Intestine: why is the organ considered the second brain?

It is through the digestive system that you remove all the energy that your body uses.

The food you eat travels a few inches from your mouth to your stomach, where much of it is digested. But this is only the beginning of the journey.

After the stomach, the food goes to the small intestine and then to the large intestine. This is the long way.

The two intestines, together, can be 6 to 8 meters long, curled there inside your belly.

Much of the absorption of nutrients takes place within it, but this organ is capable of much more. To understand, it is important to learn a little about the central nervous system .

Central Nervous System

The Central Nervous System (CNS) affects the entire body in several ways.

It is what makes you feel pain to know that you need to take your hand off the fire, allows you to move your arms, balance with your legs, speak, feel tastes and smells, and see.

It is the Central Nervous System that controls the speed at which your heart beats and which coordinates your feelings as well. It is thanks to the central nervous system that you can feel happy, sad, excited, peaceful.

Neurotransmitter imbalances in the CNS are believed to cause depression , anxiety and many other emotional problems.

So it affects his whole life, but there are a few things he doesn’t do. Control your digestion, for example. Who does this is Enteric Nervous System.

Enteric Nervous System

Your digestive system is like a second brain in your body. It is extremely long and has around 500 million neurons.

It’s not even close to the 86 billion neurons in your actual brain, but it’s still a considerably high number.

The intestine is the only organ in the body that works perfectly well without the commands of the brain. That is why the gut neuronal system is called the Enteric Nervous System , or the SNE.

These neurons make your stomach produce stomach acids when you start to chew, they are the ones that decide when food is digested enough to go from the stomach to the intestine and they are also the ones that tell the intestinal muscles to move.

Most of these neurons are found in the walls of the intestine. They coordinate the organ’s movements and, only at the end of the path, when the urge to evacuate appears, the brain (and the CNS) regains control.

For years, scientists have been studying the SNE to find out about the connection between it and the brain.

One of the main findings involves the intestinal microbiome . The intestinal microbiome, or intestinal flora, is the set of bacteria living in the intestines.

Microbioma

Bacteria are the biggest cause of death for mankind. Infections have been killing for millennia and it was only in the last century that we discovered antibiotics , an incredible weapon against this great enemy.

But not all bacteria are bad. Most, in fact, are necessary for our survival.

On average, the human body has 30 trillion cells and 39 trillion bacteria.

That’s right. Your body, in numbers, has more bacteria than human cells.

Most of these bacteria live in your intestines, where they can receive food. Thus, they help you with digestion and nutrient absorption. But they also affect the environment where they live.

Read more: Step by step: how to make water and milk kefir?

How does it all connect?

The Enteric Nervous System is able to function independently, but that does not mean that it is isolated from the Central Nervous System. The two communicate.

One of the main ways in which this communication takes place is through the intestinal flora.

The bacteria present in the intestine interact with the intestine and the SNE, which in turn sends signals to the CNS through hormones, the immune system and the vagus nerve (communication channel between brain and organs).

This communication means that what happens in your gut influences the rest of your body.

The term stale comes from, you might imagine, feces. Do you know when someone is in a bad mood because they are constipated ? So, that’s why. Constipation affects people’s mood. It is not for less, it is a very unpleasant situation.

This is just one example of this influence, but studies indicate that it can go much further than that.

Neuroscientists, in recent decades, have also studied how the presence of certain bacteria in the intestine can influence psychiatric diseases such as anxiety , depression and schizophrenia .

There is research that even indicates that the intestinal flora can influence the behavior of people with autism .

The intestinal flora of people with depression is different from that of people with anxiety, which in turn differs from a person without any psychiatric illness.

To test this, a Canadian study switched feces between naturally anxious mice and naturally less anxious mice.

The result was surprising when there was a change in behavior in both cases.

The anxious animals, which received the intestinal flora from the most tranquil, became calmer as well.

Likewise, the rats without the anxious trait that received the transplant were more agitated. The intestinal flora altered the animals’ behavior.

What does that mean?

The findings indicate that the central nervous system and the enteric system greatly influence each other, in addition to pointing out that the intestinal flora is very important in this process.

Learning to control and identify the causes of these influences can open a new path for the treatment of psychiatric illnesses.

In the not too distant future, a treatment option for depression, for example, may be altering the intestinal flora, which can be done in ways as simple as inserting a different yogurt in the diet.

While we haven’t figured out exactly how to do this, remember to treat your second brain well. Eat plenty of fiber, eat well and take care of your intestinal health. So she can take care of you too.


The gut has so many neurons that it can almost be considered a second brain in our body. The Enteric Nervous System is able to influence our mood to the point of having effects on diseases such as depression and anxiety.

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