Gum Bacteria Threaten Heart Valve
A new preliminary study, the results of which were presented at the American Heart Association’s Scientific Sessions on Basic Cardiovascular Science in Boston, has revealed a potential link between a bacterium that causes gum disease and the progression of “calcific aortic stenosis,” one of the most common and serious valve heart diseases.
Calcification is the gradual accumulation of calcium in the aortic valve, causing it to stiffen and narrow, thereby obstructing blood flow from the heart to the rest of the body.
Researchers focused on Porphyromonas gingivalis, a bacterium primarily associated with gum disease. Previous studies had also linked it to infections extending beyond the mouth, including vascular inflammation and coronary artery disease, making it a logical candidate for investigating the potential relationship between gum disease and heart valve damage.
• Human Tissues: Researchers measured levels of this bacterium in heart valves removed during valve replacement surgeries, comparing samples from patients with calcific stenosis to those from patients with other valve disorders. Although this bacterium was not the most common among those detected, its presence differed sharply between calcified and non-calcified valves. Researcher Li described the team’s surprise at the extent and specificity of its presence in diseased valves.
• Mouse Experiments: Researchers repeatedly exposed some mice to live bacteria, which accumulated in their aortic valves and led to increased calcification and more pronounced symptoms of stenosis, while preventive antibiotic treatment reduced these effects. In another group, researchers genetically disrupted the inflammatory pathway associated with interleukin-1 beta, a signaling protein primarily secreted by immune cells that stimulates inflammation. They found that this bacterium activates this pathway within valve cells, which may partially explain the mechanism by which infection transforms into actual calcification in valve tissue.
Researchers emphasize that these results are preliminary and have not yet been published in a peer-reviewed journal, and that they do not directly change current medical recommendations. However, they reinforce the importance of preventing and treating gum disease early, as doing so may offer benefits beyond oral health, potentially protecting heart health in the long term.
