The Brain gut connection is a mass of neural tissue filled with neurotransmitters known as the enteric nervous system. It runs from our esophagus to our anus and is nearly 9 meters long. It does much more than just handle the digestion or inflict the occasional nervous pang. It appears, as scientists have nicknamed it the second brain, that the little brain is connected to the big one and partly determines our mental state and plays a key role in certain diseases and disabilities throughout our body.
The second brain consists of sheaths of neurons embedded in the walls of our gut. Much of this neural firepower is used in the daily grind of digestion. Breaking down food, absorbing nutrients, and expelling waste require a great deal of “thought” that our big brain would rather not do. Thus the second brain appears to have independent functions from the big brain. It has its own reflexes and senses.
The second brain is a big part of our emotions landscape. Gastrointestinal problems can sour our mood, everyday emotional well-being may rely on messages between the brains. Although it seems to be a one way street, with the second brain sending and the big brain only receiving.
Given the two brains’ commonalities, other depression treatments that target the mind can unintentionally influence the gut. The enteric nervous system uses more than 30 neurotransmitters, just like the brain, and in fact, 95 percent of the body’s serotonin is found in the bowels. Because antidepressant medications called selective serotonin reuptake inhibitors (SSRIs) increase serotonin levels, it is little wonder that meds meant to cause chemical changes in the mind often provoke GI issues as a side effect. Irritable bowel syndrome—that afflicts more than two million Americans—also arises in part from too much serotonin in our entrails, and could perhaps be regarded as a “mental illness” of the second brain.
Scientists have learned that serotonin made by the second brain plays a role in bone density and may even play a role in autism.
Because of these discoveries between the brain and the gut, colon health has become a key focus for overall health and especially mental health. So the next time you get butterflies or you have a gut feeling just know the second brain is talking to you.