There are several kinds of natural fibers which include vegetable, wood, animal, and mineral.
Of the kinds of fiber, there is soluble fiber and insoluble fiber. In terms of definitions of these kinds of fiber:
Insoluble fiber...does not dissolve in water because it contains high amounts of cellulose.
Insoluble fiber can be found in:
grain brans, fruit pulp, and vegetable peels or skins
Whole wheat, nuts and seeds also contain insoluble fiber.
If insoluble fiber does not dissolve in water, then soluble fiber does dissolve in water. Soluble fiber is found specifically in things like:
apples, oatmeal and oat bran, rye flour and dried beans...
Soluble fiber is also found in berries and bananas, as well as barley and some vegetables.
In terms of the work done by fiber, insoluble fiber speeds the process of food moving through the digestive process, and can help prevent cancer. A wonderful benefit of soluble fiber is that it can lower cholesterol levels in the blood stream because it helps the body get rid of cholesterol.
In any event, fiber has been found to provide excellent benefits to the body for improved health.