The purpose of scientific research was to study the morphofunctional changes in brain cortex in terms of chronic toxaemia of the body caused by the negative influence of LPS of E.coli. The main object of the study were areas from the somatosensory cortex of the hemispheres of the brain (fields 1-2 of the parietal area of the cortex), the bits of which were placed in the appropriate holders, depending on the research methods. The threshold of nociceptive sensitivity was evaluated according to the standard "hot plate" test, which allows us to judge the nature of the reaction on the supraspinal level. Results show, that the chronic impact of the E.coli LPS causes markable psychoneurological disorders, which are manifested by sensory lesions. So patients with increased reproduction of pathogenic intestinal flora, who are those with digestive problems, dysbiosis, forced to take antibiotics or potent drugs for a long period of time – all of them belong to a group of risk by development of behavioral changes and sensory disorders. They need to be directed to the neurologist and should be administered appropriate therapy as a component of complex treatment.