Neurogastroenterology. The intestines are the second brain. True or Fiction?

[Teacher]

Recently, specialties at the intersection of sciences have gained popularity all over the world due to their potential for providing high-quality medical care in the prevention and treatment of many diseases, including neurological and mental ones. One of them, deserving close attention not only of doctors, but also of parents, is neurodietology as a branch of neurogastroenterology.

Folk wisdom in proverbs notices the connection between food and our health, gives recommendations for the correct attitude to food in order to avoid diseases. Here are just some of them: "A hundred illnesses enter through the mouth", "Hurry to work, not for food", "Who is greedy for food, will live to see trouble", "Eat breakfast yourself, share lunch with a friend, give dinner to the enemy", "He who chews well, he lives for a long time","When I eat, I am deaf and dumb","Any excess is harmful."

All famous doctors of antiquity also emphasized the extreme importance of nutrition as the basis of health and considered the cause of many diseases precisely to the problems of the gastrointestinal tract. So, the following statements belong to Hippocrates, which have not lost their relevance after 2500 years: "All diseases originate in the intestines", "Let food become your medicine until medicines become your food."

And, of course, there is hardly a person who knows firsthand what it is: “I feel in my gut”, “butterflies in my stomach”, “sucks in the stomach from fear”, “bear disease”. Also, many are familiar with the expressions: "I do not digest them", "it takes time to digest all this." Obviously, there is an invisible connection between our nervous system, psychological state and the gastrointestinal tract.

Since 1999, in connection with the discovery of molecular genetic research methods, a new era has begun in the study of the intestinal microbiome. By DNA sequencing (this is the determination of the amino acid or nucleotide sequence of DNA / RNA), it was found that more than 1000 species of bacteria live in the intestine. It became known that only 7-10% of the microbiota can be determined by the culture method (seeding feces for dysbiosis), therefore, this analysis is not informative and cannot be used in the diagnosis and treatment of a wide range of diseases. But there are always exceptions to each rule, and in some cases it remains relevant.

The term "microflora" is considered obsolete, therefore it has now been replaced by the term "microbiota". It is customary to distinguish between intestinal microbiota, skin microbiota, respiratory tract microbiota, urinary system microbiota, reproductive system microbiota, and the totality of the entire microbiota of an organism is denoted by the term "microbiome", ie the totality of their genes.

The total number of microorganisms constantly living in our body is simply amazing - one hundred trillion. You can try to figuratively imagine: one drop of intestinal juice contains more than a billion microorganisms and these are not only bacteria, but also viruses, fungi that help us in every possible way in life processes, and most importantly, protect us from foreign agents ... In fact, the intestinal microbiota is not only intracavitary, but also parietal, as our compatriot, academician AM Ugolev back in the 1970s, and for this discovery was nominated for the Nobel Prize.

According to your unique bacterial "portrait", you can learn everything about you: hereditary predisposition to diseases, how the pregnancy proceeded, where and in what way of delivery you were born, were fed with breast milk or artificial formula, where you lived, as well as about your food addictions, lifestyle, habits, attitude to hygiene, what diseases you suffered, what were treated, your hormonal and even emotional background will not remain a secret.

Some more surprising facts about our gut microbiota:

• The weight of the intestinal microbiota of an adult is 1.5-2 kg
• 95% of all bacteria in the body are localized in the gastrointestinal tract (GIT)
• The total area of the gastrointestinal tract is 400 square meters, which is equal to the area of 2 tennis courts!
• The number of human own cells to microbial cells is 1:10
• The genome of bacteria (microbiome) is 150 times larger than the human genome
• 90% of known diseases are associated with some degree of gut microbiota
• Each person has their own unique composition of the intestinal microbiota, by analogy with fingerprints.

The Axisgut-brain axis is of great interest among scientists and doctors around the world.

The internal mechanisms by which the brain-intestine interaction is carried out have not yet been identified, but there are many hypotheses: via neurotransmitters, metabolites, cells of the immune system, via nerve impulses of the vagus nerve, and many others.

Functional disorders of the gastrointestinal tract according to Rome IV criteria (2016) are now recommended to be referred to as disorders of the interaction between the brain and the gastrointestinal tract (disordersofgut-braininteraction).

The influence of the gut microbiota on our emotional state (depression, anxiety, impulsivity, cognition) and eating behavior has also been proven and actively studied.

