Overview

• In melanoma-bearing mice, a four-week exercise regimen shrank tumors and extended survival but lost its effect when gut microbes were removed
• Machine learning analysis pinpointed formate as the key exercise-induced microbial metabolite driving anti-tumor CD8 T-cell activity
• Daily oral formate in mouse models of melanoma, adenocarcinoma and lymphoma markedly inhibited tumor growth and strengthened responses to checkpoint inhibitors
• In advanced melanoma patients undergoing immunotherapy, higher blood formate levels correlated with longer progression-free survival
• Fecal transplants from high-formate donors enhanced T-cell activation and tumor control in mice, and researchers are now assessing formate as an adjuvant therapy