A recent study indicates that beard hairs carry enteric bacteria, the same bacteria that live in the gut. Enteric bacteria are also a component of fecal matter. Researchers are divided as to whether this bacteria constitutes a health risk or not.

The study, which was conducted by Jon Golobic of Quest Diagnostics, was based on samples of facial hair collected by a TV news network in New Mexico. “I’m usually not surprised, and I was surprised by this,” said Golobic about the results of the study.

Another study, published in the journal Anesthesia, found that surgeons with beards shed more bacteria from their faces than clean-shaven surgeons did. However, Professor Anthony Hilton of Aston University noted that there is as of yet no proof that the increased bacteria levels in beards are a cause for concern. “It’s not uncommon to find 20,000 bacteria on the skin, and this isn’t harmful,” said Hilton.

Other experts note that enteric bacteria is also present on the skin, so it does not necessarily pose a health risk.

Not all bacteria experts agree that dirty beards are completely safe, however. The Birmingham Trichonology Center’s Carol Walker said that the shape of beard hair causes it to hold on to bacteria more than hair found on the top of the head. Since facial hair is more coarse, it has more bends and folds that trap germs.

It is possible that the bacteria in facial hair can be passed on to other people, especially to romantic partners. “If you’re affectionate with someone, if you kiss them, you can pass on bacteria,” said Walker.