"Have you ever had a gut feeling or butterflies in your stomach? Has hunger ever changed your mood? Our bellies and brains are physically and biochemically connected in a number of ways, meaning the state of our intestines can alter the way our brains work and behave, giving a whole new meaning to 'Food for thought'. As a nutritionist, microbiologist and neuroscientist, Ruairi Robertson is passionate about the link between our bellies and brains. His research is examining how our intestines and the microbes within them can influence both physical and mental health, and most importantly how our diets influence this relationship. Ruairi has travelled the world researching food, and believes it is the key to global public health. Ruairi is a PhD student in University College Cork in Ireland and current Fulbright Scholar (2015/16) to Harvard University. This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at http://ted.com/tedx