A research team reports that a person who shares the bathroom with someone else might be using a toothbrush contaminated with fecal matter.

The research has been conducted by a team from the Quinnipiac University in Hamden, Connecticut. According to the researchers, nearly 60 percent of the toothbrushes belonging to a person who shares the bathroom with someone else is likely to be contaminated with fecal matter. There's an 80 percent chance, the researchers said, that the contamination is from the fecal matter of someone other than the toothbrush owner. 

The study findings were based on the analysis of a communal bathroom being used by the undergraduate students at the university.

“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 study author and university graduate student Lauren Aber, in a statement.

According to the researchers, Enterobacteriaceae and Pseudomonadaceae, the two bacterial species, are more likely to contaminate the toothbrushes. The researchers said that even though these species are already present in the human gut, a few of its forms may be disease-causing.

In addition, the researchers further claimed that keeping the toothbrush covered might not even help prevent the toothbrush from the contamination. Instead, the protective cover outside the toothbrush bristles might provide a suitable environment for bacteria to grow, thus keeping the bristles moist all the time.

The study findings were recently presented at the annual meeting of the American Society for Microbiology.