The Brain in Your Gut: Gut health linked to brain health
by Carolyn C. Ross, M.D., M.P.H
You may already know that different parts of the body communicate and send signals back and forth. Researchers have recently discovered that “cross-talk” between gut bacteria and the brain may reduce your risk for a variety of health issues, including psychiatric illness, intestinal problems and even obesity.
Gut flora is made of the microorganisms (bacteria) that naturally live in our digestive tracts. Gut bacteria (flora) has been linked to diseases like inflammatory bowel disease and even asthma.
According to scientists, stress can alter the natural balance of bacteria in the intestines, leading to a decrease in immune system function. When scientists reduced the number of bacteria in the intestines using antibiotics, some of the effects of stress on the immune system were prevented. This led researchers to discover that stress can not only change the bacteria levels in the gut but also this decrease in bacteria levels and perhaps an increase in more harmful bacteria caused by stress can have a detrimental effect on the immune system.
Other important functions of the gut-brain axis include animal research showing that the colonization of the gut with healthy bacteria right after birth can actually regulate the set point for how we respond to stress and can affect behavior, learning and memory. Colonization occurs in humans by vaginal birth (vs. C-Section) and by breast feeding. Animals without the healthy bacteria right after birth in their gut were more likely to be anxious and were more likely to engage in behaviors deemed risky. Yet, when young bacteria-free mice were exposed to microorganisms they developed more normal behaviors while adult germ-free mice exposed to microorganisms did not experience any behavioral changes. This suggests the normal colonization of flora during infancy influences early brain development.