Human tolerance to a single, high dose of D-tagatose

The addition of 29 g D-tagatose added as a sweetener to a continental break fast was tested for the appearance of gastrointestinal side effects in a do uble-blind randomized cross-over study with 29 g sucrose as a control treat ment. The subjects reported the side effects during 72 h following the test meal on a questionnaire grading the symptoms on a five-level scale ranging from "none" to "very strong." Although "rumbling in the stomach," "distent ion," "nausea," "rumbling in the gut," "flatulence," and "diarrhea" scored significantly higher with D-tagatose, the sugar otherwise was well tolerate d in most of the subjects. Two cases of vomiting after D-tagatose were reco rded but in one of the cases its relation to the D-tagatose intake was ques tionable. Only the "distention" score remained higher with D-tagatose for m ore than 24 h. Nausea, vomiting, and perceived distension may be due to an osmotic effect in the small intestine of unabsorbed D-tagatose. The increas ed flatus is caused by D-tagatose being fermented in the large intestine. D iarrhea may be explained by osmotic effects in the colon from nondegraded D -tagatose or nonabsorbed short-chain fatty acids produced by the increased fermentation. (C) 1999 Academic Press.