Differential modulation of the immune response by breast- or formula-feeding of infants

Early-immune development in asthma: A review of the literature

This review presents a comprehensive examination of the various factors contributing to the immunopathogenesis of asthma from the prenatal to preschool period. We focus on the contributions of genetic and environmental components as well as the role of the nasal and gut microbiome on immune development. Predisposing genetic factors, including inherited genes associated with increased susceptibility to asthma, are discussed alongside environmental factors such as respiratory viruses and pollutant exposure, which can trigger or exacerbate asthma symptoms. Furthermore, the intricate interplay between the nasal and gut microbiome and the immune system is explored, emphasizing their influence on allergic immune development and response to environmental stimuli. This body of literature underscores the necessity of a comprehensive approach to comprehend and manage asthma, as it emphasizes the interactions of multiple factors in immune development and disease progression.

Mechanism of transepithelial migration of lymphocytes into the milk in porcine mammary glands

Lymphocytes in the colostrum play many important roles during lactation, including protecting newborn piglets against infections. The lymphocytes constantly enter the mammary gland from the mother's bloodstream before and during lactation. However, little is known about the mechanism of transport of maternal lymphocytes across the mammary glands into the milk (lumen). In this study, the maternal lymphocytes were detected in sow colostrum by immunofluorescent staining and fluorescence-activated cell sorting and lymphocytes were observed transmigrating into the breast acinar lumen. Furthermore, immunohistochemical staining revealed that CD3⁺ T, γδ⁺ T, and IgA⁺ B cells were primarily located at the base area of the mammary gland. Meanwhile, more lactating alveoli and blood capillaries were distributed in this area. Finally, a mammary epithelial cell (EpH4-Ev)/T cell co-culture system was established to explore the mechanism of lymphocyte transmigration across the mammary epithelial cells. The expression of CCL2 and CCL28 in EpH4-Ev cells, which facilitated the transmigration of lymphocytes, significantly increased in the presence of prolactin. Our results provide a better understanding of the concept of lactogenic immunity and pave the way for vaccination strategies for the induction of lactogenic immunity in pregnant swine.

Feeding in the first six months of life is associated with the probability of having bronchiolitis: a cohort study in Spain

Background

Breastfeeding is associated with lower incidence and severity of lower respiratory tract disease. However, little is known about the relationship between feeding type and breastfeeding duration with bronchiolitis in a child’s first year.

Methods

A prospective cohort study of 969 newborn babies were followed-up for 12 months to determine breastfeeding duration, feeding type, feeding trajectory, and bronchiolitis episodes at Marqués de Valdecilla University Hospital, Spain in 2018. Type of feeding was recorded by interviewing mothers at the time of hospital discharge and at 2, 4, 6, 9 and 12 months of life, in three categories: breastfeeding, mixed feeding and infant formula. Type of feeding at hospital discharge refers to feeding from birth to discharge. In any other times studied, it refers to feeding in the last 24 h. The association between the feeding type and bronchiolitis was analysed using logistic regression. Poisson regression was used to evaluate the association between feeding type and the number of bronchiolitis episodes with Kaplan-Meier estimators presenting the cumulative probability of suffering bronchiolitis. The results were adjusted for mother and child characteristics.

Results

Our data shows exclusive breastfeeding and mixed breastfeeding reduce the number of episodes of bronchiolitis. Regarding feeding at 4 months, exclusive breastfeeding reduced by 41% the number of episodes of bronchiolitis (adjusted incidence Ratio (aIR) 0.59, 95% CI 0.46, 0.76) and mixed feeding by 37% (aIR 0.63, 95% CI 0.47, 0.86). Moreover, changing from exclusive breastfeeding to mixed feeding increased the incidence of bronchiolitis compared with continuing exclusive breastfeeding. An early swap to mixed breastfeeding before months 2 or 4, was associated with a reduced the number of episodes of bronchiolitis, (aIR 0.53, 95% CI 0.39, 0.73 if introduction of mixed breastfeeding before month 2, and aIR 0.61, 95% CI 0.45, 0.83 if introduction of mixed breastfeeding before month 4), when compared with infant formula alone.

Conclusions

Any breastfeeding was associated with lower incidence of bronchiolitis and number of episodes of bronchiolitis in the first year of life. Consequently, promoting programmes facilitating exclusive or mixed breastfeeding would be a relevant measure in the prevention of bronchiolitis.

Early-Life Supplementation of Bovine Milk Osteopontin Supports Neurodevelopment and Influences Exploratory Behavior

INTRODUCTION

Osteopontin (OPN) is a whey protein found at high concentration in human milk and is involved in processes such as bone cell proliferation and differentiation. Milk OPN has shown to be involved in various aspects of development, including the immune system and gut health. However, the influence of dietary bovine milk OPN inclusion on brain and cognitive development has not been studied extensively until recently. This research examines whether dietary supplementation of bovine milk OPN supports brain and cognitive development in the translational pig model.

METHODS

From postnatal day (PND) 2 to 34, twenty-one intact male pigs were provided ad libitum access to one of two dietary treatments, a standard soy protein isolate-based milk replacer to serve as a control diet (n = 11) and the same base diet supplemented with bovine milk OPN to serve as a test diet (n = 10). In addition to growth and health outcomes, recognition memory was tested using the novel object recognition (NOR) task from PND 28 to 32, and magnetic resonance imaging was conducted at PND 34 to evaluate brain development.

RESULTS

No dietary effects were observed for growth performance or health indices. For the behavioral analysis, pigs that received the test diet exhibited shorter (p < 0.05) latency to the first object visited compared with pigs fed the control diet. Although the control group exhibited novelty preference, there was no difference in recognition index between dietary groups. Neuroimaging outcomes revealed increased (p < 0.05) relative brain volumes of the corpus callosum, lateral ventricle, left and right internal capsule, left and right putamen-globus pallidus, and right hippocampus, and right cortex in the test group. Diffusion tensor imaging revealed higher (p < 0.05) radial diffusivity in the corpus callosum and lower (p < 0.05) fractional anisotropy in pigs provided the test diet.

CONCLUSION

Dietary supplementation of bovine milk OPN increased the relative volume of several brain regions and altered behaviors in the NOR task. Underlying mechanisms of bovine milk OPN influencing the development of brain structures and additional behaviors warrant further investigation.

Prebiotic oligosaccharides in early life alter gut microbiome development in male mice while supporting influenza vaccination responses

Beneficial modulation of the gut microbiota is an attractive therapeutic approach to improve the efficacy of vaccine-induced immunity. In this study, mice were supplemented with the prebiotic milk oligosaccharide 2'-fucosyllactose (2'FL) as well as a complex mixture of immune modulatory prebiotic short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides (scGOS/lcFOS) from different stages in early life. Adult mice were vaccinated with trivalent influenza vaccine (TIV) and both development of the gut microbiota and antibody-mediated vaccine responses were followed over time. Within the control group, female mice demonstrated a larger antibody response to TIV vaccination than male mice, which was accompanied by enhanced cytokine production by splenocytes and a higher percentage of plasma cells in skin draining lymph nodes. In addition, the prebiotic diet improved vaccine-specific antibody responses in male mice. Introduction of prebiotics into the diet modulated the gut microbiota composition and at the genus level several bacterial groups showed a significant interaction effect which potentially contributed to the immunological effects observed. This study provides insight in the effect of scGOS/lcFOS/2'FL in influenza vaccination antibody production.

