Comment on "Safety and Tolerance Evaluation of Milk Fat Globule Membrane-Enriched Infant Formulas: A Randomized Controlled Multicenter Non-Inferiority Trial in Healthy Term Infants"

Serum cytokine patterns are modulated in infants fed formula with probiotics or milk fat globule membranes: A randomized controlled trial

Background

Proteins and lipids of milk fat globule membrane (MFGM) and probiotics are immunomodulatory. We hypothesized that Lactobacillus paracasei ssp. paracasei strain F19 (F19) would augment vaccine antibody and T helper 1 type immune responses whereas MFGM would produce an immune response closer to that of breastfed (BF) infants.

Objective

To compare the effects of supplementing formula with F19 or bovine MFGM on serum cytokine and vaccine responses of formula-fed (FF) and BF infants.

Design

FF infants were randomized to formula with F19 (n = 195) or MFGM (n = 192), or standard formula (SF) (n = 194) from age 21±7 days until 4 months. A BF group served as reference (n = 208). We analyzed seven cytokines (n = 398) in serum at age 4 months using magnetic bead-based multiplex technology. Using ELISA, we analyzed anti-diphtheria IgG (n = 258) and anti-poliovirus IgG (n = 309) concentrations in serum before and after the second and third immunization, respectively.

Results

Compared with SF, the F19 group had greater IL-2 and lower IFN-γ concentrations (p<0.05, average effect size 0.14 and 0.39). Compared with BF, the F19 group had greater IL-2, IL-4 and IL-17A concentrations (p<0.05, average effect size 0.42, 0.34 and 0.26, respectively). The MFGM group had lower IL-2 and IL-17A concentrations compared with SF (p<0.05, average effect size 0.34 and 0.31). Cytokine concentrations were comparable among the MFGM and BF groups. Vaccine responses were comparable among the formula groups.

Conclusions

Contrary to previous studies F19 increased IL-2 and lowered IFN-γ production, suggesting that the response to probiotics differs across populations. The cytokine profile of the MFGM group approached that of BF infants, and may be associated with the previous finding that infectious outcomes for the MFGM group in this cohort were closer to those of BF infants, as opposed to the SF group. These immunomodulatory effects support future clinical evaluation of infant formula with F19 or MFGM.

Milk fat globule membrane: the role of its various components in infant health and development

Breastfeeding confers many benefits to the breast-fed infant which are reflected by better short-term and long-term outcomes as compared to formula-fed infants. Many components of breast milk are likely to contribute to these favorable outcomes, and there has recently been focus on the milk fat globule membrane (MFGM). This fraction is a heterogenous mixture of proteins (many of them glycosylated), phospholipids, sphingolipids, gangliosides, choline, sialic acid and cholesterol which is lacking in infant formula as milk fat (which is also low in these components) is replaced by vegetable oils. Many of these components have been shown to have biological effects, and there is considerable evidence from preclinical studies and clinical trials that providing bovine MFGM results in improved outcomes, in particular with regard to infections and neurodevelopment. Since bovine MFGM is commercially available, it is possible to add it to infant formula. There are, however, considerable variations in composition among commercial sources of bovine MFGM, and as it is not known which of the individual components provide the various bioactivities, it becomes important to critically review studies to date and to delineate the mechanisms behind the activities observed. In this review, we critically examine the preclinical and clinical studies on MFGM and its components in relation to resistance to infections, cognitive development, establishment of gut microbiota and infant metabolism, and discuss possible mechanisms of action.

Sources, Production, and Clinical Treatments of Milk Fat Globule Membrane for Infant Nutrition and Well-Being

Research on milk fat globule membrane (MFGM) is gaining traction. The interest is two-fold; on the one hand, it is a unique trilayer structure with specific secretory function. On the other hand, it is the basis for ingredients with the presence of phospho- and sphingolipids and glycoproteins, which are being used as food ingredients with valuable functionality, in particular, for use as a supplement in infant nutrition. This last application is at the center of this Review, which aims to contribute to understanding MFGM's function in the proper development of immunity, cognition, and intestinal trophism, in addition to other potential effects such as prevention of diseases including cardiovascular disease, impaired bone turnover and inflammation, skin conditions, and infections as well as age-associated cognitive decline and muscle loss. The phospholipid composition of MFGM from bovine milk is quite like human milk and, although there are some differences due to dairy processing, these do not result in a chemical change. The MFGM ingredients, as used to improve the formulation in different clinical studies, have indeed increased the presence of phospholipids, sphingolipids, glycolipids, and glycoproteins with the resulting benefits of different outcomes (especially immune and cognitive outcomes) with no reported adverse effects. Nevertheless, the precise mechanism(s) of action of MFGM remain to be elucidated and further basic investigation is warranted.

