Breastfeeding modulates neonatal innate immune responses: a prospective birth cohort study

Effect of Feeding Human Milk on Development of the Infant Immune System and Allergic Outcomes-An Area of Research Challenge and Need

Surprisingly little is known about the effect of breastfeeding on the infant's immune system development. Systematic reviews have suggested the role of breastfeeding in the prevention against asthma, autoimmune diseases, inflammatory bowel disease, and childhood leukemia. However, studies on atopic disease suffer from reverse causation, small size, and those assessing food allergy (FA) have often relied on parent-reported outcomes. Randomized controlled trials (RCTs) are not possible for ethical reasons. In addition, epidemiological studies have not considered that there is a large interindividual variation in human milk (HM) composition and feeding at the breast versus pumped HM potentially impacting the effect of breastfeeding between mothers. While prevention strategies such as early introduction of highly allergenic food are impactful in preventing peanut and egg allergies, implementation of early introduction guidelines has been slow, and many infants are already sensitized by 4-6 months of age. To be more effective, primary prevention strategies must commence much earlier, during breastfeeding. There are studies that imply a definitive effect of breastfeeding on the gut microbiome and regulatory T cells (Tregs) as well as a higher rate of FA in populations with historically low rates of breastfeeding. These provide a strong rationale for assessing the effect of feeding HM in the context of HM composition and mode of feeding on immune development. The lack of well-conducted, large studies assessing the role of breastfeeding and HM composition in the development of immune system development is a significant gap when designing prevention strategies.

The developing immune system in preterm born infants: From contributor to potential solution for respiratory tract infections and wheezing

Moderate-late preterm-born infants experience more frequent and severe respiratory tract infections and wheezing compared to term-born infants. Decreasing the risk on respiratory tract infections and wheezing in this group is vital to improve quality of life and reduce medical consumption during infancy, but also to reduce the risk on asthma and COPD later in life. Until now, moderate-late preterm infants are underrepresented in research and mechanisms underlying their morbidity are largely unknown, although they represent 80% of all preterm-born infants. In order to protect these infants effectively, it is essential to understand the role of the immune system in early life respiratory health and to identify strategies to optimize immune development and respiratory health. This review elaborates on risk factors and preventative measures concerning respiratory tract infections and wheezing in preterm-born infants, exploring their impact on the immune system and microbiome. Factors discussed are early life antibiotic use, birth mode, feeding type and living environment. Further, differences in adaptive and innate immune maturation between term and preterm infants are discussed, as well as differences in local immune reactions in the lungs. Finally, preventative strategies are being explored, including microbiota transplantation, immune modulation (through pre-, pro-, syn- and postbiotics, bacterial lysates, vaccinations, and monoclonal antibodies) and antibiotic prophylaxis.

Multi-Omics Profiles of Small Intestine Organoids in Reaction to Breast Milk and Different Infant Formula Preparations

Ensuring optimal infant nutrition is crucial for the health and development of children. Many infants aged 0-6 months are fed with infant formula rather than breast milk. Research on cancer cell lines and animal models is limited to examining the nutrition effects of formula and breast milk, as it does not comprehensively consider absorption, metabolism, and the health and social determinants of the infant and its physiology. Our study utilized small intestine organoids induced from human embryo stem cell (ESC) to compare the nutritional effects of breast milk from five donors during their postpartum lactation period of 1-6 months and three types of Stage 1 infant formulae from regular retail stores. Using transcriptomics and untargeted metabolomics approaches, we focused on the differences such as cell growth and development, cell junctions, and extracellular matrix. We also analyzed the roles of pathways including AMPK, Hippo, and Wnt, and identified key genes such as ALPI, SMAD3, TJP1, and WWTR1 for small intestine development. Through observational and in-vitro analysis, our study demonstrates ESC-derived organoids might be a promising model for exploring nutritional effects and underlying mechanisms.

