Background
We evaluated the effect of age on the results of a cornflakes breath test that determines the efficiency of starch digestion. MATERIAL/METHods: Two groups of 12 fasted healthy subjects (group Y, 24.7+/-0.6 years; and group MA, 49.7+/-1.3 years) consumed a 521-kcal test breakfast of 100 g cornflakes naturally abundant in 13C (-14.00 per thousand 13C enrichment relative to the Vienna Pee Dee belemnite standard). Then, the 13CO2 concentration was measured in samples of exhaled air collected over 9 hours.
Material and Method

Results
We noted a maximum momentary 13CO2 breath excretion of 7.54+/-0.19% dose/h at 298 +/- 15 minutes in group Y and 7.70+/-0.27% dose/h at 305+/-10 minutes in group MA. The group curves of the cumulative 13C recovery in breath air exhibited a virtually overlapping time course. The 6-hour cumulative 13C recovery was 29.33+/-0.70%dose in group Y and 29.87+/-1.18%dose in group MA. Extending the collection period from 6 to 9 hours produced an increase in the cumulative 13C recovery of 58.4+/-2.1%. The 9-hour cumulative 13C recovery was 46.58+/-1.04%dose in the Y group and 46.93+/-1.84%dose and the MA group.
Conclusions
An age difference of more than 2 decades was not associated with a negative impact on the in vivo ability to digest starch. The reference values of the cornflakes breath test can be derived from healthy subjects in a relatively wide age range.

Keywords: Starch - metabolism, Health, Cereals, Exhalation, Carbon Isotopes, Carbon Dioxide - analysis, Breath Tests - methods, Aging - physiology