[Stem cells of intestine epithelium. Survival mechanisms and microbiota role].

The thanatogenetic mechanisms of stem cells (SC) of rapidly renewing system of intestinal epithelium still remain unclear. On the one hand, they are definitely involved into basic mechanisms of carcinogenesis in the gastrointestinal tract, because dysregulation of programs responsible for elimination of "unwanted" mutant cells (which are normally under immune and own intrinsic control) is one of the reasons of neoplastic expansion. On the other hand, elucidation and characterization of the regulatory machinery controlling SC survival are interrelated with problems of clinical medicine, including the increase of therapeutic efficiency of treatment of inflammatory and ulcer lesions of the gut, traumatic and surgical wounds, as well as restriction of side effects in normal tissues induced by application of intensive methods chemo- and radiotherapy of cancer. The latter is especially important for treatment of blood diseases and tumors of peritoneal cavity organs mainly due to bone marrow and intestinal epithelium damage. (These tissues are the most sensitive to these treatments.) The review considers data on exogenous and genetic modifiers of SC survival, and also the basic principles of mechanisms involved into renewal and regeneration of SC and the effects of microbiota on these processes.