A novel infant milk formula concept: Mimicking the human milk fat globule structure

Abstract

Human milk (HM) provides all nutrients to support an optimal growth and development of the neonate. The composition and structure of HM lipids, the most important energy provider, have an impact on the digestion, uptake and metabolism of lipids. In HM, the lipids are present in the form of dispersed fat globules: large fat droplets enveloped by a phospholipid membrane. Currently, infant milk formula (Control IMF) contains small fat droplets primarily coated by proteins. Recently, a novel IMF concept (Concept IMF) was developed with a different lipid architecture, Nuturis(®), comprising large fat droplets with a phospholipid coating. Confocal laser scanning microscopy (CLSM), with appropriate fluorescent probes, and transmission electron microscopy were used to determine and compare the interfacial composition and structure of HM fat globules, Concept IMF fat droplets and Control IMF fat droplets. The presence of a trilayer-structured HM fat globule membrane, composed of phospholipids, proteins, glycoproteins and cholesterol, was confirmed; in addition exosome-like vesicles are observed within cytoplasmic crescents. The Control IMF fat droplets had a thick protein-only interface. The Concept IMF fat droplets showed a very thin interface composed of a mixture of phospholipids, proteins and cholesterol. Furthermore, the Concept IMF contained fragments of milk fat globule membrane, which has been suggested to have potential biological functions in infants. By mimicking more closely the structure and composition of HM fat globules, this novel IMF concept with Nuturis(®) may have metabolic and digestive properties that are more similar to HM compared to Control IMF.

Towards infant formula biomimetic of human milk structure and digestive behaviour

“…most frequent size in the distribution in volume, of 6.25 mm) covered by milk phospholipids (2 g/L). Thus the particle size distribution, emulsion interfacial composition and organization is very close, although not totally similar, to HM (Gallier et al, 2015). The administration during the neonatal period (from day 16 to 42) of this Nuturis ® formula in mice, followed by a western diet challenge, resulted during adulthood to lower fat accumulation, lower fasting plasma leptin, resistin, glucose and lipid (TG and total cholesterol) than in the group fed conventional formula (Oosting et al, 2012).…”

“…These compounds can be added in the IF premix. An important aspect of such addition is not only their protein/phospholipids ratios but also the order of introduction of these two amphiphiles in the emulsion which can impact on the emulsion interfacial composition and structure (Bourlieu et al, 2015a;Gallier et al, 2015). The precise interfacial composition of such biomimetic IF remains to be characterized as well as its susceptibility to digestion.…”

“…Since HM is a complex and dynamic fluid very difficult to mimic, most improvements of IF have consisted in the addition of components individually identified as bioactive in HM, in the optimized IF (Committee on the evaluation of the addition of ingredients new to infant formula, 2004; Gallier et al, 2015;Zou et al, 2016). Notably, components such as long chain polyunsaturated fatty acids (LCPUFA), lactoferrin, nucleotides, essential amino-acids (AA), oligosaccharides (OS), prebiotics, probiotics can be added into some IF.…”

Dietary lipid emulsions and endotoxemia

“…Unlike soybean PL, milk PL in the high fat diet were found to increase the number of colonic goblet cells, thereby possibly contributing to an improved gut barrier that can prevent LPS translocation from the colon to the circulation (Lecomte et al, 2016). Consequences in the field of infant nutrition regarding the metabolic impact of native breastmilk fat globules vs artificially formulated fat droplets would deserve to be elucidated (Bourlieu and Michalski, 2015;Gallier et al, 2015).…”

Digestibility and structural changes of ingredients in infant formulae during the gastrointestinal digestion

“…The oil droplet size distribution in infant formula is in the range of 0.1-1 μm which is smaller than in mothers' milk 0.1-10 μm . Also, due to the way the fat globules in mothers' milk are made and secreted from the mammary gland cells, the fat droplets in mothers' milk are covered by a phospholipid trilayered membrane composed of phospholipids, proteins and cholesterol (Gallier et al, 2015). However, oil droplets in infant formula are stabilized by an absorbed proteins layer based on caseins, whey proteins, whey protein aggregates, and even soy proteins on the surface of oil droplets (Bourlieu, Ménard, et al, 2015;Reis, Holmberg, Watzke, Leser, & Miller, 2009).…”