Abstract
The microbiome is a key regulator of host homeostasis and immune activity, in part through the production of metabolites. These microbiota-derived metabolites can modulate both the innate and adaptive immune system, as well as directly target tumour cells, thereby regulating anti-tumour immunity and response to immunotherapy. Here, we describe the current mechanistic knowledge on how these metabolites exert their effects and outline the methodologies used to detect and assess these metabolites. Finally, we summarize microbiota-targeted therapies capable of improving microbial functionality to ultimately enhance immunotherapy responses and improve patient survival.