. gingivalis could improve the heart's ability to heal after a heart attack and potentially reduce the risk of fatal outcomes. This underscores the importance of oral health not only for dental care but also for overall cardiovascular health.