Introduktion. Analysis of scientific literature indicates the importance of using probiotics both prophylactically and in clinical practice to normalize the microecology of patients’ biotopes in order to prevent infectious complications during treatment. The use of probiotic strains of lactobacilli and bifidobacteria is an important factor in correcting the microecology of human biotopes and preventing the risk of infectious inflammation. 

Aim is to investigate the complex effect of probiotics on the microbiological and immunological parameters of patients with leukemia and the feasibility of their use to prevent the development of infectious and inflammatory complications in the clinical practice of hematology departments. 

Materials and methods. We examined 87 patients with leukemia, including 30 patients with chronic lymphocytic leukemia, 15 patients with chronic myeloid leukemia, and 42 patients diagnosed with acute myeloid leukemia. Patients were prescribed probiotic preparations, the starter cultures of which were lactobacilli, bifidobacteria, and thermophilic streptococci. Microbiological and selected immunological parameters of patients were studied using standard methods. 

Results. Under the influence of probiotic therapy, a decrease in the titer and/or elimination of conditionally pathogenic bacteria and restoration of representatives of the normal flora of the biotope were observed in the intestinal biotope of patients. The microflora of the upper respiratory tract of patients was characterized by improvement due to the elimination or reduction of titers of probable factors of infectious and inflammatory complications. The use of probiotics of patients with leukemia contributed to the improvement of the body’s anti-infective function due to an increase in the indicators of the phagocytic link of immunity, a decrease in the production of gamma interferon and autoimmune antibodies to alpha interferon. 

Conclusions. The obtained results confirm the feasibility of using probiotics in patients with leukemia. Their beneficial effects have been established, including: correction of intestinal dysbiosis through the restoration of key representatives of the normal microbiota (Lactobacillus, Bifidobacterium); elimination or reduction of opportunistic bacteria in the biotopes of the upper respiratory tract; enhancement of neutrophil granulocyte phagocytosis completion; immunomodulatory activity; and a potential role in the correction of autoimmune disorders.

Keywords: leukemia patients, biotope microflora, probiotic preparations.