Unexpected questions arise in science. If we ask ordinary people where the second brain can be found, very few think about looking for it in the intestine. However, the digestive system has two hundred million neurons: more than the dog's brain or the entire spinal cord. That is, a number of neurons like that must definitely fulfill certain functions. This cerebro-enteral system is mainly connected by the vagus nerve, but still works independently of the central nervous system.
That is, although it is known that there have been long-term joint surgeries (where, for example, psychological problems affect the intestine in stressful situations such as examination or danger), the importance of enteral-brain relations is now of significant importance. It is assumed that this path also returns, that is, the intestine through millions of neurons, its neurotransmitters and the microbes it contains can modify the brain.
Thus there is a round trip route from the main connection namely the vagus nerve, a long interaction structure between the intestine and the brain. But a relationship is also established with the spinal cord of the central nervous system, from the entire local autonomic system, which regulates body balance and intestinal function unconsciously. Regulators that connect the spinal cord (with autonomic medullary neurons) with a system of neurons in the gastrointestinal wall, in diffuse form.
The important number of neurons possessed by the digestive system regulates bowel movements, which have special rhythmic and sequential activities. It also regulates digestion, secretion of digestive substances and enzymes. It also synthesizes neurotransmitters, some of which are found first in the intestine, such as neuropeptides. Human intestinal cells produce 90 percent of important neurotransmitter serotonin from the entire human body. This substance is very basic in the functioning of various physiological processes, including the state of mind, anxiety and pain in the central nervous system. The reduction causes affective states and also reduces physiological anxiety, a function needed for normal human behavior. At the intestinal level, serotonin produces a synchronous arrangement of bowel movements (peristalsis).
Connection of the intestinal nervous system to the brain seems to be involved in various diseases. Among them are depression, anxiety, obesity and intestinal irritation. There are causal hypotheses from even more serious problems, such as neurodegenerative disease (Parkinson's), autism, and schizophrenia; allegations not related to controversy.
This system is more complicated if it is considered that especially the large intestine or large intestine maintains in a particular flora space, which is needed not only for proper digestion, but also for the functioning of the enteric nervous system. There are one hundred billion microorganisms in the intestine (microbiome). This place is very special and different from the conventional. For now, most are anaerobic, meaning they contain organisms that do not use oxygen, which makes them different in both the disease and in their treatment. These bacteria metabolize substances such as carbohydrates into short chain fatty acids, which strengthen and make the digestive system active, but also have transcendent activity in neurological functions, strengthen the blood-brain barrier that separates the brain from the rest of the organism.
A study by Rebecca Knickmeyer of the University of North Carolina investigated the relationship of the microbiome to the development of nerves: it benefits glia (supporting cells and the protection of neurons) from the central nervous system and myelinization. The project investigates animals raised in sterile conditions, where they observe physiological changes in nerve development.
Humans enter normal germs from birth and are symbiotic in building human life. Many animals live with other lives, which are needed to function. Humans need it in the intestine, vagina, skin and mouth. This symbiosis is key and will be a non-pathological germ that will inhabit us in life. They will be different among people, but are very similar during each individual's life. In general, one third of the microbiomes are similar between different people, the rest are different.
The Karolinska Institute group (Pettersson and Diaz Heijtz) studied modifications that occur when there are no germs in the intestines of mice. They change their behavior, are less responsive to stress, and modify their routines. Before germ replacement, animals return to normal behavior, except that sterilization has occurred in nerve development, where they will continue to be affected as a neurological sign.
Depression, anxiety, obesity, and intestinal irritation appear to be involved in relationships
The germs that we fill coincide with us at the beginning of life three thousand five hundred million years ago. Then evolution divides us and those who have simple evolution are in our organisms as unicellular germs, billions of them. This microbial circuit starts early in life and is generally stable around it. One of the first places of incorporation was in the birth canal which contained normal germs (producing other needs for studies of caesarean section). They are needed for health and living together from our existence.
An important news about the intestinal flora appeared at the US Congress of Neuroscience. in 2018, celebrated in San Diego, California. Rosalinda Roberts, Courtney Walker and Charlene Farmer, from the Department of Psychiatry and Behavioral Neurobiology at the University of Alabama School of Medicine in Birmingham, revealed that they had found intestinal bacteria in the human brain. Without producing pathology, we don't know how they got there, maybe because of the vagus nerve or the blood-brain barrier.
Some scientists suggest that the enteric nervous system precedes the nervous system and that its enormous complexity is needed for large human brains to develop. There will be a genetic transfer between the same microbiome and also with our body and nervous system. Intruders who are us and who provide key information to our brain.
These microorganisms contain a total of three million genes (this gene is called a microbiota) versus twenty-three thousand genes that humans have and that govern all of our structures and functions. This includes the source of extraordinary genetic information that must be found. There are billions of bacteria in the intestine that are interconnected with the digestive system but also very active with the nervous system. In turn, there are ten microbes in the intestine by the body's own cells, which means that our tiny visitors are a clear constituent of the human body.
Doctors in medicine and philosophy.
Prof. Tit UBA. Pte Humanas Foundation