On Oct. 9, 2024, in a Northwestern University-led study, microbiologists found that showerheads and toothbrushes were teeming with an extremely diverse collection of viruses — most of which have never been seen before.

The microorganisms collected in the study were bacteriophage, or “phage,” a type of virus that infects and replicates inside of bacteria. Although researchers know little about them, phage recently received attention for their potential use in treating antibiotic-resistant bacterial infections.