The prevailing theory behind this increased risk is that the anaerobic bacteria which cause gum disease ultimately spread beyond the oral cavity into other systems and organs in the body-including the heart. These bacteria may attach themselves to the fatty proteins (plaques) which clot the arteries and thus further obstruct blood flow and effectively increase chances for a heart attack. In time, these bacteria may break off and travel through the blood stream and become lodged in the brain causing stroke or even death.