The Digestive Tract Is Roughly Nine Meters Long

Transit time varies from person to person and depends on diet and health.

An enzyme called amylase begins turning starch into sugars before food is even swallowed.

These microbes help break down food, make some vitamins and interact with the immune system.

Rhythmic contractions push food through the esophagus and intestines, which is why swallowing works even upside down.