Cow's milk allergy: a complex disorder

Reduction in the antigenicity of beta-lactoglobulin in whole milk powder via supercritical CO2 treatment

Cow milk allergy is a common phenomenon experienced in early childhood (<5 yr of age) with an average occurrence rate of roughly 2.5%. The most prevalent allergen in cow milk is believed to be β-LG. The objective of this study was to evaluate the use of hydrophobic supercritical CO2 (ScCO2) to modify the chemical structure β-LG, thus impairing its recognition by antibodies. Whole milk powder (WMP) was selected because of its closest compositional resemblance to bovine fluid milk and its applications in reconstitution and in the beverage (infant, toddler, and adult), confectionary, bakery, and meat industries. For this study, WMP was treated with food-grade CO2 at temperatures of 50, 63, and 75°C under operating pressures of 100, 150, 200, 250, and 300 bar. Proteins in WMP were examined using SDS-PAGE, western blot, and ELISA. Orbitrap Fusion liquid chromatography-tandem MS (LC-MS/MS) and periodic staining was performed to confirm post-translational modifications in β-LG. Functional properties of WMP before and after treatment were assessed by its solubility index, oil holding capacity, emulsion capacity and stability, zeta potential, particle size, and color analysis. SDS-PAGE of treated samples yielded fuzzy bands (variable mobility of molecules due to different molecular weights results in ill-defined bands) indicative of an increase in molecular weight, presumably due to chemical change in the protein, and demonstrated a maximum of 71.13 ± 0.29% decrease in the band intensity of β-LG under treatment conditions of 75°C/300 bar for 30 min. These changes were small with samples treated with heat only. Lighter, diffused bands were observed using western blot analysis. The ELISA tests proved that ScCO2 treatment specifically and significantly affected the antigenicity of β-LG with a reduction of 42.9 ± 2.83% and 54.75 ± 2.43% at 63°C/200 bar and 75°C/300 bar, respectively. Orbitrap fusion detected the presence of fatty acids and sugar moieties bound to β-LG and the latter was confirmed by periodic staining. Functional properties of ScCO2-treated milk powder yielded a decrease in solubility index and an increase in emulsion capacity of WMP was observed under ScCO2 treatment at 75°C/300 bar, with small and insignificant changes at other treatments producing a decrease in antigenicity. Color changes were small for most samples, except at 63°C/200 bar, where a significant increase in yellowness was observed. Zeta potential and particle size measurements indicated that most changes were temperature driven. This study demonstrates 2 approaches to mitigate β-LG antigenicity via fatty acid binding and lactosylation using hydrophobic ScCO2.

BCM-7: Opioid-like Peptide with Potential Role in Disease Mechanisms

Bovine milk is an essential supplement due to its rich energy- and nutrient-rich qualities. Caseins constitute the vast majority of the proteins in milk. Among these, β-casein comprises around 37% of all caseins, and it is an important type of casein with several different variants. The A1 and A2 variants of β-casein are the most researched genotypes due to the changes in their composition. It is accepted that the A2 variant is ancestral, while a point mutation in the 67th amino acid created the A1 variant. The digestion derived of both A1 and A2 milk is BCM-7. Digestion of A2 milk in the human intestine also forms BCM-9 peptide molecule. The opioid-like characteristics of BCM-7 are highlighted for their potential triggering effect on several diseases. Most research has been focused on gastrointestinal-related diseases; however other metabolic and nervous system-based diseases are also potentially triggered. By manipulating the mechanisms of these diseases, BCM-7 can induce certain situations, such as conformational changes, reduction in protein activity, and the creation of undesired activity in the biological system. Furthermore, the genotype of casein can also play a role in bone health, such as altering fracture rates, and calcium contents can change the characteristics of dietary products. The context between opioid molecules and BCM-7 points to a potential triggering mechanism for the central nervous system and other metabolic diseases discussed.

Investigation of gut microbiota changes and allergic inflammation of mice with milk protein-induced allergic enteritis

This study aimed to investigate the changes of gut microbiota and allergic inflammation in mice with allergic enteritis caused by milk protein. In this study, female BALB\C mice in the whey protein (WP-sensitized) group were gavaged with WP and normal saline, the sham-sensitized group was given normal saline once a week for 5 weeks. One week later, the WP-sensitized mice were administered 60 mg β-lactoglobulin (BLG). The results showed that mice's body weight decreased, feces with loose and bloody, and systemic allergic reactions and ear swelling increased in the WP-sensitized group. The levels of WP-specific Ig, mMCP-1, calprotectin of feces, and inflammation-related factors in the WP-sensitized group were increased. WP-sensitized group intestine tissues were damaged severely and the expressions of ZO-1, Claudin-1, and Occludin reduced. The results of 16S rRNA sequencing showed that there were differences in operational taxonomic units (OUT) levels of gut microbes between the two groups, o_Clostridiales, c_Clostridia, and f_Lachnospiraceae were more abundant in the WP-sensitized group. In conclusion, the WP sensitization can induce the allergic inflammation, intestinal injury and intestinal barrier dysfunction in mice, and the gut microbes were also changed, which provided a reference for the treatment of WP-sensitized mice.

Preparation of Hypoallergenic Whey Protein Hydrolysate by a Mixture of Alcalase and Prozyme and Evaluation of Its Digestibility and Immunoregulatory Properties

Whey protein (WP) has nutritional value, but the presence of β-lactoglobulin (β-LG) and α-lactalbumin (α-LA) cause allergic reactions. In this study, hypoallergenic whey protein hydrolyate (HWPH) was prepared by decomposing β-LG and α-LA of WP using exo- and endo-type proteases. The enzyme mixing ratio and reaction conditions were optimized using response surface methodology (RSM). Degradation of α-LA and β-LG was confirmed through gel electrophoresis, and digestion, and absorption rate, and immunostimulatory response were measured using in vitro and in vivo systems. Through RSM analysis, the optimal hydrolysis conditions for degradation of α-LA and β-LG included a 1:1 mixture of Alcalase and Prozyme reacted for 10 h at a 1.0% enzyme concentration relative to substrate. The molecular weight of HWPH was <5 kDa, and leucine was the prominent free amino acid. Both in vitro and in vivo tests showed that digestibility and intestinal permeability were higher in HWPH than in WP. In BALB/c mice, as compared to WP, HWPH reduced allergic reactions by inducing elevated Type 1/Type 2 helper T cell ratio in the blood, splenocytes, and small intestine. Thus, HWPH may be utilized in a variety of low allergenicity products intended for infants, adults, and the elderly.

