Final answer:
Cellulose is the source of dietary fiber that promotes timely movement through the colon by adding bulk to fecal matter and aiding in regular bowel movements. It is an indigestible carbohydrate found in plant-based foods and has numerous health benefits.
Step-by-step explanation:
The source of dietary fiber that promotes timely movement through the colon is cellulose. Cellulose is a type of indigestible carbohydrate found primarily in plant-based foods such as whole grains, legumes, vegetables, and fruits. Unlike other compounds like polypeptides, triglycerides, or enzymes such as amylase, cellulose cannot be broken down by the human digestive system. Instead, it adds bulk to the food waste, easing bowel movements and stimulating the stretch reflex in the large intestine which aids in defecation.
Consuming cellulose from plant-based foods has several health benefits, including promoting a healthy digestive tract, reducing the risk of heart disease, colon cancer, and type 2 diabetes. It's classified as a carbohydrate, although it's considered a nonessential nutrient because the body can't digest it. Its role in gastrointestinal health is to absorb water, increase the fecal mass, and support the microbiota in the large intestine.