Respiratory Syncytial Virus is the Most Common Causative Agent of Viral Bronchiolitis in Young Children: An Updated Review

BACKGROUND

Viral bronchiolitis is a common condition and a leading cause of hospitalization in young children.

OBJECTIVE

This article provides readers with an update on the evaluation, diagnosis, and treatment of viral bronchiolitis, primarily due to RSV.

METHODS

A PubMed search was conducted in December 2021 in Clinical Queries using the key terms "acute bronchiolitis" OR "respiratory syncytial virus infection". The search included clinical trials, randomized controlled trials, case control studies, cohort studies, meta-analyses, observational studies, clinical guidelines, case reports, case series, and reviews. The search was restricted to children and English literature. The information retrieved from the above search was used in the compilation of this article.

RESULTS

Respiratory syncytial virus (RSV) is the most common viral bronchiolitis in young children. Other viruses such as human rhinovirus and coronavirus could be etiological agents. Diagnosis is based on clinical manifestation. Viral testing is useful only for cohort and quarantine purposes. Cochrane evidence-based reviews have been performed on most treatment modalities for RSV and viral bronchiolitis. Treatment for viral bronchiolitis is mainly symptomatic support. Beta-agonists are frequently used despite the lack of evidence that they reduce hospital admissions or length of stay. Nebulized racemic epinephrine, hypertonic saline and corticosteroids are generally not effective. Passive immunoprophylaxis with a monoclonal antibody against RSV, when given intramuscularly and monthly during winter, is effective in preventing severe RSV bronchiolitis in high-risk children who are born prematurely and in children under 2 years with chronic lung disease or hemodynamically significant congenital heart disease. Vaccines for RSV bronchiolitis are being developed. Children with viral bronchiolitis in early life are at increased risk of developing asthma later in childhood.

CONCLUSION

Viral bronchiolitis is common. No current pharmacologic treatment or novel therapy has been proven to improve outcomes compared to supportive treatment. Viral bronchiolitis in early life predisposes asthma development later in childhood.

Birth cohort studies using symptom diaries for assessing respiratory diseases-a scoping review

BACKGROUND

Respiratory infections are the most frequent health problem in childhood leading to morbidity and socioeconomic burden. Studying symptoms of respiratory infections in home based settings requires dedicated prospective cohort studies using diaries. However, no information is available on which birth cohort studies using symptom diary data. A review of birth cohort studies with available symptom diary data, follow-up data, and bio samples is needed to support research collaborations and create potential synergies.

METHODS

We conducted a scoping review of birth cohort studies using diaries for the collection of respiratory symptoms. The scoping review was conducted in accordance with the PRISMA Extension. We searched the electronic databases PubMed, Embase, Web of science and CINAHL (last search November 2020) resulting in 5872 records (based on title and abstract screening) eligible for further screening.

RESULTS

We examined 735 records as full text articles and finally included 57 according to predefined inclusion criteria. We identified 22 birth cohort studies that collect(ed) data on respiratory symptoms using a symptom diary starting at birth. Numbers of participants ranged from 129 to 8677. Eight studies collected symptom diary information only for the first year of life, nine for the first two years or less and six between three and six years. Most of the cohorts collected biosamples (n = 18) and information on environmental exposures (n = 19).

CONCLUSION

Information on respiratory symptoms with daily resolution was collected in several birth cohorts, often including related biosamples, and these data and samples can be used to study full spectrum of infections, particularly including those which did not require medical treatment.

