Expression data from oxaliplatin-treated tumors from mice pre-treated or not with antibiotics cocktail

The gut microbiota influences both local and systemic inflammation. Inflammation contributes to development, progression and treatment of cancer, but it remains unclear whether commensal bacteria affect inflammation in the sterile tumor microenvironment. Here we show that disruption of the microbiota impairs the response of subcutaneous tumors to CpG-oligonucleotide immunotherapy and platinum chemotherapy. In antibiotic-treated or germ-free mice, tumor-infiltrating myeloid-derived cells responded poorly to therapy, resulting in lower cytokine production and tumor necrosis after CpG-oligonucleotide treatment, and deficient production of reactive oxygen species and cytotoxicity following chemotherapy. Thus, optimal responses to cancer therapy require an intact commensal microbiota that mediates its effects by modulating myeloid-derived cell functions in the tumor microenvironment. These findings underscore the importance of the microbiota in the outcome of disease treatment. Oxaliplatin treatment induces expression of pro-inflammatory genes, which are inhibited by antibiotic pretreatment.