I have long adhered to the “hygiene hypothesis”, which suggests that increased exposure to microorganisms can benefit our health. However, in our modern, relatively sterile world, neither adults nor children have daily contact with potentially health-boosting bacteria and other microorganisms. New studies suggest this can have an impact on the immune system and even mental health.

A team of scientists at the University of Colorado (UC), Boulder, has now identified an anti-inflammatory fat in the soil bacterium Mycobacterium vaccae, which might explain how the organism can dampen stress-related disorders.

play in the dirt
“We think there is a special sauce driving the protective effects in this bacterium, and this fat is one of the main ingredients in that special sauce,” said integrative physiology professor Christopher Lowry, PhD, who is senior author of the team’s published paper in Psychopharmacology. “This is just one strain of one species of one type of bacterium that is found in the soil but there are millions of other strains in soils. We are just beginning to see the tip of the iceberg in terms of identifying the mechanisms through which they have evolved to keep us healthy. It should inspire awe in all of us.”

“The idea is that as humans have moved away from farms and an agricultural or hunter-gatherer existence into cities, we have lost contact with organisms that served to regulate our immune system and suppress inappropriate inflammation,” said Lowry, “That has put us at higher risk for inflammatory disease and stress-related psychiatric disorders.” The prevalence of anxiety disorders, for example, is now more than 10% in Euro/Anglo cultures, the authors wrote.

Personally, my mother knew the cure to our boredom: GO PLAY OUTSIDE! We might all do well to heed such advice.

Lowry and colleagues reported their findings in a paper titled, “Identification and characterization of a novel anti-inflammatory lipid isolated from Mycobacterium vaccae, a soil-derived bacterium with immunoregulatory and stress resilience properties.”