John O. Warner

Factors affecting breast milk composition and potential consequences for development of the allergic phenotype

There is conflicting evidence on the protective role of breastfeeding in relation to allergic sensitization and disease. The factors in breast milk which influence these processes are still unclear and under investigation. We know that colostrum and breast milk contain a variety of molecules which can influence immune responses in the gut‐associated lymphoid tissue of a neonate. This review summarizes the evidence that variations in colostrum and breast milk composition can influence allergic outcomes in the infant, and the evidence that maternal and environmental factors can modify milk composition. Taken together, the data presented support the possibility that maternal dietary interventions may be an effective way to promote infant health through modification of breast milk composition.

Dietary management of peanut and tree nut allergy: What exactly should patients avoid?

Peanut and tree nut allergies are the commonest cause of life‐threatening food‐allergic reactions and significantly affect quality of life in children and their families. Dietary nut avoidance and provision of emergency medication is currently the mainstay of treatment. Nut avoidance has consequences on both quality of life and nutrition. We review the terminology that may cause confusion and lead to unnecessary dietary restrictions. In peanut or tree nut‐allergic children, introduction of specific nuts to which the child is not allergic may improve quality of life and should be considered in patients with multiple foods allergies, vegan or ethnic‐specific diets, in whom nuts are an important source of protein. Nut‐allergic consumers do not just need to avoid foods containing nuts as an ingredient, but also contend with pre‐packed foods which frequently have precautionary allergen labelling (PAL) referring to possible nut contamination. Although the published rate of peanut contamination in ‘snack’ foods with PAL (see Box ) ranges from 0.9–32.4%, peanut contamination in non‐snack items with PAL is far less common. We propose that in some peanut‐allergic patients (depending on history of reactivity to trace levels of peanut, reaction severity, other medical conditions, willingness to always carry adrenaline, etc.), consideration may be given to allow the consumption of non‐snack foods containing PAL following discussion with the patients (and their familys) specialist. More work is needed to provide consumers with clearer information on the risk of potential nut contamination in pre‐packed food. We also draw attention to the change in legislation in December 2014 that require mandatory disclosure of allergens in non‐pre‐packed foods.

Prebiotic‐supplemented partially hydrolysed cow's milk formula for the prevention of eczema in high‐risk infants: a randomized controlled trial

Prevention guidelines for infants at high risk of allergic disease recommend hydrolysed formula if formula is introduced before 6 months, but evidence is mixed. Adding specific oligosaccharides may improve outcomes.

Human Milk and Allergic Diseases: An Unsolved Puzzle.

There is conflicting evidence on the protective role of breastfeeding in relation to the development of allergic sensitisation and allergic disease. Studies vary in methodology and definition of outcomes, which lead to considerable heterogeneity. Human milk composition varies both within and between individuals, which may partially explain conflicting data. It is known that human milk composition is very complex and contains variable levels of immune active molecules, oligosaccharides, metabolites, vitamins and other nutrients and microbial content. Existing evidence suggests that modulation of human breast milk composition has potential for preventing allergic diseases in early life. In this review, we discuss associations between breastfeeding/human milk composition and allergy development.

Immune components in human milk are associated with early infant immunological health outcomes: A prospective three-country analysis

The role of breastfeeding in improving allergy outcomes in early childhood is still unclear. Evidence suggests that immune mediators in human milk (HM) play a critical role in infant immune maturation as well as protection against atopy/allergy development. We investigated relationships between levels of immune mediators in colostrum and mature milk and infant outcomes in the first year of life. In a large prospective study of 398 pregnant/lactating women in the United Kingdom, Russia and Italy, colostrum and mature human milk (HM) samples were analysed for immune active molecules. Statistical analyses used models adjusting for the site of collection, colostrum collection time, parity and maternal atopic status. Preliminary univariate analysis showed detectable interleukin (IL) 2 and IL13 in HM to be associated with less eczema. This finding was further confirmed in multivariate analysis, with detectable HM IL13 showing protective effect OR 0.18 (95% CI 0.04–0.92). In contrast, a higher risk of eczema was associated with higher HM concentrations of transforming growth factor β (TGFβ) 2 OR 1.04 (95% CI 1.01–1.06) per ng/mL. Parental-reported food allergy was reported less often when IL13 was detectable in colostrum OR 0.10 (95% CI 0.01–0.83). HM hepatocyte growth factor (HGF) was protective for common cold incidence at 12 months OR 0.19 (95% CI 0.04–0.92) per ng/mL. Data from this study suggests that differences in the individual immune composition of HM may have an influence on early life infant health outcomes. Increased TGFβ2 levels in HM are associated with a higher incidence of reported eczema, with detectable IL13 in colostrum showing protective effects for food allergy and sensitization. HGF shows some protective effect on common cold incidence at one year of age. Future studies should be focused on maternal genotype, human milk microbiome and diet influence on human milk immune composition and both short- and long-term health outcomes in the infant.

