Much of the food you eat is absorbed by your digestive system, which includes your stomach and your intestines.

The brown color of poop comes from the bile that is added by the liver to your bowl of cereal as it makes its way through the small intestine. The bile is changed by bacteria from green to brown.

Digestion and breathing may seem unrelated, but they are intimately connected. Here's how they work together to support health.

Shukla is currently on-board in the International Space Station (ISS) for a 14-day mission. In a recent educational video he explains everything about human digestive system works in space.