Unbiased Screening Identifies Functional Differences in NK Cells After Early Life Psychosocial Stress

Early Life Adversity (ELA) is closely associated with the risk for developing diseases later in life, such as autoimmune diseases, type-2 diabetes and cardiovascular diseases. In humans, early parental separation, physical and sexual abuse or low social-economic status during childhood are known to have great impact on brain development, in the hormonal system and immune responses. Maternal deprivation (MD) is the closest animal model available to the human situation. This paradigm induces long lasting behavioral effects, causes changes in the HPA axis and affects the immune system. However, the mechanisms underlying changes in the immune response after ELA are still not fully understood. In this study we investigated how ELA changes the immune system, through an unbiased analysis, viSNE, and addressed specially the NK immune cell population and its functionality. We have demonstrated that maternal separation, in both humans and rats, significantly affects the sensitivity of the immune system in adulthood. Particularly, NK cells’ profile and response to target cell lines are significantly changed after ELA. These immune cells in rats are not only less cytotoxic towards YAC-1 cells, but also show a clear increase in the expression of maturation markers after 3h of maternal separation. Similarly, individuals who suffered from ELA display significant changes in the cytotoxic profile of NK cells together with decreased degranulation capacity. These results suggest that one of the key mechanisms by which the immune system becomes impaired after ELA might be due to a shift on the senescent state of the cells, specifically NK cells. Elucidation of such a mechanism highlights the importance of ELA prevention and how NK targeted immunotherapy might help attenuating ELA consequences.

Bioactive Compounds in Infant Formula and Their Effects on Infant Nutrition and Health: A Systematic Literature Review

Infant formulas are an alternative to replace or supplement human milk when breastfeeding is not possible. The knowledge of human milk's bioactive compounds and their beneficial effects has attracted the interest of researchers in the field of infant nutrition, as well as researchers of technology and food sciences that seek to improve the nutritional characteristics of infant formulas. Several scientific studies evaluate the optimization of infant formula composition. The bioactive compound inclusion has been used to upgrade the quality and nutrition of infant formulas. In this context, the purpose of this systematic literature review is to assess the scientific evidence of bioactive compounds present in infant formulas (α-lactalbumin, lactoferrin, taurine, milk fat globule membrane, folates, polyamines, long-chain polyunsaturated fatty acids, prebiotics, and probiotics) and their effects on infant nutrition and health. Through previously determined criteria, studies published in the last fifteen years from five different databases were included to identify the advances in the optimization of infant formula composition. Over the last few years, there has been optimization of the infant formula composition, not only to increase the similarities in their content of macro and micronutrients but also to include novel bioactive ingredients with potential health benefits for infants. Although the infant food industry has advanced in the last years, there is no consensus on whether novel bioactive ingredients added to infant formulas have the same functional effects as the compounds found in human milk. Thus, further studies about the impact of bioactive compounds in infant nutrition are fundamental to infant health.

Ambient PM2.5 and its chemical constituents on lifetime-ever pneumonia in Chinese children: A multi-center study

The long-term effects of ambient PM_2.5 and chemical constituents on childhood pneumonia were still unknown. A cross-sectional study was conducted in 30,315 children in the China Children, Homes, Health (CCHH) project, involving 205 preschools in six cities in China, to investigate the long-term effects of PM_2.5 constituents on lifetime-ever diagnosed pneumonia. Information on the lifetime-ever pneumonia and demographics were collected by validated questionnaires. The lifetime annual average ambient PM_2.5, ozone and five main PM_2.5 constituents, including SO₄^2-, NO₃^-, NH₄⁺, organic matter (OM) and black carbon (BC), were estimated according to preschool addresses by a combination of satellite remote sensing, chemical transport modeling and ground-based monitors. The prevalence of lifetime-ever diagnosed pneumonia was 34.5% across six cities and differed significantly among cities (p = 0.004). The two-level logistic regression models showed that the adjusted odds ratio for PM_2.5 (per 10 µg/m³) and its constituents (per 1 µg/m³)-SO₄^2-, NO₃^-, NH₄⁺, and OM were 1.12 (95% CI:1.07-1.18), 1.02 (1.00-1.04), 1.06 (1.04-1.09), 1.05 (1.03-1.07) and 1.09 (1.06-1.12), respectively. Children in urban area, aged < 5 years and breastfeeding time < 6 months enhanced the risks of pneumonia. Our study provided robust results that long-term levels of ambient PM_2.5 and its constituents increased the risk of childhood pneumonia, especially NH₄⁺, NO₃^- and OM.