At the beginning of the twentieth century, the English physiologist and histologist Newport Langley (the founder of the theory of the autonomic nervous system) calculated the number of nerve cells in the stomach and intestines. At that time, it was 100 million. More than the spinal cord! And these are not randomly scattered nerve cells, they clearly and harmoniously interact with each other. In addition, it is a completely independent structure, capable of continuing to work fully without commands coming from the "central control panel", which is our brain. In this regard, an assumption arose: could such an accumulation of nerve cells be considered a kind of "abdominal" brain?

A number of diseases are currently associated with disturbed intestinal microbiota: irritable bowel syndrome (IBS), allergic diseases such as allergic bronchial asthma, atopic eczema, food allergies, celiac disease, thyroid diseases, obesity, multiple sclerosis, autism, autism spectrum disorders, behavioral disorders, inflammatory bowel disease - Crohn's disease, NUC, metabolic syndrome, cardiovascular diseases. And this is far from a complete list, but most likely it will be replenished. A natural question arises: "Is the change in the microbiota a trigger (provoking) factor in the development of certain diseases, or are these changes a consequence of diseases?" Time will show.

The answer to the question: "What comes first: intestinal dysbiosis or allergies?" - already has a scientifically proven solution. Primarily a violation of the intestinal microbiota, and already against this background, a cascade of allergic reactions is triggered.

Neurotechnologist from the University of Massachusetts Richard Wertman and his colleagues discovered in the middle of the 20th century that the synthesis of neurotransmitters - serotonin and others - can be modeled using a specific diet. Neurotransmitters are biologically active chemicals through which an electrochemical impulse is transmitted from a nerve cell through the synaptic space between neurons, as well as, for example, from neurons to muscle tissue or glandular cells). in the blood, which, in turn, enter our body from food. Thus, the concentration of neurotransmitters in the brain depends on what we eat.

It is known that in children with autism, a diet with the exclusion of products containing casein (milk protein), lactose (milk sugar), gluten (a protein of some cereals), as well as glutamate (a food supplement, "flavor enhancer"). Unfortunately, the latest data from systematic reviews from 2008, 2010 and 2014 did not confirm the effectiveness of a gluten-free diet for treating autism in all groups receiving such treatment. In practice, this diet works 50% of the time. Obviously, gluten alone will not produce such a positive significant trend. You should always choose a diet individually - all children, even with the same disease, are different, live in different conditions and psychological atmosphere.

It is known that 80% of the cells of the immune system are concentrated in the gastrointestinal tract, therefore, the healthier our intestines are, the healthier we ourselves will be in all aspects. In the first place in the treatment of gastrointestinal diseases and associated diseases in children should be diet diagnosis and diet therapy. Despite the proven efficacy of some probiotics, it is most effective and long-lasting to restore and maintain your own unique gut microbiota. The body is a self-regulating and self-healing system, it just needs not to interfere and help a little. And the child's body is the most grateful in treatment, as it has a huge supply of vitality and accelerated regenerative capabilities.

I would like to end this brief excursion into neurogastroenterology with the phrase of American scientists ST Borra and KWWear (2001):"... in providing nutrition to the brain, scientific research in the field of dietetics opens the door for the entire medical profession."

 

[Brother]

How does the brain suppress willpower?​

Emotions helped our ancestors to make decisions in conditions of lack of information

Emotions are an ancient acquisition. It was they who helped our ancient ancestors, who have not yet acquired complex analysis systems, to make decisions in conditions when information is sorely lacking. If you are a small monkey, then your main task in life is to have time to grow up and leave offspring before the first tiger you meet considers you a great snack. Therefore, all decisions need to be made quickly: the opportunity to call a meeting and arrange a brainstorming session on the topic “Is it worth eating all the berries from this bush, or is it better to leave some for tomorrow?” you do not have. But the help of colleagues is not required: as soon as you spot the delicious sweet berries, there are no questions about what to do: pick and immediately swallow. Emotions unmistakably tell animals what to do, long before their slow thinking reaches the same conclusion.

The Emotional Rapid Response System has helped us survive for millions of years precisely because it is tuned to make the right decisions - from a biological expediency point of view. Food is good, it must be consumed immediately, and the sweeter and fatter it is, the better. Sex is very good, so you need to do it more often and with as many partners as possible (especially if you are a male). A tiger is bad, you have to get away from him, and quickly, and not think, he could become a business partner in other circumstances. Rest when no one is chasing you is great, so if there is an opportunity to laze around, you should do just that. Everything is logical and unambiguous.

