There are two different types of fiber -- soluble and insoluble. Both are important for health, digestion, and preventing diseases.
Soluble fiber attracts water and turns to gel during digestion. This slows digestion. Soluble fiber is found in oat bran, barley, nuts, seeds, beans, lentils, peas, and some fruits and vegetables. Soluble fiber may help lower cholesterol, which can help prevent heart disease.
Insoluble fiber is found in foods such as wheat bran, vegetables, and whole grains. It adds bulk to the stool and appears to help food pass more quickly through the stomach and intestines.
See also: Fiber
Insoluble vs. soluble fiber; Fiber - soluble vs. insoluble