Volunteers sweat for science at NC Museum of Natural Sciences

On Thursday, a day when temperatures hit 91 degrees, several dozen people paid a visit to the N.C. Museum of Natural Sciences to offer a roomful of scientists and onlookers a peek at their underarms.

This is part one of a two-part study that will examine the microbiome, or community of tiny organisms, living in human armpit sweat.

“I always like to help out science,” said volunteer Glenn Hennessee, a retired laboratory supervisor at N.C. State University.

Other participants were museum employees, graduate students and people who saw a flier or a tweet and signed up to make their own personal contributions to science.

To collect microbes, museum interns and staff rolled long Q-tips in participants’ armpits. Then they taped a cotton patch in one armpit and asked the participants to go outside for half an hour and work up a sweat.

“I think you can pretty much just stand outside today,” said Julie Horvath, director of the Genomics & Microbiology Research Laboratory at the museum and a lead investigator of the study.

While the Q-tips collected material to be sequenced for microbiota DNA, the cotton patches will be analyzed for metabolites, which are the chemical products of bacteria and human metabolism.

After half an hour, the flushed participants returned and relinquished their patches. Their armpits were then swabbed one last time with a cotton ball. This would be analyzed for volatile chemicals, a metabolite that dissipates quickly, Horvath said. These chemicals are often responsible for odors.

The average person is habitat for trillions of individual bacteria, as well as some archaea – single-celled organisms more closely related to people than to bacteria – and microscopic fungi. Scientists are just beginning to identify these microbes, which may represent thousands of species and which are harmless or even beneficial to healthy people.

Just as the bacteria in our gut might be altered by what we eat and the medicines we take, what lives in our armpits likely varies with the beauty products we use, where we live and even who we share our beds with.

For the next three days, participants will not use deodorant or antiperspirant, will wash with unscented soap and use unscented lotion, will use towels and sleep in sheets laundered with unscented detergent and will wear the same T-shirt to sleep in – alone and without pets – every night.

On Sunday, they’ll come back to the museum to be swabbed and sampled again so that researchers can compare their armpit communities with and without the effects of deodorant. They’ll also bring in the T-shirt they’ve been sleeping in the past three nights.

Volunteers have signed up to sniff these T-shirts in a “smell-off” on Sunday from 3 to 5 p.m. in the museum’s SECU Daily Planet auditorium.

A lot of primates use scent to communicate, said Horvath, and scent may be important in humans as well. A person’s scent may make him or her more or less attractive to potential mates.

In that way, our microbiome might even influence our behavior.

The study is a collaboration between researchers at the museum, N.C. State University, and the non-profit research group RTI International.

This story was originally published June 25, 2015 at 7:30 PM with the headline "Volunteers sweat for science at NC Museum of Natural Sciences."