The gut, our second "brain"
After five decades of research, scientists have concluded that there is a second brain, and it is found in our intestines. In fact, the enteric nervous system involves both the digestive system and the autonomic nervous system since they both work together and intervene in the regulation of our emotions and behaviors.
The launch of the Human Microbiome Project represented a great boost to better understand what the microorganisms that live in our intestines do. In fact, researchers soon began to suspect that bacteria in the gut are not only responsible for metabolizing food and producing vitamins.
They found that these bacteria produce a large number of chemicals similar to those used by neurons to communicate, such as dopamine, serotonin, and GABA. In fact, today it is known that approximately 50% of dopamine and a large amount of serotonin originate in the intestine.
Therefore, it is not surprising that different studies have found a correlation between intestinal disorders and problems such as major depression and pathological anxiety. For example, in 2014 Norwegian researchers analyzed 37 people diagnosed with depression and 18 healthy people, and found that certain intestinal bacteria were more common in depressed people.
Other research published in the journal Cell revealed a relationship between a type of bacteria and some typical behaviors of autism. In this case, the researchers discovered that bacteroides fragilis could correct intestinal permeability, change the composition of the microbiome, and alleviate symptoms such as obsessions and repetitive behaviors. It is worth clarifying that the study was developed in mice but the researchers think that it is one more step to design new, less invasive drugs that can alleviate psychological and psychiatric disorders.
Your sixth sense could speak to you through the gut
The connection between the intestine and the brain exists from the moment we are born and it is likely that it plays an important role in the formation of neural connections and even influences memory and moods since it directly affects the amygdala and the hippocampus, two structures linked to primary emotions, memory and learning.
In fact, scientists recently discovered that the brain is not as isolated as they thought. There is evidence that some beneficial bacteria manage to cross the blood-brain barrier. A study published in 2011 revealed that some of these microorganisms have a kind of sensory nerve that transmits impulses to the vagus nerve and to the oldest structures of the brain, which is precisely where basic emotions are generated. These organisms have been called "psychobiotics."
Of course, this second "brain" is not rational, but we can use it to our advantage if we learn to decode the signals it sends us. In fact, it is responsible for our feeling "butterflies" fluttering in our stomach when we are in love or that feeling of "knot in the stomach" when we have to deal with a situation that overwhelms us. The enteric nervous system provides us with a first, basic and intense emotional reaction, which indicates a strong preference. So maybe next time, you should pay more attention to what he has to say.