Breastfeeding and the Developmental Origins of Asthma: Current Evidence, Possible Mechanisms, and Future Research Priorities

Breastfeeding has many established health benefits, but its impact on asthma development is uncertain. Breastfeeding appears to have a positive and dose-dependent impact on respiratory health, particularly during early childhood and in high-risk populations; however, the strength and causality of these associations are unclear. It is challenging to compare results across studies due to methodological differences and biological variation. Resolving these inconsistencies will require well-designed, prospective studies that accurately capture asthma diagnoses and infant feeding exposures (including breastfeeding duration, exclusivity, and method of feeding), account for key confounders, evaluate dose effects, and consider effect modification and reverse causality. Mechanistic studies examining human milk bioactives and their impact on lung health and asthma development are beginning to emerge, and these will be important in establishing the causality and mechanistic basis of the observed associations between breastfeeding and asthma. In this review, we summarize current evidence on this topic, identify possible reasons for disagreement across studies, discuss potential mechanisms for a causal association, and provide recommendations for future research.

Mother's Milk: A Purposeful Contribution to the Development of the Infant Microbiota and Immunity

Breast milk is the perfect nutrition for infants, a result of millions of years of evolution. In addition to providing a source of nutrition, breast milk contains a diverse array of microbiota and myriad biologically active components that are thought to guide the infant’s developing mucosal immune system. It is believed that bacteria from the mother’s intestine may translocate to breast milk and dynamically transfer to the infant. Such interplay between mother and her infant is a key to establishing a healthy infant intestinal microbiome. These intestinal bacteria protect against many respiratory and diarrheal illnesses, but are subject to environmental stresses such as antibiotic use. Orchestrating the development of the microbiota are the human milk oligosaccharides (HMOs), the synthesis of which are partially determined by the maternal genotype. HMOs are thought to play a role in preventing pathogenic bacterial adhesion though multiple mechanisms, while also providing nutrition for the microbiome. Extracellular vesicles (EVs), including exosomes, carry a diverse cargo, including mRNA, miRNA, and cytosolic and membrane-bound proteins, and are readily detectable in human breast milk. Strongly implicated in cell–cell signaling, EVs could therefore may play a further role in the development of the infant microbiome. This review considers the emerging role of breast milk microbiota, bioactive HMOs, and EVs in the establishment of the neonatal microbiome and the consequent potential for modulation of neonatal immune system development.

Maternal Immunization: New Perspectives on Its Application Against Non-Infectious Related Diseases in Newborns

The continuous evolution in preventive medicine has anointed vaccination a versatile, human-health improving tool, which has led to a steady decline in deaths in the developing world. Maternal immunization represents an incisive step forward for the field of vaccination as it provides protection against various life-threatening diseases in pregnant women and their children. A number of studies to improve prevention rates and expand protection against the largest possible number of infections are still in progress. The complex unicity of the mother-infant interaction, both during and after pregnancy and which involves immune system cells and molecules, is an able partner in the success of maternal immunization, as intended thus far. Interestingly, new studies have shed light on the versatility of maternal immunization in protecting infants from non-infectious related diseases, such as allergy, asthma and congenital metabolic disorders. However, barely any attempt at applying maternal immunization to the prevention of childhood cancer has been made. The most promising study reported in this new field is a recent proof of concept on the efficacy of maternal immunization in protecting cancer-prone offspring against mammary tumor progression. New investigations into the possibility of exploiting maternal immunization to prevent the onset and/or progression of neuroblastoma, one of the most common childhood malignancies, are therefore justified. Maternal immunization is presented in a new guise in this review. Attention will be focused on its versatility and potential applications in preventing tumor progression in neuroblastoma-prone offspring.

Leukocytes in expressed breast milk of asthmatic mothers

OBJECTIVE

Infants are born immunologically immature. However, breastfeeding mothers retain an immunological link to their infants. While it is generally accepted that infants are at an immunological advantage when compared with formula-fed infants, the benefit of long-term exclusive breastfeeding by atopic mothers remains controversial. Inconsistency in the conferral of benefit may be due to differences in the immunological constituents passed to the recipient infant. The aim of this investigation was to examine the profile of human milk cells and cytokines from asthmatic compared to non-asthmatic mothers.

METHODS

Twenty-five exclusively breastfeeding mothers with a clinical diagnosis of asthma were postpartum age matched in a double-control 2:1 design with 50 non-asthmatic controls. Each mother provided a single milk sample which was assayed for cell differential by flow cytometry, for ex vivo cytokine production in culture and for aqueous phase cytokines.

RESULTS

Milks from asthmatic mothers differed from non-asthmatics in that they contained a higher proportion of polymorphonuclear (PMN) cells and lower proportion of lymphocytes, predominantly CD3⁺/CD4⁺ T helper cells, reflected by a decrease in the chemokine CCL5 in the milk aqueous phase. More PMN and lymphocytes from asthmatic mothers expressed the adhesion molecule CD11b and lymphocytes the IgE receptor CD23, than those from non-asthmatic mothers.

CONCLUSIONS

Changes to human milk leucocyte prevalence, activation state and cytokines due to maternal asthma may result in changes to immunological priming in the infant. Consequently, the protective effect of long-term breastfeeding may be altered in these mother-infant pairs.

Effects of nongenetic factors on immune cell dynamics in early childhood: The Generation R Study

BACKGROUND

Numbers of blood leukocyte subsets are highly dynamic in childhood and differ greatly between subjects. Interindividual variation is only partly accounted for by genetic factors.

OBJECTIVE

We sought to determine which nongenetic factors affect the dynamics of innate leukocytes and naive and memory lymphocyte subsets.

METHODS

We performed 6-color flow cytometry and linear mixed-effects modeling to define the dynamics of 62 leukocyte subsets from birth to 6 years of age in 1182 children, with 1 to 5 measurements per subject. Subsequently, we defined the effect of prenatal maternal lifestyle-related or immune-mediated determinants, birth characteristics, and bacterial/viral exposure-related determinants on leukocyte subset dynamics.

