Transforming growth factor-beta is elevated in unpasteurized cow's milk

Environmental influences on childhood allergies and asthma - The Farm effect

Asthma and allergies are major health problems and exert an enormous socioeconomic burden. Besides genetic predisposition, environmental factors play a crucial role in the development of these diseases in childhood. Multiple worldwide epidemiological studies have shown that children growing up on farms are immune to allergic diseases and asthma. Farm-related exposures shape children's immune homeostasis, via mediators such as N-glycolylneuraminic acid or arabinogalactan, or by diverse environmental microbes. Moreover, nutritional factors, such as breastfeeding or farm milk and food diversity, inducing short-chain fatty acids-producing bacteria in the intestine, contribute to farm-related effects. All farm-related exposures induce an anti-inflammatory response of the innate immunity and increase the differentiation of regulatory T cells and T helper cell type 1. A better understanding of the components of the farm environment, that are protective to the development of allergy and asthma, and their underlying mechanisms, will help to develop new strategies for the prevention of allergy and asthma.

Effects of Pre/Probiotic Supplementation on Breast Milk Levels of TGF-b1, TGF-b2, and IgA: A Systematic Review and Meta-Analysis of Randomized-Controlled Trial

Background: Previous studies have proposed that the maternal intake of pre/probiotics may affect the immune composition of breast milk. Nevertheless, the available findings are contradictory. This meta-analysis aimed to examine the impact of maternal supplementation with pre/probiotics on the levels of total immunoglobulin A (IgA), secretory IgA (SIgA), transforming growth factor beta 1 (TGF-β1), and TGF-2 in breast milk. Methods: PubMed and Scopus were systematically searched using a comprehensive search strategy for eligible randomized-controlled trials published up to February 2021. A random-effects model was applied to pool weighted mean difference and 95% confidence interval (CI) as effect size. Cochran's Q statistic and the I2 statistic were used to measure the between-study variance. Egger's regression test was used to assess publication bias. Results: A total of 12 different studies, with a total sample size of 1722 individuals (probiotic group: 858, placebo group: 864), were included in this meta-analysis. In the overall analysis, compared with placebo, maternal supplementation with pre/probiotics had no significant effect on concentrations of total IgA, SIgA, TGF-β1, and TGF-β2 in the breast milk. In the subgroup analysis, pre/probiotics did not affect total IgA, TGF-β1, and TGF-β2 in both colostrum/transitional and mature milk. However, a significant increase in SIgA was found in colostrum/transitional milk following pre/probiotic administration (WMD = 19.33, 95% CI: 0.83-37.83; p = 0.04), without evidence for remarkable heterogeneity (I² = 0.0, p = 0.57). Conclusions: Maternal supplementation with pre/probiotics may increase SIgA in colostrum/transitional milk, without any effect on total IgA, TGF-β1, and TGF-β2.

Immunomodulatory Effects of Human Colostrum and Milk

The immune system is not fully developed in human neonates and infants; breastfeeding is important in this stage as the bioactive components of human breast milk are known to have anti-microbial, anti-inflammatory, and immunomodulatory effects, and can therefore contribute to an infant's immunity against allergies, asthma, autoimmune diseases, and inflammatory bowel disease. Herein, the positive effect on the immune system by human colostrum and milk are reviewed.

The Role of the Environment and Exposome in Atopic Dermatitis

PURPOSE OF REVIEW

Atopic dermatitis (AD) is a chronic inflammatory skin disorder affecting up to 20% of children and up to 5% of adults worldwide, contributing to significant disease-related morbidity in this patient cohort. Its aetiopathogenesis is underpinned by multiple factors, including genetic susceptibility, skin barrier defects, a skewed cutaneous immune response and microbiome perturbation in both the skin and the gut. In this review, we aim to examine the biological effects of key environmental exposures (the sum of which is termed the "exposome") at the population, community and individual levels in order to describe their effect on AD pathogenesis.

RECENT FINDINGS

It is now understood that as well as considering the type of environmental exposure with regard to its effect on AD pathogenesis, the dosage and timing of the exposure are both critical domains that may lead to either exacerbation or amelioration of disease. In this review, we consider the effects of population-wide exposures such as climate change, migration and urbanization; community-specific exposures such as air pollution, water hardness and allergic sensitisation; and individual factors such as diet, microbiome alteration, psychosocial stress and the impact of topical and systemic therapy.

