If you like chewing gum -- you might be shocked to learn you could also be chewing hundreds of microplastics.

A new study from the University of California tested a dozen popular gum brands.

It found that 1 gram of gum released about 100 microplastics. Other brands released more than 600.

Experts say microplastics can carry potentially harmful bacteria - leading to a growth in antibiotic-resistant superbugs.