Title: An infant formula with large, milk phospholipid-coated lipid droplets containing a mixture of dairy and vegetable lipids supports adequate growth and is well-tolerated in healthy, term infants
| Authors: | Laura M. Breij, Marieke Abrahamse-Berkeveld, Yvan Vandenplas, Sabine N.J. Jespers, Amerik C. de Mol, Poh Choo Khoo, Masendu Kalenga, Stefaan Peeters, Ron H.T van Beek, Obbe F. Norbruis, Stefanie Schoen, Dennis Acton, Anita C.S. Hokken-Koelega, for the Mercurius Study Group |
| Published: | 2019 |
| Journal: | Am J Clin Nutr 2019; 109(3): 586-596 doi:10.1093/ajcn/nqy322 |
Exclusive human milk is the preferred feeding for infants providing the optimal nutrition to fully support their growth and development. Lipids are of utmost importance for fulfilling the nutritional needs: the lipid fraction in human milk provides almost half of the required caloric intake of infants. Lipids in human milk have a unique fatty acid composition, structure and complexity. Human milk lipids are present as lipid droplets, with a mode diameter of 3-5 µm, enveloped by a tri-layered membrane which is mainly consisting of phospholipids, membrane-specific proteins and cholesterol. The structural complexity of the lipid droplets originates from their synthesis and excretion by the epithelial cells of the mammary gland. Lipids in infant milk formula lack this structural complexity and are present as smaller lipid droplets mostly containing vegetable oils, with a mode diameter of 0.5 µm, with mainly proteins adhering to the outer surface.
Human milk fat substitutes have been developed to more closely mimic the composition and structural complexity of natural lipid (droplets). Infant formulae containing structured lipids or dairy lipids to increase the level of sn-2 palmitic acid have been shown to reduce calcium soaps, soften stools and improve fatty acid absorption. Recently, an innovative formulation was designed using an adapted production process resulting in larger lipid droplets with a thin interface of milk phospholipids, other polar lipids, (glyco)proteins and cholesterol (Nuturis®).
In this multicenter, randomized, double-blind equivalence study, the investigators evaluated the impact of this novel infant formula on infant growth outcomes following the procedures of stringent safety evaluation. In addition, this study evaluated tolerance, stool characteristics, fat-soluble vitamin levels and adverse events.
A total of 223 fully-formula fed infants were randomized to either a control formula with small lipid droplets comprised of vegetable oil or a concept formula with large, milk phospholipid coated lipid droplets ((Nuturis®). The intervention formulas were iso-caloric containing similar amounts of protein, lipids and the prebiotic mixture scGOS/lcFOS (9:1); having compositions compliant with Directive 2006/141/EC. The key differences were:
- the size of their lipid droplets
- the coating of their lipids droplets and
- the origin of their lipid sources.
A group of breastfed infants served as reference. The infants were enrolled before 35 days of age and followed up until 17 weeks of age. During monthly visits anthropometrics data was collected and the occurrence and nature of adverse events. Furthermore, 7-d diary data on gastrointestinal tolerance, stool characteristics and formula intake was evaluated by the investigators. At 13 weeks of age, a blood sample was collected and fat-soluble vitamins were determined to evaluate a potential impact of the altered lipid droplet structure on their bioavailability.
Equivalence in daily weight gain was demonstrated and no clinically relevant differences were observed in growth, tolerance, fat soluble-vitamin levels and number, severity or relatedness of adverse events. The weight, height and head circumference values of both formula groups were close to the median of the WHO growth standards, indicative for adequate growth. Most of the formula-fed infants had a stool consistency categorized as ‘soft stools’, which is in line with the known stool-softening effect of the prebiotic mixture scGOS/lcFOS (9:1). Interestingly, the concept group showed stool characteristics closer to the stool characteristics observed in breastfed infants between 5 and 12 weeks of age, most probably due to the presence of dairy fat containing sn2-palmitate.
This first clinical evaluation in infants of a concept formula with large, milk phospholipid-coated lipid droplets containing dairy lipids demonstrates that it supports an adequate infant growth, is well-tolerated and safe for use in infants. This new dimension in lipid quality aims to bring the functional properties of infant milk formulas closer to that observed in breastfed infants.
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