SUMMARY

This review summarises the interaction of the above environmental factors with the other domains of AD pathogenesis, namely, the inherent genetic defects, the skin barrier, the immune system and the cutaneous and gut microbiota. We specifically emphasise the timing and dosage of exposures and its effect on the cellular and molecular pathways implicated in AD.

Effects of milk feeding strategies on short- and long-term productivity of Holstein heifers

Research investigating the effects of feeding raw or pasteurized nonsaleable milk (NSM) on heifers' performance beyond the period of supplementation is limited. This study aimed to examine the effects of type of milk [NSM or milk replacer (MR)] and pasteurization of NSM on preweaning and first-lactation performance of heifers born with low (<36.3 kg) or normal birth weight (≥36.3 kg). Holstein heifers (n = 154) were sequentially assigned to 1 of 3 treatments: MR, pasteurized NSM, or raw NSM. Heifers assigned to raw NSM were fed raw colostrum, whereas heifers assigned to MR and pasteurized NSM were fed pasteurized colostrum. The low birth weight heifers were fed 1.4 L at each feeding until they reached 36.3 kg body weight, whereas normal birth weight heifers were fed 1.9 L at each feeding. A grain mix starter was offered throughout the study. Heifers were weaned ≥42 d old if consuming at least 0.9 kg/d of starter for 3 consecutive days. Data were analyzed with the MIXED procedure of SAS (SAS Institute Inc., Cary, NC), and the basic model included milk treatments, birth weight group, and treatment × birth weight group. The low birth weight heifers fed raw colostrum and NSM versus pasteurized colostrum and NSM had lower serum protein concentrations. Heifers fed MR versus NSM had or tended to have greater concentrations of hematocrit, red blood cells, and eosinophils but lesser concentrations of platelets, although some of those responses were temporary. Pasteurization tended to increase blood lymphocyte concentrations. Heifers with normal birth weight had greater concentrations of blood neutrophils, lymphocytes, and monocytes, compared with low birth weight heifers. For the first 42 d of life, low birth weight heifers fed pasteurized versus raw NSM had greater weight gain, grain intake, and feed efficiency and were weaned earlier (hazard ratio for weaning by 56 d: 2.90). These pasteurization effects for low birth weight heifers tended to be sustained through 24 wk of age, indicated by greater weight gain and hip height growth. In their first lactation, low birth weight heifers produced less mature-equivalent (MEq) protein and tended to produce less MEq milk and fat than normal birth weight heifers. However, the negative effects of low birth weight on MEq milk and fat yield was only evident in heifers fed raw NSM, whereas the performance of low birth weight heifers was similar to that of normal birth weight when fed MR or pasteurized NSM. These findings confirm that calf management practices influence future performance; in this case, failing to pasteurize milk and colostrum for low birth weight heifers had effects that remained apparent for more than 2 years.

The exposome in atopic dermatitis

Atopic dermatitis (AD) is a complex inflammatory disorder with multiple interactions between genetic, immune and external factors. The sum of external factors that an individual is exposed to throughout their lifetime is termed the exposome. The exposome spans multiple domains from population to molecular levels and, in combination with genetic factors, holds the key to understanding the phenotypic diversity seen in AD patients. Exposomal domains are categorized into nonspecific (human and natural factors affecting populations), specific (eg humidity, ultraviolet radiation, diet, pollution, allergens, water hardness) and internal (cutaneous and gut microbiota and host cell interaction) exposures. The skin, as the organ that most directly interacts with and adapts to the external environment, is a prime target for exploration of exposomal influences on disease. Given the well-recognized physical environmental influences on AD, this condition could be much better understood through insightful exposomal research. In this narrative review, we examine each domain in turn, highlighting current understanding of the mechanisms by which exposomal influences modulate AD pathogenesis at distinct points in time. We highlight current approaches to exposome modification in AD and other allergic disease and propose future directions for exposome characterization and modification using novel research techniques.

