The main ingredient for chewing gum is the ‘gum base’ which is essentially a synthetic type of rubber. These gum bases are then mixed with sweeteners and flavourings (either natural or artificial) to make chewing gum. About 60-70 years ago, the gum base was commonly made from chicle, a milky white sap, which can be found on the sapodilla tree native to southern Mexico, Central America and the Caribbean.
Swallowing small pieces of gum is quite harmless as the gum should pass through your system like any other food. The sweeteners and flavourings will be digested but the ‘gum base’ cannot be broken down so all that happens is it will pass through the digestive system intact at about the same rate as the broken-down food.
Rik Sargent, Science Museum