Colostrum and Mature Human Milk of Women from London, Moscow, and Verona: Determinants of Immune Composition

Cytokines and growth factors in colostrum and mature milk may play an important role in infant immune maturation, and may vary significantly between populations. We aimed to examine associations between environmental and maternal factors, and human milk (HM) cytokine and growth factor levels. We recruited 398 pregnant/lactating women in the United Kingdom, Russia, and Italy. Participants underwent skin prick testing, questionnaire interview, and colostrum and mature milk sampling. HM cytokine and growth factor levels were quantified by electro-chemiluminescence. We found significant geographical variation in growth factor levels, but no evidence of variation between sites in cytokine detectability. There was an inverse correlation between time of milk sampling and growth factor levels in colostrum for Hepatocyte Growth Factor (HGF) and TGFβ1 and TGFβ3, but not TGFβ2, and levels were significantly higher in colostrum than mature milk for all growth factors. The kinetics of decline were different for each growth factor. Cytokines were present at much lower levels than growth factors, and the decline over time was less consistent. HM growth factors and cytokine levels vary between populations for unknown reasons. Levels of HM mediators decline at different rates postpartum, and these findings suggest specific biological roles for HM growth factors and cytokines in early postnatal development.

Exposures influencing total IgA level in colostrum.

Immunoglobulin A (IgA) is a predominant immunoglobulin present in human breast milk and is known to play an important role in infant gut immunity maturation. Breast milk composition varies between populations, but the environmental and maternal factors responsible for these variations are still unclear. We examined the relationship between different exposures and levels of IgA in colostrum. The objective of this study was to examine whether exposures analysed influence levels of IgA in colostrum. The present study used 294 colostrum samples from the MecMilk International cohort, collected from women residing in London, Moscow and Verona. Samples were analysed in automated Abbott Architect Analyser. We found an inverse correlation between time postpartum and colostrum total IgA level (r=-0.49, P<0.001). Adjusting for maternal parity, smoking, fresh fruit and fish consumption and allergen sensitization, multiple regression model showed that IgA levels were influenced by colostrum collection time (P<0.0001) and country of collection (P<0.01). Mode of delivery influence did not appear to be significant in univariate comparisons, once adjusted for the above maternal characteristics it showed a significant influence on total IgA (P=0.01). We conclude that the concentration of IgA in colostrum drops rapidly after birth and future studies should always consider this factor in analysis. IgA concentration varied significantly between countries, with the highest level detected in Moscow and lowest in Verona. Mode of delivery effect should be confirmed on larger cohorts. Further work is needed to determine ways to correct for IgA decline over time in colostrum, and to find the cause of variations in IgA levels between the countries.

Intestinal microbiota in infants at high risk for allergy: Effects of prebiotics and role in eczema development

Background: Development of the gut microbiota in infancy is important in maturation of the immune system. Deviations in colonization patterns have been associated with allergic manifestations such as eczema, but exact microbiome dysfunctions underlying allergies remain unclear. We studied the gut microbiota of 138 infants at increased risk of allergy, participating in a clinical trial investigating the effectiveness of a partially hydrolyzed protein formula supplemented with nondigestible oligosaccharides on the prevention of eczema. Objective: The effects of interventions and breast‐feeding on fecal microbiota were investigated. Additionally, we aimed to identify microbial patterns associated with the onset of eczema. Methods: Bacterial taxonomic compositions in the first 26 weeks of life were analyzed by using 16S rRNA gene sequencing. Additionally, fecal pH and microbial metabolite levels were measured. Results: Fecal microbial composition, metabolites, and pH of infants receiving partially hydrolyzed protein formula supplemented with nondigestible oligosaccharides was closer to that of breast‐fed infants than that of infants receiving standard cows milk formula. Infants with eczema by 18 months showed discordant development of bacterial genera of Enterobacteriaceae and Parabacteroides species in the first 26 weeks, as well as decreased acquisition of lactate‐utilizing bacteria producing butyrate, namely Eubacterium and Anaerostipes species, supported by increased lactate and decreased butyrate levels. Conclusions: We showed that a partially hydrolyzed protein infant formula with specific prebiotics modulated the gut microbiota closer to that of breast‐fed infants. Additionally, we identified a potential link between microbial activity and onset of eczema, which might reflect a suboptimal implementation of gut microbiota at specific developmental stages in infants at high risk for allergy. GRAPHICAL ABSTRACT Figure. No caption available.

