Second Brain Theory

QUOTE

Emeran Mayer once said…

“The gut is not like Las Vegas—what happens in the gut does not stay in the gut.”

(Gastroenterologist and author.)

CONCEPT

Second Brain Theory

The Second Brain Theory refers to the idea that our gastrointestinal tract functions like a second brain in our body.

This concept is rooted in the scientific discovery of the enteric nervous system (ENS), a complex system of about 100 million nerves found in the lining of the gut. The ENS is so extensive that it can operate independently of the brain and spinal cord, which is why it’s often referred to as the body's second brain.

This second brain communicates with the brain via the vagus nerve and produces many of the same neurotransmitters, including a large amount (about 95%) of the body's serotonin, a key mood-regulating neurotransmitter.

STORY

You Are What You Eat … For Real?

A profound illustration of the Second Brain Theory in action is the story of how changes in gut health have been observed to affect mental health.

Researchers have found compelling evidence linking the condition of the gastrointestinal tract to mood disorders such as anxiety and depression. One notable study is the research conducted by scientists at McMaster University in Canada.

In this study, researchers experimented with two groups of mice: one group with normal gut bacteria and another that was germ-free, meaning they had been raised without the normal microorganisms that colonize the gut.

The germ-free mice showed significantly less anxiety than their normal counterparts. However, when the germ-free mice were colonized with bacteria from anxious mice, they began to exhibit anxiety-like behavior.

This research highlighted the influence of gut bacteria on behavior and supported the Second Brain Theory by showing how the gut's health directly affects the brain's function.

Discovering this connection has opened up new possibilities for treating mood disorders through dietary changes or therapies aimed at altering gut bacteria, leading to an increased interest in the microbiome's role in mental health and its potential as a target for new types of treatment.