There are two barriers in front of the brain: 1. Intestine Brain Barrier; 2. Blood Brain Barrier. The healthy maintenance of both barriers is closely related to the intestinal microbiota balance. The brain is protected by two barriers in front of it. Not every molecule should reach the brain, it should be filtered. The disruption of both barriers makes the brain vulnerable to chemical and biological threats and risks. The fact that some molecules and substances can reach the brain causes many unwanted reactions to be triggered in the brain (neuroinflammation, activation of oxidative stress pathways, activation of microglia cells, etc.). This situation results in the occurrence of different pathologies in the brain, which are the explanatory reasons for many disease mechanisms.