Intestinal microbiota: unexpected alliance with tumor therapy.

Evaluation of: Iida N, Dzutsev A, Stewart CA et al. Commensal bacteria control cancer response to therapy by modulating the tumor microenvironment. Science 342, 967-970 (2013). Intestinal microbiota is essential for host physiological processes, including the maintenance of epithelial barrier and immune functions. However, paradoxically, the intestinal microbiota can promote various types of experimental carcinogenesis. The paper under evaluation demonstrates that disruption of the microbiota impairs the response of tumors to CpG-oligonucleotide immunotherapy and platinum chemotherapy in a context-dependent manner. Thus, intestinal microbiota may have a great impact on the tumor response to chemotherapy and/or immunotherapy.