Oral Tolerance Induction to Newly Introduced Allergen is Favored by a Transforming Growth Factor-β-Enriched Formula

Food allergies have become a major healthcare concern, hence preventive efforts to ensure oral tolerance induction to newly introduced antigens are particularly relevant. Given that transforming growth factor-β (TGF-β) plays a key role in immune tolerance, we tested whether an infant formula enriched with TGF-β would improve oral tolerance induction. A partially hydrolyzed whey protein-based formula was enriched with cow's-milk-derived TGF-β (TGF-β-enriched formula) by adding a specific whey protein isolate (WPI). The manufacturing process was optimized to achieve a concentration of TGF-β within the range of human breast milk concentrations. Protection from allergic sensitization and immune response was assessed in a mouse model. Adult mice received the TGF-β-enriched formula, a control non-enriched formula, or water ad libitum for 13 days before sensitization and suboptimal tolerization to ovalbumin (OVA). When compared to non-tolerized mice, suboptimally-tolerized mice supplemented with the TGF-β-enriched formula showed significantly lower levels of total immunoglobulin-E (IgE) and OVA-specific (IgG1). Mouse mast-cell protease-1 (mMCP-1) and cytokine levels were also significantly decreased in suboptimally-tolerized mice fed the TGF-β-enriched formula. In conclusion, oral supplementation with cow's-milk-derived TGF-β decreased allergic responses to newly introduced allergens and thus reduced the risk of developing food allergy.

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.

Raw Cow's Milk and Its Protective Effect on Allergies and Asthma

Living on a farm and having contact with rural exposures have been proposed as one of the most promising ways to be protected against allergy and asthma development. There is a significant body of epidemiological evidence that consumption of raw milk in childhood and adulthood in farm but also nonfarm populations can be one of the most effective protective factors. The observation is even more intriguing when considering the fact that milk is one of the most common food allergens in childhood. The exact mechanisms underlying this association are still not well understood, but the role of raw milk ingredients such as proteins, fat and fatty acids, and bacterial components has been recently studied and its influence on the immune function has been documented. In this review, we present the current understanding of the protective effect of raw milk on allergies and asthma.

Raw cow's milk consumption and allergic diseases - The potential role of bioactive whey proteins

The prevalence of allergic diseases has increased significantly in Western countries in the last decades. This increase is often explained by the loss of rural living conditions and associated changes in diet and lifestyle. In line with this 'hygiene hypothesis', several epidemiological studies have shown that growing up on a farm lowers the risk of developing allergic diseases. The consumption of raw, unprocessed, cow's milk seems to be one of the factors contributing to this protective effect. Recent evidence indeed shows an inverse relation between raw cow's milk consumption and the development of asthma and allergies. However, the consumption of raw milk is not recommended due to the possible contamination with pathogens. Cow's milk used for commercial purposes is therefore processed, but this milk processing is shown to abolish the allergy-protective effects of raw milk. This emphasizes the importance of understanding the components and mechanisms underlying the allergy-protective capacity of raw cow's milk. Only then, ways to produce a safe and protective milk can be developed. Since mainly heat treatment is shown to abolish the allergy-protective effects of raw cow's milk, the heat-sensitive whey protein fraction of raw milk is an often-mentioned source of the protective components. In this review, several of these whey proteins, their potential contribution to the allergy-protective effects of raw cow's milk and the consequences of heat treatment will be discussed. A better understanding of these bioactive whey proteins might eventually contribute to the development of new nutritional approaches for allergy management.

