Carbohydrate Absorption From Fruit Juices in Infants

To compare the absorption of carbohydrate in particular from a lower (10 mL/kg⁻¹) quantity than that previously tested, of white grape juice and pear juice after a single feeding and after ingestion twice daily for 2 weeks, and determine their respective effects on stool water content, in healthy infants.

Twelve healthy, well-nourished infants, 5 to 9 months of age, who were recruited from the general population.

Infants underwent a breath hydrogen test after a serving of pear juice. Three to 5 days later, the test was repeated after a serving of white grape juice. Infants were randomly assigned to receive a 10 mL/kg⁻¹ serving of grape juice or pear juice twice daily for 2 weeks. The breath tests were repeated after the ingestion of the juices in the same sequence. With the second breath test with pear juice, a charcoal marker and 20 mg¹³C fructose, a stable, nonradioactive isotope, were mixed with the juice. Water content of the stools was compared before and after the 2-week feeding of the juice, and fecal samples were analyzed for ¹³C enrichment by mass spectrometry.

After the ingestion of the fruit juices, only 1 infant had an abnormal peak hydrogen (H₂; ≥10 ppm), which followed the pear juice. That same infant was the only one who had H₂ levels ≥10 ppm after grape juice. There was no significant difference in the peak breath H₂ levels after grape juice and pear juice either at the beginning of the study or 2 weeks after taking the juice assigned (2.8 ppm ± 2.9 vs 6.2 ppm ± 9, respectively). The difference in breath H₂response before and after the 2 weeks of fruit juice intake was not significant. Mean (±standard deviation) fecal ¹³C enrichment at baseline was 3.0 Δ%o (±2.4), which was not significantly different from after 2 weeks of juice intake (2.4 Δ%o [±1.5]), regardless of the juice assigned: 2.7 Δ%o (±1.6) for grape juice and 2.2 Δ%o (±1.5) for pear juice. Mean (±standard deviation) percentage of fecal water at baseline was 24.1% (±5.1), which was not significantly different from after 2 weeks of juice (22.5% [±6]), regardless of the juice received: 21.8% (±5.8) for grape juice and 23.2% (±6.7) for pear juice.

When either grape or pear juice is administered in a dosage of 10 mL/kg/day, the carbohydrate is well absorbed, produces no adverse gastrointestinal symptoms, and has no effect on stool water in healthy infants.