Found: The Bacteria That Are Making You Stink

Scientists have finally discovered the culprit behind smelly armpits

237/Chris Ryan/Ocean/Corbis

What’s that smell? If it’s coming from your armpits, chances are it’s Staphylococcus hominis. For the first time, researchers have isolated the group of microbes that make our underarms stink—and their findings just might change the way we fight the funk.

A group of microbiologists have discovered the reason body odor is so smelly, reports Poncie Rutsch for NPR. Spurred on by questions about the processes that make us smell, scientists from the University of York in England studied the microbiome of human underarms. The answer, they found, lies in thioalcohols—which is produced when human sweat interacts with armpit bacteria.

“These odorless molecules come out from the underarm, they interact with the active microbiota, [and] they're broken down inside the bacteria,” study lead Dan Bawdon told NPR. Accordng to Bawdon, thioalcohols, which smell comparable to meat, sulfur, onions and other stinky substances, are “very, very pungent.” When they evaporate from the underarm, Rutsch continues, they start to smell.

In a release, the team describe how they isolated over 150 thioalcohols produced by different bacteria, then pointed the finger at three particularly smelly culprits: S. hominis and two other species of Staphylococcus. When they reverse-engineered the process, they knew they were right—these bacteria produce B.O.

The team hopes their research might change the way we fight back against smelly armpits, allowing scientist to produce deodorants that kill the right bacteria instead of laying waste to all bacteria under the arms or blocking sweat glands. By “leaving the underarm microbiota intact,” says the team, companies like Unilever (who helped fund the project) can develop safer and more effective deodorants.

While you wait for deodorant tech to catch up with this stinky new research, why not try a new (old) trend in current-day deodorants? The New York Times reports that spray deodorants, which went out of fashion in the United States during the 1970s and 80s, are back with a vengeance, fueled by consumers who can’t bear the thought of leaving white streaks on their favorite clothes.

Get the latest stories in your inbox every weekday.