Rob Knight gave a presentation about the guts of human beings and about the microbes that inhabit our intestines. Microbes he claims can affect human behaviour. The early use of antibiotics can lead to obesity. The gut: can it be mapped? He is running an experiment that invites people to submit fecal samples in order to develop the map. He claims that the map may allow us to know more about our immune systems. Microbes have implications for all sorts of diseases.