Objective: Glutamine depletion has negative effects on the functional integrity of the gut and leads to immunosuppression. Very low birth weight (VLBW) infants are susceptible to glutamine depletion, as enteral nutrition is limited in the first weeks of life. Enteral glutamine supplementation may have a positive effect on feeding tolerance, infectious morbidity and short-term outcome. The aim of the study was to determine the effect of enteral glutamine supplementation on plasma amino acid concentrations, reflecting one aspect of safety of enteral glutamine supplementation in VLBW infants.
Methods: In a double-blind placebo-controlled randomized controlled trial, VLBW infants (gestational age <32 weeks or birth weight <1500 g) received enteral glutamine supplementation (0.3 g/kg per day) or isonitrogenous placebo supplementation (alanine) between day 3 and day 30 of life. Supplementation was added to breast milk or to preterm formula. Plasma amino acid concentrations were measured at four time points: before the start of the study and at days 7, 14 and 30 of life.
Results: Baseline patient and nutritional characteristics were not different in glutamine (n = 52) and control (n = 50) groups. Plasma concentrations of most essential and non-essential amino acids increased throughout the study period. There was no effect of enteral glutamine supplementation. In particular, the increase of plasma glutamine and glutamate concentrations was not different between the treatment groups (P = 0.49 and P = 0.34 respectively, day 30).
Conclusions: Enteral glutamine supplementation in VLBW infants does not alter plasma concentrations of glutamine, glutamate or other amino acids. Enteral supplementation in a dose of 0.3 g/kg per day seems safe in VLBW infants.