RESULTS

Functionally similar leukocyte populations were grouped by using unbiased hierarchical clustering of patterns of age-related leukocyte dynamics. Innate leukocyte numbers were high at birth and predominantly affected by maternal low education level. Naive lymphocyte counts peaked around 1 year, whereas most memory lymphocyte subsets more gradually increased during the first 4 years of life. Dynamics of CD4⁺ T cells were predominantly associated with sex, birth characteristics, and persistent infections with cytomegalovirus (CMV) or EBV. CD8⁺ T cells were predominantly associated with CMV and EBV infections, and T-cell receptor γδ⁺ T cells were predominantly associated with premature rupture of membranes and CMV infection. B-cell subsets were predominantly associated with sex, breast-feeding, and Helicobacter pylori carriership.

CONCLUSIONS

Our study identifies specific dynamic patterns of leukocyte subset numbers, as well as nongenetic determinants that affect these patterns, thereby providing new insights into the shaping of the childhood immune system.

Effects of Health and Nutrition on Cognitive and Behavioural Development in Children in the First Three Years of Life: Part 1: Low Birthweight, Breastfeeding, and Protein-Energy Malnutrition

The following paper and its accompanying paper (Grantham-McGregor SM, et al. Effects of health and nutrition on cognitive and behavioural development in children in the first three years of life. Part 2: Infections and micronutrient deficiencies: iodine, iron, and zinc. Food Nutr Bull 1999;20:76–99) review the literature on the conditions that are prevalent and considered to be likely to affect child development and are therefore of public health importance. the reviews are selective, and we have generally focused on recent work, particularly in areas that remain controversial. the reviews are restricted to nutritional and health insults that are important in the first three years of life. Where possible, we have discussed the better studies. This paper considers the effects of low birthweight (focusing on small-for-gestational-age babies) and early childhood protein-energy malnutrition on mental, motor, and behavioural development. We have also included a section on breastfeeding because of its importance to child health and nutrition programmes.

A mixture of milk and vegetable lipids in infant formula changes gut digestion, mucosal immunity and microbiota composition in neonatal piglets

PURPOSE

Although composition of infant formula has been significantly improved during the last decade, major differences with the composition and structure of breast milk still remain and might affect nutrient digestion and gut biology. We hypothesized that the incorporation of dairy fat in infant formulas could modify their physiological impacts by making their composition closer to that of human milk. The effect of milk fat and milk fat globule membrane (MFGM) fragments in infant formulas on gut digestion, mucosal immunity and microbiota composition was evaluated.

METHODS

Three formulas containing either (1) vegetable lipids stabilized only by proteins (V-P), (2) vegetable lipids stabilized by a mixture of proteins and MFGM fragments (V-M) and (3) a mixture of milk and vegetable lipids stabilized by a mixture of proteins and MFGM fragments (M-M) were automatically distributed to 42 newborn piglets until slaughter at postnatal day (PND) 7 or 28, and compared to a fourth group of sow's suckling piglets (SM) used as a breast-fed reference.

RESULTS

At both PND, casein and β-lactoglobulin digestion was reduced in M-M proximal jejunum and ileum contents compared to V-P and V-M ones leading to more numerous β-Cn peptides in M-M contents. The IFNγ cytokine secretion of ConA-stimulated MLN cells from M-M piglets tended to be higher than in V-P ones at PND 7 and PND 28 and was closer to that of SM piglets. No dietary treatment effect was observed on IL-10 MLN cell secretion. Changes in faecal microbiota in M-M piglets resulted in an increase in Proteobacteria and Bacteroidetes and a decrease in Firmicutes phyla compared to V-P ones. M-M piglets showed higher abundances of Parabacteroides, Escherichia/Shigella and Klebsiella genus.

CONCLUSIONS

The incorporation of both milk fat and MFGM fragments in infant formula modifies protein digestion, the dynamic of the immune system maturation and the faecal microbiota composition.

Maternal and Infant Secretory Immunoglobulin A across the Peripartum Period

BACKGROUND

Salivary secretory immunoglobulin A (sIgA) concentrations change over early infancy. The primary immunoglobulin in breast milk is sIgA, however, no study has examined the role of maternal sIgA in relation to infant salivary sIgA.

OBJECTIVES

This study aimed to examine within-source associations and mean level changes of maternal and infant sIgA across the first 6 months of life, to examine the interrelations between maternal and infant sIgA across the first 6 months of life, and to determine the association between breastfeeding and infant sIgA.

METHODS

Participants were a convenience sample of 51 mother-infant dyads. Salivary sIgA was collected from the mother in the third trimester. Infant and maternal salivary and maternal breast milk sIgA was collected at approximately 1, 3, and 6 months postpartum.

RESULTS

Maternal salivary sIgA showed no mean level change across the visits, and levels were moderately associated over time. Breast milk sIgA was moderately associated over time; infant salivary sIgA was weakly associated over time. Both breast milk and infant sIgA levels decreased from 1 to 3 months postpartum. Maternal salivary sIgA was not related to infant or breast milk sIgA. Breastfed infants had lower levels of salivary sIgA. Likewise, higher concentrations of breast milk sIgA were related to lower concentrations of infant sIgA.

CONCLUSION

Maternal salivary sIgA is highly stable over the peripartum period, whereas breast milk and infant salivary sIgA was variable. Infant secretory IgA development does not depend positively on maternal salivary or breast milk sIgA.

Decreased memory B cells and increased CD8 memory T cells in blood of breastfed children: the generation R study

Background

Breastfeeding provides a protective effect against infectious diseases in infancy. Still, immunological evidence for enhanced adaptive immunity in breastfed children remains inconclusive.

Objective

To determine whether breastfeeding affects B- and T-cell memory in the first years of life.

Methods

We performed immunophenotypic analysis on blood samples within a population-based prospective cohort study. Participants included children at 6 months (n=258), 14 months (n=166), 25 months (n=112) and 6 years of age (n=332) with both data on breastfeeding and blood lymphocytes. Total B- and T-cell numbers and their memory subsets were determined with 6-color flow cytometry. Mothers completed questionnaires on breastfeeding when their children were aged 2, 6, and 12 months. Multiple linear regression models with adjustments for potential confounders were performed.

Results

Per month continuation of breastfeeding, a 3% (95% CI -6, -1) decrease in CD27+IgM+, a 2% (95 CI % -5, -1) decrease in CD27+IgA+ and a 2% (95% CI -4, -1) decrease in CD27-IgG+ memory B cell numbers were observed at 6 months of age. CD8 T-cell numbers at 6 months of age were 20% (95% CI 3, 37) higher in breastfed than in non-breastfed infants. This was mainly found for central memory CD8 T cells and associated with exposure to breast milk, rather than duration. The same trend was observed at 14 months, but associations disappeared at older ages.

Conclusions

Longer breastfeeding is associated with increased CD8 T-cell memory, but not B-cell memory numbers in the first 6 months of life. This transient skewing towards T cell memory might contribute to the protective effect against infectious diseases in infancy.

Mothers' attitudes and beliefs about infant feeding highlight barriers to exclusive breastfeeding in American Samoa

BACKGROUND

In American Samoa, initiation of breastfeeding is almost universal but exclusive breastfeeding, a promising target for obesity prevention, is short in duration.

