The video begins with a close-up of a mouth with white teeth. A piece of bread is then placed in the mouth, and saliva begins to break it down. As the bread is chewed, the saliva breaks it down into smaller pieces, and the enzymes in the saliva begin to digest the bread. The video shows the process of digestion in detail, with the bread being broken down into smaller and smaller pieces until it is completely digested. The video is a detailed and informative representation of the digestive process.