“Our initial hypothesis was that the synthetic gums would have a lot more microplastics because the base is a type of plastic,” Lisa Lowe, the study’s co-collaborator and a graduate student in Mohanty’s lab, explained in a statement. (Yes, certain types of synthetic gum contain petroleum-based polymers.)

A new study found that chewing gum releases hundreds to thousands of microplastics into saliva. Both synthetic and natural gums were found to contain microplastics, the health effects of which are not yet fully understood.