What is the blood brain barrier?

  The blood-brain barrier is a barrier between plasma and brain cells formed by the capillary walls of the brain and glial cells, and between plasma and cerebrospinal fluid formed by choroidal flora. These barriers can prevent certain substances (mostly harmful). ) From the blood to the brain tissue.

  Many solutes in the blood enter the brain tissue through the brain capillaries. Some problems can be easily solved with simple steps. Some are slow, some are slow, and some cannot. This selective permeation phenomenon makes people think that the specific structure through which the solute passes is limited. This structure minimizes the damage to the brain tissue from harmful substances in the circulating blood and maintains the basic stability of the internal environment of the brain tissue. This is very important for maintaining the normal physiological state of the central nervous system.

  How do gut microbes affect the blood-brain barrier? In 2001, scientists first confirmed that intestinal microbes can enhance the body's biological barrier and block the "intestinal wall" (intestinal defense) through a large number of microbes expressing active genes in the intestine. I found that the wall (wall) can be encoded as the blood circulation of harmful substances in intestinal diseases.

  The microbes in our body are 10 times larger than our own cells. These microbes show that the microbes in our body help digest food and maintain immunity.

  was published in the November 19th "Science" sub-journal "Science Translational Medicine", found that the maternal intestinal flora can affect the development of the fetal blood-brain barrier, and can resist the erosion of the brain by exogenous pathogens. done. The pregnant woman's diet and antibiotic intake can affect this barrier of the fetus. It also helps explain the demyelinating disease of the central nervous system-multiple sclerosis. Environmental factors such as diet during pregnancy affect genes related to the formation and maintenance of the blood-brain barrier. The blood-brain barrier protects the brain from many common bacterial infections. Sven Pettersson, an intestinal biologist at the Karolinska Institute in Stockholm, and his postdoc Viorica Braniste studied the formation of the blood-brain barrier in embryonic mice. By planning two sets of experiments, one group grew mouse embryos or growths in mothers with normal and healthy gut bacteria, and the other group grew in mothers with sterile intestines. I will. Two groups of pregnant mice were injected with labeled antibodies, which were too large to cross the blood-brain barrier and were observed to enter the brain. According to this study, embryonic mice grown in mothers with normal intestinal flora formed a complete blood-brain barrier, unable to pass through labeled antibodies, while embryos grown in mothers maintained a sterile intestine . Mice do not have this blood-brain barrier.

  Researcher's Voice: The influence of intestinal flora on the blood-brain barrier is an interesting study

  I did not participate in this research. Professor Elaine Hsiao, a neurobiologist at the California Institute of Technology, said: “It has an amazing effect. This research is conducive to the important role of microorganisms in regulating brain development and function. However, this research also has Defects. That is, "study the flora. All germ-free mice are useful, but these results will affect humans because aseptic conditions are artificial and can impair certain functions of the human body, such as decreased immune function and decreased intestinal integrity. Laura Hooper, an immunologist at the University of Texas Southwestern Medical Center, said,

  also did not participate in this research, at least in terms of human health and disease. New insights into the progression of irregular diseases and other reasons, therefore, it is very attractive that human microorganisms change the blood-brain barrier, thereby making the brain vulnerable to damage.

  In addition, Hooper added: Scientists should also study whether microorganisms can help stimulate the development of the human fetal blood-brain barrier. After all, due to accidental antibiotics during pregnancy, the child may have an abnormal blood-brain barrier.