Short-term symptom improvement in infants with suspected cow's milk protein allergy using amino acid formula: a prospective cohort analysis

Background

Cow's milk protein allergy (CMPA) occurs commonly in infants. While the long-term efficacy of amino acid formulas for managing CMPA is well-established, there is limited data on the short-term symptom improvement of using amino acid formula (AAF).

Objective

This study aimed to determine the short-term effects of managing suspected CMPA in infants aged 6 months and under using a commercial AAF.

Methods

Healthcare providers who treated infants with suspected CMPA aged 6 months or younger (n = 104) provided de-identified survey data in this prospective study. Healthcare providers scored symptoms for severity from 0 to 3 (none, low, moderate, severe) before using a commercial AAF at Visit 1 and at Visit 2 (3-6 weeks later).

Results

Gastrointestinal (94%), skin (87%), respiratory (86%), and uncategorized symptoms (89%) improved from AAF initiation, and these findings were consistent across different follow-up visit durations.

Conclusion

This study is the most extensive prospective analysis conducted in the United States examining the short-term change in suspected CMPA symptoms using an AAF. These findings suggest that AAF may decrease the severity of suspected CMPA symptoms in infants 6 months or younger, often by the next follow-up visit. Further randomized controlled trials are required to confirm these initial findings.

Evaluation of the fermentation potential of lactic acid bacteria isolated from herbs, fruits and vegetables as starter cultures in nut-based milk alternatives

Fermentation of plant-based milk alternatives (PBMAs), including nut-based products, has the potential to generate new foods with improved sensorial properties. In this study, we screened 593 lactic acid bacteria (LAB) isolates from herbs, fruits and vegetables for their ability to acidify an almond-based milk alternative. The majority of the strongest acidifying plant-based isolates were identified as Lactococcus lactis, which were found to lower the pH of almond milk faster than dairy yoghurt cultures. Whole genome sequencing (WGS) of 18 plant-based Lc. lactis isolates revealed the presence of sucrose utilisation genes (sacR, sacA, sacB and sacK) in the strongly acidifying strains (n = 17), which were absent in one non-acidifying strain. To confirm the importance of Lc. lactis sucrose metabolism in efficient acidification of nut-based milk alternatives, we obtained spontaneous mutants defective in sucrose utilisation and confirmed their mutations by WGS. One mutant containing a sucrose-6-phosphate hydrolase gene (sacA) frameshift mutation was unable to efficiently acidify almond, cashew and macadamia nut milk alternatives. Plant-based Lc. lactis isolates were heterogeneous in their possession of the nisin gene operon near the sucrose gene cluster. The results of this work show that sucrose-utilising plant-based Lc. lactis have potential as starter cultures for nut-based milk alternatives.

Immunoproteomics of cow's milk allergy in Mexican pediatric patients

Immunological mechanisms of non-IgE-mediated cow's milk protein allergy (CMPA) are not well understood. Such a circumstance requires attention with the aim of discovering new biomarkers that could lead to better diagnostic assays for early treatment. Here, we sought both to investigate the mechanism that underlies non-IgE-mediated CMPA and to identify cow's milk immunoreactive proteins in a Mexican pediatric patient group (n = 34). Hence, we determined the IgE and IgG_1-4 subclass antibody levels against cow's milk proteins (CMP) by ELISA. Then, we performed 2D-Immunoblots using as first antibody immunoglobulins in the patients'serum that bound specifically against CMP together with CMP enrichment by ion-exchange chromatography. Immunoreactive proteins were identified by mass spectrometry-based proteomics. The serological test confirmed absence of specific IgE in the CMPA patients but showed significant increase in antigen-specific IgG₁. Additionally, we identified 11 proteins that specifically bound to IgG₁. We conclude that the detection of specific IgG₁ together with an immunoproteomics approach is highly relevant to the understanding of CMPA's physiopathology and as a possible aid in making a prognosis since current evidence indicates IgG₁ occurrence as an early signal of potential risk toward development of IgE-mediated food allergy. SIGNIFICANCE: Allergies are one of the most studied topics in the field of public health and novel protein allergens are found each year. Discovery of new principal and regional allergens has remarkable repercussions in precise molecular diagnostics, prognostics, and more specific immunotherapies. In this context, specific IgE is widely known to mediate physiopathology; however, allergies whose mechanism does not involve this immunoglobulin are poorly understood although their incidence has increased. Therefore, accurate diagnosis and adequate treatment are delayed with significant consequences on the health of pediatric patients. The study of type and subtypes of immunoglobulins associated with the immunoreactivity of cow's milk proteins together with an immunoproteomics approach allows better comprehension of physiopathology, brings the opportunity to discover new potential cow's milk protein allergens and may help in prognosis prediction (IgG₁ occurrence as an early signal of possible risk toward development of IgE-mediated food allergy).

Wahab N. In Vitro Infant Digestion of Whey Proteins Isolate-Lactose

The model in vitro protein digestion technique has received greater attention due to providing significant advantages compared to in vivo experiments. This research employed an in vitro infant digestive static model to examine the protein digestibility of whey proteins isolate-lactose (WPI-Lac). The polyacrylamide gel electrophoresis (PAGE) pattern for alpha-lactalbumin of WPI at 60 min showed no detectable bands, while the alpha-lactalbumin of the WPI-Lac was completely digested after 5 min of gastric digestion. The beta-lactoglobulin of the WPI-Lac was found to be similar to the beta-lactoglobulin of the WPI, being insignificant at pH 3.0. The alpha-lactalbumin of the WPI decreased after 100 min of duodenal digestion at pH 6.5, and the WPI-Lac was completely digested after 60 min. The peptides were identified as ~2 kilodalton (kDa) in conjugated protein, which indicated that the level of degradation of the protein was high, due to the hydrolysis progress. The conjugated protein increased the responsiveness to digestive proteolysis, potentially leading to the release of immunogenic protein by lactose, and to the creation of hypoallergenic protein.

