The Beatles sang the words, “You say you got a real solution,” in their song, Revolution, but little did we know that it all starts in the gut. The correlation between the mind and the gut, our second brain, is revolutionizing medicine’s understanding of the links between digestion, anxiety, mood, health and even the way you think.

We’ve all experienced the infamous butterflies before a big speech, sporting event, or social outing. Underlying this sensation is an often-overlooked network of neurons lining our guts that is so extensive some scientists have nicknamed it our “second brain” or technically speaking, the enteric nervous system (ENS). The ENS is one of the main divisions of the nervous systems and governs the function of the gastrointestinal system (Gut).

The Gut, or the second brain, is proving that it does much more than merely handle digestion, but in connection with our main brain, partly determines our mental state and plays key roles in certain dis-EASEs in our body.

The second brain running from the esophagus to the rectum contains some 100 million neurons, more than in either the spinal cord or the peripheral nervous system. As important as the neurons in the gut, is the kind of bacteria found there. What do they have to do with psychiatry? The gut and brain have a steady ability to communicate through this nervous system, hormones, and the immune system. The communication is driven from gut bacteria that can alter the biochemistry of our brain (in our head).

The notion that the state of our gut governs our state of mind actually dates back more than 100 years. Many 19^th and 20^th-century scientists believed accumulating wastes in the colon triggered a state of “autointoxication,” whereby poisons emanating from the gut produced infections that were linked with depression, anxiety, and psychosis. Patients were treated with colonics and enemas until these practices were dismissed as quackery.

Currently, John F. Cryan, PhD, a neuropharmacologist and micriobiome expert from the University College Cork in Ireland, is one of the scientists at the forefront of exploring the link between gut and brain health today. Dr. Cryan and his colleagues discovered that when mice are bred in sterile conditions – lacking of beneficial bacteria (think the Standard American Diet) – they do not interact with other mice and behave with social awkwardness. Also, when they disrupted the microbiome, the mice mimicked human anxiety, depression, and autism.

So what are we to do? The answer has always been there. It’s not the easiest one and it takes commitment and dedication, but eating a healthy diet is, and always will be, the vintage solution. There will continue to be studies that steer us to one belief to the next, but the most important thing is listening to our gut, the most intelligent healer of all, to truly understand what works for individual needs.