Cardiotoxic oral microbial dysbiosis modulates adaptive immunity through molecular mimicry and drives heart failure progression

Heart and gum health may be more closely connected than previously thought. Our research shows that certain harmful bacteria in the mouth, which cause gum disease, can trigger the immune system to create a type of aggressive white blood cell called cytotoxic CD4 T-cells. These cells, normally meant to fight infections, can mistakenly attack the heart when they confuse bacterial proteins for heart proteins, a process called molecular mimicry. We discovered that people with severe gum disease and heart failure have high levels of these cells in their blood, and that their presence is linked to worse survival after heart transplants. We also identified a specific bacterial protein from common oral microbes that closely resembles a heart muscle protein, explaining why the immune system gets confused. Altogether, our work uncovers how oral infections can train the immune system in a harmful way, linking poor gum health to heart damage, and highlights the importance of oral care not just for teeth and gums, but also for protecting the heart