symbiotic bacteria, as a powerful helper for the intestine, can decompose difficult-to-digestible compounds and other compounds to generate energy. When the beneficial bacteria group adheres to the surface of the intestinal mucosa, a solid microorganism "armor" is formed to resist the invasion of pathogenic bacteria through competition, immunity and other mechanisms. Intestinal microorganisms are even involved in regulating the human circadian rhythm, and also affect the brain - our body's highest "command". The two seem to be incompatible, but in fact they share the same woes. If you want to clarify the inseparable connection, you have to talk about the intestinal axis, the highway between the intestine and the brain.
In summary, the intestinal brain axis refers to the regulatory pathway involving multiple biological systems, which builds a unique communication method between intestinal bacterial group and the brain: the brain can regulate the composition and behavior of intestinal microorganisms through central nervous system , and intestinal microorganisms can also participate in the regulation of brain signals through various systems such as nerves, endocrine, immune, and circulation, maintain human health, and even affect brain activities.
Vaginal nerve:
The telephone line that transmits information
The fastest signal transmission in the human body is undoubtedly the nervous system . This kind of communication method has naturally been established between the brain and intestines. This is mainly mediated by the vagus nerve. The vagus nerve is the longest-extended and most widely distributed pair of nerves in the brain nerves. These nerves start from brain stem and extend the diffuse endings to the intestinal nervous system. The intestinal nerves and the vagus nerve intersect, forming an synaptic connection, so that the "phone line" between the brain and the intestine is connected. Then, this "phone line" centrally transports the detected intestinal signals to the brain, and spreads feedback information from the brain to all parts of the body.
The "phone line" transmits electrical signals. The neurotransmitters are the ones that help the electrical signals transmit in the nerves. So how do neurotransmitters be produced?
Microorganisms themselves can produce neurotransmitters and stimulate the central nervous system through the conduction of nerve cells; in addition, off-site support can also be requested. Microorganisms stimulate the endocrine system by producing active substances, thereby inducing intestinal cells to produce neurotransmitters. For example, we are well-known as "fast Lexin " - 5-hydroxytryptamine , which is produced dependent on enterochromium cells. Microorganisms can interfere with serotonin release by affecting the number or function of enterochrome cells and ultimately regulate brain cognition, learning, and memory.
Part.2
Microglia:
Double-edged sword of immune cooperation
Contact between the intestine and the brain will also form through the immune system. There is a key immune effector cell in the brain called microglia. This cell has different morphological functions during different developmental periods or physiological states, which is closely related to diseases such as Parkinson's disease , Alzheimer's disease and Alzheimer's disease . But can you imagine it? The healthy development and activation of microglia are inseparable from the help of intestinal microorganisms.
The immune program mediated by microglia depends on signals generated by microorganisms, among which short-chain fatty acid (SCFA) contributes a lot. Intestinal microorganisms will ferment dietary fiber and -resistant starch that are difficult to digest into short-chain fatty acids. This substance can regulate the development and maturation process of microglia and induce cell morphology changes. Collaborative relationships like
seem to be happy, but they also have to grasp the limits. Because if it is overactivated by short-chain fatty acids, microglia will go crazy and swallow and clear synaptic regardless of the enemy, which will cause cognitive decline.
Part.3
Blood-brain barrier:
The number one pass to guard the important places
Our body is well versed in the position of the head of the brain. It is not only equipped with hard skull protection outside, but also has a very meticulous level inside - the blood-brain barrier. This title is very domineering and its strength cannot be underestimated.The blood-brain barrier is a solid layer of sturdy outside the blood vessels of the brain. It is formed by blood vessel wall cells and glial cells and . It can prevent harmful substances from entering the brain from the blood and ensure the high stability of the environment within the central nervous system. In addition to familiar "old friends" such as oxygen and blood sugar, all "suspicious molecules" were rejected.
However, many metabolites from intestinal microorganisms have "clearance orders". For example, butyrate can cross the blood-brain barrier and enter the central nervous system and protect neurons from damage, which has a certain anti-depressant effect.
Not only that, the development and permeability of the blood-brain barrier itself also contributes to intestinal microorganisms. The key to its composition - the gap junction protein , which will be expressed by activation of intestinal microorganisms. Although the weight is small and weighs a thousand pounds, this tightly guarded pass must be protected by microorganisms.
Microorganisms, intestines and brains have been independent topics in history. As research continues to deepen, their connections are becoming closer, promoting the transformative progress of biomedical .
Source: Knowledge is power