AIMS

(1) To examine American Samoan mothers' feeding experiences and attitudes and beliefs about infant feeding and (2) to identify potential barriers to exclusive breastfeeding.

METHODS

Eighteen semi-structured interviews were conducted with American Samoan mothers at 16-32 days postpartum. Interviews focused on mother's knowledge and beliefs about infant feeding, how their infants were fed, why the mother had chosen this mode of infant feeding, and how decisions about feeding were made within her social surroundings. A thematic qualitative analysis was conducted to identify salient themes in the data.

FINDINGS

Intention to exclusively breastfeed did not predict practice; most women supplemented with formula despite intending to exclusively breastfeed. The benefits of breastfeeding were well-recognized, but the importance of exclusivity was missed. Formula-use was not preferred but considered an innocuous "back-up option" where breastfeeding was not possible or not sufficient for infant satiety. Identified barriers to exclusive breastfeeding included: the convenience of formula; perceptions among mothers that they were not producing enough breast milk; and pain while breastfeeding. The important support role of family for infant feeding could be utilized in intervention design.

CONCLUSION

This study identified barriers to exclusive breastfeeding that can be immediately addressed by providers of breastfeeding support services. Further research is needed to address the common perception of insufficient milk in this setting.

Formula-feeding is associated with shift towards Th1 cytokines

PURPOSE

Breast-feeding (BF) versus formula-feeding (FF) may be a factor for the development and differentiation of T-cell subsets and cytokine production in infancy and childhood. We therefore investigated T-cell subpopulations and their cytokine production by flow cytometry as well as cytokine levels in serum samples in breast-fed versus formula-fed infants and children.

METHODS

Heparinised blood was taken from 191 healthy infants and children. Peripheral blood mononuclear cells were stimulated with phorbol-mystriate-acetate and ionomycin in the presence of brefeldin. T-cell subsets and cytokines were determined by flow cytometry. Furthermore, serum concentrations of IFNγ and IL4 were measured using ELISA. An IFNγ/IL4 ratio was calculated to estimate the Th1/Th2 balance.

RESULTS

Children who were formula-fed show higher numbers of memory T and T helper cells. After stimulation, the number of IFNγ-positive memory T-cells was increased up to the age of 6 years. Breast-fed infants show higher percentages of IL4-positive T helper cells. At ELISA determination, formula-fed children showed higher IFNγ levels than breast-fed children, while IL4 levels did not differ. The IFNγ/IL4 ratio (FACS and ELISA) was elevated in formula-fed infants and children.

CONCLUSION

This systematic analysis of cytokine profiles during childhood in dependency of BF allows a better understanding of immune maturation and demonstrates the influence of early feeding on immune function throughout childhood, even after cessation of BF. FF induces a shift towards Th1 cytokines in children. This may have an influence on the development of autoimmune disease in later life.

Breast milk: proactive immunomodulation and mucosal protection against viruses and other pathogens

The majority of microorganisms infecting humans cross through the mucosal barrier. This is particularly true in infants who explore the world with their mouths while their immune system is still developing. Human milk not only supplies the nutritional needs of the newborn and protects the baby against infection by confering trophic protection to the intestinal mucosa, but additionally shapes the infant’s gut microbiota and instructs immunomodulation. Reflecting maternal environmental exposition and in virtue of its multiple mechanism of action, secretory IgA in milk exerts a decisive role in direct and cross-protection against a variety of pathogens. Its active role in priming the infant’s immune system is an intriguing hypothesis. From this perspective, breast milk antibodies produced by means of maternal immunization might represent protective and proactive factors able to shape and enhance the infant’s immune responses. Strategies to optimize the benefits of maternal immunization include novel vaccine formulations and mucosal route of delivery.

Early diet impacts infant rhesus gut microbiome, immunity, and metabolism

Epidemiological research has indicated a relationship between infant formula feeding and increased risk of chronic diseases later in life including obesity, type-2 diabetes, and cardiovascular disease. The present study used an infant rhesus monkey model to compare the comprehensive metabolic implications of formula- and breast-feeding practices using NMR spectroscopy to characterize metabolite fingerprints from urine and serum, in combination with anthropometric measurements, fecal microbial profiling, and cytokine measurements. Here we show that formula-fed infants are larger than their breast-fed counterparts and have a different gut microbiome that includes higher levels of bacteria from the Ruminococcus genus and lower levels of bacteria from the Lactobacillus genus. In addition, formula-fed infants have higher serum insulin coupled with higher amino acid levels, while amino acid degradation products were higher in breast-fed infants. Increases in serum and urine galactose and urine galactitol were observed in the second month of life in formula-fed infants, along with higher levels of TNFα, IFN-γ, IL-1β, IL-4, and other cytokines and growth factors at week 4. These results demonstrate that metabolic and gut microbiome development of formula-fed infants is different from breast-fed infants and that the choice of infant feeding may hold future health consequences.

'Cosmeceuticals'. Of men, science and laws…

Through the hybrid term 'Cosmeceuticals', the present paper aims at reviewing some scientific and legal sources of ambiguities or uncertainties that, in many regulatory cases, added confusions to the respective roles of drugs and cosmetics. The origins of such questions, likely arose from new anti-ageing claims from the cosmetic industry in the late 80s which faced a rather old regulatory backdrop. Based on the analysis of some legal statements and scientific facts from a 2012 vision, this review tentatively aims at re-defining the respective roles of these two branches that both fill the two vital needs of humans, 'being' and 'well-being'.

Human immune responses to vaccines in the first year of life: biological, socio-economic and ethical issues - a viewpoint

Human newborns are vulnerable to infectious diseases that account for majority of the morbidity and mortality, particularly in first year of life. Vaccines have become the most effective public health intervention strategy to curtail the prevalence of these infectious diseases. Although vaccines against a number of diseases exist, there are no vaccines against many other diseases that commonly affect children. The adequate assessment of immune responses to vaccines is an important step in the development of vaccines. However, a number of biological and "non-medical" socio-economic and ethical factors could influence either the administration and/or evaluation of vaccines in infants. Recognition and understanding of these determinants are crucial in planning interventions and for logical interpretations of results.

Tolerance and safety evaluation in a large cohort of healthy infants fed an innovative prebiotic formula: a randomized controlled trial

Background

the addition of oligosaccharides to infant formula has been shown to mimic some of the beneficial effects of human milk. The aim of the study was to assess the tolerance and safety of a formula containing an innovative mixture of oligosaccharides in early infancy.