Can breastfeeding protect against antimicrobial resistance?

BACKGROUND

The proportion of infections among young children that are antimicrobial-resistant is increasing across the globe. Newborns may be colonized with enteric antimicrobial-resistant pathogens early in life, which is a risk factor for infection-related morbidity and mortality. Breastfeeding is actively promoted worldwide for its beneficial impacts on newborn health and gut health. However, the role of breastfeeding and human milk components in mitigating young children's carriage of antimicrobial-resistant pathogens and antibiotic resistance genes has not been comprehensively explored.

MAIN BODY

Here, we review how the act of breastfeeding, early breastfeeding, and/or human milk components, such as the milk microbiota, secretory IgA, human milk oligosaccharides, antimicrobial peptides, and microRNA -bearing extracellular vesicles, could play a role in preventing the establishment of antimicrobial-resistant pathogens in young children's developing gut microbiomes. We describe findings from recent human studies that support this concept.

CONCLUSION

Given the projected rise in global morbidity and mortality that will stem from antimicrobial-resistant infections, identifying behavioral or nutritional interventions that could decrease children's susceptibility to colonization with antimicrobial-resistant pathogens may be one strategy for protecting their health. We suggest that breastfeeding and human milk supplements deserve greater attention as potential preventive measures in the global effort to combat antimicrobial resistance, particularly in low- and middle-income settings.

Neonatal Diet Impacts the Large Intestine Luminal Metabolome at Weaning and Post-Weaning in Piglets Fed Formula or Human Milk

The impact of human milk (HM) or dairy milk-based formula (MF) on the large intestine’s metabolome was not investigated. Two-day old male piglets were randomly assigned to HM or MF diet (n = 26/group), from postnatal day (PND) 2 through 21 and weaned to a solid diet until PND 51. Piglets were euthanized at PND 21 and PND 51, luminal contents of the cecum, proximal (PC) and distal colons (DC), and rectum were collected and subjected to metabolomics analysis. Data analyses were performed using Metaboanalyst. In comparison to MF, the HM diet resulted in higher levels of fatty acids in the lumen of the cecum, PC, DC, and rectum at PND 21. Glutamic acid was greater in the lumen of cecum, PC, and DC relative to the MF group at PND 21. Also, spermidine was higher in the DC and rectal contents of HM relative to MF at PND 21. MF diet resulted in greater abundances of amino acids in the cecal lumen relative to HM diet at PND 21. Additionally, several sugar metabolites were higher in various regions of the distal gut of MF fed piglets relative to HM group at PND 21. In contrast, at PND 51, in various regions there were higher levels of erythritol, maltotriose, isomaltose in HM versus MF fed piglets. This suggests a post weaning shift in sugar metabolism that is impacted by neonatal diet. The data also suggest that infant diet type and host-microbiota interactions likely influence the lower gut metabolome.

Functional analysis of granulocyte and monocyte subpopulations in neonates

BACKGROUND

Neonate immune cell functions lack full protection against pathogens. This could be either defect or protective mechanism against overshooting proinflammatory immune responses. We here analysed the function of classical, pro- and anti-inflammatory monocytes and granulocytes from neonates in comparison with adults to investigate if suppressed functions of subpopulations are causative for the unique neonatal immune status. Therefore, reactive oxygen species (ROS) and surface activation markers were quantified in subpopulations.

METHODS

In a prospective, longitudinal study granulocyte and monocyte subpopulations were analysed in healthy term infants (> 37 week; n = 13) in comparison with healthy young adults (n = 11). Percentage (%) of cells expressing surface marker (HLA-DR, CD11b, CD62L, CD32, Toll-Like-Receptor-2) and expression per cell, determined by mean fluorescence intensity (MFI), were measured by flow cytometry. ROS production was induced by fMLP, PMA and E. coli in term neonates (> 37 week; n = 13).

