Your Toothbrush Likely Has Poop On It, Study Finds

06/03/2015 07:17 pm ET | Updated Jun 03, 2015
Shutterstock / YanLev

There's a solid chance your toothbrush is riddled with fecal bacteria, according to a new study.

Researchers at an American Society for Microbiology meeting on Tuesday presented a study showing that 60 percent of toothbrushes analyzed in communal bathrooms at Quinnipiac University in Connecticut tested positive for fecal coliform bacteria.

To make matters worse, the research shows that if you're sharing a bathroom, there's an 80 percent chance that those fecal bacteria came from someone else's bum.

Tiny fecal coliforms are a part of everyday life -- they can be found in natural waterways and even on your skin. But don't poo poo this study just yet. Researchers said your own coliforms are fine, but your gut isn't used to the bacteria in, say, your roommate's gut.

"The main concern is not with the presence of your own fecal matter on your toothbrush, but rather when a toothbrush is contaminated with fecal matter from someone else, which contains bacteria, viruses or parasites that are not part of your normal flora," said Lauren Aber, a graduate student at the university.

So what can you do to stop the spread of poo? The study found that mouthwash, hot water and cold water were all ineffective at thwarting the fecal menace. Toothbrush covers, it says, are even worse for your brush because they create a moist, protected environment for bacteria to grow.

The American Dental Association has some tips for toothbrush care, but they're pretty obvious:

  • Do not share toothbrushes. Sharing a toothbrush could result in an exchange of body fluids and/or microorganisms between the users of the toothbrush, placing the individuals involved at an increased risk for infections.
  • Thoroughly rinse toothbrushes with tap water after brushing to remove any remaining toothpaste and debris. Store the brush in an upright position if possible and allow the toothbrush to air-dry until used again. If more than one brush is stored in the same holder or area, keep the brushes separated to prevent cross-contamination.
  • Do not routinely cover toothbrushes or store them in closed containers. A moist environment such as a closed container is more conducive to the growth of microorganisms than the open air.
  • Replace toothbrushes at least every three to four months. The bristles become frayed and worn with use and cleaning effectiveness will decrease.

The American Dental Association also says there's "insufficient clinical evidence to support that bacterial growth on toothbrushes will lead to specific adverse oral or systemic health effects." So keep brushing, folks.

If you want to see a good visual study on toothbrush fecal matter, check out this clip from MythBusters. Surprisingly, this study found fecal coliforms on all of their toothbrushes, even ones that had never been used in the bathroom.

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