Microbes in your gut may trigger your motivation to exercise, a new study in mice has found. Compounds produced by the microbes signal the release of dopamine – a neurotransmitter produced in the brain that promotes the “runner’s high” and the desire to exercise.

Researchers analyzed the gut microbial species and the byproducts of their metabolism from nearly 200 mice with diverse genetic backgrounds. They also tracked the animals' daily exercise activity and measured their endurance.

They found that mice that had certain species of gut microbes – Eubacterium rectale and Coprococcus eutactus – exercised more and had greater endurance than mice lacking these microbes. These two species produce compounds called fatty acid amides, which interact with gut neurons and ultimately activate dopamine-producing neurons in the brain, turning on the brain’s reward circuits and triggering the desire to exercise.

This study in mice reveals a novel way in which the gut microbiome influences human health and behavior. It may also provide evidence to support the use of therapeutic microbial transfer to promote exercise behavior and improve aspects of mood.

• Read study abstract.

• Learn more about how gut microbes influence human health and behavior in this episode featuring Dr. Eran Elinav.