Neuropathic pain is a common adverse effect of chemotherapeutic agents, such as oxaliplatin. The authors here showed that antibiotic-mediated eradication of the gut microbiota protects mice against both oxaliplatin-induced inflammation in the dorsal root ganglia and mechanical hyperalgesia. The permissive effect of the gut microbiota on chemotherapy-induced pain was found to be mediated by the interaction of microbiota-derived lipopolysaccharides with haemopoietic cells expressing Toll-like receptor 4.