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Simultaneous assessment of intestinal permeability and lactase activity in human-milk-fed preterm infants by sugar
Elise Mank1, Dewi van Harskamp2, Letty van Toledo1
1Amsterdam UMC, University of Amsterdam, Vrije Universiteit, Emma Children's Hospital, Department of Neonatology, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands.
Insights
A new method simultaneously assesses intestinal permeability and lactase activity in preterm infants using a sugar absorption test. This technique helps monitor nutritional interventions and infant gut maturation.
Area of Science:
- Neonatal nutrition
- Gastroenterology
- Analytical chemistry
Background:
- Preterm infant nutrition focuses on intestinal maturation for better enteral feeding tolerance.
- Intestinal permeability and lactase activity are key markers of gut maturation.
- Current methods for assessing these markers can be limiting.
Purpose of the Study:
- To develop a protocol for simultaneously assessing intestinal permeability and lactase activity in human-milk-fed preterm infants.
- To establish a novel gas chromatography-mass spectrometry (GC-MS) method for analyzing specific sugars in urine and milk samples.
- To validate the developed protocol and analytical method for monitoring nutritional interventions.
Main Methods:
- A sugar absorption test was conducted on 12 preterm infants (26-32 weeks gestational age) on postpartum days 4, 7, and 14.
- Urine and human milk samples were collected during the test.
- Samples were analyzed using a newly developed GC-MS method after derivatization.
Main Results:
- The GC-MS method accurately measured lactulose, lactose, and mannitol concentrations.
- A decreasing lactulose/mannitol ratio in urine indicated reduced intestinal permeability over time.
- An increasing urine-to-milk lactulose/lactose ratio indicated increasing lactase activity.
Conclusions:
- The developed protocol enables simultaneous assessment of intestinal permeability and lactase activity in preterm infants.
- This method is valuable for evaluating the impact of nutritional interventions on gut maturation.
- The GC-MS method provides accurate analysis of samples collected during the sugar absorption test.
Background & Aims:
Experimental (nutritional) interventions in preterm infants frequently focus on intestinal maturation, as improving tolerance to enteral nutrition is a major goal. Intestinal permeability and lactase activity serve as markers for intestinal maturation. We aimed to develop a protocol for the simultaneous assessment of both markers in human-milk-fed preterm infants by a sugar absorption test. In addition, we developed a new gas chromatography-mass spectrometry (GC-MS) method for the analysis of lactulose, lactose, and mannitol in urine and milk collected during the sugar absorption test.
Methods:
The sugar absorption test was performed on days 4, 7, and 14 postpartum in 12 preterm infants (gestational age of 26-32 weeks). Human milk was collected, pooled, and divided into equal portions to provide a stable lactose intake for 24 h. Urine was collected in the last 6 h of this 24 h period, after administration of a bolus test sugar solution. Samples were analyzed by GC-MS after derivatization by oxime formation combined with acetylation.
Results:
The GC-MS method was validated and used for the accurate measurement of lactulose, lactose, and mannitol concentrations. The urinary lactulose/mannitol ratio declined with time, suggesting a decreased intestinal permeability. The urine-to-milk-lactulose/lactose ratio increased as a result of increased lactase activity with time.
Conclusions:
The developed protocol for simultaneous assessment of intestinal permeability and lactase activity can be used to monitor the effect of experimental (nutritional) interventions in human-milk-fed preterm infants. Urine and milk samples obtained during the sugar absorption test can be accurately analyzed by GC-MS.
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