Search Here

When the subject of feet comes up, people often think of the words 'stinky' and 'dirty.' Even though feet is associated with being dirty since it touches everything on the floor, people are unaware of just how dirty the human feet are. According to a new study, the feet are home to over 100 species of fungi. Fortunately for us, the bacteria, viruses and fungi that reside on the outside and the inside of the human body generally have very healthy relationships. These microbes exist to help fight off diseases and infections. However, when there are bad bacteria present on the feet, they can lead to infections, such as athlete's foot.

The researchers, with senior researcher, Julie Segre from the U.S. National human Genome Research Institute, recruited 10 healthy volunteers and analyzed the fungi makeup of their skin. The researchers use DNA-sequencing technology in order to map the diversity of the fungi environment living on the feet. The team discovered that the most diverse group of fungi existed on the sole of the foot, which is under the heel. Other populous areas were around the toenails and on the webbing in between toes.

"[The concentration] probably has to do with temperature and the exposures our feet have," Segre said in regards to why fungi accumulate here.

"They're encloses in this tight container called the shoe. And it gets hot and humid in there, which are conditions the fungi like," added Dr. David Relman, a professor of microbiology and immunology at Standford University School of Medicine in Palo Alto, CA. Relman was not a part of this study.

Despite these findings, the researchers are not quite sure what the wide range of fungi does for the feet or the body. The researchers theorized, based from previous studies, that fewer fungi communities increased the risk of infections. Therefore, the abundance of fungi on the feet could help protect the feet from infections. The researchers presented one more theory stated that the use of antifungal medications could have broadened the diversity of fungi as well.

The study was published in Nature. More information can be found on the NIH website.