«Brain-gut-microbiota axis» includes central, neuroendocrine and neuroimmunological nervous systems, sympathetic and parasympathetic parts of autonomic nervous system and gut microbiota. In the present article are discussed the mechanisms of mutual impact of gut microbiota and nervous and immune systems during PD, rôle of gut microbiota in the launch of process of neurodegeneration. Gastrointestinal tract dysfunction during PD uncludes constipation, hypotrophy, periodontitis and gingivitis, dysphagy, gastric emptying troubles, defecation difficulties, infections, caused by helicobacteriosis and intestinal dysbiosis. Gut microbiota's composition during PD has its own particularitites: there have been observed increase of Enterobacteriaceae type of bacteria, decrease in quantity of Faecalibacterium prausnitzii, bacteria belonging to the families Lactobacillaceae and Prevotellaceae. There have been several discriptions of relations between gut microbiota composition and motor and non-motor manifestations of the disease. «Brain-gut-microbiota axis» works in two directions and participates in modulations of pro and antiinflammatory reactions, there has been discovered an impact of gut microbiota on the immune mechanisms of PD development, neuroinflammation and balance of pro- and antiinflammatory cytokines. Inflammation related to the changes in intestine microbiocenosis can contribute to Alpha-Synuclein development, further developments lead to peripheral inflammation, immunosypressive; also, autoimmune processes lead to degradation of dopaminergic neurons. Further research related of the «Brain-gut-microbiota axis» during PD can lead to discover new aspects of pathophysiology of the disease, discovery of peripheral biomarkers in enteric nervous system, development of new therapeutic methods based on corrections of gut microbiocenosis disfunction with help of probiotics, autoprobiotics or even fecal microbiota transplantation.