Methodology/Principal Findings

this study was performed as a multi-center, randomized, double-blind, placebo-controlled trial including healthy term infants. Infants were recruited before the age of 8 weeks, either having started with formula feeding or being fully breast-fed (breastfeeding group). Formula-fed infants were randomized to feeding with a regular formula containing a mixture of neutral oligosaccharides and pectin-derived acidic oligosaccharides (prebiotic formula group) or regular formula without oligosaccharides (control formula group). Growth, tolerance and adverse events were assessed at 8, 16, 24 and 52 weeks of age. The prebiotic and control groups showed similar mean weight, length and head circumference, skin fold thicknesses, arm circumference gains and stool frequency at each study point. As far as the anthropometric parameters are concerned, the prebiotic group and the control group did not attain the values shown by the breastfeeding group at any study point. The skin fold thicknesses assessed in the breastfeeding group at 8 weeks were strikingly larger than those in formula fed infants, whereas at 52 weeks were strikingly smaller. The stool consistency in the prebiotic group was softer than in the control group at 8, 16 and 24 weeks (p<0.001) and closer to that of the breastfeeding group. There was no difference in the incidence of adverse events between the two formula groups.

Conclusions

our findings demonstrate the tolerability and the long term safety of a formula containing an innovative mixture of oligosaccharides in a large cohort of healthy infants.

Trial Registration:

drks-neu.uniklinik-freiburg.de DRKS 00000201

Nutritionally mediated programming of the developing immune system

A growing body of evidence highlights the importance of a mother's nutrition from preconception through lactation in programming the emerging organ systems and homeostatic pathways of her offspring. The developing immune system may be particularly vulnerable. Indeed, examples of nutrition-mediated immune programming can be found in the literature on intra-uterine growth retardation, maternal micronutrient deficiencies, and infant feeding. Current models of immune ontogeny depict a "layered" expansion of increasingly complex defenses, which may be permanently altered by maternal malnutrition. One programming mechanism involves activation of the maternal hypothalamic-pituitary-adrenal axis in response to nutritional stress. Fetal or neonatal exposure to elevated stress hormones is linked in animal studies to permanent changes in neuroendocrine-immune interactions, with diverse manifestations such as an attenuated inflammatory response or reduced resistance to tumor colonization. Maternal malnutrition may also have a direct influence, as evidenced by nutrient-driven epigenetic changes to developing T regulatory cells and subsequent risk of allergy or asthma. A 3rd programming pathway involves placental or breast milk transfer of maternal immune factors with immunomodulatory functions (e.g. cytokines). Maternal malnutrition can directly affect transfer mechanisms or influence the quality or quantity of transferred factors. The public health implications of nutrition-mediated immune programming are of particular importance in the developing world, where prevalent maternal undernutrition is coupled with persistent infectious challenges. However, early alterations to the immune system, resulting from either nutritional deficiencies or excesses, have broad relevance for immune-mediated diseases, such as asthma, and chronic inflammatory conditions like cardiovascular disease.

Long-term health outcomes and mechanisms associated with breastfeeding

Breastfeeding is superior to formula feeding because it has factors that have long term consequences for early metabolism and disease later in life. In this paper, the scientific evidence in support of why breast milk is beneficial for infants is summarized and the mechanisms in which breastfeeding impacts on disease are explored. Human milk may show a reduced occurrence of disease because mammalian evolution promotes survival, and because of specific factors in milk that promote active stimulation of the infant's immune system and gastrointestinal mucosal maturation decrease the incidence of infection and alter the gut microflora. Bioactive factors, including: hormones, growth factors, colony-stimulating factors and specific nutrients, may have such far-reaching effects on the infant's immune response that normal development depends heavily on its provision. All mothers should be encouraged and supported to continue breastfeeding for 6 months and beyond in order to promote the good health of their infants.

Breastfeeding and risk for fever after immunization

OBJECTIVE

The objective of this study was to evaluate the effects of breastfeeding on the risk for fever after routine immunizations.

METHODS

A prospective cohort study was conducted at a pediatric vaccination center in Naples, Italy. The mothers of the infants scheduled to receive routine immunizations were instructed on how to measure and record infant temperature on the evening of the vaccination and for the subsequent 3 days. The information about the incidence of fever was obtained by telephone on the third day after vaccination. The relative risk for fever in relation to the type of breastfeeding was estimated in multivariate analyses that adjusted for vaccine dose, maternal education and smoking, and number of other children in the household.

RESULTS

A total of 460 infants were recruited, and information on the outcome was obtained for 450 (98%). Fever was reported for 30 (25%), 48 (31%), and 94 (53%) of the infants who were being exclusively breastfed, partially breastfed, or not breastfed at all, respectively (P < .01). The relative risk for fever among infants who were exclusively and partially breastfed was 0.46 (95% confidence interval: 0.33-0.66) and 0.58 (95% confidence interval: 0.44-0.77), respectively. The protection conferred by breastfeeding persisted even when considering the role of several potential confounders.

CONCLUSIONS

In this study, breastfeeding was associated with a decreased incidence of fever after immunizations.

Exploration of basal immune parameters in healthy infants receiving an infant milk formula supplemented with prebiotics

This double-blind, randomized, placebo-controlled study, aimed to explore the effect of an infant milk formula (IMF) with 6 g/l short-chain galacto- and long-chain fructo-oligosaccharides (scGOS/lcFOS, ratio 9:1) on basal immune parameters in 215 healthy, term infants during the first 26 wk of life. After birth, the infants received breast milk or were randomized to receive an IMF with or without scGOS/lcFOS. Blood samples were collected at the age of 8 wk and 26 wk for the analysis of serum immunoglobulins, lymphocyte subpopulations, and cytokines. The scGOS/lcFOS group and the control group were compared in the statistical analysis. A breast fed group was included as a reference. In total, 187 Infants completed the study. No significant differences were observed between both formula groups in the different studied immune parameters at weeks 8 and 26. This explorative study indicates that supplementation of infant formula with a mixture of prebiotic oligosaccharides did not change the basal level of the measured parameters of the developing immune system in healthy infants with a balanced immune system during the first 6 months of life in comparison to feeding a standard infant formula and in comparison to exclusive breastfeeding.

Interaction of early diet and the development of the immune system

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

Prenatal and postnatal mercury exposure, breastfeeding and neurodevelopment during the first 5 years

OBJECTIVE

We evaluated the association between infant hair-Hg and Gesell schedules (GS).

BACKGROUND

Longitudinal assessment of prenatal and postnatal Hg exposure during the first 60 months.

METHODS

We used hair-Hg as a marker of postnatal Hg exposure (inorganic and methyl-Hg from breast milk, and ethyl-Hg from thimerosal) and GS measured at 6, 36, and 60 months.

RESULTS

Hair-Hg at 6 months responded to events related to Hg exposure and breastfeeding. However, most neurodevelopment delays observed at 6 months were overcome with infant growth; at 60 months 87% of children showed adequate GS (>85). Length of lactation and hair-Hg were each significantly correlated with GS, but in opposite ways: length of lactation was positive and significantly correlated with all GS at 60 months; hair-Hg concentrations were negative and significantly correlated with GS at 6 months (r=-0.333; P=0.002) and 60 months (r=-0.803; P=0.010), but not at 36 months. Multiple regression models showed that the GS outcome at 60 months depended on GS at 36 months that in turn was influenced by infants' developmental and Hg exposure variables. GS at 6 months was significantly influenced by prenatal (maternal and infant hair-Hg at birth) and postnatal Hg exposure at 6 months.

