Answer:
Dietary fiber
Step-by-step explanation:
Dietary fiber are a form of complex protein that can not be digested by the human digestive enzymes, they comprise of soluble fibers which easily be dissolved in water and insoluble fiber which does not dissolve in water. Fibers in general aids digestion in humans. Examples of these dietary fibers found in plants are lignins, pectins, inulin, cellulose etc.
Examples of foods that contain dietary fibers are nuts, grains, cereals, fruits and vegetables; they either be found in the leaves, stems, skins, seeds and hulls.