Prevention of febrile neutropenia in cancer patients by probiotic strain Enterococcus faecium M-74. Phase II study.

Febrile neutropenia (FN) remains a potentially life-threatening complication of anticancer chemotherapy. Bacterial translocation via intestinal mucosa is a significant mechanism of FN development. Competitive inhibition of bowel colonization by pathogenic microorganisms by lactic acid bacteria could be a useful prevention of FN. The aim of the study was the prevention of FN by probiotic strain Enterococcus faecium M-74 enriched with selenium in leukemic patients. Fourteen (six males/eight females) patients with myelogenous leukemia treated by induction or consolidation chemotherapy were included in the study. Patients received prophylaxis with E. faecium M-74 during one cycle of chemotherapy. The daily dose was 36 x 10(9) CFU tid. Prophylaxis started between day -2 and day +2 of chemotherapy and continued until the absolute neutrophile count (ANC) was >1,000/microl. All patients experienced febrile neutropenia. During 231 days of severe neutropenia, 30 febrile episodes occurred. No any febrile episode or infection provoked by the strain tested was noticed. Tolerance of therapy was excellent without significant adverse effects. Our results demonstrate the safety of the probiotic strain E. faecium M-74 enriched with selenium in leukemic patients with severe neutropenia. However, its administration was not effective in the prevention of febrile neutropenia, but this does not preclude the protective effect of other probiotic strains.