Fiber content in foods and youll see legumes leading the pack. Navy beans, like other beans, are rich indietary fiber. Soluble fiber forms a gel like substance in the digestive tract that combines with bile (which contains cholesterol) and ferries it out of the body. Research studies have shown that insoluble fiber not only helps to increase stool bulk and prevent constipation, but also helps prevent digestive disorders like irritable bowel syndrome and diverticulosis.