New studies reveal: we have a second brain in our body

Start training

Our brain is the place where our thoughts and emotions are formed. But have you ever experienced situations in which you were incredibly sad or extremely happy? Where in your body did you experience these feelings? Did you get a headache, was your brain in pain? Or did you rather feel these emotions in your stomach - as endlessly hollow sadness or joyful butterflies jumping around? We experience these emotions in our stomach, in our gut. This means that there is some sort of connection between our gut and our emotions. 

But what exactly does this connection look like? Is our gut a recipient of signals - such as emotions - coming from the brain or does it actually have an influence on the formation of emotional processes in our brain?

Our second brain

Our body's second brainWe can get a feeling of how clever our gut really is, when looking at the huge amount of neurons living there. The number of neurons in our gut is higher than in the entire so-called peripheral nervous system, a system responsible for transmitting information from our body to our brain and vice versa. Altogether, there are 100 million neurons living in our gut, which is the reason why many scientists call this part of the body our second brain [1]. These millions of neurons operate our complex digestive system, and they also play a vital part in our immune responses. More than 70% of our immune system is located in our gut, and this is where germs and viruses potentially harmful to us are being destroyed. Certain foods, such as yoghurt, are beneficial to our gut, as they support its function to strengthen our immune and digestive system.

The Vagus nerve 

On top of that, our gut is also connected to our brain. There is a brisk exchange between the nervous system in our gut and the so-called vagus nerve. The vagus nerve is a nerve in our brain, responsible for our heartbeat amongst other things. Surprisingly enough, this exchange flows mostly from our gut's nervous system to the vagus nerve and not the other way around, as was assumed before.  

Neurotransmitter in our second brain

Our brain uses the same neurotransmitters as our intestinal nervous system. Neurotransmitters transfer information from one neuron to another. They are vital in the treatment of psychological illness, such as depression. Antidepressants, for example, increase the amount of a neurotransmitter called serotonin in the brain of patients suffering from depression. Their effect is not only noticeable in the brain but can also create byeffects in our intestinal area. Our gut also uses serotonin to transfer information, thus the information transfer in our gut can be disturbed and become unbalanced when taking antidepressants.

Our gut's potential

With all this knowledge at hand, could we use our second brain in the treatment of diseases? Science is looking to examine this question and a possible answer could come from a study published in Canada [2].

Communication between brain and gut

In this study, mice were put in a basin filled with water deep enough to prevent them from standing on the ground, with edges steep enough to prohibit them from getting out of the basin on their own

The researchers measured how long the mice were able to swim before they resigned and surrendered. At this point, they immediately took them out of the basin. Following this, they divided the mice in two groups, with one group receiving a specific diet that contained a particular bacterium, which is believed to be responsible for the production of a neurotransmitter called GABA. This neurotransmitter leads to relaxation and sedation and is also used in the treatment of anxiety disorders.

Increased endurance

A few weeks later, the researchers repeated the same experiment. What they now found was that the mice that had received the specific diet had on average a higher endurance in the water than the ones that had not received the bacterium responsible for the production of GABA. Even after being retrieved from the water, the recipients of the specific diet showed less depressive symptoms than the rest of the mice. The researchers believe that the diet had enhanced the production of the neurotransmitter GABA, which had a relaxing effect on the mice, who in turn were less despaired and anxious than their fellow mice who did not have an increased production of GABA. This indicates that processes in our gut - which can be altered by our diet - have an influence on some of our complex behavioural patterns and our emotional comfort.

Blood-Brain Barrier

Understanding the mindThere is hope that our second brain can influence our first brain through - for example - an increase or reduction of the amount of neurotransmitters in our body.

Generally speaking, medication cannot affect our brain that easily due to our Blood-Brain Barrier that is in charge of fighting off toxins and exogenous substances - such as medication - that try to get into our brain. But as bacteria in our gut can be reached and influenced more easily, scientists are optimistic that in the future, dysfunctions in our brain can be treated through the gateway of our second brain in our gut. 

All in all, we should try to listen to our gut feeling more often. Because listening to our gut means listening to our second brain, which - with its more than 100 million neurons - has a significant say in the sensitive equilibrium of our emotional balance. And because the second brain communicates via the same neurotransmitters as our first brain, processes formed in the second brain can directly influence our emotional and behavioural patterns formed in our first brain. We should never underestimate the importance of our second brain for our overall well-being and health and make sure we treat it nicely as we have a lot to thank it for - like the feeling of those joyful wonderful butterflies. 

Start training


Sign in with Google