Randomised controlled trial of a synthetic triglyceride milk formula for preterm infants

AIMS To test whether use of infant formula containing synthetic structured triglycerides results in: (i) increased palmitate absorption; (ii) increased total fat absorption; (iii) reduction in calcium soap formation in the gut; and hence (iv) increased calcium absorption. METHODS A randomised study was made of 24 infants comparing three formulas, one containing the synthetic fat Betapol with 74% of palmitate in the 2-position, which was substantially higher than in the two comparison diets (8.4% and 28%). The hypothesised outcomes were tested using balance studies, detailed chemical analysis of stool specimens and dual calcium isotope tracers (44calcium orally and 46calcium intravenously). RESULTS Three of the four hypotheses were confirmed: use of a formula rich in 2-position palmitate (i) improved palmitate (16:0) and also (18:0) absorption; (ii) reduced the formation of insoluble calcium soaps in the stool; and (iii) improved calcium absorption, determined by the dual tracer technique from 42 (SE 3)% to 57 (7)%. CONCLUSION Synthetic triglycerides that mimic the stereoisometric structure of those in breast milk may have a valuable role in the design of formulas used for preterm infants in neonatal intensive care units. Key messages Synthetic structured triglycerides can provide palmitic acid predominantly in the 2-position, like breast milk, rather than predominantly in the 1 and 3 positions as in modern formulas. Use of such fats in formula for preterm infants can improve absorption of saturated fats, palmitate, and stearate. Improved saturated fat absorption reduces calcium soap formation in the intestine. In turn, this improves calcium absorption, determined by dual calcium isotope kinetics.