Cow's Milk and Immune Function in the Respiratory Tract: Potential Mechanisms

During the last decades, the world has witnessed a dramatic increase in allergy prevalence. Epidemiological evidence shows that growing up on a farm is a protective factor, which is partly explained by the consumption of raw cow’s milk. Indeed, recent studies show inverse associations between raw cow’s milk consumption in early life and asthma, hay fever, and rhinitis. A similar association of raw cow’s milk consumption with respiratory tract infections is recently found. In line with these findings, controlled studies in infants with milk components such as lactoferrin, milk fat globule membrane, and colostrum IgG have shown to reduce respiratory infections. However, for ethical reasons, it is not possible to conduct controlled studies with raw cow’s milk in infants, so formal proof is lacking to date. Because viral respiratory tract infections and aeroallergen exposure in children may be causally linked to the development of asthma, it is of interest to investigate whether cow’s milk components can modulate human immune function in the respiratory tract and via which mechanisms. Inhaled allergens and viruses trigger local immune responses in the upper airways in both nasal and oral lymphoid tissue. The components present in raw cow’s milk are able to promote a local microenvironment in which mucosal immune responses are modified and the epithelial barrier is enforced. In addition, such responses may also be triggered in the gut after exposure to allergens and viruses in the nasal cavity that become available in the GI tract after swallowing. However, these immune cells that come into contact with cow’s milk components in the gut must recirculate into the blood and home to the (upper and lower) respiratory tract to regulate immune responses locally. Expression of the tissue homing-associated markers α4β7 and CCR9 or CCR10 on lymphocytes can be influenced by vitamin A and vitamin D3, respectively. Since both vitamins are present in milk, we speculate that raw milk may influence homing of lymphocytes to the upper respiratory tract. This review focuses on potential mechanisms via which cow’s milk or its components can influence immune function in the intestine and the upper respiratory tract. Unraveling these complex mechanisms may contribute to the development of novel dietary approaches in allergy and asthma prevention.

Maternal short-chain fructooligosaccharide supplementation influences intestinal immune system maturation in piglets

Peripartum nutrition is crucial for developing the immune system of neonates. We hypothesized that maternal short-chain fructooligosaccharide (scFOS) supplementation could accelerate the development of intestinal immunity in offspring. Thirty-four sows received a standard or a scFOS supplemented diet (10 g scFOS/d) for the last 4 weeks of gestation and the 4 weeks of lactation. Colostrum and milk immunoglobulins (Ig) and TGFβ1 concentrations were evaluated on the day of delivery and at d 6 and d 21 postpartum. Piglet intestinal structure, the immunologic features of jejunal and ileal Peyer's patches, and mesenteric lymph node cells were analysed at postnatal d 21. Short-chain fatty acid concentrations were measured over time in the intestinal contents of suckling and weaned piglets. Colostral IgA (P<0.05) significantly increased because of scFOS and TGFβ1 concentrations tended to improve (P<0.1). IFNγ secretion by stimulated Peyer's patch and mesenteric lymph node cells, and secretory IgA production by unstimulated Peyer's patch cells were increased (P<0.05) in postnatal d 21 scFOS piglets. These differences were associated with a higher proportion of activated CD25+CD4α+ T cells among the CD4+ helper T lymphocytes (P<0.05) as assessed by flow cytometry. IFNγ secretion was positively correlated with the population of activated T lymphocytes (P<0.05). Total short-chain fatty acids were unchanged between groups during lactation but were higher in caecal contents of d 90 scFOS piglets (P<0.05); specifically propionate, butyrate and valerate. In conclusion, we demonstrated that maternal scFOS supplementation modified the intestinal immune functions in piglets in association with increased colostral immunity. Such results underline the key role of maternal nutrition in supporting the postnatal development of mucosal immunity.

Traditional cheeses: rich and diverse microbiota with associated benefits

The risks and benefits of traditional cheeses, mainly raw milk cheeses, are rarely set out objectively, whence the recurrent confused debate over their pros and cons. This review starts by emphasizing the particularities of the microbiota in traditional cheeses. It then describes the sensory, hygiene, and possible health benefits associated with traditional cheeses. The microbial diversity underlying the benefits of raw milk cheese depends on both the milk microbiota and on traditional practices, including inoculation practices. Traditional know-how from farming to cheese processing helps to maintain both the richness of the microbiota in individual cheeses and the diversity between cheeses throughout processing. All in all more than 400 species of lactic acid bacteria, Gram and catalase-positive bacteria, Gram-negative bacteria, yeasts and moulds have been detected in raw milk. This biodiversity decreases in cheese cores, where a small number of lactic acid bacteria species are numerically dominant, but persists on the cheese surfaces, which harbour numerous species of bacteria, yeasts and moulds. Diversity between cheeses is due particularly to wide variations in the dynamics of the same species in different cheeses. Flavour is more intense and rich in raw milk cheeses than in processed ones. This is mainly because an abundant native microbiota can express in raw milk cheeses, which is not the case in cheeses made from pasteurized or microfiltered milk. Compared to commercial strains, indigenous lactic acid bacteria isolated from milk/cheese, and surface bacteria and yeasts isolated from traditional brines, were associated with more complex volatile profiles and higher scores for some sensorial attributes. The ability of traditional cheeses to combat pathogens is related more to native antipathogenic strains or microbial consortia than to natural non-microbial inhibitor(s) from milk. Quite different native microbiota can protect against Listeria monocytogenes in cheeses (in both core and surface) and on the wooden surfaces of traditional equipment. The inhibition seems to be associated with their qualitative and quantitative composition rather than with their degree of diversity. The inhibitory mechanisms are not well elucidated. Both cross-sectional and cohort studies have evidenced a strong association of raw-milk consumption with protection against allergic/atopic diseases; further studies are needed to determine whether such association extends to traditional raw-milk cheese consumption. In the future, the use of meta-omics methods should help to decipher how traditional cheese ecosystems form and function, opening the way to new methods of risk-benefit management from farm to ripened cheese.