CONCLUSIONS

Until there is more refined approach to recognize children sensitive to Hg exposure, and in situations of uncertainty (EtHg exposure), the neurodevelopment benefit of breastfeeding should be recommended.

Breastfeeding is an essential complement to vaccination

AIM

This article explores the role of breastfeeding in different aspects of vaccination in the first 6 months when infants are still developing: (1) pain management; (2) immunomodulation of infants' vaccine responses; (3) metabolism of thimerosal.

METHODS

Major databases were searched for studies that addressed outcomes of related issues.

RESULTS

Studies reveal that breastfeeding can: (1) help mothers and infants to cope with the stressful situations that accompany parenteral vaccines; (2) improve response to vaccines in the still maturing immunologic and enterohepatic systems of infants; (3) influence physiologic parameters that can change metabolism of ethylmercury derived from some vaccines.

CONCLUSION

Health promotion that supports vaccinations should also emphasize early initiation and maintenance of exclusive breastfeeding up until 6 months for maximum protection of the infants with a possible beneficial effect on the vaccine response. Paediatric professionals should inform mothers of the proven benefits of breastfeeding and its importance in complementing vaccination and lowering stress and the risk of untoward reactions on susceptible infants.

Breast-feeding and a subsequent diagnosis of measles

BACKGROUND

Breast-feeding protects against many infectious diseases and may also influence immunization outcomes.

AIM

This study investigated if breast-feeding protects against clinical measles and if it modified the effect of immunization.

METHODS

We used logistic regression with data for 10 207 individuals from the 1970 British Cohort study (BCS70). Breast-feeding data were collected at five years of age, and information on clinical measles infection, as well as socio-economic measures was collected at the age of ten years. Breast feeding was categorized as: breast-fed <1 month (n = 1611), breast-fed for 1-3 months (n = 1016), breast-fed for more than three months (n = 1108), breast-feeding of uncertain duration (n = 21) and never breast-fed (n = 6451).

RESULTS

Breast-feeding for more than three months was negatively associated with a diagnosis of clinical measles infection after adjustment for crowding, social class, measles vaccination, parity and sex with an odds ratio (95% confidence interval) of 0.69 (0.60-0.81) compared with those who never breast-fed. Measles vaccination was highly associated with low risk for measles with: 0.14 (0.13-0.16). Age at acute measles infection was not associated with breastfeeding. Breast-feeding did not notably alter measles immunization efficacy.

CONCLUSION

Immunization against measles provides effective protection against the disease. A more modest reduction in the risk of a measles diagnosis is associated with breast-feeding. The associations with a diagnosis of measles for breast-feeding and measles immunization are independent of each other.

The long-term effects of breastfeeding on asthma and atopic disease

In this review, the primary objective is to assess the evidence of whether breastfeeding protects against asthma and atopic disease for the long-term (long-term is defined here as >5 years of age). Two main types of observational epidemiological studies have been used to test this hypothesis. These are cohort studies of random samples of children and cohort studies of children with a family history of asthma or atopy. In each study type, exposure and outcome data are collected either prospectively or retrospectively. The 12 criteria for assessing the adequate measurement of exposure, outcome and statistics of cohort studies in this context are given in Table 17-1.

Factors determining the outcome of children hospitalized with severe pneumonia

Background

Pneumonia is one of the leading causes of morbidity and mortality in under fives. We carried out a comprehensive study to identify factors influencing both mortality and morbidity for children less than 5 years of age hospitalized with severe pneumonia.

Methods

200 hospitalized children aged 2–60 months with World Health Organization (WHO) defined severe pneumonia were enrolled in the study. The children were managed using a standard protocol. They were closely followed up for need for change in antibiotics, prolonged hospital stay, need for mechanical ventilation and mortality. Data on the factors influencing the outcome were collected.

Results

Of 200 children enrolled in the study, 113 (56.5%) needed a change in antibiotics, 102 (51%) stayed for more than 5 days in the hospital, 41 (20.5%) needed mechanical ventilation and 21 (10.5%) died. On multivariate analysis, lack of exclusive breastfeeding [RR (95%CI) 2.63 (2.16–2.86)], overcrowding [RR (95%CI) 1.94 (1.35–2.38)] and an abnormal chest x-ray [RR (95%CI) 2.29 (1.22–3.44)] were associated with the need for change of antibiotics. Lack of exclusive breastfeeding [RR (95%CI) 2.56 (2.0–2.93)], overcrowding [RR (95%CI) 2.59 (1.78–3.23)] and an abnormal chest x-ray [RR (95%CI) 2.99 (1.65–4.38)] were identified as determinants for prolonged hospital stay. Head nodding [RR (95%CI) 8.34 (2.71–12.77)], altered sensorium [RR (95%CI) 5.44 (1.34–17.56)], abnormal leukocyte counts [RR (95%CI) 5.85(1.36–17.14)] and pallor [RR (95%C) 10.88 (2.95–20.40)] were associated with mortality. Head nodding (RR (95% CI) 4.73 (1.50–6.36)] and cyanosis (RR (95%CI) 5.06 (1.80–11.34)] were the determining factors for mechanical ventilation.

In radiographically confirmed pneumonia, the determining factors for change of antibiotics were: lack of exclusive breast feeding [RR (95% CI) 2.05 (1.69–2.2)] and low birth weight [RR (95% CI) 1.59 (1.1–1.89)]. For prolonged hospital stay, the factors identified were mothers' education less than graduation [RR (95% CI) 1.5 (1.19–1.7)], lack of exclusive breast feeding [RR (95% CI) 1.77 (1.19–2.09)] and oxygen saturation of < 90% at time of presentation [RR (95% CI) 2.06 (1.42–2.42)]. Determinants for mechanical ventilation were mothers' education less than graduation [RR (95% CI) 3.6 (1.15–6.3)] and cyanosis at presentation [RR (95% CI) 10.9 (1.56–18.9)]. For mortality, the only determinant was pallor [RR (95% CI) 10.54 (1.8–21.79)].

Conclusion

Children hospitalized with severe community acquired pneumonia [as defined by World Health Organization (WHO)] who had not received exclusive breast feeding, had stayed in an overcrowded homes and had an abnormal chest radiograph were more likely to fail to respond with primary antibiotic regimen and require change of antibiotics and prolonged hospital stay.

In children with radiographically confirmed pneumonia, lack of breast feeding and low birth weight was associated with need for change in antibiotics.

Thymus size at 6 months of age and subsequent child mortality

OBJECTIVE

To examine determinants of thymus size at age 6 months and investigate whether thymus size at this age is a determinant of subsequent mortality.

STUDY DESIGN

Thymus size was measured by transsternal sonography in 923 6-month-old children participating in a measles vaccination trial in Guinea-Bissau.

