Metabolic fate of ingested [14C]-maltitol in man

Six healthy male subjects were given a single oral dose of 0.4 g of maltitol per kg body weight containing [U-14C]-maltitol (50 microCi) and their breath, urine, feces and blood were collected at appropriate intervals for 48 h to measure the recovery of administered radioactivity. Further, to measure breath hydrogen, 15 healthy male subjects ingested 30 g of maltitol and samples of their breath were collected for a 10-h period. The expired 14CO2 showed a wide peak about 3 h after ingestion and 56% of the administered radioactivity was recovered in 48 h. An additional 0.2% of administered radioactivity was recovered as expired 14CH4, 2.6% in urine and 14.3% in feces, respectively. The obvious increase of breath hydrogen was detected at 1 h after maltitol ingestion and then a big peak at 3.5 h, whereas maltose ingestion did not increase breath hydrogen. Both excretion profiles of breath 14CO2 and hydrogen coincided well. These results demonstrate that a greater part of ingested maltitol is fermented by intestinal microbes than is hydrolyzed by digestive enzymes. Although maltitol is catabolized to carbon dioxide via intestinal microbes, the available energy is much lower than that of digestible sugars such as sucrose.