We all have nearly 200 different types of fungi colonising our feet, scientists have discovered.
Fungi live all over the human body, but their favourite spots are the heel, under toenails and between the toes, according to a US study.
A new map of the body’s fungal diversity could help combat skin conditions such as athlete’s foot, researchers report in Nature journal.
Harmless fungi live naturally on skin but cause infection if they multiply.
In the first study of its kind, a US team catalogued the different groups of fungi living on the body in healthy adults.
A team 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.
Samples were taken from the ear canal, between the eyebrows, the back of the head, behind the ear, the heel, toenails, between the toes, forearm, back, groin, nostrils, chest, palm, and the crook of the elbow.
The data reveal that fungal richness varies across the body. The most complex fungal habitat is the heel, home to about 80 types of fungi. The researchers found about 60 types in toenail clippings and 40 types in swabs between the toes.
Other favoured fungal hotspots include the palm, forearm and inside the elbow. These had moderate levels of fungi, with each location supporting 18 to 32 types. …
We are communal organisms. We may learn that in addition to beneficial bacteria in our microbiome, there are good fungi which provide us with things like immune system support.
When it comes to the trillions of microorganisms that inhabit our bodies, bacteria get almost all the attention.
Changes in our resident microbiota and their collective genome — called the microbiome — have been linked with a wide range of diseases, from various forms of arthritis to depression. At this point scientists tend to focus on which bacterial species might hinder or maintain health.
But our biota comprises a menagerie of microbes. And a growing number of researchers feel that alongside bacteria, the fungi that inhabit our bodies – or, collectively, the “mycobiome” — may also be influential in both our well-being and, at times, disease.
Also found in the baseline biome were, after Candida, the most common disease causing fungi: Aspergillus, Fusarium and Cryptococcus. That so many potentially harmful fungi were found to be common, Ghannoum believes, could mean that under normal conditions other fungi and microbes may keep these pathologic strains in check.
Supporting this idea that disrupting the body’s fungal equilibrium can bring about disease was a paper Ghannoum published a few years later looking at the fungi present in the mouths of HIV-infected patients. They found that Pichia – a yeast used in agriculture to prevent the growth of other fungi on various crops – inhibits the growth of Candida and other pathologic fungal species.
“By growing Pichia in the lab we found that it secretes a compound that can treat fungal infections in animals,” Ghannoum explains. In mice with compromised immune systems, which served as an animal model of HIV, those exposed to Pichia developed far less severe infections when inoculated with Candida.