Effect of spring oilseed rape crop density on plant root biomass and ... by Cepuliene, Rita; Marcinkeviciene, Ausra; Velicka, Rimantas; Kosteckas, Robertas; Pupaliene, Rita / Estonian Journal of Ecology.
A study in Washington State gathered 154 first to fifth graders from two elementary schools. The students were given four gummy bears made with either xylitol or maltitol (types of sugars used in many types of sugarless chewing gum) three times a day during school hours. All were checked for plaque and bacteria in their mouths at the start of the study and six weeks later.
Assuming you mean one or a few pieces, nothing much. It will pass through your digestive tract as quickly as food. Chewing gum is made out of gum base, sweeteners, colouring and flavouring. The gum base is pretty indigestible - it is a mixture of elastomers, resins, fats, emulsifiers and waxes. Most of the time, your stomach really cannot break down the gum the way it would other foods. However, your digestive system has another way to deal with things you swallow.