Why does an apple a day keep the doctor away? Danish microbiologists fed rats a diet high in whole apples and apple products such as apple juice and puree to check if eating apples affected the level of “ friendly “ bacteria in the rats’ digestive system. It seemed that when apples were eaten regularly over a period of time, these bacteria helped produce short-chain fatty acids that provided ideal pH conditions for ensuring a beneficial balance of microorganisms. They also produced a chemical called butyrate, an important fuel for cells
of the intestinal wall. Apples are rich in pectin, a component of dietary fibre in apples, and boot the level of certain bacteria that may improve intestinal health and reduce risk of some diseases.