RESULTS

Classical granulocytes were down- and proinflammatory granulocytes upregulated in neonates compared with adults. Percentage of TLR-2 expressing granulocytes was increased in neonates. Granulocytic ROS production depended on stimulation. The percentage of anti-inflammatory monocytes was increased, while classical monocytes were reduced in neonates. HLA-DR (%, MFI) showed reduction for all monocyte subpopulations, while CD32, CD11b, CD62L and TLR-2 were differently regulated in comparison with adults.

CONCLUSIONS

Differentially regulated granulocyte and monocyte subpopulations indicate a unique state of neonatal immunity to fight infections and prevent dysregulation. Further studies are needed to investigate the role of reduced granulocytic ROS formation and reduced monocytic HLA-DR in active disease.

Food Consumption, Nutrient Intake and Status during the First 1000 days of Life in the Netherlands: a Systematic Review

Adequate nutrition is essential for growth and development in early life. Nutritional data serves as a basis for national nutritional guidelines and policies. Currently, there is no insight into the availability of such data during the first 1000 days of life. Therefore, a systematic review was performed, following the PRISMA reporting guideline, to identify studies on food consumption, nutrient intake or status in the Netherlands. Potential gaps were identified, and the quality of the studies is discussed. The databases Embase and Medline were used, as well as databases from national institutes. Articles published in 2008-2018 were screened by two independent reviewers. In total 601 articles were identified, of which 173 were included. For pregnant women, 32 studies were available with nutritional data, for young children 40 studies were identified. No studies were available for breastfeeding women. A large variety of foods and nutrients were assessed, however certain nutrients were lacking (e.g., vitamin K). Overall, the studies had methodological limitations, making the data unsuitable to assess nutrient inadequacies. There is a need for recent, high quality nutritional research to strengthen the understanding of the nutritional needs and deficiencies during early life, and is fundamental for national guidelines and policies.

Caesarean delivery, immune function and inflammation in early life among Ecuadorian infants and young children

Caesarean delivery has been linked to a number of inflammatory conditions in childhood and adolescence. Yet the mechanisms underlying these associations and their generalizability across contexts with different postnatal feeding and pathogenic exposures remain unclear. This study tests the association between delivery type and three measures of immune function, inflammation, morbidity and leukocyte proportions, in Ecuadorian infants and children aged 6 months to 2 years. Data were collected from mother-child pairs participating in a nationally representative health and nutrition survey Encuesta Nacional de Salud y Nutricion (ENSANUT-ECU) conducted in 2012. The analytic sample includes 828 mothers and infants with delivery information and measured biomarkers. Poisson regression models were used to examine the association between delivery type and markers of immune function, controlling for maternal and infant characteristics, including age, sex, sociodemographic characteristics and medical indications. 40.8% (n=338) of sample infants and children were delivered by caesarean. Compared to those born vaginally, infants born by caesarean were less likely to have elevated C-reactive protein (CRP) [CRP>2 mg/l; risk ratio (RR): 0.76, 95% confidence interval (CI): 0.58-1.00] and more likely to have illness symptoms (RR: 1.22, 95% CI: 1.01-1.46) and elevated basophils (RR: 1.83, 95% CI: 1.03-3.25). No other immune cell proportions differed by delivery type. The results suggest that differences in the perinatal exposures accompanying caesarean delivery may alter immune development and function, particularly in the inflammatory response to infection and in cells involved in the allergic response, across infancy and early childhood. Understanding the pathways linking perinatal exposures to immune development is important for preventing the development of inflammatory conditions.

Women's Pregnancy Life History and Alzheimer's Risk: Can Immunoregulation Explain the Link?

BACKGROUND

Pregnancy is associated with improvement in immunoregulation that persists into the geriatric phase. Impaired immunoregulation is implicated in Alzheimer's disease (AD) pathogenesis. Hence, we investigate the relationship between pregnancy and AD.

METHODS

Cross-sectional cohort of British women (N = 95). Cox proportional hazards modeling assessed the putative effects of cumulative months pregnant on AD risk and the mutually adjusted effects of counts of first and third trimesters on AD risk.

