Answer:
changes in brain chemistry and behavior caused by the gut microbiota.
Explanation:
The group of millions of microorganisms that coexist in symbiosis, mainly in our digestive tract, is called microbiota. Its importance lies in the functions they perform, some vital, and many, still unknown. One of them is the role it plays in the relationship between the intestine and the brain (intestine-brain axis). This connection, bidirectional and increasingly studied, is being postulated as a possible explanation for some of the most frequent neurological disorders in our environment, such as Alzheimer's disease, Parkinson's disease or multiple sclerosis. The greater knowledge about the microbiota can help, on the one hand, to open new lines of research that help to improve its pathogenesis and, on the other, to establish future therapeutic strategies.
At the present time there are many aspects that are unknown about the functioning of the microbiota. However, its crucial role is established in the immune, metabolic and hormonal system, as well as in the <u>gut-brain axis </u>relationship.
This axis is formed by the microbiota, the enteric nervous system, the autonomic nervous system, the neuroendocrine system, the neuroimmune system and the central nervous system. The enteric nervous system is responsible for basic gastrointestinal functioning (motility, mucous secretion, blood flow), and central control of bowel functions is carried out thanks to the vagus nerve. This complex axis forms a long-known two-way neurohumoral communication system. There are many works that support its existence. Thus, there is a correlation between alterations of the microbiota and hepatic encephalopathy, anxiety, autism or irritable bowel. In these diseases there is a dysbiosis (changes in the normal composition of the microbiota) that generates changes in gastrointestinal motility, affects secretions and produces a visceral hypersensitivity. Under these circumstances, neuroendocrine cells and those of the immune system are altered, modifying the release of neurotransmitters, which could translate into different psychiatric manifestations. In turn, studies in animal models exposed to different stress situations have shown variations in the composition of the microbiota. In this way, bidirectional communication on this axis can be postulated; The microbiota affects human behavior and, in turn, alterations in it produce changes in the microbiota.
