The Effect of Intestinal Microbiome on the Effectiveness of Antitumor Immunotherapy

Results of numerous studies confirm the high degree of involvement of the intestinal microbiota in most processes in the human body. There is evidence for the effect of the intestinal microbiota on the success of chemo- and immunotherapy of oncological diseases. This effect of the intestinal microbiota in this process is considered both in the context of contribution of representatives of certain microbial taxa and the entire microflora, realizing a joint metabolic potential. It is assumed that the effect of intestinal microbiota on antitumor therapy can be mediated by such mechanisms as general immunomodulation, an increase in cells that specifically respond to antigens of both microbial and tumor origin, metabolism, and degradation (utilization) of drug substances. Currently, the intestinal microbiota is considered as an additional, but important target for studying the effective use of oncotherapy and reducing its toxicity, as well as a predictor of the success of immunotherapy. In this review, we analyze the results of studies confirming the relationship between the gut microbiome and antitumor efficacy of immune control point inhibitors. Despite the promising and theoretically substantiated conclusions, there is still some inconsistency between existing data that should be resolved for the further development of this direction.