John Cryan

John Cryan is a neuroscientist whose germ-free animal model studies have demonstrated that the gut microbiome is essential for normal brain development, stress responses, and immune function, all of which influence cancer susceptibility and progression. His research on microbial metabolites such as short-chain fatty acids and tryptophan derivatives has revealed neuroimmune signaling pathways relevant to cancer biology. He co-directs the APC Microbiome Ireland center, a global hub for gut-brain axis research.