The article is dedicated to a clinical trial of Bifidumbacterin Multi-1, a biologically active food supplement (BAFS) for children aged 0 to 3 years. The study showed that application of BAFS in children with intestinal dysbiosis helped to cope with the symptoms of alimentary disturbances, promoted improvement of body mass index, increase of hemoglobin end erythrocyte level, suppression of zymotic and putrefactive dyspepsia, decrease of inflammation of the intestinal mucosa, elimination of bibidobacterial deficit, and reduction of conditionally pathogenic microflora. Bifidumbacterin Multi-1 was well tolerated and highly effective according to clinical and laboratory data. This preparation may be recommended as a component of complex therapy in children aged 0 to 3 years old.