Review: Genetic and protein variants of milk caseins in goats

The milk casein genes in goats, are highly polymorphic genes with numerous synonymous and non-synonymous mutations. So far, 20 protein variants have been reported in goats for alpha-S1-casein, eight for beta-casein, 14 for alpha-S2-casein, and 24 for kappa-casein. This review provides a comprehensive overview on identified milk casein protein variants in goat and non-coding DNA sequence variants with some affecting the expression of the casein genes. The high frequency of some casein protein variants in different goat breeds and geographical regions might reflect specific breeding goals with respect to milk processing characteristics, properties for human nutrition and health, or adaptation to the environment. Because protein names, alongside the discovery of protein variants, go through a historical process, we linked old protein names with new ones that reveal more genetic variability. The haplotypes across the cluster of the four genetically linked casein genes are recommended as a valuable genetic tool for discrimination between breeds, managing genetic diversity within and between goat populations, and breeding strategies. The enormous variation in the casein proteins and genes is crucial for producing milk and dairy products with different properties for human health and nutrition, and for genetic improvement depending on local breeding goals.

Diagnosis and Rationale for Action against Cow's Milk Allergy (DRACMA) Guidelines update - III - Cow's milk allergens and mechanisms triggering immune activation

Background

The immunopathogenesis of cow's milk protein allergy (CMPA) is based on different mechanisms related to immune recognition of protein epitopes, which are affected by industrial processing.

Purpose

The purpose of this WAO DRACMA paper is to: (i) give a comprehensive overview of milk protein allergens, (ii) to review their immunogenicity and allergenicity in the context of industrial processing, and (iii) to review the milk-related immune mechanisms triggering IgE-mediated immediate type hypersensitivity reactions, mixed reactions and non-IgE mediated hypersensitivities.

Results

The main cow’s milk allergens – α-lactalbumin, β-lactoglobulin, serum albumin, caseins, bovine serum albumins, and others – may determine allergic reactions through a range of mechanisms. All marketed milk and milk products have undergone industrial processing that involves heating, filtration, and defatting. Milk processing results in structural changes of immunomodulatory proteins, leads to a loss of lipophilic compounds in the matrix, and hence to a higher allergenicity of industrially processed milk products. Thereby, the tolerogenic capacity of raw farm milk, associated with the whey proteins α-lactalbumin and β-lactoglobulin and their lipophilic ligands, is lost.

Conclusion

The spectrum of immunopathogenic mechanisms underlying cow's milk allergy (CMA) is wide. Unprocessed, fresh cow's milk, like human breast milk, contains various tolerogenic factors that are impaired by industrial processing. Further studies focusing on the immunological consequences of milk processing are warranted to understand on a molecular basis to what extent processing procedures make single milk compounds into allergens.

Characterisation of Zamorano-Leonese Donkey Milk as an Alternative Sustainably Produced Protein Food

The Zamorano-Leonese donkey is the local breed of the Castilla y León region of Spain and is a protected endangered species. The best way to preserve it is to explore viable alternatives such as milk production. Unlike other donkey breeds, this one has not been previously characterised. The aim of this work is the complete nutritional characterisation of its milk for human consumption, either directly or as an ingredient, to meet the new consumer expectations of sustainability and health concerns. This breed did not differ from others in terms of amino acid and protein profile. Its low concentration of β-lactoglobulin may be correlated to a low allergenicity. The presence of lactozyme and lactoferrin, which are potent antimicrobials, stand out among the proteins. This milk presented a higher content of unsaturated fatty acids, being oleic fatty acid the main one. Zamorano-Leonese donkey milk did have a higher content of vitamin C, riboflavin, folic acid and vitamin E than the other donkey breeds. It also had a high concentration of vitamin D despite its low-fat content. However, its mineral concentration was lower than other donkey breeds in line with its lower ash content. In terms of micronutrients, it had a high amount of zinc and selenium. Based on these results we can conclude that donkey milk is a food and/or ingredient with beneficial effects on cardiovascular health and the proper functioning of the immune system, as well as being a good source of protein. Therefore, donkey milk from this local species from Spain is a food and/or ingredient with beneficial nutritional properties and sustainable from an environmental point of view.

The Basophil Activation Test for Clinical Management of Food Allergies: Recent Advances and Future Directions

The basophil activation test (BAT) is an ex vivo functional assay that measures by flow cytometry the degree of basophil degranulation after stimulation with an allergen. In recent years, there has been an increased interest in the diagnostic value of the BAT as it has the potential to mimic the clinical phenotype of sIgE sensitized patients, in contrast to allergen-specific IgE levels. This diagnostic potential would be of particular interest for food allergies present early in life such as peanut, cow’s milk and eggs, which require an expensive, time-consuming and patient unfriendly oral food challenge (OFC) for diagnosis. However, routine applications of the BAT for clinical use are not yet feasible due to the lack of standardized protocols and large clinical validation studies. This review will summarize the current data regarding the application of the BAT in food allergy (FA) for cow’s milk, egg and peanut, being the most common causes of FA in children. Additionally, it will discuss the hurdles for widespread clinical use of the BAT and possible future directions for this diagnostic procedure.