RESULTS

Thymus size was strongly associated with anthropometric measurements. Boys had larger thymuses than girls, controlling for anthropometry. Crying during sonography made the thymus appear smaller. Children who were not vaccinated with Bacille Calmette-Guérin (BCG) or were vaccinated with BCG in the preceding 4 weeks before inclusion into the study had larger thymuses. Children who had malaria or had been treated with chloroquine or Quinimax in the previous week before inclusion had smaller thymuses. Controlled for background factors associated with thymus size and mortality, small thymus size remained a strong and independent risk factor for mortality (hazard ratio = 0.31; 95% confidence interval = 0.18 to 0.52).

CONCLUSIONS

Small thymus size at age 6 months is a strong risk factor for mortality. To prevent unnecessary deaths, it is important to identify preventable factors predisposing to small thymus size.

Antiinfective properties of human milk

The unfavorable effects of neonatal immunodeficiency are limited by some naturally occurring compensatory mechanisms, such as the introduction of protective and immunological components of human milk in the infant. Breast-feeding maintains the maternal-fetal immunological link after birth, may favor the transmission of immunocompetence from the mother to her infant, and is considered an important contributory factor to the neonatal immune defense system during a delicate and crucial period for immune development. Several studies have reported that breast-feeding, because of the antimicrobial activity against several viruses, bacteria, and protozoa, may reduce the incidence of infection in infants. The protection from infections may be ensured either passively by factors with antiinfective, hormonal, enzymatic, trophic, and bioactive activity present in breast milk, or through a modulator effect on the neonatal immune system exerted by cells, cytokines, and other immune agents in human milk.

Structural and functional aspects of prebiotics used in infant nutrition

Breast-feeding is associated with several benefits. Among them, the balanced postnatal development of the immune system is 1 of the key functions of breast-feeding. Although this effect is of multifactorial origin, it is widely accepted that the entire intestinal microbiota of breast-fed infants represents an important stimulating factor of the postnatal development of the immune system. The effect of breast-feeding on the intestinal microbiota can not be attributed to a single compound, but there is accumulating evidence that human milk oligosaccharides play a crucial role. Because there is a broad consensus that the intestinal microbiota plays an important physiological role for the host, many attempts have been made to influence the intestinal flora by dietary interventions. This article summarizes results of intervention studies in which nonmilk oligosaccharides have been used to mimic the prebiotic effect of breast-feeding. A second focus has been related to the question of whether the prebiotic activity has beneficial effects on the postnatal development of the immune system. The data clearly demonstrate that prebiotics of nonmilk origin can mimic the prebiotic effect of breast-feeding, and this has positive consequences for the postnatal development of the immune system.

Probiotics and prebiotics in inflammatory bowel disease: microflora 'on the scope'

The intestinal microflora is a large bacterial community that colonizes the gut, with a metabolic activity equal to an organ and various functions that affect the physiology and pathology of the host's mucosal immune system. Intestinal bacteria are useful in promotion of human health, but certain components of microflora, in genetically susceptible individuals, contribute to various pathological disorders, including inflammatory bowel disease. Clinical and experimental observations indicate an imbalance in protective and harmful microflora components in these disorders. Manipulation of gut flora to enhance its protective and beneficial role represents a promising field of new therapeutic strategies of inflammatory bowel disease. In this review, we discuss the implication of gut flora in the intestinal inflammation that justifies the role of probiotics and prebiotics in the prevention and treatment of inflammatory bowel disease and we address the evidence for therapeutic benefits from their use in experimental models of colitis and clinical trials.

Time of perinatal immunization, thimerosal exposure and neurodevelopment at 6 months in breastfed infants

AIM

Brazilian newborns immunized with hepatitis-B (thimerosal containing vaccine, TCV) receive the first dose within 24 h if delivered in public hospitals, but at a later time if born in private hospitals. We compared neurodevelopment (ND) in infants born in a state hospital (immunized within 24 h) and in privately run hospitals (immunized 2-4 days postnatally).

METHODS

We used the Gesell Developmental Schedules in 82 healthy exclusively breastfed infants at 6 months to assess motor skills, language development, comprehension capacity and social skills.

RESULTS

Compared to the group immunized 2-4 days after hospital discharge, the group immunized within 24 h showed no significant difference in ND delays. Despite the variation in gestational age (range 36-42 weeks) and TCV-ethylmercury (EtHg) dose (5.7-11.3 microg Hg/kg b.w.) at birth, time of exposure to TCV showed no significant association with ND. Gesell Developmental Score was not significantly correlated with total parenteral EtHg/unit of body mass neither with the relative increase in hair-Hg (as an additional challenge to prenatal Hg exposure).

CONCLUSION

In breastfed infants, differences in early exposure to TCV-EtHg cannot portend clinical neurodevelopment delays at 6 months. We speculate that breastfeeding remains a significant strategy to improve central nervous system protection of infants facing early exposure challenges.

Dietary supplementation of neutral and acidic oligosaccharides enhances Th1-dependent vaccination responses in mice

Immunomodulatory effects of oligosaccharide preparations that resemble chemical and functional aspects of human milk oligosaccharides (HMOS) were studied for the development of new concepts in infant nutrition. A dose range of 1-5% (w/w) dietary pectin-derived acidic oligosaccharides (AOS) was tested in a murine influenza vaccination model. In addition, combinations of AOS and a 9:1 mixture of galacto-oligosaccharides and long-chain fructo-oligosaccharides (GOS/FOS) were tested at a fixed total dietary dose of 2% (w/w). It was found that AOS significantly enhanced vaccine-specific delayed-type hypersensitivity (DTH) responses in a dose-dependent manner. This was accompanied by a reduction in T-helper2 (Th2) cytokine production by splenocytes in vitro. Overall, this indicates that the systemic immune response to the vaccine was Th1-skewed by the dietary intervention. Combinations of GOS/FOS and AOS were more effective in enhancing DTH responses than either of the oligosaccharides alone, suggesting interaction effects between these agents. Similar to effects in infants, supplementation of the murine diets with GOS/FOS and combinations of GOS/FOS and AOS for 6-wk enhanced the proportion of fecal bifidobacteria and lactobacilli, but AOS alone did not. In conclusion, these data indicate that GOS/FOS and AOS enhance systemic Th1-dependent immune responses in a murine vaccination model. As Th1-responses are weak in early life in humans, this might suggest that application of these oligosaccharides in infant formulas will be beneficial for the development of the infant's immune system.

Breastfeeding enhances the antibody response to Hib and Pneumococcal serotype 6B and 14 after vaccination with conjugate vaccines

BACKGROUND

This study was performed in order to investigate the relationship between breastfeeding and the antibody response after vaccination with conjugate vaccines against Hib and pneumococcal diseases.

