On current estimates it is likely that about 30 g carbohydrate per day
enters the colon. It is probable that our estimates of starch and its
degradation products entering the colon, true resistant starch, in a
physiological sense, are too low, With total starch intakes of the ord
er of 150 g one might expect a contribution of the order of, for examp
le, 15 g assuming a digestion/ absorption efficiency of 90%. However,
the digestion of starch and the hydrolysis of the disaccharides and ma
ltooligosaccharides in the brush border of the small intestine are ext
remely efficient, so that the overall efficiency of digestion/ absorpt
ion will be very dependent on the physical structure and properties of
foods. More detailed analyses of the oligosaccharides in foods, espec
ially cereals, may lead to revised estimates, Estimates of the amounts
of carbohydrates required to support the bacterial mass produced shou
ld also be examined more closely. It is also questionable whether esti
mates of breath hydrogen production on a typical diet are indicative o
f the current estimates of carbohydrate substrate required for the pro
duction of bacterial mass. Eur J Cancer Prev 7 (suppl 2): S81-S82 (C)
1998 Lippincott-Raven Publishers.