Barry Marshall, Scientist

Nobel prize-winner Dr Barry Marshall made a medical discovery which rendered obsolete a multi-billion dollar drugs market aimed at treating stomach ulcers.

To do this he was his own guinea-pig, deliberately drinking a petri-dish full of bacteria to test out his theory.

Luckily he lived to tell the tale, and discovered the cure for ulcers - however the medical establishment and drug companies didn't want to listen at first.

He tells his story to Owen Bennett-Jones.