Which polysaccharide is primarily indigestible and beneficial for digestion?

The correct answer is fiber because it is the polysaccharide that is primarily indigestible and plays a crucial role in digestive health. Fiber serves as a key component of a balanced diet, as it promotes regular bowel movements by adding bulk to the stool and helping to prevent constipation. Additionally, fiber can aid in maintaining a healthy gut microbiome by serving as a food source for beneficial gut bacteria.

While glycogen and starch are polysaccharides that can be broken down by the body for energy, they do not provide the same digestive benefits as fiber. Glycogen is the stored form of glucose in animals, and starch serves as a carbohydrate storage form in plants, both of which can be digested and utilized for energy. Glucose, on the other hand, is a simple sugar and is highly digestible, serving as a primary source of energy for the body's cells. In contrast, fiber remains largely undigested, making it beneficial for digestion rather than a direct energy source.