some info that could lead you to the answer-
humans and other multi-cellar organisms all work together. the body has levels such as cells that make up tissues that make up organisms witch leads to organs systems. every organ is made up of 2 or more tissues. but what mostly goes with the digestive track is the stomach witch has acid that is composed of hydroelectric acid that has a ph of 2.0 -
sorry if its not as helpful as you need.