Why do horses roll around in the dirt during the summer? This was the question that prompted MIT scientist Dave Whitlock to refrain from taking a shower for over a decade to help preserve “good bacteria” on his skin.

Instead of taking a shower, the chemical engineer sprays Mother Dirt ,a mist containing live bacteria, on his skin twice a day, the mist is manufactured by a Cambridge-based company, AOBiomein, which Whitlock is a cofounder.

“I have not taken a shower in over 12 years,” said Whitlock. “No one did clinical trials on people taking showers every day. So what’s the basis for assuming that that is a healthy practice.”

The staff of AOBiomein pictured with MIT scientist Dave Whitlock in the center

Whitlock got the idea after a friend of his asked him about her horses’ summer habit. “The only way that horses could evolve this behavior was if they had substantial evolutionary benefits from it,” the Dailymail quoted him as saying on Saturday.

Humans need to reconnect with their environment, says Jasmina Aganovic, the general manager of consumer products at the company. “We’ve taken the dirt out of our lives. We don’t spend as much time outdoors as we used to, even little children.”

She added that people have confused “clean with sterile,” which has selectively depleted the natural balance of the skin microbiome.