An Expert Panel Statement on the Beneficial Effects of Human Milk Oligosaccharides (HMOs) in Early Life and Potential Utility of HMO-Supplemented Infant Formula in Cow's Milk Protein Allergy

This review by pediatric gastroenterology and allergy-immunology experts aimed to address the biological roles of human milk oligosaccharides (HMOs) and the potential utility of HMOs in prevention of allergy with particular emphasis on cow^’s milk protein allergy (CMPA). The participating experts consider HMOs amongst the most critical bioactive components of human milk, which act as antimicrobials and antivirals by preventing pathogen adhesion to epithelial cells, as intestinal epithelial cell modulators by enhancing maturation of intestinal mucosa and intestinal epithelial barrier function, as prebiotics by promoting healthy microbiota composition and as immunomodulators by modulating immune cells indirectly and directly. Accordingly, the participating experts consider the proposed link between HMOs and prevention of allergy to be primarily based on the impact of HMO on gut microbiota, intestinal mucosal barrier, immunomodulation and immune maturation. Along with the lower risk of respiratory and gastrointestinal infections, HMO-supplemented formulas seem to be promising alternatives in the management of CMPA. Nonetheless, the effects of individual as well as complex mixtures of HMO in terms of clear clinical and immunological effects and tolerance development need to be further explored to fully realize the immunomodulatory mechanisms and the potential for HMOs in prevention of allergic diseases and CMPA.

Bioactive Peptides from Liquid Milk Protein Concentrate by Sequential Tryptic and Microbial Hydrolysis

Recently, bioactive peptides as a health-promoting agent have come to the forefront of health research; however, industrial production is limited, possibly due to the lack of the required technological knowledge. The objective of the investigation was to prepare bioactive peptides with hypoallergenic properties from liquid milk protein concentrate (LMPC), through sequential enzymatic and microbial hydrolysis. LMPC was produced from ultra-heat-treated (UHT) skimmed cow’s milk using a nanofiltration membrane. The effect of the concentration of trypsin (0.008–0.032 g·L−1) on the hydrolysis of LMPC was studied. Subsequently, the hydrolysis of tryptic-hydrolyzed LMPC (LMPC-T) with lactic acid bacteria was performed, and the effect of glucose in microbial hydrolysis was studied. Aquaphotomic analysis of the hydrolysis of LMPC was performed using the spectral range of 1300–1600 nm (near-infrared spectra). Changes in antioxidant capacity, anti-angiotensin-converting enzyme activity, and antibacterial activity against Bacillus cereus, Staphylococcus aureus and Listeria monocytogenes were noted after the sequential tryptic and microbial hydrolysis of LMPC. Allergenicity in LMPC was reduced, due to sequential hydrolysis with 0.016 g·L−1 of trypsin and lacteal acid bacteria. According to the aquaphotomic analysis result, there was a dissociation of hydrogen bonds in compounds during the initial period of fermentation and, subsequently, the formation of compounds with hydrogen bonds. The formation of compounds with a hydrogen bond was more noticeable when microbial hydrolysis was performed with glucose. This may support the belief that the results of the present investigation will be useful to scale up the process in the food and biopharmaceutical industries.

Nonlinear modeling to describe the pattern of 15 milk protein and nonprotein compounds over lactation in dairy cows

The protein profile of milk includes several caseins, whey proteins, and nonprotein nitrogen compounds, which influence milk's value for human nutrition and its cheesemaking properties for the dairy industry. To fill in the gap in current knowledge of the patterns of these individual nitrogenous compounds throughout lactation, we tested the ability of a parametric nonlinear lactation model to describe the pattern of each N compound expressed qualitatively (as % of total milk N), quantitatively (in g/L milk), and as daily yield (in g/d). The lactation model was tested on a data set of detailed milk nitrogenous compound profiles (15 fractions-12 protein traits and 3 nonproteins-for each expression mode: 45 traits) obtained from 1,342 cows reared in 41 multibreed herds. Our model was a modified version of Wilmink's model, often used for describing milk yield during lactation because of its reliability and ease of parameter interpretation from a biological point of view. We allowed the sign of the persistency coefficient (parameter c) that explained the variation in the long-term milk component (parameter a) to be positive or negative. We also allowed the short-term milk component (parameter b) to be positive or negative, and we estimated a specific speed of adaptation parameter (parameter k) for each trait rather than assumed a value a priori, as in the original model (k = 0.05). These 4 parameters were included in a nonlinear mixed model with cow breed and parity order as fixed effects, and herd-date as random. Combinations of the positive and negative signs of the b and c parameters allowed us to identify 4 differently shaped lactation curves, all found among the patterns exhibited by the nitrogenous fractions as follows: the "zenith" curve (with a maximum peak; for milk yield and 10 other N traits), the "nadir" curve (with a minimum point; for 20 traits, including almost all those expressed in g/L of milk), the "downward" curve (continuously decreasing; for 14 traits, including almost all those in g/d), and the "upward" curve (continuously increasing; only for κ-casein, in % N). Direct estimation of the k parameters specific to each trait showed the large variability in the adaptation speed of fresh cows and greatly increased the model's flexibility. The results indicated that nonlinear parametric mathematical models can effectively describe the different and complex patterns exhibited by individual nitrogenous fractions during lactation; therefore, they could be useful tools for interpreting milk composition variations during lactation.

Recent perspective on cow's milk allergy and dairy nutrition

Cow's milk is a highly nutritious biological fluid that provides nourishment and immunity to infants when breastfeeding declines. However, some infants, children, and adults are allergic to cow's milk because milk contains potential allergens in the form of proteins. Casein and whey proteins and their coagulated sub-fractions in the milk such as αS₁-casein, αS₂-casein, β-casein, κ-casein and α-lactalbumin, β-lactoglobulin, bovine serum albumin, immunoglobulins, lactoferrin, respectively are the major etiological determinant of cow's milk allergy (CMA). Moreover, milk processing techniques such as homogenization and pasteurization alter the milk fat and whey protein's molecular structure and serve them as allergens to the immune system of allergic individuals. Strict exclusion of nutrient-rich milk and other dairy products from diet puts children with CMA at higher nutritional risk. Thus, regular nutritional monitoring, the inclusion of protein and mineral-rich supplements as a substitute for cow's milk, management of animal genetics (sheep, goats, buffaloes, camel, mare, donkey, yak), and milk processing to produce non-allergenic milk by inactivating allergic proteins for designer nutrition is essentially required. This review paper details the prevalence, molecular profiling of milk allergens (proteins), body immune response against CMA, consequences of milk processing, treatment, and novel role of galectins as potentially allergy suppressors.

