Targeting the Gut Microbiome to Mitigate Immunotherapy-Induced Colitis in Cancer

Immune checkpoint inhibitors (ICIs) have been a transformational advance in cancer therapy in the past decade. However, ICIs can produce immune-related adverse effects (irAEs), which can lead to both morbidity and premature termination of therapy. Recent studies suggest that the gut microbiota and its metabolites affect ICI efficacy and toxicity. Herein, we review such evidence in the context of ICI-induced colitis. In particular, the short-chain fatty acid butyrate, a microbial metabolite, has known protective effects on the intestine. We discuss how the use of dietary prebiotics, which can be metabolized by bacteria to produce butyrate, can be an intriguing new investigational approach to prevent ICI-associated colitis and lead to improved patient outcomes.