Many people experience the mind-body connection through their gut via intuition, nervous “butterflies” or irregularity under stress. But would you believe that some of the normal, healthy bacteria in the gut, known as “probiotics”, can have a direct impact on the brain chemicals that affect mood?
Research from University College Cork, published in the prestigious Proceedings of the National Academy of Sciences showed that probiotic bacteria in mice altered their brain neurochemistry and thus impacted their mood and anxiety levels. The mice that were fed a broth containing the probiotic Lactobacillus rhamnosus were found to have significantly fewer behaviors associated with depression, anxiety and stress than mice that were give plain broth without the microbes. The mice given the probiotic also produced less of the stress hormone cortisol.
They even showed that the probiotic changed the expression of GABA receptors, the first time it’s been shown that gut bacteria can have a direct effect on brain chemistry. [GABA is a calming brain chemical, and some of the most powerful anti-anxiety drugs like Valium, Xanax and Ativan work through the GABA receptors.]
How can a bacteria in the gut communicate with the brain? The researchers showed that this happens through the vagus nerve, which transmits information between the “microbiome” (bacteria in the gut) and the brain (think of a fiber-optic cable that carries information across long distances).
There is the hope that this research may lead to new adjunctive treatments for mood, anxiety and other stress-related disorders. You do not need to wait for drug companies to develop these products, however. Refer to this month’s feature article, which lists two probiotic products containing several different microbes, including Lactobacillus rhamnosus.
Javier A. Bravo, Paul Forsythe, Marianne V. Chew, Emily Escaravage, Hélène M. Savignac, Timothy G. Dinan, John Bienenstock, John F. Cryan. Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. Proceedings of the National Academy of Sciences, 2011; DOI: 10.1073/pnas.1102999108