Fermentation of plant-based milk alternatives for improved flavour and nutritional value

Non-dairy milk alternatives (or milk analogues) are water extracts of plants and have become increasingly popular for human nutrition. Over the years, the global market for these products has become a multi-billion dollar business and will reach a value of approximately 26 billion USD within the next 5 years. Moreover, many consumers demand plant-based milk alternatives for sustainability, health-related, lifestyle and dietary reasons, resulting in an abundance of products based on nuts, seeds or beans. Unfortunately, plant-based milk alternatives are often nutritionally unbalanced, and their flavour profiles limit their acceptance. With the goal of producing more valuable and tasty products, fermentation can help to the improve sensory profiles, nutritional properties, texture and microbial safety of plant-based milk alternatives so that the amendment with additional ingredients, often perceived as artificial, can be avoided. To date, plant-based milk fermentation mainly uses mono-cultures of microbes, such as lactic acid bacteria, bacilli and yeasts, for this purpose. More recently, new concepts have proposed mixed-culture fermentations with two or more microbial species. These approaches promise synergistic effects to enhance the fermentation process and improve the quality of the final products. Here, we review the plant-based milk market, including nutritional, sensory and manufacturing aspects. In addition, we provide an overview of the state-of-the-art fermentation of plant materials using mono- and mixed-cultures. Due to the rapid progress in this field, we can expect well-balanced and naturally fermented plant-based milk alternatives in the coming years.

Cow's Milk Substitutes for Children: Nutritional Aspects of Milk from Different Mammalian Species, Special Formula and Plant-Based Beverages

Cow's milk and dairy are commonly consumed foods in the human diet and contribute to maintaining a healthy nutritional state, providing unique sources of energy, calcium, protein, and vitamins, especially during early childhood. Milk formula is usually made from cow's milk and represents the first food introduced into an infant's diet when breastfeeding is either not possible or insufficient to cover nutritional needs. Very recently, increased awareness of cow's milk protein allergy and intolerance, and higher preference to vegan dietary habits have influenced parents towards frequently choosing cows' milk substitutes for children, comprising other mammalian milk types and plant-based milk beverages. However, many of these milk alternatives do not necessarily address the nutritional requirements of infants and children. There is a strong need to promote awareness about qualitative and quantitative nutritional compositions of different milk formulas, in order to guide parents and medical providers selecting the best option for children. In this article, we sought to review the different compositions in terms of macronutrients and micronutrients of milk from different mammalian species, including special milk formulas indicated for cow's milk allergy, and of plant-based milk alternatives.

Effect of thermal and microwave processing on secondary structure of bovine β-lactoglobulin: A molecular modeling study

Milk allergy is known to cause severe allergic reactions in hypersensitive patients, especially in infants and children. β-Lactoglobulin is one of the major allergens in bovine milk. The influence of thermal and microwave processing on the structural deviations of β-lactoglobulin protein have been studied using molecular modeling techniques. The structural deviations are studied using root mean square deviations, radius of gyration, dipole moment, and solvent accessible surface area. STRIDE analysis showed significant changes in the β-lactoglobulin, especially when oscillating electric fields were applied along with heat. Root mean square fluctuations (RMSF) has been assessed for known epitopes in the β-lactoglobulin molecule. This showed that when the protein is exposed to certain thermal stress, it compacts by burying hydrophobic residues in the core. However, few allergic epitope residues also exhibit increased RMSF leading to higher reactive sites on the surface of the protein molecule. PRACTICAL APPLICATIONS: This study showed that molecular modeling can be used to gain valuable insights regarding the structural changes during processing. In the future, with more computational capacity, it can be used to make comparison between results obtained from simulations and real-time experiments. The current techniques used in food industries such as Nuclear Magnetic Resonance Imaging, Fourier Transformation Infrared Spectroscopy, X-ray diffraction can analyze pre- and post-processing effects. Hence, it become necessary to understand the changes that takes place during the processing techniques. Molecular dynamic simulation could be a useful technique in analyzing the changes occurring during the processing.

Hypoallergenic and anti-inflammatory feeds in children with complicated severe acute malnutrition: an open randomised controlled 3-arm intervention trial in Malawi

Intestinal pathology in children with complicated severe acute malnutrition (SAM) persists despite standard management. Given the similarity with intestinal pathology in non-IgE mediated gastrointestinal food allergy and Crohn’s disease, we tested whether therapeutic feeds effective in treating these conditions may benefit children with complicated SAM. After initial clinical stabilisation, 95 children aged 6–23 months admitted at Queen Elizabeth Central Hospital, Blantyre, Malawi between January 1^st and December 31^st, 2016 were allocated randomly to either standard feeds, an elemental feed or a polymeric feed for 14 days. Change in faecal calprotectin as a marker of intestinal inflammation and the primary outcome was similar in each arm: elemental vs. standard 4.1 μg/mg stool/day (95% CI, −29.9, 38.15; P = 0.81) and polymeric vs. standard 10 (−23.96, 43.91; P = 0.56). Biomarkers of intestinal and systemic inflammation and mucosal integrity were highly abnormal in most children at baseline and abnormal values persisted in all three arms. The enteropathy in complicated SAM did not respond to either standard feeds or alternative therapeutic feeds administered for up to 14 days. A better understanding of the pathogenesis of the gut pathology in complicated SAM is an urgent priority to inform the development of improved therapeutic interventions.

