Soluble fiber dissolves in water, and insoluble fiber does not. Both types help the body in different ways. The fibers called gums, mucilages, and pectin are all soluble. Fiber from psyllium seed husk, an ingredient in some bulk-forming natural laxatives, is also in this group. Cellulose, hernicellulose, and lignin are all insoluble fibers.
Wheat bran is an excellent source.
Most foods contain mixtures of soluble and insoluble fibers. The foods listed as good sources of one type of fiber may also contain some of the other type of dietary fiber. When you add fiber rich foods to your diet, you usually get the benefits of both types of fibers. How fiber affects your health Soluble fiber can help you in two ways. If you have diabetes, eating foods containing soluble fiber can help control the level of sugar in your blood.