Banana may contain fructooligosaccharide. Fructololigosaccharide is prebiotic because it nourishes probiotic bacteria in the colon. These beneficial bacteria produce vitamins and digestive enzymes. These digestive enzymes improve our ability to absorb nutrients including calcium and the compounds that may protect us against pathogens. In addition, banana may lessen the gastrointestinal transit time, which may decrease the risk of colon cancer.