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Once again, two opposing views about beards have been in the news - that they harbor all sorts of nasty disease-causing bacteria vs they are hygienic. An earlier May 5, 2015 post was about the question of whether bearded men have more bacteria on their faces than clean shaven ones. I cited a 2014 study found that they don't, and that we are all covered with bacteria, all sorts of bacteria, and this is normal.

Now another study has looked at the issue of hospital workers with and without beards and whether they carry infectious bacteria. Researchers swabbed the faces (center of the cheek and the skin of the upper lip under the nostrils) of both clean shaven individuals and individuals with facial hair (beards) that worked in two hospitals (they all had direct contact with patients) and looked at the bacteria present. They especially looked for the presence of the bacteria Staphylococcus aureus, which surprisingly was found more in the clean-shaven men. Also to their surprise, it was more of the clean shaven men who carried the pathogenic bacteria Methicillin-resistant Staphylococcus aureus (also known as MRSA). For those bacterial groups most closely associated with hospital acquired infections, such as Klebsiella species, Pseudomonas species, Enterobacter species., and Acinetobacter species, prevalence was low in both groups, and less than 2% for each group.

For other, less harmful bacteria, researchers found that bearded employees harbored no more bacteria than their clean-shaven colleagues. In summary: The researchers say that "results suggest that male hospital workers with facial hair do not harbour more potentially concerning bacteria than clean-shaven workers, and that in some instances, clean-shaven individuals are significantly more likely to be colonized with potential nosocomial pathogens". (NOTE: nosocomial means a disease originating or acquired in a hospital.)

And why is that? According to the study, one explanation is "microtrauma to the skin," which occurs during shaving and results in abrasions, which could support bacterial colonisation and growth of bacteria on the clean-shaven men. However, some other researchers have a different hypothesis — that beards themselves actually fight infection. This stems from an experiment carried out by Dr. Michael Mosley who recently swabbed the beards of a variety of men and sent the samples to Dr. Adam Roberts, a microbiologist at University College London. Roberts grew more than 100 different bacteria from the beard samples, but found that in a few of the petri dishes a microbe was killing the other bacteria -  a bacteria called Staphylococcus epidermidis, and which they believe has antibiotic properties.

From the Journal of Hospital Infection: Bacterial ecology of hospital workers’ facial hair: a cross-sectional study

Summary: It is unknown whether healthcare workers' facial hair harbours nosocomial pathogens. We compared facial bacterial colonization rates among 408 male healthcare workers with and without facial hair. Workers with facial hair were less likely to be colonized with Staphylococcus aureus (41.2% vs 52.6%, P = 0.02) and meticillin-resistant coagulase-negative staphylococci (2.0% vs 7.0%, P = 0.01). Colonization rates with Gram-negative organisms were low for all healthcare workers, and Gram-negative colonization rates did not differ by facial hair type. Overall, colonization is similar in male healthcare workers with and without facial hair; however, certain bacterial species were more prevalent in workers without facial hair.

[Excerpts from Discussion]:Several studies to date have demonstrated that physician white coats and neck ties can act as significant sources of nosocomial bacteria. Our study suggests that facial hair does not increase the overall risk of bacterial colonization compared to clean-shaven control subjects. Indeed, clean-shaven control subjects exhibited higher rates of colonization with certain bacterial species. This finding may be explained by microtrauma to the skin during shaving resulting in abrasions, which may support bacterial colonization and proliferation. This may be akin to the enhanced risk of surgical site infections in patients shaved with razors prior to surgery. Further, our results are consistent with prior evidence pertaining to bacterial colonization on the hands and nares of HCWs (Health care workers).

IMG_3880 Credit:Mara Silgailis at Lacto Bacto

Wondering about microbes found in beards? Recent TV stories made it sound as if they are incredibly filthy and harbor bacteria. Well, the news stories were not good because they asked the wrong question (should have asked: do bearded men have more bacteria on their faces than clean shaven ones? - and a 2014 study found that they don't) and they neglected to say that we are all covered with bacteria, all sorts of bacteria, and this is normal. And the "enteric bacteria" they found? Well, they're all over - the human gut, normal human skin, cheese,etc. Microbiologist David Coil from Slate:

Your Beard Is Covered in Bacteria

The irrational germophobia story of the week is that beards harbor “dangerous germs.” This story hits almost all the sweet spots of the genre: It has no actual data, no controls, nonsensical interpretation of results (such as they are), and a punch line that can be summed up in 140 characters or fewer.

In this “study,” the news station swabbed a few beards, sent them off to a company for analysis, and got back a report that the beards contained “germs,” specifically enteric bacteria, which are part of the human gut microbiome and therefore also found in feces. Voila: “Your beard is as dirty as a toilet,” and “Beards contain poop” sweep the Internet. Let’s take apart each piece of this misleading viral phenomenon.

The original story doesn’t say how many beards were tested … just a “handful.” Let’s be generous and call it 10 beards. Not exactly a great sample size, but not the end of the world. The real problem here is the lack of swabs from clean-shaven men. People are covered, absolutely covered in bacteria. Yes, that means you too … 15 showers a week notwithstanding. Everything is covered in bacteria, most of which are harmless or beneficial. Any story that starts with “we found germs on X” is already pointless unless you’re talking about Mars, the moon, or something that’s supposed to have been sterilized (like surgical equipment). So of course they found bacteria on beards. And I can promise you that if they swabbed any other part of those dudes, they’d also find bacteria. Amazing!

What we’d want to know is whether men with beards harbored more bacteria than men with clean-shaven faces. Which of course they didn’t look at.Fortunately, this question has been addressed in the scientific literature. A recent article titled “Bacterial ecology of hospital workers’ facial hair: a cross-sectional study” concluded that health care workers with and without beards harbored similar numbers of bacteria.

OK, so what about the kinds of bacteria? If we’re concerned about health, then the type of bacteria is far more important that the numbers....The microbiologist in this story says that they found “enteric” bacteria, which were the “kind of things that you’d find in feces.” Well, OK. Many members of the Enterobacteriaceae family are found in the gut (and therefore feces). Some are even pathogens. Most are not; some are beneficial, even essential for human health. Assuming that finding enteric bacteria equates to finding feces is like saying that finding cat hair on your couch means you’re at risk of being eaten by a lion. Members of the Enterobacteriaceae family can also be found on normal human skin, cheese, plants, seeds, water, and soil. I’d be willing to bet that you can find enteric bacteria pretty much everywhere if you look hard enough. And do those present a health risk? Probably not, as even the microbiologist in the original story admits.

IMG_3880Credit:Mara Silgailis at Lacto Bacto