This week Aoibhinn Ní Shúilleabháin, Kathriona Devereux and Jonathan McCrea look at all things gut including: The beneficial qualities of probiotics and the challenge of getting them into our gut given the hostile environment created by the stomach’s acidic juices. Can our guts actually affect our brains? The link between food and mood is a proven fact but scientists are now investigating which bacteria are key to this and developing potential medications out of it. Is breast best? Ireland is one of the world leaders in the technology behind improving infant formula and we look how it is being developed to further mimic mother’s milk. In Weird Science we look at the sea cucumber’s unusual method of defence – literally spilling its guts!