If you think about it, it is not only our stomach that hurts when we are nervous, our chest can hurt, we can lose our appetite, have anxiety or compulsive hunger.
The simple and most scientifically accurate answer to your question is that when we are nervous, our body produces a series of neurotransmitters and hormones, such as cortisol or adrenaline, which are detected by receptors in the intestine and the gastrointestinal system responds. And it responds differently in each person. There are those who do not have a stomach ache when they are nervous, there are those who do, there are people who feel like vomiting or there are those who have diarrhea because there is an increase in intestinal motility.
The key to all this is that the gastrointestinal system has a very sophisticated nervous system, in fact, it is called the “second brain”. The human nervous system consists of: the central nervous system, made up of the brain and spinal cord; the enteric nervous system, which is what we find in the intestine, and the autonomic nervous system, in charge of communicating them. The enteric nervous system is made up of two thin layers of neurons in the walls of the entire intestinal tube. It has about 100,000 neurons, which are, for example, the same number as in the spinal cord, so it is very large. And these neurons are connected not only with each other but with the rest of the body, but mainly with the central nervous system, which is what is called the brain-gut axis.
The thing to remember is that, in the end, everything is connected. We cannot understand each part of the body by isolating it from the others because what makes us living organisms is the fact that they are connected. For a few years, the enteric nervous system, whose main function is to regulate digestion, nutrient absorption or intestinal motility, has been associated with the brain. Until now, it had been shown that certain anxiety states or certain very important traumas in people’s lives cause a pathological response in the gastrointestinal system. For example, a certain tendency to develop functional digestive diseases such as irritable bowel syndrome has been observed in people who have suffered traumatic events throughout their lives, such as having participated in wars or being abused (Impact of psychological stress on irritable bowel syndromeHong-Yan Qin)
But it is very interesting to know that the opposite also happens: many diseases or intestinal imbalances end up destabilizing this axis and causing mental disorders. It has been seen that the brain-gut axis is bidirectional, you can have depression or episodes of anxiety, etc, simply because you have an intestinal disorder.
And here comes another factor that is the intestinal microbiota, which plays a vital role in maintaining proper intestinal function. When it is not well balanced, it greatly exacerbates this disruption of the gut-brain axis. There are more and more studies on events that end up causing intestinal disorders. And they are not only emotional situations of impact but also, for example, taking antibiotics, poor diet, gastroenteritis, that is, situations that can alter the intestinal flora and digestive balance, and it is this intestinal disorder that can secondarily be related to the onset of a mental illness (feel what you eat, Amanda Rodríguez-Urrutia). As Dr. Rodríguez-Urrutia points out in her recent publication, “this is just the tip of the iceberg in the world of brain-gut connections. Everything in the body is connected, and the environment with us”. It is important to go one step further in understanding your body, understanding that health is a global concept where each one of us must do our bit every day to obtain it. It may not be an easy task, but it is worth it.
Marina Fortea Guillamon She is a doctor in Biochemistry, Molecular Biology and Biomedicine and a researcher in the nervous system of the digestive system at Leuven University (Belgium).
Question sent via email by Paula Garcia
Coordination and drafting: victory bull
we answer is a weekly scientific consultation, sponsored by the Dr. Antoni Esteve Foundation and the program L’Oréal-Unesco ‘For Women in Science’, which answers readers’ questions about science and technology. They are scientists and technologists, partners of AMIT (Association of Women Researchers and Technologists), which answer those questions. Send your questions to [email protected] or on Twitter #nosotrasrespondemos.
The advice in this office is of a general nature and is not a substitute for medical advice. If you have questions about your specific problem, ask your doctor or pharmacist.