Special digestive enzymes are responsible for breaking down the alpha links that hold the individual Glucose molecules together. This breakdown process begins in the mouth using digestive enzymes that are a part of our saliva. Vegetable starch also referred to as Cellulose is a different kind of polysaccharide. Therefore, we are not capable of breaking down such links and the cellulose must be absorbed into the intestines undigested. Other species of the animal kingdom are capable of digesting cellulose.
Termites also posses the necessary enzyme.
Although the human body cannot breakdown cellulose, it does serve as a very important part of our nutrition. It has been shown that there is a positive correlation between the amount of cellulose and the occurrence of intestinal and colon cancers. The more bulk or roughage foods that are in the diet the fewer occurrences of these types of cancer. These should be important foods found in any diet. A third complex carbohydrate or polysaccharide is called Glycogen.