Potential of immunoglobulin A to prevent allergic asthma

Allergic asthma is characterized by bronchial hyperresponsiveness, a defective barrier function, and eosinophilic lower airway inflammation in response to allergens. The inflammation is dominated by Th2 cells and IgE molecules and supplemented with Th17 cells in severe asthma. In contrast, in healthy individuals, allergen-specific IgA and IgG4 molecules are found but no IgE, and their T cells fail to proliferate in response to allergens, probably because of the development of regulatory processes that actively suppress responses to allergens. The presence of allergen-specific secretory IgA has drawn little attention so far, although a few epidemiological studies point at a reverse association between IgA levels and the incidence of allergic airway disease. This review highlights the latest literature on the role of mucosal IgA in protection against allergic airway disease, the mechanisms described to induce secretory IgA, and the role of (mucosal) dendritic cells in this process. Finally, we discuss how this information can be used to translate into the development of new therapies for allergic diseases based on, or supplemented with, IgA boosting strategies.

Human milk composition: nutrients and bioactive factors

This article provides an overview of the composition of human milk, its variation, and its clinical relevance. The composition of human milk is the biological norm for infant nutrition. Human milk also contains many hundreds to thousands of distinct bioactive molecules that protect against infection and inflammation and contribute to immune maturation, organ development, and healthy microbial colonization. Some of these molecules (eg, lactoferrin) are being investigated as novel therapeutic agents. Human milk changes in composition from colostrum to late lactation, within feeds, by gestational age, diurnally, and between mothers. Feeding infants with expressed human milk is increasing.

A bovine whey protein extract can induce the generation of regulatory T cells and shows potential to alleviate asthma symptoms in a murine asthma model

The number of people with asthma has dramatically increased over the past few decades and the cost of care is more than $11·3 billion per year. The use of steroids is the major treatment to control asthma symptoms, but the side effects are often devastating. Seeking new drugs or new strategies to reduce the dose of steroid taken has always been an important task. A bovine whey protein extract (WPE), which is enriched in transforming growth factor-β (TGF-β), has been demonstrated to have the potential for reducing symptoms associated with mild-to-moderate T-helper cell type 1-mediated psoriasis in human subjects. However, whether WPE also has potential for inhibiting T-helper cell type 2 (Th2)-mediated disease remains unclear. In the present study, using a murine asthma model, we found that sensitised mice fed WPE daily, before they were challenged, resulted in reducing airway inflammation, serum ovalbumin-specific IgE, Th2-related cytokine production and airway hyperresponsiveness. Increase in the regulatory T cell (Treg) population in vitro and in vivo was observed when treated with WPE. According to the results from the TGF-β-blocking antibody study, we suggest that TGF-β is the main component that endows WPE with the potential to reduce the generation of Treg. Thus, the present data suggest that WPE has the potential to alleviate the symptoms of asthma by inducing the generation of Treg. Therefore, regular administration of WPE might be potentially beneficial for patients with asthma.

Lesson from the farm environment

PURPOSE OF REVIEW

Several population-based studies have replicated the finding that exposure to a farm environment is protective against the development of atopic diseases. From these studies, novel insights into potential allergy-protective mechanisms were retrieved. This review focuses on consistent and novel findings of immune mechanisms involved in the 'farm effect'.

