Human Feet Home to Nearly 200 Different Types of Fungi

Scientists have recently discovered that the human foot is home to more than 200 different types of fungi, according to the BBC News.

Although fungi live "all over the human body," a new study reveals that feet, particularly the heel and under toenails, are their favorite spots to the harmless fungi to exist and grow.

The team of researchers led by the National Human Genome Research Institute in Bethesda, Maryland "sequenced the DNA of fungi living on the skin at 14 different body areas in 10 healthy adults." Fungi samples were extracted from the ear canal, heel, toenails, between the eyebrows, palm, chest, between the toes, forearm, nostrils and groin of healthy adults, and the data revealed that "fungal richness varies across the body."

In the study, 60 types of fungi were found in toenail clippings, 40 types between the toes, and 80 types on the heel, the most complex of fungal habitats. Other "favored fungal hotspots" included the palm, forearm and inside of the elbow, which had about 18 to 32 types of fungi each. In contrast, the head and the trunk had just two to 10 types each.

"The data from our study gives us a baseline about normal individuals that we never had before," lead researcher Dr. Julia Segre said. "The bottom line is your feet are teeming with fungal diversity, so wear your flip flops in locker rooms if you don't want to mix your foot fungi with someone else's fungi." 

Although fungi on the skin is normal and generally harmless, if it multiplies it may result in infection. In 20 percent of volunteers studied, researchers found problems consisting of such fungal infections. They believe that an imbalance of microbes may "provide an opportunity for harmful microbes to flourish and establish disease."

Fungal expert Dr. Paul Dyer of Nottingham University said normally fungi can co-exist on the human body without causing illness or any harm, unless someone has a poor immune system.

"It illustrates the tremendous diversity of fungi that grow on the human body," he said on the topic of the new study. "This is much higher than we previously knew."