PROFESSOR JOHN CRYAN is head of the Department of Anatomy and Neuroscience and principal investigator at APC Microbiome Ireland at University College Cork. He is co-author of The Psychobiotic Revolution: Mood, Food, And The New Science Of The Gut-Brain Connection (National Geographic, £17.99)
Gut instinct, gut wrenching, gutsy, butterflies in the stomach – many phrases we use to describe emotions seem to reference our digestive system. But it’s less literary device, more scientific fact – our brains and our guts have a strong connection, and the past decade has seen huge advances in our knowledge of the microbiome (the collective name for the trillions of microbes that live in our gut). We’re finding out that these microbes aren’t just vital to our digestive and metabolic health; they’re the body’s master puppeteers, affecting all aspects of physiology, from brain function to the stress response.
The brain-gut axis