Surgeons in Alabama transplanted a pig’s kidneys into a brain-dead man — a step-by-step rehearsal for an operation they hope to try in living patients possibly later this year.

A man receives the first pig heart transplant. Astronomers witness a star go supernova. Researchers identify a biomarker of depression. And a goldfish goes for a drive. 

Chicago Tonight spoke with Dr. Stacy Kahn, who specializes in the treatment of digestive diseases at the University of Chicago Medicine Comer Children's Hospital, about Fecal Microbiota Tranplants.