The gut does far more than digest food, and this DW Documentary follows three people whose lives revolve around it. Jana Eberhart, a model and Ironman competitor, works with sports nutritionist Dr. Jens Freese to test whether changing her diet can improve her athletic performance. Actor and fitness influencer Philipp Stehler describes nearly dying from ulcerative colitis, which led to surgical removal of his large intestine, and how he rebuilt his health with a vegan diet, yoga, and daily meditation. Social media manager Carina Speck, living with irritable bowel syndrome for thirteen years, talks about bloating, cramps, and diarrhea while refusing to let the condition isolate her, posting tips for traveling with IBS on Instagram and TikTok under guidance from Dr. Miriam Stengel of SRH Klinikum Sigmaringen. Interviews with doctors and researchers connect these personal stories to broader science on how the gut interacts with the immune system and mental health. The film treats a subject often avoided in polite conversation with direct, practical detail.