Taking care of your teeth and gums might do more than just keep your smile bright—it could also help protect your heart. A new study from researchers in Japan, at Tokyo Medical and Dental University (TMDU), has found a surprising link between gum disease and heart health.
Their research shows that a common mouth bacterium may make it harder for the heart to heal after a heart attack.
Heart attacks happen when the blood vessels that carry oxygen and nutrients to the heart—called coronary arteries—become blocked. When this happens, parts of the heart muscle don’t get the oxygen they need and begin to die.
To reduce further damage, heart cells try to clean up the mess through a process called autophagy. This process helps clear out damaged parts of the cell so they don’t cause more harm.
The Japanese researchers focused on a bacterium called Porphyromonas gingivalis, which is often found in people with gum disease.
Previous studies had shown that this bacterium can travel from the mouth to other parts of the body and has even been found at the site of blocked arteries during heart attacks. But until now, scientists didn’t fully understand how it might affect the heart.
To dig deeper, the team studied a special version of the bacterium that was changed in the lab so it didn’t produce a substance called gingipain. Gingipain is known to be the most harmful part of P. gingivalis. It helps the bacteria survive in the body and has been shown to block certain cell functions, including the ability of damaged cells to die and be removed.
The researchers infected heart cells and mice with either the normal version of the bacteria or the modified version without gingipain.
The results were striking. The heart cells infected with the modified bacteria survived better than those infected with the regular, more harmful version. In mice, the effects of a heart attack were also much worse in those infected with the regular P. gingivalis.
A closer look showed that gingipain disrupts a key step in the autophagy process. Normally, a cell uses structures called autophagosomes to gather damaged materials. These autophagosomes then fuse with other structures called lysosomes to break down and remove the waste.
But gingipain blocks this fusion step, which means the cells can’t finish the cleanup job. As a result, damaged materials build up in the heart cells, causing them to swell and function poorly. This can increase the risk of heart tissue breaking down, a dangerous complication after a heart attack.
These findings suggest that people with gum disease, especially those infected with P. gingivalis producing gingipain, may be at greater risk of serious complications if they suffer a heart attack. The bacteria may make it harder for the heart to heal, leading to worse outcomes.
This study reveals an important connection between oral bacteria and heart recovery. It adds to growing evidence that mouth health is closely tied to whole-body health. While scientists have long suspected a link between gum disease and heart disease, this research helps explain how that connection might work on a cellular level.
What makes this research especially valuable is the detailed understanding of how gingipain interferes with autophagy, a natural repair process in the body. By blocking this process, the bacteria indirectly damage the heart, making recovery from a heart attack more difficult and increasing the chance of further injury.
This study also raises an important possibility: by targeting the harmful effects of gingipain, we might find new ways to protect the heart in people with gum disease. It highlights the need for good dental hygiene, not just for preventing cavities and gum infections but also as part of a broader strategy for protecting heart health.
Going forward, more studies will be needed to see whether similar results occur in humans and to explore whether treating gum infections could reduce heart attack complications. In the meantime, brushing, flossing, and regular dental checkups might do more than just keep your teeth clean—they could help your heart stay healthy, too.
If you care about gum health, please read studies about an important causes of tooth decay and gum disease, and common tooth disease that may increase risks of dementia.
For more health information, please see recent studies about mouthwash that may increase your tooth damage, and results showing this diet could help treat gum disease.
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