Heart disease and the gut microbe

In the case of eggs, the chain of events starts when the body digests lecithin, breaking it into its constituent parts, including the chemical choline. Intestinal bacteria metabolize choline and release a substance that the liver converts to trimethylamine N-oxide. The more TMAO in your blood, the more likely you are to have a heart attack or stroke. 

NYT: Eggs, Too, May Provoke Bacteria to Raise Heart Risk