Although fungi also inhabit other areas of the body - such as behind our ears - the researchers found that most of them are living between our toes.
The study, carried out and published in the journal Nature, is the most extensive analysis of the body's fungal diversity to date.
Although only about half of all types of fungi are harmful, they commonly live on the skin and can be a major cause of infection. This finding is key to discovering new ways to treat skin conditions caused by fungal infection.
If you have a weakened immune system or take antibiotics you are more likely to develop a fungal infection.
Although there are treatment options available for fungal infections, research published in the journal Nature has shown that fungi have a lot of potential for "horizontal" gene transfer, similar to the mechanisms that allow bacteria to evolve so quickly, which may lead to antibiotic resistance.
Common fungal infections include:
- Yeast infections - a fungus that lives almost everywhere, including in your body. Yeast infections of the skin cause itching and rashes.
- Athlete's foot - A very common infection caused by fungi. It affects the space between the toes. Symptoms include itching, burning, and cracked, scaly skin between your toes.
- Ringworm - a red skin rash that forms a ring around normal-looking skin - the condition is not caused be a worm.
The study was led by researchers at the National Human Genome Research Institute in Bethesda, Maryland.
10 healthy adults participated in the study, the scientists sequenced the DNA of fungi living on their skin and other parts of the body.
They took samples from behind their ears, between their toes, their backs, toenails, groin, chest, forearm, nostrils, heel, and palm.
The part of the body with the most fungi was the heel with 80 different types of fungi, followed by toenail clippings (60 types) and the toes (40 types). The head contained the fewest types of fungi (only 10).
Lead researcher of the study, Dr Julia Segre, said:
"The data from our study gives us a baseline about normal individuals that we never had before. 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."
The researchers believe that an imbalance of microbes may be the reason why harmful ones spread. In conclusion the diversity of fungi living on the human body was much higher than expected.
Written by Joseph Nordqvist