Caloric availability of palatinitR (isomalt) in the small intestine of rats: Implications of dose dependency on the energy value

A digestive tolerance study of maltitol after occasional and regular consumption in healthy humans

AIM

We aimed to evaluate the gastro-intestinal tolerance to an indigestible bulking sweetener containing sugar alcohol using a double-blind random cross-over study.

METHOD

In order to simulate their usual pattern of consumption, 12 healthy volunteers ingested maltitol or sucrose throughout the day, either occasionally (once a week for each sugar, first period) or regularly (every day for two 9 day periods, second period). In both patterns of consumption, daily sugar doses were increased until diarrhea and/or a grade 3 (ie severe) digestive symptom occurred, at which the dose level was defined as the threshold dose (TD).

RESULTS

In the first period (occasional consumption), the mean TD was 92+/-6 g with maltitol and 106+/-4 g with sucrose (P=0.059). The mean intensity of digestive symptoms was 1.1 and 1.3, respectively (P=NS). Diarrhea appeared in six and one subjects respectively (P=0.035). In the second period (regular consumption), the mean TD was 93+/-9 g with maltitol and 113+/-7 g with sucrose (P=0.008). The mean intensity of digestive symptoms was 1.7 and 1.2, respectively (P=NS). However, diarrhea appeared in eight and three subjects, respectively (P=0.04). Maltitol and sucrose TDs between the two periods were not different.

CONCLUSIONS

Under our experimental conditions, in comparison to sucrose: (a) occasional or regular consumption of maltitol is not associated with severe digestive symptoms; (b) in both patterns of maltitol consumption, diarrhea frequency is higher, but it appeared only for very high doses of maltitol, much greater than those currently used; (c) maltitol does not lead to intestinal flora adaptation after a 9 day period of consumption.

The comparative gastrointestinal responses of children and adults following consumption of sweets formulated with sucrose, isomalt and lycasin HBC

OBJECTIVES

To determine the gastrointestinal responses of children and adults following consumption of sucrose, isomalt and lycasin HBC and to compare these at two different dose levels in adults.

DESIGN

Both studies were randomised, double-blind, cross-over designs.

SUBJECTS

Fifty-one children aged 6-9 y were recruited from primary schools in the Salford area of Greater Manchester. Forty-eight children completed the study. Fifty healthy adult volunteers aged 18-24 y were recruited from the student population of the University of Salford. All subjects completed the study.

INTERVENTIONS

Children consumed either 25 g of sucrose, isomalt or lycasin HBC and adults 25 and 40 g in hard boiled sweets per day for two consecutive test days. Test periods of 2 days were separated by 7 day washout periods. Children consumed sweets throughout test days and adults in no less than 30 min but no more than 90 min. Subjects reported the prevalence and magnitude of flatulence, borborygmi, bloating, colic, bowel movements and watery faeces.

RESULTS

Consumption of 25 g isomalt provoked a mild laxative effect in children but not in adults. Consumption of 25 g isomalt significantly increased the prevalence and magnitude of gastrointestinal responses in both children and adults. Consumption of 25 g lycasin HBC significantly increased borborygml in children and adults but no other gastrointestinal responses. Consumption of 40 g lycasin HBC or isomalt by adults significantly increased the mean frequency of bowel movements and the number of subjects passing watery faeces. In adults, 40 g isomalt and lycasin HBC provoked significantly more gastrointestinal responses compared to 25 g of either product.

CONCLUSIONS

Consumption of 25 g lycasin HBC does not provoke an unacceptable laxative effect or gastrointestinal response in children or adults compared to 25 g isomalt, which is associated with a mild laxative effect and increase in gastrointestinal responses. In adults gastrointestinal responses following consumption of products were found to be dose dependent.

Dose dependency of fermentation and the extent of renal excretion of palatinit (isomalt) in rats with respect to its energy value

The impact of dose-dependent caloric salvage by microbial fermentation processes in the lower gut and the extent of renal excretion for the overall energetic availability of the alternative bulk sweetener Palatinit were investigated in rats. To evaluate the extent of dose-dependent fermentation a conventional and a germ-free rat model were used and fecal excretions of Palatinit after intragastric application were compared. Because of the lack of bacterial colonization in the gastrointestinal tract in germ-free rat the difference in fecal excretion of Palatinit between germ-free and conventional rat is mainly due to bacterial fermentation. To determine the amount of renal excretion of Palatinit the urine was collected. The experiments were conducted using different amounts of Palatinit (300 and 1,200 mg/kg body weight = mg/kg b.w.). Fecal excretions of Palatinit and its monomers (sorbitol and mannitol) were measured by high-performance liquid chromatography (HPLC) and for the determination of renal excretions a gas chromatography system was used. After the application of 300 mg/kg b.w. Palatinit only the breakdown product sorbitol could be recovered in the feces of germ-free rats (29% of the applied dose). No intact Palatinit could be found. In contrast, neither Palatinit nor the breakdown products sorbitol or mannitol could be detected in the feces of conventional rats after application of the same dose. After the application of the higher dose only small amounts of intact Palatinit were found in the feces of germ-free rats (average 12%). There was no intact measurable Palatinit in the feces of conventional rats. The fecal excretions of sorbitol and mannitol in the feces of the germ-free rats were 55% and 39%; in conventional rats only 21% sorbitol was excreted. Only traces of Palatinit, sorbitol or mannitol were found in the urine of conventional and germ-free rats after application of the low as well as the high dose. In conclusion, this study clearly shows the dose dependency of fermentation and therefore the dose dependency of the energetic (i.e., caloric) availability of this disaccharide sugar alcohol. In the calculation of the energy value of Palatinit the renal excretion of Palatinit and its monomers can be neglected.

Gastrointestinal transit and digestibility of maltitol, sucrose and sorbitol in rats: a multicompartmental model and recovery study

Using data obtained with a dye marker and the gavage technique, the kinetics of gastrointestinal transit of different loads of sugar substitutes (maltitol, sorbitol) and sugar (sucrose) in the rat were analysed using a linear multicompartmental model over a range from the realistic to the non-physiologic high, of carbohydrate intake levels and using only a few experimental time points. The model gave detailed insight into intestinal propulsion and gastrocecal transit time. Rate constants of transport between the compartments investigated were determined; they showed characteristics which could be related to the substance and the dosage administered. Analyses of the gastrointestinal content and calculations of the intestinal net water movement showed that the digestibility and absorption of the disaccharide sugar alcohol, maltitol, in the small gut depended inversely on the dose ingested. For all substances tested, caloric availability in the small intestine was calculated. At a physiological low level of maltitol intake, the results also indicated an insignificant calorie-saving effect in comparison to sucrose, an effect based mainly on the slow absorption rate of the maltitol cleavage product sorbitol.