Feeding Infants Formula With Probiotics or Milk Fat Globule Membrane: A Double-Blind, Randomized Controlled Trial

Purpose: To evaluate effects on growth and infection rates of supplementing infant formula with the probiotic Lactobacillus paracasei ssp. paracasei strain F19 (F19) or bovine milk fat globule membrane (MFGM). Methods: In a double-blind, randomized controlled trial, 600 infants were randomized to a formula supplemented with F19 or MFGM, or to standard formula (SF). A breastfed group was recruited as reference (n = 200).The intervention lasted from age 21 ± 7 days until 4 months, and infants were followed until age one year. Results: Both experimental formulas were well tolerated and resulted in high compliance. The few reported adverse events were not likely related to formula, with the highest rates in the SF group, significantly higher than for the F19-supplemented infants (p = 0.046). Weight or length gain did not differ during or after the intervention among the formula-fed groups, with satisfactory growth. During the intervention, overall, the experimental formula groups did not have more episodes of diarrhea, fever, or days with fever than the breastfed infants. However, compared to the breastfed infants, the SF group had more fever episodes (p = 0.021) and days with fever (p = 0.036), but not diarrhea. Compared with the breastfed group, the F19-supplemented infants but not the other two formula groups had more visits/unscheduled hospitalizations (p = 0.015) and borderline more episodes of upper respiratory tract infections (p = 0.048). Conclusions: Both the MFGM- and F19-supplemented formulas were safe and well-tolerated, leading to few adverse effects, similar to the breastfed group and unlike the SF group. During the intervention, the MFGM-supplemented infants did not differ from the breastfed infants in any primary outcome.

Benefits of Lactoferrin, Osteopontin and Milk Fat Globule Membranes for Infants

The provision of essential and non-essential amino acids for breast-fed infants is the major function of milk proteins. In addition, breast-fed infants might benefit from bioactivities of milk proteins, which are exhibited in the intestine during the digestive phase and by absorption of intact proteins or derived peptides. For lactoferrin, osteopontin and milk fat globule membrane proteins/lipids, which have not until recently been included in substantial amounts in infant formulas, in vitro experiments and animal models provide a convincing base of evidence for bioactivities, which contribute to the protection of the infant from pathogens, improve nutrient absorption, support the development of the immune system and provide components for optimal neurodevelopment. Technologies have become available to obtain these compounds from cow´s milk and the bovine compounds also exhibit bioactivities in humans. Randomized clinical trials with experimental infant formulas incorporating lactoferrin, osteopontin, or milk fat globule membranes have already provided some evidence for clinical benefits. This review aims to compare findings from laboratory and animal experiments with outcomes of clinical studies. There is good justification from basic science and there are promising results from clinical studies for beneficial effects of lactoferrin, osteopontin and the milk fat globule membrane complex of proteins and lipids. Further studies should ideally be adequately powered to investigate effects on clinically relevant endpoints in healthy term infants.

Supplementation of Infant Formula with Bovine Milk Fat Globule Membranes

Studies have shown that supplementation of infant formula with bovine milk fat globule membranes (MFGMs) may substantially narrow the gap in health outcomes between formula-fed and breastfed infants. In one study, consumption of a formula supplemented with a lipid-rich MFGM concentrate between 2 and 6 mo of age improved cognitive performance at 24 wk of age. In another study, a formula supplemented with a protein-rich MFGM concentrate given between 2 and 6 mo of age improved cognitive performance at 12 mo of age, decreased infectious morbidity until 6 mo of age, and yielded serum cholesterol concentrations closer to those of breastfed infants. A third study that assessed the safety of supplementing infant formula with a lipid-rich or a protein-rich MFGM concentrate found a noninferior weight gain for both groups compared with a nonsupplemented formula. In this study, there was an increased risk of eczema in the protein-rich group, but no serious adverse events. Infant formulas with supplemental MFGMs have been launched on the market in several countries. However, the evidence base must still be considered quite limited. Based on 3 randomized controlled trials that are not comparable, the intervention seems safe, but there is not enough evidence for a general recommendation on which MFGM fraction to use and at what concentration as formula supplement for a given outcome.

Clinical Benefits of Milk Fat Globule Membranes for Infants and Children

The milk fat globule membrane (MFGM) in breast milk contains many bioactive components. Infant formulas traditionally have been devoid of the MFGM fraction, but dairy technology now has made the addition of bovine MFGM technically feasible. We identified 6 double-blinded randomized controlled trials exploring the effects of MFGM supplementation on the diets of infants or children. Results suggest that supplementation is safe and indicate positive effects on both neurodevelopment and defense against infections. MFGM supplementation of infant formula may narrow the gap in cognitive performance and infection rates between breastfed and formula-fed infants. Because of the small number of studies and the heterogeneity of interventions, more high-quality double-blinded randomized controlled trials are needed, with well characterized and clearly defined MFGM fractions, before firm conclusions on the effects of MFGM supplementation on the health and development of infants can be drawn.