Seasonal variations in the concentration of gangliosides and sialic acids in milk from different mammalian species

Lipidomic Comparisons of Whole Cream Buttermilk Whey and Cheese Whey Cream Buttermilk of Caprine Milk

Buttermilk is a potential material for the production of a milk fat globule membrane (MFGM) and can be mainly classified into two types: whole cream buttermilk and cheese whey cream buttermilk (WCB). Due to the high casein micelle content of whole cream buttermilk, the removal of casein micelles to improve the purity of MFGM materials is always required. This study investigated the effects of rennet and acid coagulation on the lipid profile of buttermilk rennet-coagulated whey (BRW) and buttermilk acid-coagulated whey (BAW) and compared them with WCB. BRW has significantly higher phospholipids (PLs) and ganglioside contents than BAW and WCB. The abundance of arachidonic acid (ARA)- and eicosapentaenoic acid (EPA)-structured PLs was higher in WCB, while docosahexaenoic acid (DHA)-structured PLs were higher in BRW, indicating that BRW and WCB intake might have a greater effect on improving cardiovascular conditions and neurodevelopment. WCB and BRW had a higher abundance of plasmanyl PL and plasmalogen PL, respectively. Phosphatidylcholine (PC) (28:1), LPE (20:5), and PC (26:0) are characteristic lipids among BRW, BAW, and WCB, and they can be used to distinguish MFGM-enriched whey from different sources.

Whole Goat Milk as a Source of Fat and Milk Fat Globule Membrane in Infant Formula

Cow milk is the most common dairy milk and has been extensively researched for its functional, technological and nutritional properties for a wide range of products. One such product category is infant formula, which is the most suitable alternative to feed infants, when breastfeeding is not possible. Most infant formulas are based on cow milk protein ingredients. For several reasons, consumers now seek alternatives such as goat milk, which has increasingly been used to manufacture infant, follow-on and young child formulas over the last 30 years. While similar in many aspects, compositional and functional differences exist between cow and goat milk. This offers the opportunity to explore different formulations or manufacturing options for formulas based on goat milk. The use of whole goat milk as the only source of proteins in formulas allows levels of milk fat, short and medium chain fatty acids, sn-2 palmitic acid, and milk fat globule membrane (MFGM) to be maximised. These features improve the composition and microstructure of whole goat milk-based infant formula, providing similarities to the complex human milk fat globules, and have been shown to benefit digestion, and cognitive and immune development. Recent research indicates a role for milk fat and MFGM on digestive health, the gut–brain axis and the gut–skin axis. This review highlights the lipid composition of whole goat milk-based infant formula and its potential for infant nutrition to support healthy digestion, brain development and immunity. Further work is warranted on the role of these components in allergy development and the advantages of goat milk fat and MFGM for infant nutrition and health.

Milk Polar Lipids: Underappreciated Lipids with Emerging Health Benefits

Milk fat is encased in a polar lipid-containing tri-layer milk fat globule membrane (MFGM), composed of phospholipids (PLs) and sphingolipids (SLs). Milk PLs and SLs comprise about 1% of total milk lipids. The surfactant properties of PLs are important for dairy products; however, dairy products vary considerably in their polar lipid to total lipid content due to the existence of dairy foods with different fat content. Recent basic science and clinical research examining food sources and health effects of milk polar lipids suggest they may beneficially influence dysfunctional lipid metabolism, gut dysbiosis, inflammation, cardiovascular disease, gut health, and neurodevelopment. However, more research is warranted in clinical studies to confirm these effects in humans. Overall, there are a number of potential effects of consuming milk polar lipids, and they should be considered as food matrix factors that may directly confer health benefits and/or impact effects of other dietary lipids, with implications for full-fat vs. reduced-fat dairy.

Safety of synthetic N-acetyl-d-neuraminic acid as a novel food pursuant to Regulation (EC) No 258/97

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion on synthetic N‐acetyl‐d‐neuraminic acid (NANA) as a novel food (NF) submitted pursuant to Regulation (EC) No 258/97. The information on the composition, the specifications, the batch‐to‐batch variability, stability and production process of the NF is sufficient and does not raise concerns about the safety of the NF. The NF is intended to be marketed as an ingredient in formulae and foods for infants and young children as well as an ingredient in a variety of foods and in food supplements for the general population. NANA is naturally present in human milk, in a bound and free form. The Margin of Exposure, which was based on the no‐observed‐adverse effect level (NOAEL) of 493 mg/kg body weight (bw) per day from a subchronic study and the anticipated daily intake of the NF, was considered to be sufficient for fortified foods for the general population and for food supplements for individuals above 10 years of age, as the anticipated daily intake was in the range of the exposure to free NANA from the consumption of early human milk, which is considered to be safe. The Panel concludes that the NF is safe when added to foods other than food supplements at the proposed uses and use levels for the general population; is safe in food supplements alone at the proposed uses and use levels for individuals above 10 years of age; is safe at the combined intake from fortified foods plus food supplements in individuals above 10 years of age; the safety of the NF is not established in food supplements alone at the proposed uses and use levels for individuals below 10 years of age.

Evaluation of Sialic Acid in Infant Feeding: Contents and Bioavailability

Sialic acid (Sia) contents and bioaccessibility (BA) in human milk (HM) and infant formulas (IFs) were determined, and Sia intakes by infants between 0 and 6 months of age were evaluated. Total Sia contents in HM decreased during lactation from 136.14 to 24.47 mg/100 mL. The total Sia contents in IFs (13.15-25.78 mg/100 mL) were lower than in HM and were not related to the addition of ingredients acting as sources of Sia in their formulation. The Sia intakes derived from IF consumption were lower than in HM, and only one IF reached the intakes provided by HM from the age of 2 months. Despite the lower total Sia content in IFs, the BA of Sia in IFs (88.08-92.96%) was significantly greater than in mature HM (72.51%) and similar to that found in colostrum (96.43%). However, the Sia contents in the available soluble fraction of IFs did not reach those provided by HM.