RECENT FINDINGS

The most recent studies suggest that the 'farm effect' mediated by microbial exposure may be attributed to both microbial diversity and species specificity. There is convincing evidence that farm milk components and grass arabinogalactan, commonly found in cowshed, may be important. Furthermore, early exposure to a farming environment, in particular in utero, showed stronger effects than exposure later in life, potentially through modulation of the immature immune system by microbes, also involving epigenetic changes. This protective 'farm effect' remains in later adulthood. Regarding gene-environment interactions, polymorphisms in GRM1 interacted with farming in a genome-wide interaction scan for asthma.

SUMMARY

The novel studies strengthen the role of microbial exposure and farm milk and grass components, especially early in life, in the modulation of the immune system towards a Th1/Treg predominance. This may subsequently lead to a long-lasting lower risk of developing atopic diseases.

How changes in nutrition have influenced the development of allergic diseases in childhood

The increasing prevalence of allergic diseases in childhood in the last decades could be linked to concomitant dietary changes, especially with the modified and lower consumption of fruit, vegetables and minerals. The consumption of these foods by pregnant women and children in the first years of life seems to be associated with a reduced risk of asthma and related symptoms. Foods that can prevent the development of wheezing through their antioxidant effects contain vitamin C and selenium; blood levels of these elements correlate negatively with the risk of wheezing. Intake of vitamin E during pregnancy also appears to be correlated with a reduced risk of wheezing for the unborn child. Similarly, low intake of zinc and carotenoids by pregnant women is associated with an increased risk of wheezing and asthma in childhood. Fiber also has anti-inflammatory properties and protective effects against allergic diseases such as atopic dermatitis and asthma. The consumption of fat influences the development of the airways. Populations in Western countries have increased their consumption of n-6 PUFAs and, in parallel, reduced n-3 PUFAs. This has led to decreased production of PGE2, which is believed to have a protective effect against inflammation of the airways. Conflicting hypotheses also concern vitamin D; both an excess and a deficiency of vitamin D, in fact, have been associated with an increased risk of asthma. Further studies on the role of these substances are necessary before any conclusions can be drawn on a clinical level.

The protective effect of farm milk consumption on childhood asthma and atopy: the GABRIELA study

BACKGROUND

Farm milk consumption has been identified as an exposure that might contribute to the protective effect of farm life on childhood asthma and allergies. The mechanism of action and the role of particular constituents of farm milk, however, are not yet clear.

OBJECTIVE

We sought to investigate the farm milk effect and determine responsible milk constituents.

METHODS

In rural regions of Germany, Austria, and Switzerland, a comprehensive questionnaire about farm milk consumption and other farm-related exposures was completed by parents of 8334 school-aged children, and 7606 of them provided serum samples to assess specific IgE levels. In 800 cow's milk samples collected at the participants' homes, viable bacterial counts, whey protein levels, and total fat content were analyzed. Asthma, atopy, and hay fever were associated to reported milk consumption and for the first time to objectively measured milk constituents by using multiple regression analyses.

RESULTS

Reported raw milk consumption was inversely associated to asthma (adjusted odds ratio [aOR], 0.59; 95% CI, 0.46-0.74), atopy (aOR, 0.74; 95% CI, 0.61-0.90), and hay fever (aOR, 0.51; 95% CI, 0.37-0.69) independent of other farm exposures. Boiled farm milk did not show a protective effect. Total viable bacterial counts and total fat content of milk were not significantly related to asthma or atopy. Increased levels of the whey proteins BSA (aOR for highest vs lowest levels and asthma, 0.53; 95% CI, 0.30-0.97), α-lactalbumin (aOR for interquartile range and asthma, 0.71; 95% CI, 0.52-0.97), and β-lactoglobulin (aOR for interquartile range and asthma, 0.62; 95% CI, 0.39-0.97), however, were inversely associated with asthma but not with atopy.

CONCLUSIONS

The findings suggest that the protective effect of raw milk consumption on asthma might be associated with the whey protein fraction of milk.

