A research team working at NC State’s Dunn Laboratory has recently concluded that all humans over the age of 18 have species of microscopic mites living on their faces. The researchers hope the discovery of these mites can help shed light on early human history and on the interaction of different mammals.
The study has been conducted by several NC State researchers, including Robert Dunn, an associate professor of biological sciences, Megan Thoemmes, a graduate research assistant in biological sciences, and Dan Fergus, Ph. D. in biological sciences. Julie Urban, assistant director of the Genomics & Microbiology Research Laboratory of the Museum of Natural Sciences, and Michelle Trautwein, assistant director of the Biodiversity Laboratory of the Museum of Natural Sciences, also participated in the study.
Their research, which was conducted largely through North Carolina’s Museum of Natural Sciences, indicates that there are two distinct species of mites living on people’s skin: the D. folliculorum, which generally inhabits hair follicles and the D. brevis, which lives deeper in the oil gland, underneath the hair follicle.
According to the results of the study, there are about three to six D. folliculorum mites and one
D. brevis mite in every hair follicle.
“It’s so awesome to hear about these mites,” said Sarah Lucas, a freshman in engineering.
“I mean, you learn something new every day. But I guess the scientist in me wants to know what the implications this is going to have.”
The team hopes its research can be used to help find out more about the early history of humans.
“One of the results of the study shows that human populations from different geographic locations have mites with different genetic mutations,” Thoemmes said. “The mite’s DNA may reflect how humans have moved around the world.”
The presence of microscopic mites living on the surface of our skin has been suspected for about 200 years because similar mites were found on other mammals. Mites were also found on 100 percent of corpses. However, scientists had difficulty finding evidence on living humans until this study officially confirmed that mites were present on all adults.
Collecting samples and looking for live mites is extremely difficult, according to Thoemmes. There are several different methods, including pulling tape from the skin and using a laboratory spatula to scrape skin cells away.
“We used a scraping method with mineral oil, which yielded more results, but I was surprised at how difficult it was to find any mites,” Thoemmes said.
Rather than simply looking for mites, the team instead tested the samples for mite DNA. This proved much more successful, because the mites generally live deep under the surface of the skin. However, they rise to the surface of the skin to defecate.
“That’s how we found the evidence of mites on 100 percent of adults,” Thoemmes said.
This is also most likely why corpses are more easily tested for the presence of mites. Thoemmes suspects that the mites rise to the surface because a corpse no longer provides an adequate food source. However, there is still uncertainty about what the mites eat.
“There are still so many questions that we haven’t found the answers to,” Thoemmes said.
The mites do not seem to pose any danger to our health, according to Thoemmes. The research does not indicate that the mites can transmit any diseases.
“What they are doing on our body is also not clearly understood, but they are probably communalistic. We are more likely working with each other rather than against each other,” Thoemmes said.
However, previous studies have shown that there may be a correlation between high population of mites and medical conditions such as acne and rosacea, but the nature of that relationship remains unclear. Currently, Fergus and Urban are continuing research into this relationship through a secondary study in which they examine the bacteria associated with the mites.
In addition to finding out more about early human colonization, the researchers hope they can compare the genetic sequence of mites from different mammals to see how different mammal species interacted.
For example, the study found that D. brevis is more closely related to the species of mite that lives on domesticated dogs than D. folliculorum. Although only about nine species of mites from other mammals have been sequenced, research team at Dunn Laboratory are continuing research on different mammals.
“It’s possible that every mammal has at least one species of this type of mites,” Thoemmes said. “There could be upwards of 10,000 species that have been undescribed.”