Current Trends in Tolerance Induction in Cow's Milk Allergy: From Passive to Proactive Strategies

This review addresses the current strategies of inducing tolerance development in infant and childhood cow's milk protein allergy (CMPA). The change in prevention strategies for CMPA has been emphasized based on the lack of evidence to support the efficacy of food allergen avoidance in infancy and the concept of the dual-allergen-exposure hypothesis, which suggests that allergen exposure through the skin leads to sensitization, whereas early oral consumption of allergenic food protein induces oral tolerance. The new approach is based on the likelihood of early introduction of allergenic foods to the infant's diet to reduce the development of food allergies through oral tolerance induction. The latest treatment guidelines recommend the continuation of breast feeding and the elimination of cow's milk and products from the maternal diet in exclusively breast-fed infants with CMPA, the use of an extensively hydrolyzed infant formula (eHF) with proven efficacy in CMPA as the first elimination diet in formula-fed infants with CMPA and the use of amino acid-based formula (AAF) in severe cases, such as anaphylaxis, enteropathy, eosinophilic esophagitis, and food protein-induced enterocolitis syndrome (FPIES), as well as cases of multiple system involvement, multiple food allergies, and intolerance to extensively hydrolyzed formula (eHF). In conclusion, this paper presents the current knowledge on tolerance development in infants and children with CMPA to increase the awareness of the clinicians concerning the new approaches in CMPA treatment Tolerance development is considered a relatively new concept in CMPA, inducing a shift in interventions in CMPA from a passive (avoidance of responsible allergen) toward a proactive (tolerance induction) strategy.

The Sensory Quality and Volatile Profile of Dark Chocolate Enriched with Encapsulated Probiotic Lactobacillus plantarum Bacteria

Cocoa and dark chocolate have a wide variety of powerful antioxidants and other nutrients that can positively affect human health. Probiotic dark chocolate has the potential to be a new product in the growing number of functional foods. In this study, encapsulated potential probiotic Lactobacillus plantarum 564 and commercial probiotic Lactobacillus plantarum 299v were added in the production of dark chocolate. The results show very good survival of probiotic bacteria after production and during storage, reaching 10⁸cfu/g in the first 60 days and over 10⁶cfu/g up to 180 days. No statistically significant difference (p > 0.05) in chemical composition and no major differences in the volatile profiles between control and experimental chocolate samples were observed, indicating no impact of probiotic bacteria on compositional and sensory characteristics of dark chocolate. The sensory evaluation of control and both probiotic dark chocolate samples showed excellent sensory quality after 60 and 180 days of storage, demonstrating that probiotics did not affect aroma, texture and appearance of chocolate. Due to a high viability of bacterial cells and acceptable sensory properties, it can be concluded that encapsulated probiotics Lb. plantarum 564 and Lb. plantarum 299v could be successfully used in the production of probiotic dark chocolate.

Effects of two different domestic boiling practices on the allergenicity of cow's milk proteins

BACKGROUND

The sale of raw drinking milk through automatic dispensers is permitted in some EU member states, but consumers are usually advised to boil the milk before consumption. The present study has been conducted to evaluate the effects of two common domestic boiling techniques on the proteins of raw milk and, in particular, on their potential allergenicity.

RESULTS

Native one-dimensional electrophoresis, N-terminal amino acid sequencing and immunoblotting have been used to characterize the protein pattern and to evaluate the possible changes in the allergenic properties of the processed milk. The main result of this investigation is that heating induces the aggregation of β-lactoglobulin in higher-molecular-weight products, while caseins seem to be more resistant to the treatments. β-Lactoglobulin aggregates have been found to be non-immunoreactive with the sera of subjects suffering from cow's milk protein allergy.

CONCLUSION

Domestic boiling modifies the milk protein profile, causing a minor reduction in milk allergenicity. © 2017 Society of Chemical Industry.

Development of novel quinoa-based yoghurt fermented with dextran producer Weissella cibaria MG1

The aim of this study was to develop a novel beverage fermented with Weissella cibaria MG1 based on aqueous extracts of wholemeal quinoa flour. The protein digestibility of quinoa based-milk was improved by applying complex proteolytic enzymes able to increase protein solubility by 54.58%. The growth and fermentation characteristics of Weissella cibaria MG1, including EPS production at the end of fermentation, were investigated. Fermented wholemeal quinoa milk using MG1 showed high viable cell counts (>10⁹cfu/ml), a pH of 5.16, and significantly higher water holding capacity (WHC, 100%), viscosity (0.57mPas) and exopolysaccharide (EPS) amount (40mg/l) than the chemical acidified control. High EPS (dextran) concentration in quinoa milk caused earlier aggregation because more EPS occupy more space, and the chenopodin were forced to interact with each other. Microstructure observation indicated that the network structures of EPS-protein improve the texture of fermented quinoa milk. Overall, Weissella cibaria MG1 showed satisfactory technology properties and great potential for further possible application in the development of high viscosity fermented quinoa milk.

Past, present and future: The strength of plant-based dairy substitutes based on gluten-free raw materials

Plant-based foods are gaining popularity and the market is developing fast. This trend is based on several factors, like the change of lifestyle, interest in alternative diets, and the increasing awareness about sustainable production of food and especially proteins. Plant-based dairy substitutes can serve as an option to traditional food products, meeting many of these interests. However, the market is in its infancy and needs to progress. Trends show, that the market will change from being focused on mainly soya, almond and rice-based products, due to their unsustainable farming, and nutritional concerns, like genetic modification and low protein content. The market is likely to shift towards alternative plants to meet consumers' needs and desire for healthy, flavourful and intriguing products. In this regard, the aspect of allergy-free, like gluten-free products gain in importance. Research studies are approaching the nutritional quality of plant-based dairy substitutes, such as improving the protein quality and glycaemic properties. Furthermore, the application of these products or plant proteins as functional ingredients or substitutes for cow's milk in dairy products like cheese and yoghurt are disseminated. However, there is still a need for much more diversified studies in order to overcome stability, textural, nutritional and sensory problems.

