Digestion, absorption, fermentation, and metabolism of functional
sugar substitutes and their available energy*
Tsuneyuki Oku** and Sadako Nakamura
Department of Nutritional Sciences, Faculty of Nursing
and Nutrition, Siebold University of Nagasaki, Nagayo, Nagasaki 851-2195,
Abstract: Many kinds of oligosaccharides and sugar
alcohols have been newly developed as bulking sugar substitutes that
have beneficial health effects. A sugar substitute that is not digested
and absorbed in the small intestine reaches the large intestine, where
it is completely fermented by intestinal bacteria and produces short-chain
fatty acids, which are converted to energy. The available energy of
a nondigestible sugar substitute, which is completely fermented by intestinal
microbes, is estimated as approximately 2 kcal/g.
On the other hand, a sufficiently high ingestion of nondigestible sugar
substitutes regularly causes overt diarrhea in human and animals. However,
the diarrhea disappears within a few days because intestinal microbes,
which readily utilize these saccharides, increase during ingestion.
The maximum permissible dose, by which transitory diarrhea is not caused
by the ingestion of nondigestible sugar substitutes, is estimated as
approximately 0.3 g per kg body weight in single ingestion for Japanese
adults. The value is varied by some factors, such as separate ingestion,
repeat ingestion, test substance, and body condition, etc.
* A special topic issue on the
science of sweeteners.
** Corresponding author. Tel. and Fax: 095-813-5211; E-mail: [email protected]
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