title: Intestinal threonine utilization for protein and mucin synthesis is decreased in formula-fed preterm pigs.
abstract: Threonine is an essential amino acid necessary for synthesis of intestinal (glyco)proteins such as mucin MUC2 to maintain adequate gut barrier function. In premature infants, reduced barrier function may contribute to the development of necrotizing enterocolitis (NEC). Human milk protects against NEC compared with infant formula. Therefore, we hypothesized that formula feeding decreases the MUC2 synthesis rate concomitant with a decrease in intestinal first-pass threonine utilization, predisposing the preterm neonate to NEC. Preterm pigs were delivered by caesarian section and received enteral feeding with formula (FORM; n = 13) or bovine colostrum (COL; n = 6) for 2 d following 48 h of total parenteral nutrition. Pigs received a dual stable isotope tracer infusion of threonine to determine intestinal threonine kinetics. NEC developed in 38% of the FORM pigs, whereas none of the COL pigs were affected (P = 0.13). Intestinal fractional first-pass threonine utilization was lower in FORM pigs (49 ± 2%) than in COL pigs (60 ± 4%) (P = 0.02). In FORM pigs compared with COL pigs, protein synthesis (369 ± 31 mg·kg(-1)·d(-1) vs. 615 ± 54 mg·kg(-1)·d(-1); P = 0.003) and MUC2 synthesis (121 ± 17%/d vs. 184 ± 15%/d; P = 0.02) were lower in the distal small intestine (SI). Our results suggest that formula feeding compared with colostrum feeding in preterm piglets reduces mucosal growth with a concomitant decrease in first-pass splanchnic threonine utilization, protein synthesis, and MUC2 synthesis in the distal SI. Hence, decreased intestinal threonine metabolism and subsequently impaired gut barrier function may predispose the formula-fed infant to developing NEC.
authors: Pediatrics, Neonatology, Erasmus MC-Sophia, Rotterdam 3015GJ, The Netherlands.
authors: Patrycja J
authors: PJ
authors: Puiman
authors: Mikkel
authors: M
authors: Jensen
authors: Barbara
authors: B
authors: Stoll
authors: Ingrid B
authors: IB
authors: Renes
authors: Adrianus C J M
authors: AC
authors: de Bruijn
authors: Kristien
authors: K
authors: Dorst
authors: Henk
authors: H
authors: Schierbeek
authors: Mette
authors: M
authors: Schmidt
authors: Günther
authors: G
authors: Boehm
authors: Douglas G
authors: DG
authors: Burrin
authors: Per T
authors: PT
authors: Sangild
authors: Johannes B
authors: JB
authors: van Goudoever