Amount of carbohydrate entering the human colon

Amount of carbohydrate entering the colon

It is difficult to measure the amount of carbohydrate entering the human colon. However, it has been esti-mated that at least 30 g of carbohydrate is required to support the growth of the bacterial population in the colon of an individual on a typical Western diet pro-ducing about 100 g stool per day. About half of that amount will come from nonstarch polysaccharide (NSP, also known as dietary fiber), 1–2 g from indi- gestible oligosaccharides, and probably about 1–2 g from intestinal mucopolysaccharides. These compo-nents add up to only 18–20 g. Where does the other 10–12 g come from? It is believed to come from starch, because experiments in humans show that about 5– 15% of the starch in foods enters the colon. Typical Western diets contain about 120–150 g starch per day, and, if 8% of this enters the colon, this will provide the additional 10–12 g carbohydrate. The amount of carbohydrate entering the colon, however, can be increased several-fold, up to 100 g/day or more, by changes in diet such as increased intake of NSP, non-digestible or partially digestible carbohydrates (ingredients in functional foods), total starch, resis-tant starch, or slowly digested, low-GI foods.