What type of polysaccharide is mainly found in dietary fiber?

Dietary fiber primarily consists of cellulose, a type of polysaccharide. Cellulose is a complex carbohydrate made up of long chains of glucose units linked together by β-1,4-glycosidic bonds. Unlike starch and glycogen, which are energy storage forms of glucose in plants and animals respectively, cellulose is not easily digestible by humans, as we lack the necessary enzymes to break down its β-glycosidic linkages. Instead, cellulose passes through the digestive system largely intact, contributing to the bulk of stool and aiding in digestive health.

Starch, on the other hand, is a polysaccharide that serves as an energy reserve in plants and can be broken down by human enzymes into glucose. Glycogen is a storage form of glucose in animals and is also not a component of dietary fiber. Maltose is a disaccharide formed from two glucose molecules and does not fit the definition of a polysaccharide. Therefore, cellulose stands out as the primary type of polysaccharide found in dietary fiber.