Your toothbrush reflects you, not your toilet

Microbes on your toothbrush match microbes inside your mouth

  • Researchers studied microbial communities on used toothbrushes
  • They found microbes on toothbrushes match those inside mouths and on skin
  • They did not find microbes associated with the human gut
  • It did not matter where a person stored their toothbrush in the bathroom
  • People with better oral hygiene had toothbrushes with slightly less microbial diversity but more antimicrobial resistance genes

EVANSTON, Ill. — Good news: The bacteria living on your toothbrush reflect your mouth – not your toilet.

After studying microbial communities living on bristles from used toothbrushes, Northwestern University researchers found those communities matched microbes commonly found inside the mouth and on skin. This was true no matter where the toothbrushes had been stored, including shielded behind a closed medicine cabinet door or out in the open on the edge of a sink.

The study’s senior author, Erica Hartmann, was inspired to conduct the research after hearing concerns that flushing a toilet might generate a cloud of aerosol particles. She and her team affectionately called their study “Operation Pottymouth.”

“I’m not saying that you can’t get toilet aerosols on your toothbrush when you flush the toilet,” Hartmann said. “But, based on what we saw in our study, the overwhelming majority of microbes on your toothbrush probably came from your mouth.”

Media Contacts  Amanda Morris

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