As discussed above, inulin-type fructans are nondigestible oligosaccharides that are also very efficiently fermented by the anaerobic colonic microflora. Additionally, and as a result of selective fermentation, bifidobacteria (and, possibly, a few other genera) are preferentially stimulated to grow, causing significant changes in the composition of the gut microflora by increasing the number of potentially health-promoting bacteria and, eventually, by reducing the number of potentially harmful species. Thus, inulin-type fructans meet all the criteria introduced in the preceding text, and so they are prebiotic. They are also the most extensively tested food ingredient and, for that reason, they need to be considered as the "model prebiotic." As reviewed recently, the only other compounds that fulfill the criteria for prebiotic classification are the food ingredient transgalactooligosaccharides and the drug lactu-lose.9 For a few other food ingredients, i.e., isomaltooligosaccharides, lactosucrose, xylooligosaccharides, soybean oligosaccharides, and glucooligosaccharides, though preliminary and promising data are available, the data are insufficient to classify
Was this article helpful?