Well, there's a new kid on the block, psyllium. Psyllium, a plant primarily cultivated in India, is known as blond or Indian psyllium. Its seeds are rich in soluble fiber extracted from the dried seed husks.
Fiber comes in both soluble and insoluble forms.
Besides psyllium, other foods rich in soluble fibers include oats, citrus fruits, barley, apples and dried beans. Those high in insoluble fibers include wheat bran, the skins of fruits and vegetables, beans, berries and seeds. Both types promote laxation and increase bulk. Besides laxation, soluble fiber has been studied extensively for its role in reducing blood cholesterol levels. This type of fiber has the ability to bind with bile acids.