Mild protein hydrolysation of lactose-free milk further reduces milk-related gastrointestinal symptoms

Gastrointestinal symptoms associated with milk are common. Besides lactose, milk proteins may cause symptoms in sensitive individuals. We have developed a method for mild enzymatic hydrolysation of milk proteins and studied the effects of hydrolysed milk on gastrointestinal symptoms in adults with a self-diagnosed sensitive stomach. In a double blind, randomised placebo-controlled study, 97 subjects consumed protein-hydrolysed lactose-free milk or commercially available lactose-free milk for 10 d. Frequency of gastrointestinal symptoms during the study period was reported and a symptom score was calculated. Rumbling and flatulence decreased significantly in the hydrolysed milk group (P < 0·05). Also, the total symptom score was lower in subjects who consumed hydrolysed milk (P < 0·05). No difference between groups was seen in abdominal pain (P = 0·47) or bloating (P = 0·076). The results suggest that mild enzymatic protein hydrolysation may decrease gastrointestinal symptoms in adults with a sensitive stomach.

The association between maternal psychological stress and inflammatory cytokines in allergic young children

Background. Previous studies have shown that psychological stress is linked to asthma prevalence. Parental psychological stress may potentially influence inflammatory responses in their allergic children. The purpose of this study is to clarify the association between maternal psychological status and inflammatory response of allergic young children.

Methods. The study subjects were 152 young allergic children (median age: 13 months) who had not shown any allergic symptoms in the past one month. mRNA expression levels of the inflammatory response genes IL-6, IL-8, IL-10 and IL-22 were quantified by qRT-PCR. Maternal psychological status was assessed by standardized questionnaires: the Centre for Epidemiological Studies Depression Scale (CES-D) for depression and the Japanese Perceived Stress Scale (JPSS) for perceived stress.

Results. A significant positive association was observed between maternal CES-D scores and IL-6 mRNA expression in the children with asthma. The JPSS scores were also positively associated with IL-8 mRNA expression in asthmatic children and IL-6 mRNA expression in children with allergic rhinitis. Similar trends were observed among children positive for house dust mite-specific IgE, but these associations were not significant.

Conclusion. This study supports the hypothesis that maternal psychological stress affects the inflammatory response in their allergic children.

Mouse models of food allergy: how well do they simulate the human disorder?

Food allergy is a growing health problem with serious concerns due to high potential for fatality. Rapid advances in the knowledge on causes and mechanisms as well as in developing effective prevention/therapeutic strategies are needed. To meet these goals, mouse models that simulate the human disorder are highly desirable. During the past decade, several mouse models of food allergies have been reported. Here, we briefly reviewed the human disorder and then critically evaluated these models seeking answers to the following important questions: To what extent do they simulate the human disorder? What are the strengths and limitations of these models? What are the challenges facing this scientific area? Our analysis suggest that: (i) the mouse models, with inherent strengths and limitations, are available for many major food allergies; there is scope for additional model development and validation; (ii) models mostly simulate the severe forms of human disorder with similar immune and clinical features; (iii) the approaches used to develop some of the mouse models may be questionable; and (iv) the specific mechanisms of sensitization as wells as oral elicitation of fatal reactions in both humans and mice remains incompletely understood and therefore warrants further research.

Validation of a mass spectrometry-based method for milk traces detection in baked food

A simple validated LC-MS/MS-based method was set up to detect milk contamination in bakery products, taking the effects of food processing into account for the evaluation of allergen recovery and quantification. Incurred cookies were prepared at eight levels of milk contamination and were cooked to expose all milk components, including allergenic proteins, to food processing conditions. Remarkable results were obtained in term of sufficiently low LOD and LOQ (1.3 and 4 mg/kg cookies, respectively). Precision was calculated as intra-day repeatability (RSD in the 5-20% range) and inter-day repeatability (4 days; RSD never exceeded 12%). The extraction recovery values ranged from 20% to 26%. Method applicability was evaluated by analysing commercial cookies labelled either as "milk-free" or "may contain milk". Although the ELISA methodology is considered the gold standard for detecting allergens in foods, this robust LC-MS/MS approach should be a useful confirmatory method for assessing and certifying "milk-free" food products.

Position document: IgE-mediated cow's milk allergy

The present document offers an update on the recommendations for managing patients with cow's milk allergy - a disorder that manifests in the first year of life, with an estimated prevalence of 1.6-3% in this paediatric age group. The main causal allergens are the caseins and proteins in lactoserum (beta-lactoglobulin, alpha-lactoalbumin), and the clinical manifestations are highly variable in terms of their presentation and severity. Most allergic reactions affect the skin, followed by the gastrointestinal and respiratory systems, and severe anaphylaxis may occur. The diagnosis of cow's milk allergy is based on the existence of a suggestive clinical history, a positive allergy study and the subsequent application of controlled exposure testing, which constitutes the gold standard for confirming the diagnosis. The most efficient treatment for cow's milk allergy is an elimination diet and the use of adequate substitution formulas. The elimination diet must include milk from other mammals (e.g., sheep, goat, etc.) due to the risk of cross-reactivity with the proteins of cow's milk. Most infants with IgE-mediated cow's milk allergy become tolerant in the first few years of life. In those cases where cow's milk allergy persists, novel treatment options may include oral immunotherapy, although most authors do not currently recommend this technique in routine clinical practice. Enough evidence is not there to confirm the efficacy of elimination diets in the mother and infant for preventing the appearance of cow's milk allergy. Likewise, no benefits have been observed with prebiotic and probiotic dietetic supplements in infants for preventing food allergy.