New patient-reported experience measure for children with allergic disease: development, validation and results from integrated care

Objectives To develop and validate a new allergy-specific patient-reported experience measure (PREM) for children and their parents, and to collect feedback in an integrated care setting. Design Two allergy-specific PREMs were produced using focus groups, cognitive testing, two prospective validation studies (collaboration: Royal College of Paediatrics and Child Health, Picker Institute Europe, Imperial College/London): ‘Your Allergy Care’, for children aged 8–16 years; ‘Your Childs Allergy Care’, for parents of children aged 0–7 years. Setting Community event, primary/secondary/tertiary allergy care settings. Main outcome measures Performance of PREMs in validation study; reported experience of allergy care. Participants 687 children with allergic conditions and their parents/carers. Results In total, 687 questionnaires were completed; 503/687 (253 child; 250 parent) for the final survey. In both surveys, demographic variations were not associated with differences in results. Although 71% of patients reported one or more allergic conditions (food allergy/eczema/hay fever/asthma), 62% required multiple visits before receiving final diagnosis. Overall, patient experience was good for communication with patient/parent, competence and confidence in ability, and 73% felt looked after ‘very well’ and 23% ‘quite well’. Areas for improvement included communication with nurseries/schools, more information on side effects, allergic conditions and allergen/irritant avoidance. Allergy care in primary/emergency care settings was associated with higher problem-scores (worse experience) than in specialist clinics. Conclusions These new PREMs will allow allergy-specific patient experience reporting for children and parents and help identification of priority areas for improvement and commissioning of care. Efforts towards better allergy care provision must be targeted at primary and emergency care settings and underpinned by improving communication between healthcare providers and the community.

Effects of Bovine Immunoglobulins on Immune Function, Allergy, and Infection

This review aims to provide an in depth overview of the current knowledge of the effects of bovine immunoglobulins on the human immune system. The stability and functional effects of orally ingested bovine immunoglobulins in milk products are described and potential mechanisms of action are discussed. Orally ingested bovine IgG (bovine IgG) can be recovered from feces, ranging from very low levels up to 50% of the ingested IgG that has passed through the gastrointestinal tract. In infants the recovered levels are higher than in adults most likely due to differences in stomach and intestinal conditions such as pH. This indicates that bovine IgG can be functionally active throughout the gastrointestinal tract. Indeed, a large number of studies in infants and adults have shown that bovine IgG (or colostrum as a rich source thereof) can prevent gastrointestinal tract infections, upper respiratory tract infections, and LPS-induced inflammation. These studies vary considerably in target group, design, source of bovine IgG, dosage, and endpoints measured making it hard to draw general conclusions on effectiveness of bovine immunoglobulin rich preparations. Typical sources of bovine IgG used in human studies are serum-derived IgG, colostrum, colostrum-derived IgG, or milk-derived immunoglobulins. In addition, many studies have used IgG from vaccinated cows, but studies using IgG from nonimmunized animals have also been reported to be effective. Mechanistically, bovine IgG binds to many human pathogens and allergens, can neutralize experimental infection of human cells, and limits gastrointestinal inflammation. Furthermore, bovine IgG binds to human Fc receptors which, enhances phagocytosis, killing of bacteria and antigen presentation and bovine IgG supports gastrointestinal barrier function in in vitro models. These mechanisms are becoming more and more established and explain why bovine IgG can have immunological effects in vivo. The inclusion of oral bovine immunoglobulins in specialized dairy products and infant nutrition may therefore be a promising approach to support immune function in vulnerable groups such as infants, children, elderly and immunocompromised patients.