The ingestion of a sufficiently large amount of non-digestible and/or non-absorbable
sugar substitutes causes overt
diarrhea. The objective is to estimate the non-effective dosage that does not cause transitory
diarrhea for
xylitol,
lactitol, and
erythritol in healthy subjects. Twenty-seven males and 28 females gave informed and written consent to participate, were selected, and participated in the study. The oral dose levels of
xylitol were 10, 20, 30, 40 and 50 g, while those of
lactitol were 10, 20, 30, and 40 g. Those of
erythritol were 20, 30, 40 and 50 g. The test substance was ingested in 150 mL of water 2-3 h after a meal. The ingestion order progressed from the smallest to larger amounts, and stopped at the dose that caused
diarrhea, or at the largest dose level to be set up. The non-effective dose level of
xylitol was 0.37 g/kg B.W. for males and 0.42 g/kg B.W. for females. That of
lactitol was 0.25 g/kg B.W. for males and 0.34 g/kg B.W. for females, and that of
erythritol was 0.46 g/kg B.W. for males and 0.68 g/kg B.W. for females. These results appear reasonable, because
xylitol is poorly absorbed from the small intestine, and the absorption rate is less than that of
erythritol, while
lactitol is not hydrolyzed. Non-digestible and/or non-absorbable
sugar alcohols and
oligosaccharides with beneficial health effects inevitably cause overt
diarrhea. The estimation of the non-effective dose level of these
sugar substitutes is essential and important to produce processed foods that the consumer can use safely and with confidence.