How Eggs and Your Gut Can Give You a Heart Attack Scientists: lecithin found in yolks interacts dangerously with intestinal bacteria By Kevin Spak, Newser Staff Posted Apr 25, 2013 7:51 AM CDT 21 comments Comments Delicious, but deadly. (Shutterstock) (Newser) – Eggs could be hazardous to your heart health, and not just for cholesterol-related reasons. A group of researchers has discovered that a compound called lecithin interacts with our gut bacteria to produce a chemical called TMAO, which is associated with increased heart disease and stroke risk—and egg yolks happen to be full of lecithin, the New York Times reports, as are many other high-fat and high-cholesterol foods. "Heart disease perhaps involves microbes in our gut," the lead researcher says. To test their hypothesis, researchers had volunteers chow down on hard-boiled eggs, but gave some subjects antibiotics to wipe out their stomach bacteria ahead of time. Those who didn't get the antibiotics recorded boosts in TMAO levels. The study comes just two weeks after the same researchers found that a compound in red meat reacts with stomach bacteria in much the same way.