Fructooligosaccharides

Fructooligosaccharides (FOS) are oligosaccharides that occur naturally in plants such as onion, chicory, garlic, asparagus, banana, artichoke, among many others.

Fructooligosacchrides are resistant to hydrolysis by the intestinal enzymes,

and have been shown to be indigestible by enzymes in the human small intestine

but are fermented extensively by microflora in the lower digestive tract.