Starch fermentation by faecal bacteria of infants, toddlers and adults: importance for energy salvage.
OBJECTIVE
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Department of Child Health, University of Glasgow, Yorkhill Hospital, Glasgow G3 8SJ, UK.
M T
MT
Christian
C A
CA
Edwards
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T
Preston
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L
Johnston
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Varley
L T
LT
Weaver
D000328:Adult; D000367:Age Factors; D002245:Carbon Dioxide / Q000032:analysis; D003106:Colon / Q000378:metabolism* / Q000382:microbiology; D004734:Energy Metabolism / Q000502:physiology*; D005232:Fatty Acids, Volatile / Q000032:analysis*; D005243:Feces / Q000382:microbiology*; D005260:Female; D005285:Fermentation; D006801:Humans; D007223:Infant; D019344:Lactic Acid / Q000032:analysis; D008297:Male; D008697:Methane / Q000032:analysis; D008875:Middle Aged; D008954:Models, Biological; D013213:Starch / Q000378:metabolism*
D005232:Fatty Acids, Volatile; D002245:Carbon Dioxide; D019344:Lactic Acid; D013213:Starch; D008697:Methane