Soluble fiber is found in dried beans and peas, oats, barley, legumes, fruits, flax, and psyllium seed husks. Insoluble fiber is found primarily in fruits and vegetables, whole grain products, and wheat and corn bran.nsoluble fiber, on the other hand, can be found in the peels of fruit, such as apples, blueberries, and grapes. It acts as a natural laxative that speeds the passage of foods through the stomach. It also gives stool its bulk and helps it move quickly through the gastrointestinal tract.