What’s growing on your toothbrush?

A team of microbiologists discovered a collection of thriving, diverse, and mostly new-to-science viruses on toothbrushes and showerheads. Before you freak out and toss your toothbrush, though, you should know that these aren’t the kind of viruses that make humans sick.

The researchers at Northwestern University found bacteriophage, also called phage, a type of virus that targets bacteria. Phage has become a popular area of study in recent years for its potential to fight antibiotic-resistant bacterial infections, a growing problem in the world of medicine.

Per a press release, the new study is notable for the number of viruses unearthed on such everyday objects. “We found many viruses that we know very little about and many others that we have never seen before,” said study co-author Erica M. Hartmann. “It’s amazing how much untapped biodiversity is all around us.”

The ‘next frontier’ of microbiology is phage,” she added in an interview with Popular Science. “There’s a lot of interest in harnessing phage for biotechnology or medical applications. Penicillin comes from moldy bread. It could be that the next great antibiotic will be based on something that grew on your toothbrush.