[Show abstract][Hide abstract] ABSTRACT: Little is known of the degree to which the colon salvages energy through starch fermentation in young children. Using a simulated colonic environment, we aimed to account for the fate of fermented raw and cooked starch in two groups of young children and in adults.
A slurry was prepared from faecal samples from six infants (7-10 months), six toddlers (16-21 months) and seven adults (24-56 y). Each slurry was anaerobically incubated with raw or cooked maize starch in MacCartney bottles in a shaking water bath. Parallel incubations were stopped at 4 and 24 h. The headspace gas volume was analysed for CO(2) and methane. The culture supernatant was analysed for short-chain fatty acids (SCFA), lactate and residual starch.
Different patterns of fermentation were seen at 4 and 24 h. For raw starch, the production of SCFA decreased with subject age at 4 h but not at 24 h. With both substrates at 4 h, toddler stools produced significantly more CO(2) than infants or adults, but there were no statistical differences at 24 h. Methane was detected in three adults only. Lactate was detected mainly at 4 h in children.
The results suggest that fermentation, particularly of raw starch, is a more rapid process in young children than in adults. A highly efficient energy salvage process may occur in the colon of young children.
European Journal of Clinical Nutrition 11/2003; 57(11):1486-91. · 2.95 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The colon salvages energy from starch, especially when the capacity of the small intestine to digest it is limited. The aim of this study was to determine the site and relative extent of starch digestion and fermentation in infants.
Thirteen infants (10 male and 3 female infants), median age 11.8 months (range, 7.6-22.7 months), were fed a starchy breakfast containing 13C-labeled wheat flour after an overnight fast. Duplicate breath samples were obtained before breakfast and every 30 minutes for 12 hours. Breath 13CO2 enrichment was measured using isotope ratio mass spectrometry, and results were expressed as percentage dose recovered (PDR) for each 30 minutes. The PDR data were analyzed and mathematically modeled assuming either a constant estimate of CO2 production rate or adjusted for physical activity.
Mean +/- SD cumulative 13C PDR (cPDR) at 12 hours was 21.3% +/- 8.4% for unadjusted data and 26.5% +/- 11.6% for adjusted data. A composite model of two curves fit significantly better than a single curve. Modeling allowed estimation of cPDRs of small intestine (17.5% +/- 6.5% and 22.7% +/- 9.3% for unadjusted and adjusted data, respectively) and colon (4.6% +/- 2.9% and 6.3% +/- 5.4%).
Modeling of 13CO2 enrichment curves after ingestion of 13C-enriched wheat flour is an attractive means to estimate the contribution of the upper and lower gut to starch digestion and fermentation.
Journal of Pediatric Gastroenterology and Nutrition 03/2002; 34(2):158-64. · 2.87 Impact Factor