Supermarkets, fast food, drugs, selling love and computer games are recent inventions, and the system of emotions has not yet learned how to respond to them correctly. Perhaps in a couple of million years, our descendants will develop the ability to experience instant disgust at the sight of shelves with sneakers or run away when they see an open social media page, but so far the brain by default considers what we usually call temptations as a blessing. And these settings inherent in the “hardware” greatly prevent us from exercising willpower. But, fortunately, advanced mammals, including humans, have acquired the so-called neocortex - the “intellectual” component of the great brain. Thanks to her, we think, talk, perceive ourselves as a person, create, analyze, count, plan and invent. And somewhere in the depths of the brain,

Emotions are generated within a structure called the limbic system

In Christopher Nolan's excellent film Inception, the characters move along the limb of their victim - in the film, this concept denotes the deepest level of sleep, “pure subconsciousness”. Thanks to Nolan's painting, an unusual term came into use, and now even people who are very far from neurosciences know it. In the real brain, the limb is really extremely important - although it has nothing to do with Nolan's "pure subconsciousness". Translated from Latin, limbus is the border, the edge of something, and in the case of the brain, this is just the border between the new cortex and more ancient structures (more precisely, between the new cortex and the brain stem). In shape, this area resembles a ring with processes, and in anatomy textbooks it is called the limbic system.

It is here that all our emotions "sit" - from anger and rage to joy and bliss. Mother rats, who were deliberately damaged the limbic system, completely lost interest in their cubs, stopped feeding the pups, despite their desperate squeak, and generally behaved as if they were inanimate objects. An even more impressive effect than the destruction of the limbic system is its hyperstimulation. In 1954, American physiologists James Olds and Peter Milner decided to find out what would happen if certain areas of the rat's brain were excited with an electric current. They stuffed the rat's head with electrodes and turned them on if the animal ran into a certain corner of the cage. In those years, the subtle anatomy of the brain was not well understood, and researchers, without knowing it, hit the electrodes in the very “heart” of the limbic system - the famous pleasure center *. To the surprise of the experimenters, after a couple of electric shocks, the rats, instead of avoiding the ill-fated corner, began to stubbornly strive for just there. Guessing that stimulating this zone would bring pleasure to the animals, the researchers connected wires from the electrodes to a lever so the rats could turn on the current on their own. Realizing the possibilities of the mechanism thrown by the experimenters, the animals stopped eating and drinking and spent 24 hours on end, pressing and pressing the lever. The record holders managed to do this 700 times per hour! Realizing the possibilities of the mechanism thrown by the experimenters, the animals stopped eating and drinking and spent 24 hours on end, pressing and pressing the lever. The record holders managed to do this 700 times per hour! Realizing the possibilities of the mechanism thrown by the experimenters, the animals stopped eating and drinking and spent days on end, pressing and pressing the lever. The record holders managed to do this 700 times per hour!

Emotions instantly change our physical condition

The experiments of Olds and Milner demonstrate perfectly well that emotions can change behavior beyond recognition. Moreover, the limbic system directly regulates our physical state: its signals (mediated by the hypothalamus) trigger a whole complex of reactions that relax the body or, conversely, bring it into a state of alertness (in English there is a good name for this state - fight or flight, literally "fight or flight").

In a relaxed state, the body is ready for all kinds of joys: it increases salivation, enhances intestinal motility and the secretion of digestive juices in order to eat deliciously, reduces pressure and reduces ventilation of the lungs in order to properly rest, stimulates an erection in order to have sex with a feeling. In a state of anxiety, functions that are not associated with a fight or flight are ruthlessly suppressed, and all the body's resources go to the muscles, lungs and circulatory system. A separate role in the activation of the “fight or flight” state belongs to the amygdala, or simply the amygdala - a small area inside the temporal lobe (the right and left hemispheres have their own amygdala). The amygdala can receive and analyze information from the sense organs even before the cerebral cortex is “sorted out” with the new data.

