Your intestines house about ¾ of your total immune system. That means if we want our bodies to be healthy, we need to keep the friendly bacteria in our guts happy by eating lots of fiber and adding probiotics foods (foods containing active bacteria) or probiotic supplements to our diets.
Beyond the benefits a healthy gut offers our body, new research is showing that it may also lead to a healthy mind. A recent study conducted by researchers at the University of California, Los Angeles (UCLA) found that women who consumed a fermented milk product with added probiotics twice a day for four weeks showed significant changes in their processing of emotions and sensations. This small study randomly assigned 36 women to one of three groups. The first group consumed yogurt with added probiotics, the second consumed a non-fermented dairy product, and the third had no intervention at all. All women underwent magnetic resonance imaging (MRI) prior to and at the conclusion of the study. The women who consumed the yogurt with probiotics showed a marked decrease in anxiety and stress. (Tillisch, June 2013)
This study follows previous research conducted with rodents in which microbes in the intestines of timid mice were replaced with bacteria from the intestines of fearless mice, and vice versa. The mice in both groups began to exhibit the behavior of the other group when their gut bacteria was switched. This is thought to be due to the direct communication of the GI tract to the brain via the vagus nerve. Particular bacteria appear to be associated with anxiety and fear, while others appear to be associated with courage and a more out-going attitude. (Stein, 2013)
This “microbiome” research is still in its infancy, but the implications are that a healthy gut may improve mood and give us the ability to better cope with the stresses of daily life.
You can support your gut’s healthy microflora by eating healthy pre-biotic foods, like onions, garlic, and cabbage. These foods feed the healthy bacteria and help them flourish, while discouraging the growth of harmful organisms. You can also add probiotics to your diet as discussed above by eating naturally occurring active cultures of bacteria in yogurt, miso, kefir, kimchi, and other fermented foods. Probiotics also come in supplement form. Look for a supplement from a reputable manufacturer that contains several strains of beneficial bacteria.
- Stein, R. (2013, November 18). Gut Bacteria Might Guide the Workings of Our Minds. Retrieved from NPR.org: http://www.npr.org/blogs/health/2013/11/18/244526773/gut-bacteria-might-guide-the-workings-of-our-minds
- Tillisch, K. e. (June 2013). Consumption of Fermented Milk Product with Probiotic Modulates Brain Activity. Gastroenterology, 1394-1401.