Lactose is the sugar found in milk and dairy products such as cheese and yogurt. After eating dairy products that contain this sugar, usually lactase, a digestive enzyme of the small intestine, helps to breakdown this complex sugar into two simple sugars, glucose and galactose. These simple sugars are then absorbed in the small intestine and ultimately reach the blood stream where they act as nutrients. The enzyme lactase is located in the lining of the small intestine known as the intestinal villi.
