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?

We're closer than ever before to discovering if we're not alone in the universe. The host for this episode of Transistor, astrophysicist Michelle Thaller, visits the NASA lab that discovered that meteorites contain some of the very same chemical elements that we contain. Then, Michelle talks to a Vatican planetary scientist about how science and religion can meet on the topic of life beyond Earth.