b'Chapter oneGut Function101Digestion is the physical and chemical process that converts food into fuel so we can have the necessary energy and nourishment to thrive. Within 24 to 72 hours, the food we eat makes its way through the entire digestive system. The process begins in the mouth. When we chew, enzymes released in our saliva begin breaking down the food. The food is then swallowed and transported to the stomach, where more processing takes place. Breaking down food into energy requires some pretty harsh chemicals. When food enters the stomach, it is sprayed with hydrochloric acid and enzymes. A thick mucus coating that lines the inside of the stomach protects it from this acidic environment. Some very significant actions occur during each step of the digestive process, but the real magic happens in your small and large intestines. Once food travels from the stomach into the small intestine, the gut releases immune cells that check for bacterial contaminants. If contaminants are found, they are normally destroyed so they can be safely eliminated without making you sick. The walls of the small intestine absorb the water and nutrients extracted from food, transporting them across the intestinal lining into the bloodstream.A healthy intestinal lining only allows these properly digested fats, protein, and carbohydrates, along with vitamins and minerals to pass into the blood stream. Those nutrients are then delivered to the cells. A healthy intestinal lining also acts as a barrier to keep out disease-causing bacteria, foreign substances, and larger undigested food particles. After a journey through about 25 feet of small intestine, the partially digested food makes its way to the large intestinealso called the colon. This is where the remaining food is transformed into stool so that the body can eliminate it. 4the G o od Gut'