What does it mean when your stomach rumbles? How do our bodies extract nutrients and vitamins from food? Does what you eat affect your mood? Digestion is an invisible, effortless, unconscious process—and one that, until recently, we knew almost nothing about.

On this episode of Gastropod, we follow our food on its journey to becoming fuel, from the filtered blood that helps slide food into the stomach, to the velvet walls and rippling choreography of the small intestine, to the microbial magic of the colon and out the other end.

And we do it by visiting the world’s most sophisticated artificial gut at dinner time—a plumbing marvel named TIM that chews, swallows, squeezes, farts, and poops just like the real thing.