Toothbrushes stored in shared bathrooms often contain significant quantities of contaminants, including fecal matter, a new study reveals. A majority of toothbrushes stored in communal bathrooms are laced with small pieces of human waste, according to researchers from Quinnipiac University.

Medical researchers already knew that contamination by fecal coliforms, a type of bacteria, frequently occurs in bathrooms. The issue of tiny particles of feces is a much greater problem for those who live with others, compared with those with no one else in their household.

"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.

Researchers examined toothbrushes from bathrooms shared by an average of 9.4 students at the university. They found fecal matter in more than 60 percent of the oral hygiene brushes, and in 80 percent of those cases, the particulates were from another person.

Covers that fit over the head of a toothbrush do not prevent contamination by fecal matter, and can even make health problems worse. Covering the head of the toothbrush causes the bristles to take a longer time than normal to dry out, encouraging the growth of bacteria, researchers caution. Students in the study used a wide range of methods to store their toothbrushes, investigators in the study noted.

Previous research has found fecal coliforms on toothbrushes before, and similar studies have recorded contamination in the 60 percent range. However, this new examination specifically targeted university bathrooms, providing the knowledge that in such environments, eight out of every 10 such cases of contamination were from other people.

No difference was found between toothbrushes rinsed with hot or cold water or with mouthwash. Earlier research from the Houston School of Dentistry showed that hollow-tipped power toothbrushes could be even worse than traditional designs as a breeding ground for microorganisms.

"Toothbrushes can transmit microorganisms that cause disease and infections. A solid-head design allows for less growth of bacteria and bristles should be soft and made of nylon," said Donna Warren Morris, lead author of an article announcing the earlier study.

Analysis of the frequency of fecal matter on toothbrushes in shared bathrooms was delivered to the annual meeting of the American Society for Microbiology, held in New Orleans.

Photo: Ingrid Taylar | Flickr

ⓒ 2021 All rights reserved. Do not reproduce without permission.