You may want to stop worrying about the filth in your boyfriend's beard and pay a little more attention to the toothbrush you stick in your mouth twice a day.
According to a new study, toothbrushes in communal bathrooms are more than likely covered in fecal matter -- and potentially a haven for disease.
Researchers at Quinnipiac University in Connecticut recently analyzed the toothbrushes of resident students using a bathroom shared by at least nine people. They found 60 percent of the toothbrushes were contaminated with fecal matter, regardless of storage method.
Brushers who have a bathroom to themselves are likely sticking tiny poop molecules in their mouth too -- their own. But one's own fecal matter is of less concern, according to researchers.
"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 [microbes]," lead study author Lauren Aber of Quinnipiac University, said in a press release release.
Of the 60 percent of contaminated toothbrushes, 80 percent were covered in the fecal matter of someone other than the user.
Aber and her research colleagues presented their research last week at the annual meeting of the American Society for Microbiology in New Orleans.
Researchers found no practical method for daily protection from contamination, but recommend students (and other communal bathroom-users) follow the hygienic tips of the American Dental Association, including: not sharing toothbrushes, rinsing toothbrushes before and after use and avoiding the cross-contamination risks of close-quarters storage.
Scientists also recommend against using a container or case, which encourages bacterial growth by maintaining a moist environment. Toothbrushes that are stored upright and in open air will dry best.