Characterization of the Immunogenicity and Allergenicity of Two Cow's Milk Hydrolysates--A Study in Brown Norway Rats

Hypoallergenic infant formulas based on hydrolysed milk proteins are used in the diet for cow's milk allergic infants. For a preclinical evaluation of the immunogenicity and allergenicity of new protein ingredients for such hypoallergenic infant formulas as well as for the investigation of which characteristics of hydrolysates that contribute to allergenicity, in vivo models are valuable tools. In this study, we examine the immunogenicity and allergenicity of two hydrolysates in a Brown Norway (BN) rat model, using i.p. dosing, which allows for the use of small quantities. Intact BLG, hydrolysed BLG and a hydrolysed whey product suitable for use in extensively hydrolysed formulas were thoroughly characterized for protein chemical features and administered to BN rats by i.p. immunization with or without adjuvant. Sera were analysed for specific IgG and IgE for evaluation of sensitizing capacity, immunogenicity and antibody-binding capacity. For evaluation of eliciting capacity a skin test was performed. The study showed that the hydrolysates had no residual allergenicity, lacking the capacity to sensitize and elicit reactions in the BN rats. Dosing with or without adjuvant induced a large difference in immunogenicity. Only antibodies from rats sensitized to intact BLG with adjuvant were able to bind the hydrolysates, and the whey-based hydrolysate only showed immunogenicity when dosed with adjuvant. This study showed that hydrolysates can be evaluated by an i.p. animal model, but that the choice of in vitro tests used for evaluation of antibody responses may greatly influence the result as well as may the use of adjuvant.

Association of PCBs and allergies in children

Recently, the incidence rates of childhood allergies have been rising around the world. The presence of persistent chemical pollutants in the environment and exposure to air pollutants are often cited as potential causes of childhood allergies. Accordingly, epidemiological studies of the associations between exposure to low levels of pollutants and adverse health effects are essential. However, at present no useful biomarkers for evaluating such associations have been developed. Thus, using a molecular epidemiological approach we planned to identify candidate biomarkers of pollutant-induced adverse health effects that can be used in children. In asthmatic children, we found that the serum levels of several polychlorinated biphenyl (PCB) congener sub-types were significantly positively correlated with interleukin (IL)-8 mRNA expression, whereas in a sub-group of children who displayed positive immunoglobulin E (IgE) responses to milk or egg proteins IL-22 mRNA expression was demonstrated to be useful for detecting the adverse health effects of environmental pollutants, particularly PCB congeners. In conclusion, the mRNA expression levels of IL-8 and IL-22 can be used to detect children who are at particular risk of adverse health events caused by environmental pollutants, especially PCBs.

Study on reducing antigenic response and IgE-binding inhibitions of four milk proteins of Lactobacillus casei 1134

BACKGROUND

Cow's milk allergy has aroused public concern. The aim of this study was to investigate the effects of fermentation by Lactobacillus casei 1134 on the antigenicity and allergenicity (IgE-binding inhibitions) of milk proteins. The effects of pH value on the antigenicity and allergenicity of four milk proteins (α-lactalbumin, β-lactoglobulin, α-casein and β-casein) were examined by indirect competitive enzyme-linked immunosorbent assay. The free amino acids which were produced in the fermentation process were analysed and the proteolysis of milk proteins was detected.

RESULTS

Fermentation by L. casei 1134 could significantly reduce the antigenicity and allergenicity of the four proteins in reconstituted milk. The allergenicity of milk proteins was further reduced in the process of simulated gastrointestinal digestion. Moreover, we could deduce that one of the potential factors of antigenicity was lactic acid with the comparison of the antigenicity of the four proteins between L. casei 1134 fermented milk and lactic acid milk at different pH values.

CONCLUSION

There are many factors which can affect the milk proteins allergen, including lactic acid and proteolytic enzymes.

β-casomorphin-7 alters μ-opioid receptor and dipeptidyl peptidase IV genes expression in children with atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease with heterogeneous clinical phenotypes reflecting genetic predisposition and exposure to environmental factors. Reactions to food may play a significant role especially in young children. Milk proteins are particularly strong allergens and are additional source of bioactive peptides including β-casomorphin-7 (BCM7, Tyr-Pro-Phe-Pro-Gly-Pro-Ile). BCM7 exerts its influence on nervous, digestive, and immune functions via the μ-opioid receptor (MOR). Proline dipeptidyl peptidase IV (DPPIV; EC 3.4.14.5) appears to be the primary degrading enzyme of BCM7. Moreover, DPPIV is known to restrict activity of proinflammatory peptides. BCM7 is considered to modulate an immune response by affecting MOR and DPPIV genes expression. In this study, we determined the MOR and DPPIV genes expression in children diagnosed with a severe form of AD. 40 healthy children and 62 children diagnosed with severe AD (AD score ≥60) were included in the study. Peripheral blood mononuclear cells (PBMCs) from the studied subjects were incubated with the peptide extracts of raw and hydrolysed cow milk with defined β-casein genotypes (A1A1, A2A2 and A1A2) and MOR and DPPIV genes expression was determined with real-time PCR. Incubation PBMCs with peptide extracts from cow milk caused an increase of the MOR gene expression (p<0.05; p<0.001) in AD children with a simultaneous decrease in the DPPIV gene expression (p<0.001). The obtained results supplement the knowledge on the BCM7 participation in AD etiology and provide an important diagnostic tool.

Middle East Consensus Statement on the Prevention, Diagnosis, and Management of Cow's Milk Protein Allergy

Presented are guidelines for the prevention, diagnosis, and treatment of cow's milk protein allergy (CMPA) which is the most common food allergy in infants. It manifests through a variety of symptoms that place a burden on both the infant and their caregivers. The guidelines were formulated by evaluation of existing evidence-based guidelines, literature evidence and expert clinical experience. The guidelines set out practical recommendations and include algorithms for the prevention and treatment of CMPA. For infants at risk of allergy, appropriate prevention diets are suggested. Breastfeeding is the best method for prevention; however, a partially hydrolyzed formula should be used in infants unable to be breastfed. In infants with suspected CMPA, guidelines are presented for the appropriate diagnostic workup and subsequent appropriate elimination diet for treatment. Exclusive breastfeeding and maternal dietary allergen avoidance are the best treatment. In infants not exclusively breastfed, an extensively hydrolyzed formula should be used with amino acid formula recommended if the symptoms are life-threatening or do not resolve after extensively hydrolyzed formula. Adherence to these guidelines should assist healthcare practitioners in optimizing their approach to the management of CMPA and decrease the burden on infants and their caregivers.