New research reveals that fungal infections may be more common than presumed, and more than a 100 different fungi live on our feet alone.
One-of-a-kind, this study, conducted by a team from the National Institutes of Health, analyzed the DNA of fungi found in different parts of the human body.
"This is the first study of our fungi, which are yeast and other molds that live on the human body," Julie Segre, from the National Human Genome Research Institute, who led the survey, said.
Though millions and billions of microorganisms live on our bodies, and breed there, most of them are typically harmless. Many of them, on the other hand, may actually prove to be quite useful.
"A lot of medicine has to do with not just our own human cells but really about how humans interact with the bacteria and fungi that live on our bodies," Segre said.
"We did an exploration where we looked at all the different little crevices of your body," she added.
With samples of 14 different skin patches from 10 healthy volunteers, Julie and her research colleagues started with sequencing the fungal DNA obtained from those samples.
"DNA sequence-based methods of identification enabled us to differentiate among species of fungi and to conclude that the diversity of fungi is highly dependent on the body site rather than the person who is sampled. Our study focused on areas of the skin where we commonly find skin diseases that have been associated with fungi," Dr. Heidi Kong, M.D., co-senior author and an investigator in the dermatology branch of NCI's Center for Cancer Research, said.
The results so obtained were published in the journal Nature.
"What we found was that the human body is an even more diverse ecosystem than we had known when we looked only at the bacterial communities," Julie concluded.
Where fungus from the genus Malasezzia dominated over most parts of the body, 80 different species alone existed on the heel of the foot, 60 between the toes and 40 on the toenails.
Though there isn't enough evidence as to why the human feet carry with them such a broad assortment of fungi, the speculation is that this may be a result of temperature fluctuations of the feet.
Yet another possible reason may be the fact that most of us tend to walk barefoot in homes, clearly elevating the exposure.
Further research may help scientists better understand and develop novel methods to treat fungal infection such as athlete's foot, toenail infections and more.
What if we were to find the microbes on the skin either increase or decrease the risk for skin cancer, for example? That might be very important information to have," Joseph Heitman of Duke University, said.
Lastly, if you are a cleanliness freak, or if you're not so comfortable with the idea of hundreds of fungi living on your feet, here's a tip from the study lead.
"It really would certainly underlie the idea that you really do need to take very good care of your feet. So, for example, I do wear flip-flops when I walk around a locker room because I know from these studies that I don't actually want to share the fungi with the, you know, 20 other people who are showering after just going swimming," Julie explains.
