The preterm infant stomach actively degrades milk proteins with increasing breakdown across digestion time

Area of Science:

• Neonatal Physiology
• Gastrointestinal Digestion

Background:

• Preterm infants exhibit unique digestive capabilities compared to term infants.
• Human milk is the primary nutrition source for preterm infants, but its digestion is complex.
• Understanding gastric processing in preterm infants is crucial for optimizing nutritional support.

Purpose of the Study:

• To investigate the impact of post-feeding time on gastric digestion in preterm infants.
• To analyze changes in gastric pH, proteolysis, and specific gastric hormones (pepsin, gastrin, gastrin-releasing peptide) over time.
• To compare the digestion of unfortified and fortified human milk.

Main Methods:

• Gastric samples were collected from 14 preterm infants (23-32 weeks gestational age) at 1, 2, and 3 hours post-feeding.
• Analysis included gastric pH, proteolysis, general protease activity, and concentrations of pepsin, gastrin, and gastrin-releasing peptide (GRP).
• Statistical analysis employed one-way ANOVA with repeated measures and Tukey's post-hoc test.

Main Results:

• Gastric pH significantly decreased from 1 to 3 hours postprandial.
• Proteolysis and general protease activity significantly increased over time in the gastric contents.
• Gastrin-releasing peptide (GRP) was found in human milk, while gastrin was produced in the infant stomach.

Conclusions:

• The preterm infant stomach actively degrades milk proteins, with increasing breakdown over digestion time.
• Despite potential differences from term infants, preterm infants demonstrate a capacity for gastric digestion of human milk.
• These findings highlight the dynamic digestive processes occurring in the preterm infant gut.