Pediatric allergy and immunology in Italy

In Italy, according to the International Study on Asthma and Allergies in Childhood study, the prevalence of current asthma, allergic rhinoconjunctivitis, and atopic eczema in 2006 was 7.9%, 6.5%, and 10.1% among children aged 6-7 and 8.4%, 15.5%, and 7.75% among children aged 13-14 yr. University education in this field is provided by the Postgraduate Schools of Pediatrics and those of Allergology and Clinical Immunology, as well as several annual Master courses. The Italian Society of Pediatric Allergology and Immunology (SIAIP) was founded in 1996 and counts about 1000 members. SIAIP promotes evidence-based management of allergic children and disseminates information to patients and their families through a quite innovative website and the National Journal 'Rivista Italiana di Allergologia Pediatrica'. In the last decade, four major regional, inter-regional, and national web-based networks have been created to link pediatric allergy centers and to share their clinical protocols and epidemiologic data. In addition, National Registers of Primary Immune-deficiencies and on Pediatric HIV link all clinical excellence centers. Research projects in the field of pediatric allergy and immunology are founded by the Italian Ministry of Education, University and Research (MIUR) and by the National Research Council (CNR), but the overall investments in this research area are quite low. Only a handful Italian excellence centers participate in European Projects on Pediatric Allergy and Immunology within the 7th Framework Program. The European Academy of Allergy and Clinical Immunology currently hosts two Italians in its Executive Committee (EC) and one in the EC of the Pediatric Section; moreover, major European Academy of Allergy and Clinical Immunology meetings and courses in the area of pediatrics (e.g., PAAM, Venice, 2009) have been held in Italy in the last 3 yr. Italian hallmarks in the management of allergic diseases in childhood are a quite alive and spread interest in Molecular Allergology and a remarkable predominance of sublingual (SLIT) compared to the subcutaneous (SCIT) immunotherapy.

Immune regulatory cytokines in the milk of lactating women from farming and urban environments

Children living on farms have fewer allergies. It is unclear whether breastfeeding in different environments contributes to preventing allergies by exposing offspring to different cytokines that can modulate immune responses. The aim of this study was to quantify and compare levels of Transforming Growth Factor-beta1 (TGF-beta1) and Interleukin-10 (IL-10) in the colostrum and mature milk of mothers living in towns at sea level (references) and mothers on farms. Milk samples were collected within 3 days postpartum (colostrum) and at the first month of the baby's life (mature milk). Sixty-nine reference mothers and 45 farm mothers participated in the study. TGF-beta1 concentrations were significantly higher both in the colostrum (p < 0.05) and in mature milk (p < 0.05) of farm mothers. In the reference mothers, a significant decrease in TGF-beta1 concentrations was observed between colostrum (650, range 0-8000 pg/ml) and mature milk (250, range 0-8000 pg/ml) (p < 0.05). In farm mothers, TGF-beta1 concentrations were 1102 pg/ml (range 0-14,500) in colostrum and remained high in mature milk (821 pg/ml, range 0-14,650). IL-10 concentrations were higher in the mature milk of farm mothers (p < 0.05). No significant differences in IL-10 were observed between colostrum and mature milk in the control group (15 pg/ml, range 0-1800, and 0 pg/ml, range 0-230) or in farm mothers (9.5 pg/ml, range 0-1775, and 14.2 pg/ml, range 0-930), respectively. Exposure to a farm environment is associated with higher concentrations of TGF-beta1 and IL-10 in breast milk when compared to exposure to an urban environment. Higher cytokine concentrations in breast milk may influence early modulation of the development of an immune response, leading to a reduced prevalence of allergy-related diseases in farm children.

The role and potential use of oral transforming growth factor-beta in the prevention of infant allergy

The increasing prevalence of allergic diseases in infants and children as well as adults has become an important issue in public health in industrial countries. However, few preventive measures are available to reduce the risk of allergic diseases in infants; e.g. the avoidance of smoking and alcohol consumption during pregnancy and lactation. Therefore, there is an enthusiasm to identify certain factors in foods, nutrients, and environment responsible for the primary prevention of allergic diseases during infancy. In the last decade, TGF-beta in maternal milk has been implicated in the prevention of allergic diseases in infants and young children. This review summarizes the relevant epidemiological reports and highlights the recent animal studies to support the preventive role of orally administered TGF-beta, such as TGF-beta in human milk, in the development of allergic diseases in infants. We also provide suggestions for the potential use of dietary (oral) TGF-beta for the primary prevention of allergic diseases. Further studies to address the scientific validity and mechanistic insight to this Mother Nature-inspired concept are clearly required and will be important to develop new approaches to prevent allergic diseases.