METHODS

This was an open non-randomised multi-centre study enrolling 101 healthy Swedish infants. PncCRM was administered concomitantly with DTaP/IPV/Hib at 3, 5, and 12 months at separate site. Duration of breastfeeding was calculated for days of almost exclusive as well as of total (any form of) breastfeeding.

RESULTS

At 13 months of age 6 out of 83 children did not reach 0.2mug/ml against serotype 6B, and five of these were breastfed less than 90 days (Fisher's Exact test, P=0.011). Four children did not reach 1mug/ml against Hib and all those were breastfed less than 90 days (Fisher's Exact test, P=0.008). One month after the second dose, at 6 months of age, children breastfed 90 days or more showed significantly higher GMC against serotype 14 (P=0.003).

CONCLUSION

This study indicates that children exclusively breastfed 90 days or more might get a better serological protection against Hib, and the pneumococcal serotypes 6B and 14 after vaccination, compared to children less breastfed.

Diet regulates the development of gut-associated lymphoid tissue in neonatal piglets

BACKGROUND

Controversy exists concerning diet-induced changes to gut epithelia and immunocytes that occur during weaning. Furthermore, studies on dietary effects on the development of the neonatal immune system, especially gut-associated lymphoid tissue (GALT), are lacking.

OBJECTIVE

The purpose of this study was to investigate growth and development, intestinal morphology, and GALT immune maturation in sow-reared littermates in comparison with early-weaned piglets fed a casein-based liquid diet.

METHOD

Piglets were breast fed by the sow or were weaned at 48 h to a casein-based diet (formula) that provided the amount of nutrient requirements recommended by the National Research Council.

RESULTS

Gross physical appearance and visual inspection of the gastrointestinal tract and other organs at necropsy revealed normal organogenesis in both cohorts. On postnatal day 21, body weight, liver and kidney weight relative to body weight, small intestine length, and weight-to-length ratio were greater in formula-fed piglets as compared with sow-reared piglets (p<0.05). The CD21+ B lymphocyte component of GALT and spleen was reduced in the formula-fed piglets. This was associated with lower circulating IgG and IgM levels in the formula-fed as compared with the breast-fed neonatal piglets (p<0.001).

CONCLUSIONS

Feeding a casein-based formula to newborn piglets may compromise the development of GALT and systemic immune system. Further, the neonatal piglet model may be used to identify the effects of dietary factors on the development of the neonatal immune system.

Full breastfeeding duration and associated decrease in respiratory tract infection in US children

OBJECTIVE

The American Academy of Pediatrics recommends exclusive breastfeeding for an infant's first 6 months of life. When compared with exclusive breastfeeding for 4 months, greater protection against gastrointestinal infection, but not respiratory tract infection, has been demonstrated for the 6-month duration. The objective of this study was to ascertain if full breastfeeding of > or = 6 months compared with 4 to < 6 months in the United States provides greater protection against respiratory tract infection.

METHODS

Secondary analysis of data from the National Health and Nutrition Examination Survey III, a nationally representative cross-sectional home survey conducted from 1988 to 1994, was performed. Data from 2277 children aged 6 to < 24 months, who were divided into 5 groups according to breastfeeding status, were compared. Children who required neonatal intensive care were excluded. SUDAAN software was used to account for the complex sampling design. Logistic regression adjusted for confounding factors. Outcome measures included adjusted odds of acquiring pneumonia, > or = 3 episodes of cold/influenza, > or = 3 episodes of otitis media (OM), or wheezing in the past year or acquiring first OM at < 12 months of age.

RESULTS

In unadjusted analyses, infants who were fully breastfed for 4 to < 6 months (n = 223) were at greater risk for pneumonia than those who were fully breastfed for > or = 6 months (n = 136) (6.5% vs 1.6%). There were not statistically significant differences in > or = 3 episodes of cold/influenza (45% vs 41%), wheezing (23% vs 24%), > or = 3 episodes of OM (27% vs 20%), or first OM at < 12 months of age (49% vs 47%). Adjusting for demographic variables, childcare, and smoke exposure revealed statistically significant increased risk for both pneumonia (odds ratio [OR]: 4.27; 95% confidence interval [CI]: 1.27-14.35) and > or = 3 episodes of OM (OR: 1.95; 95% CI: 1.06-3.59) in those who were fully breastfed for 4 to < 6 months compared with > or = 6 months.

CONCLUSIONS

This nationally representative study documents increased risk of respiratory tract infection including pneumonia and recurrent OM in children who were fully breastfed for 4 vs 6 months. These findings support current recommendations that infants receive only breast milk for the first 6 months of life.

Lewis X component in human milk binds DC-SIGN and inhibits HIV-1 transfer to CD4+ T lymphocytes

DC-specific ICAM3-grabbing non-integrin (DC-SIGN), which is expressed on DCs, can interact with a variety of pathogens such as HIV-1, hepatitis C, Ebola, cytomegalovirus, Dengue virus, Mycobacterium, Leishmania, and Candida albicans. We demonstrate that human milk can inhibit the DC-SIGN-mediated transfer of HIV-1 to CD4+ T lymphocytes as well as viral transfer by both immature and mature DCs. The inhibitory factor directly interacted with DC-SIGN and prevented the HIV-1 gp120 envelope protein from binding to the receptor. The human milk proteins lactoferrin, alpha-lactalbumin, lysozyme, beta-casein, and secretory leukocyte protease inhibitor did not bind DC-SIGN or demonstrate inhibition of viral transfer. The inhibitory effect could be fully alleviated with an Ab recognizing the Lewis X (LeX) sugar epitope, commonly found in human milk. LeX in polymeric form or conjugated to protein could mimic the inhibitory activity, whereas free LeX sugar epitopes could not. We reveal that a LeX motif present in human milk can bind to DC-SIGN and thereby prevent the capture and subsequent transfer of HIV-1 to CD4+ T lymphocytes. The presence of such a DC-SIGN-binding molecule in human milk may both influence antigenic presentation and interfere with pathogen transfer in breastfed infants.

A review of the effects of breastfeeding on respiratory infections, atopy, and childhood asthma

The etiology of childhood asthma is not fully understood. Early exposure to certain respiratory infections may be protective for atopy and/or asthma whereas some infections have been suggested to exert the opposite effects. Wheezing lower respiratory illness (LRI) in the first year of life and atopy are independently associated with increased risk for current asthma in childhood and their effects are mediated via different causal pathways. These risk factors are multiplicative when they operate concommitantly within individual children. Exclusive breastfeeding protects against asthma via effects on both these pathways, as well as through other as yet undefined mechanisms. Furthermore, exclusive breastfeeding may protect against asthma and may reduce the incidence of lower respiratory illness, especially respiratory syncytial virus (RSV). We have previously demonstrated a protective effect of exclusive breastfeeding on asthmatic traits in children. The aim of this review was to clarify this protective association from intermediate associations with respiratory infections, atopy, or through other facets of breastfeeding. The bioactivity of breast milk and subsequent pathways that may act upon the development of asthma in children are explored.