Why do we say that the gut is our second brain?

the intestine, the digestive system, gut microbiota, etc. have never been as popular as they have been in recent years… Are we taking a closer look?

Gut, enteric nervous system and gut microbiota

The gut microbiota, it is a set of more than 100,000 billion micro-organisms (bacteria, yeasts and fungi) which are found in the intestine. Intestine which is also the seat of many nerve cells, immune cells… and whose proper functioning is intimately linked to interactions with the microbiota!

Is the gut our second brain?

It was Dr. Michael Gershon who first became interested in the concept of “second brainreported to the gut in the late 1990s. “Unlike the heart or the muscles whose activity is controlled by the central nervous system (CNS) at the level of the head, our intestine has its own nervous system, called enteric (ENS), explains this researcher, professor at Columbia University (New York)¹. This one is almost self-contained.. According to Dr. Gherson, the SNE would be a kind of co-pilot of the central nervous systeml … and could even go against a cerebral command! Made up of around 200 to 600 million neurons, the ENS deserves its reputation as 2^e brain !

But if the concept of ‘second brain’ is relatively recent, interest in the link between brain and intestine is not new! In antiquity, the awareness of the link between mood and food had motivated the development of the precepts of melancholy and black bile and diets were recommended to cure certain moods…

What does the enteric nervous system do?

In fact, the enteric nervous system is to the gut what the central nervous system is to the brain. And it is this relationship that is worth comparing the intestine to the brain… The 2^e brain thus takes the form of hundreds of millions of neurons that line the inside of the intestinal membrane. “The structure of these neurons is comparable to that of the brain. They all come from the same neural tube which develops after a few weeks in the fetus.explains Francisca Joly, gastroenterologist at the Beaujon hospital (Clichy) to the magazine “It interests me”.

The entire digestive system would therefore be governed by the enteric nervous system Who :

• would act on the regulation of transit
• control bowel functions

The role of the ENS is not confined solely to the control of digestive functions…

• It is also closely related to immune system since 70 to 80% of immune cells are concentrated in the digestive system.
• The SNE also acts on emotions thanks to the link that enteric nerve cells establish with the central nervous system via various hormones including serotonin, also called the hormone of happiness… and which seems to be produced at 95% in the intestine¹ !

Intestine and brain, what do they have in common?

“In humans, variations in the microbiota have been demonstrated in various psychiatric and neurological disorders, such as autism or mood disorders, and in various neurodegenerative diseases, such as Parkinson’s disease.details Dr. Steven Laureys, doctor, neurologist and Senior Researcher at the FNRS in “Cerveautherapy” (see reading). Its importance is such that we now speak of the microbiota-gut-brain axis, but we still do not know much about its exact role.

From then on, the interest shown in the intestine is further increased tenfold! The prospects for science, research and medicine are enormous because the intestine is much easier to access than the brain … and also because its study could make it possible to make very good advances in the fight against certain diseases. such as Parkinson’s, Crohn’s disease… and even anorexia!

To read.

1. Michael Gershon, The Second Brain.

Read also:

• Irritable Bowel Syndrome: Symptoms, Causes and Treatments

• What is the link between depression and microbiota?