Stomach-churning new research shows the majority of toothbrushes kept in communal bathrooms are contaminated with fecal matter.
A team of researchers the transmission of fecal coliforms is common in communal bathrooms, the American Society for Microbiology reported.
"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 Quinnipiac University.
The researchers collected from bathrooms shared by an average of 9.4 people. They found regardless of storage method, at least 60 percent of the toothbrushes were contaminated with fecal bacteria; there was an 80 percent change the fecal coliforms found on the toothbrushes came from another individual using the bathroom.
"Using a toothbrush cover doesn't protect a toothbrush from bacterial growth, but actually creates an environment where bacteria are better suited to grow by keeping the bristles moist and not allowing the head of the toothbrush to dry out between uses," Aber said. "Better hygiene practices are recommended for students who share bathrooms both in the storage of their toothbrush but also in personal hygiene."
The researchers noted toothbrushes stored open in a bathroom are especially vulnerable to contamination with material from the toilet, and storage methods are important in preventing this type of contamination.
The research was presented as part of the 2015 General Meeting of the American Society for Microbiology.
