In her episodes of Transistor, biologist Christina Agapakis is exploring the microbiome: the trillions of bacteria, fungi, and viruses that live in and on our body. She starts with food. Bacteria-rich foods such as tempeh, cheese, pickles and yogurt have long been praised for their probiotic effect. But can you really add enough good bacteria to your digestive system to outnumber the bad?

This episode of Transistor is hosted by biologist Christina Agapakis, and produced by Kerry Donahue and Sruthi Pinnamaneni. Mixed by Tim Einenkel.

Episode extras are at transistor.prx.org.