Imagine it is 1982, and a young physician is standing in a microbiology lab, staring at a Petri dish he nearly threw away. After more than 30 failed attempts to culture a mysterious bacterium, he is about to prove that a tiny microbe—not stress or spicy food—is the true cause of painful stomach ulcers.

In this episode of Mavericks of Science, we dive into the gut-wrenching story of Barry Marshall. Facing scoffing peers and billion-dollar drug companies that ignored his findings, Marshall did the unthinkable: he made his own body the laboratory by drinking a beaker full of infectious bacteria. It was a radical act of "personal science" that would eventually earn him the Nobel Prize and save millions of lives.