Availability, fermentability, and energy value of resistant maltodextrin: modeling of short-term indirect calorimetric measurements in healthy adults.
BACKGROUND
Determination of the metabolizable (ME) and net metabolizable (NME) energy of total carbohydrate requires estimation of its available (AC) and fermentable (FC) carbohydrate content. Modeling of indirect calorimetric observations (respiratory gas exchange) and breath hydrogen would appear to make it possible to estimate noninvasively these nutritional quantities and the approximate time-course of availability.


OBJECTIVE
We assessed the time-course of metabolism and energy availability from resistant maltodextrin (RMD) by modeling of respiratory gases after a single oral dose.


METHODS
Seventeen healthy adults (13 M, 4 F; aged 25-46 y) were randomly assigned to treatments (water, maltodextrin, or RMD) in a multiple-crossover, single-blinded trial with > or = 7 d washout. We monitored 8-h nitrogen-corrected oxygen and carbon dioxide exchanges and breath hydrogen. All treatment groups took low-carbohydrate meals at 3 and 6 h.


RESULTS
Indirect calorimetry alone provided only qualitative information about the nutritional values of carbohydrate. In contrast, modeling of gaseous exchanges along with the use of central assumptions showed that 17 +/- 2% of RMD was AC and 40 +/- 4% was FC. As compared with 17 kJ gross energy/g RMD, mean (+/- SE) energy values were 7.3 +/- 0.6 kJ ME/g and 6.3 +/- 0.5 kJ NME/g. The fiber fraction of RMD provided 5.2 +/- 0.7 kJ ME/g and 4.1 +/- 0.6 kJ NME/g.


CONCLUSIONS
Modeling with the use of this noninvasive and widely available respiratory gas-monitoring technique yields nutritional values for carbohydrate that are supported by enzymatic, microbial, and animal studies and human fecal collection studies. Improvement in this approach is likely and testable across laboratories.
Goda
Toshinao
T
Laboratory of Nutritional Physiology and the COE Program in the 21st Century, University of Shizuoka School of Food and Nutritional Sciences, Shizuoka, Japan. gouda@u-shizuoka-ken.ac.jp
Kajiya
Yuya
Y
Suruga
Kazuhito
K
Tagami
Hiroyuki
H
Livesey
Geoffrey
G
D000328:Adult; D001682:Biological Availability; D002153:Calorimetry, Indirect; D004040:Dietary Carbohydrates / Q000378:metabolism* / Q000493:pharmacokinetics; D002149:Energy Intake; D005260:Female; D005285:Fermentation; D006207:Half-Life; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011134:Polysaccharides / Q000378:metabolism* / Q000493:pharmacokinetics; D011659:Pulmonary Gas Exchange
D004040:Dietary Carbohydrates; D011134:Polysaccharides; C008315:maltodextrin