A study conducted at the University College Cork in Ireland suggests that what’s going in our guts might have a lot to do with what’s going on in our minds.

In the study, researchers introduced gut bacteria to two groups of mice. The first group was raised in a germ-free environment, and the second group was raised in a normal environment. The mice living in the germ-free environs had unusual amounts of anxiety, deficits in sociability and cognition.

“Gut microbes seem to influence miRNAs (gene regulators) in the amygdala and the prefrontal cortex,” says Dr. Gerard Clarke, one of the researchers. “This is important because these miRNAs may affect physiological processes that are fundamental to the functioning of the central nervous system and in brain regions, such as the amygdala and prefrontal cortex, which are heavily implicated in anxiety and depression.”

Dysregulation and dysfunction in miRNA is believed to be an underlying factor contributing to stress-related psychological disorders, and miRNA changes in the brain have been implicated in anxiety-like behavior.

When the gut bacteria was added back into the to the germ-free environment, changes in the mice’s miRNA normalized, hinting that a healthy gut biome could be key in regulating miRNAs.
So if your morning yogurt or kefir puts you in a good mood, keep doing what you’re doing…there may be science behind that happy feeling.