Fungus is among us - in our ears, nose and toes - what you need to know

Teresa Tanoos's picture
New study finds fungus all over your body, especially your feet
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In the first genetic study of all the fungi that live on our skin, government researchers have found that fungus is certainly among us, not to mention all over us.

From our ears and nose, to the stuff between our toes, we are covered with hundreds of different types of fungus, according to the National Institutes of Health. And while most of our bodies are covered with fungi that belong to the same species, researchers report in the journal Nature that our feet are crawling with hundreds of different species of fungi.

"This is going to make me always wear flip flops in the locker room. When you see how many fungi can live on your feet, you realize (that) you are sharing your fungi with everyone who is walking around that locker room with you,” says Julie Segre, who led the research team at the National Human Genome Research Institute.

The researchers found DNA from fungi in the nostrils, ears, scalp, as well as on the hands. But the body part where they found the most fungus was predictable for anyone who ever had athlete's foot, as your feet are loaded with fungus.

As for fungus on the head and trunk of the body, referred to as the core, the researchers found just one single family of fungus, Malassezia, of which there are 11 different species, including the one that causes dandruff.

"I was surprised that there was just one type of predominant fungus on your core body," Segre says.

However, it's the feet where fungus is predominant.

For the study, researchers at the National Human Genome Research Institute examined 10 healthy volunteers, taking samples from 14 different parts of their body in search of fungus.

Under a fluorescent microscope, they could detect bacteria and fungi surrounding a hair follicle, with fungi appearing blue-green, bacteria appearing pink, and skin cells and the hair shaft appearing yellow.

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As a result, two of the volunteers looked like they possibly had fungal infections, as indicated by their scaly heels and thick toenails. They also had a similar-looking family of fungi on their feet, while the other eight had different species of fungi on their feet.

In addition to causing disease, fungi also stink...literally.

"The fungi help to make your feet stinky," Segres says. "The odor is a byproduct of the microorganisms, the bacteria and the fungi."

Not only did researchers find Malassezia, but they also found Penicillium, the mold that penicillin comes from; Saccharomyces, the yeast used in making bread and beer; and Aspergillus on the feet of their volunteers. Fungi between the toes are different from the species found on the heels, and according to Segre's team, there were 80 different species of fungi on the feet.

Segres said it's futile to use anti-fungal creams to get rid of all the pathogenic fungi.

"Even when you really scrub your skin you are not removing all the bacteria and fungi," she said. Good fungi, just like good bacteria, help keep the skin healthy, she said.

"We have to start thinking about our bodies as ecosystems," Segres added. "Just as many of the foot powders will cause your feet to be less sweaty, when you put on moisturizer you are fertilizing the fungal microorganism garden."

So why are the feet such a magnet for fungus?

"I think it's temperature," Segres said, explaining that feet can be as much as 15 degrees cooler than the rest of the body. "Because your feet can be sometimes hot, sometimes cold, there can be different fungi."

Source: Nature journal (May 22, 2013) doi:10.1038/nature12171

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