Determination of sialic acids in milks and milk-based products

Sialic acids are becoming recognized as important components of milk-based products for infants and young children. As such, many companies now label the sialic acid content of their products. To control the labeling, suitable methods are required for this analysis. The objective of this work was to set up a rapid and sensitive method for the determination of the two most commonly occurring sialic acids, N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc), using high-performance liquid chromatography (HPLC). The sialic acids were released from their parent oligosaccharides, glycoproteins, or glycolipids by mild acid hydrolysis using formic acid. They were then derivatized using 1,2-diamino-4,5-methylenedioxybenzene (DMB) and subsequently separated on a Zorbax SB-Aq Rapid Resolution column in less than 2 min. The method developed was validated on various milk-based products and ingredients containing sialic acid at levels from 0.3 to 900 mg/100 g. Spiking experiments indicate that the sialic acid recoveries ranged from 87% to 108%. The expanded measurement uncertainty was typically below 15% for Neu5Gc and typically below 10% for Neu5Ac or the sum of the sialic acids, with a few exceptions. The proposed method is fast, specific, and easy to set up for compliance analysis in a routine laboratory.

Interaction of early diet and the development of the immune system

The present review focuses on the specific effects of nutrients on the development of the immune system in early life. There is a big gap regarding the specific mechanisms that regulate immunity at the intestinal level and their impact in the systemic immune function. For this reason, during the last few years there has been great interest in ascertaining the mechanisms that regulate the intestinal immune function, as well as to understand how specific nutrients interact with the gut-associated lymphoid tissue. We have reviewed this topic with special emphasis on how human milk, and its components, influence the early development of intestinal immunity in breast-fed infants compared with formula-fed infants. Interactions between nutrients and intestinal microbiota have also been reviewed. Some micronutrients such as nucleotides and gangliosides, which are present in human milk and also in most foods, are able to influence immune functionality at very low concentrations. The specific action of these micronutrients on some parameters of immunity, as well as their potential mechanisms of action, have been considered in detail. However, there are limited data on how other specific nutrients, namely protein and non-protein N-containing compounds, lipids, carbohydrates, and others, such as minerals, vitamins, fibre, non-nutritional dietary compounds (flavonoids, carotenoids, phyto-oestrogens, etc), influence immunity. In the present review we have provided data regarding the potential effects of these compounds on the immune response in early life. The increasing use of functional foods by the public to improve their general health and prevent the incidence of chronic diseases has become a major area of interest within the nutrition community. Of the many functional foods available, probiotics have been most studied in infancy and childhood, particularly with regard to the prevention of allergic diseases. Infant formulae and fermented milks containing large quantities of probiotics are produced and consumed by Europeans and in other industrialized countries. In the present review we cover the clinical effects of probiotics in preventing disease during early life, as well as the potential mechanisms of interaction between probiotics and the gastrointestinal tract.

The role of dietary gangliosides on immunity and the prevention of infection

Gangliosides are acid glycosphingolipids widely distributed in most vertebrate tissues and fluids. They are present in mammalian milk, where they are almost exclusively associated with the membrane fraction of the fat globule. In human milk, the content and individual distribution of gangliosides changes during lactation, GD3being the most abundant ganglioside in colostrum, while in mature milk, GM3is the major individual species. Gangliosides function as “unintended” target receptors for bacterial adhesion in specific tissues. After oral administration, they can be putative decoys that interfere with pathogenic binding in the intestine, this being the main mechanism by which these compounds can prevent infection. Ganglioside-supplemented infant formula has been reported to modify the intestinal ecology of preterm newborns, increasing theBifidobacteriacontent and lowering that ofEscherichia coli. In addition, the influence of dietary gangliosides on several parameters related to the development of intestinal immune system, such as cytokine and intestinal IgA production, has also been described in animal models. Recently, the influence of GM3and GD3on dendritic cell maturation and effector functionalities has also been reported, suggesting a role for these milk gangliosides, especially GD3, in modulating the process of oral tolerance during first stages of life. In summary, dietary gangliosides may have an important role in the modification of intestinal microflora and the promotion of intestinal immunity development in the neonate, and consequently in the prevention of infections during early infancy.

Neonatal dietary gangliosides

Gangliosides are glycosphingolipids that are widely distributed in vertebrate tissues and body fluids and which are specially abundant in neural tissues. Milk from different species has a particular ganglioside content and profile. Human milk has a higher content of gangliosides than bovine milk. GD3 and GM3 are the predominant individual gangliosides in bovine milk. In human colostrum GD3 is also the main ganglioside whereas in human mature milk GM3 predominates over the other gangliosides. Human milk also contains GM1 and a number of highly polar gangliosides, which may play an important role in infant physiology. GM1 has been shown to inhibit Escherichia coli and Vibrio cholerae enterotoxins. We have found that a ganglioside-supplemented infant formula modifies the intestinal ecology of preterm newborns, increasing the Bifidobacteria content and lowering that of Escherichia coli. Although the exact mechanism by which dietary gangliosides reduce the fecal content of Escherichia coli is unknown, in vitro experiments suggest that they may act as false intestinal receptors for some strains of this bacteria. Since GD3 and other gangliosides have been involved in mechanisms of lymphocyte activation and differentiation, dietary gangliosides might have a function in intestinal immunity development.