Sometimes after a meal, a piece of chewing gum can be the perfect way to freshen your breath. Look on the back of the package and chances are soy lecithin is one of the ingredients listed. Soy lecithin's uses in gum including acting as a preservative to help increase shelf life, help keep the gum's coating from sticking to the package and even the gum's hard outer shell is made from soy lecithin.