To start all these complex reactions and relax or, conversely, invigorate the body, the hypothalamus sends orders to the parts of the nervous system that directly control the work of internal organs. The section responsible for relaxation and recuperation is called the parasympathetic nervous system, and the section that controls the fight-or-flight state is called the sympathetic. Even from this extremely simplified description, it is clear how much the limbic system can change the functioning of the body and how much its influence was underestimated by the supporters of the theory of the superiority of "pure reason" over base emotions. How to control your desire not to order pizza for dinner, if saliva is already secreted in your mouth, your stomach growls invitingly, and pleasant warmth spreads through your body? [...] The mind, of course, warns that the scales will soon show something unpleasant, but, firstly, his advice is late, and secondly, it does not even come close to evoking such a strong response. The limbic system is powerful and demanding: we literally feel its orders physically, because their goal is nothing less to save our lives and push our genes further down the chain of generations. We are programmed to automatically respond to survival-critical stimuli, and this program cannot be overridden.

The limbic system is inextricably linked to our ability for self-control, and while it seems that for evolutionary reasons it is precisely it that prevents us from being strong-willed and firm in our intentions, in reality it is a super-powerful colossus that can be excellently used to strengthen willpower. But to understand how to do this, let's first figure out how the advanced new cortex is trying to restrain our irrepressible impulses.

We are our new bark

From an evolutionary point of view, the new cortex, or neocortex, is a completely fresh acquisition. An additional “blanket” of several layers of neurons that covers the “old” brain was acquired by mammals, and this happened some 280 million years ago, and most likely even later. In the first mammals, the new cortex was a tiny outgrowth of older areas of the brain: its area was 1–5 cm² and it did not give global advantages. In humans, the neocortex has grown to an impressive 800 cm² and occupies 80% of all gray matter. So in many ways Homo sapiens is its neocortex: it is this part of the brain that is responsible for consciousness, thinking, and so on, which distinguishes us from other animals. Scientists divide the neocortex into many parts, focusing on their structure and "fixed" tasks: although, as mentioned above,

The anterior cingulate cortex helps us cut the tension between current actions and global goals.

The main area, without which it is impossible to control your impulses, is the anterior cingulate cortex (ACC). It refers to the so-called reward system (i.e. reinforcement of actions that are correct from the point of view of survival) and provides an emotional coloring of behavior. It is thanks to this zone that we, in principle, understand that something needs to be contained there. [...] On the screens of MRI scanners, the PPK lights up with a bright light when a person is faced with a conflict situation: for example, he tries to name the correct color of letters in the Stroop test (remember, in this mocking task, words denoting names of one color are written with letters of another: for example, the word “red” is typed in blue letters, and it is necessary to suppress a strong desire to read the color that is written, and not to name the true one).

The ACC also turns on in other situations when the brain needs to overcome some kind of contradiction - for example, between true thoughts and social norms. A typical case is the encounter with racial stereotypes. […] The anterior cingulate cortex is a bodyguard who vigilantly monitors emerging conflicts.

Studies have shown that the ACC is automatically “turned on” when there is a contradiction (for example, the desire to smoke a cigarette in a quitting smoking), but the degree of its activation varies from person to person. In other words, due to the “constructional” features of the brain, some lucky ones are better at cutting off conflicts between immediate and global goals than those who are less fortunate with the ACC, and consciousness is not involved in this process. And since there is no conflict, then there is no reason to suppress any of your impulses - this is how the brain thinks and allows the limbic system to take another candy or to call a visitor from Central Asia a bad word. This vicious scheme works even when, at the level of consciousness, a person believes that sugar is terribly harmful,

PPK can be trained to better perform their duties

The news is so-so: it turns out that those who are unlucky with the “correct” PPK device will regularly become victims of their passions, even if they do not want to. But it's not all bad: several experiments have shown that strong intrinsic motivation not to succumb to the intrigues of the limbic system allows you to better control bad impulses. In other words, if you regularly convince yourself that being overweight is terribly dangerous to your health, or remind yourself that a civilized person is ashamed to consider Caucasians / Asians / women / men / gays / feminists / anyone to be inferior, sooner or later the efforts will bear fruit, and you will learn track and suppress automatic reactions. It is important that such training will teach you exactly how to see the conflict, but it will not help to stop the wrong action if it has already begun. Other systems are responsible for this.

But you can only train your ACC using intrinsic motivation. Listening to external appeals, you may be able to restrain yourself in a particular situation, but, left without a “overseer”, you will immediately return to your old habits. It is for this reason that so many people in fitness clubs obediently train with a trainer, but they are not able to perform the same exercises on their own, even if they have mastered the technique perfectly.