RESULTS

Cumulative number of months pregnant, was associated with lower AD risk (β = -1.90, exp(β) = 0.15, P = .02). Cumulative number of first trimesters was associated with lower AD risk after adjusting for third trimesters (β = -3.83, exp(β) = 0.02, P < .01), while the latter predictor had no significant effect after adjusting for the former.

CONCLUSIONS

Our observation that first trimesters (but not third trimesters) conferred protection against AD is more consistent with immunologic effects, which are driven by early gestation, than estrogenic exposures, which are greatest in late gestation. Results may justify future studies with immune biomarkers.

Breastmilk cell trafficking induces microchimerism-mediated immune system maturation in the infant

Initiating breastfeeding within the first hour of life confers an important benefit in terms of child mortality and severe morbidity. Intestinal permeability to ingested macromolecules and immunoglobulins is limited to the first days of human life. These exchanges cease in the very early post-partum period but may increase beyond the neonatal period in response to local inflammation or introduction of a weaning food. From animal- and limited human-based observations, compelling evidence points out to breastmilk cells also trafficking from mother to infant mucosal tissues and participating to the maternal microchimerism. The precise nature of breastmilk cells that are involved is presently not known but likely includes progenitor/stem cells-representing up to 6% of breastmilk cells-with possible contribution of mature immune cells. Stem cell microchimerism may induce tolerance to non-inherited maternal antigens (NIMAs), breastfeeding generating regulatory T cells (T_reg ) that suppress antimaternal immunity. Therefore, in complement to pregnancy-induced microchimerism, breastfeeding-induced microchimerism may be pivotal in infant immune development, intestinal tissue repair/growth and protection against infectious diseases. As a continuum of the gestational period, the neonatal gut may be considered as a temporary, but important developmental extension of the role played by the placenta during intrauterine life; breastmilk playing the role of maternal blood by delivering maternal soluble factors (macromolecules, Ig, cytokines) and immunologically active milk cells. A better understanding of breastfeeding-induced maternal microchimerism would provide further evidence in support of public health messages that reinforce the importance of early initiation of breastfeeding.

Breast-feeding regulates immune system development via transforming growth factor-β in mice pups

BACKGROUND

Breast milk contains important nutrients and immunoregulatory factors that are essential for newborn infants. Recently, epidemiological studies suggested that breast-feeding prevents a wide range of infectious diseases and lowers the incidence of infant allergic diseases.

METHODS

To examine the effects of breast milk on immunological development in infancy, we established an artificial rearing system for hand-feeding mice and compared mouse pups fed with either breast milk or milk substitute. All mice were killed at 14 days of age and immune cells in the thymus, spleen, and small intestine were examined on flow cytometry.

RESULTS

The number of thymocytes was higher whereas that of total immune cells of peripheral lymphoid tissues was lower in mice fed breast milk compared with milk substitute-fed mice. In peripheral lymphoid tissues, the proportion of B cells was higher and that of CD8+ T cells, macrophages, dendritic cells, and granulocytes was significantly lower in breast milk-fed mice. The same alteration in immune cells of the thymus and peripheral lymphoid tissues in milk substitute-fed mice was also observed in pups reared by mother mice treated with anti-transforming growth factor-β (anti-TGF-β) monoclonal antibody.

CONCLUSIONS

Breast milk regulates the differentiation and expansion of innate and adaptive immune cells partly due to TGF-β. Hence, TGF-β in breast milk may be a new therapeutic target for innate immune system-mediated diseases of infancy.

Early-Life Intestine Microbiota and Lung Health in Children

The gastrointestinal microbiota plays a critical role in nutritional, metabolic, and immune functions in infants and young children and has implications for future lung health status. Understanding the role of intestinal dysbiosis in chronic lung disease progression will provide opportunities to design early interventions to improve the course of the disease. Gut microbiota is established within the first 1 to 3 years of life and remains relatively stable throughout the life span. In this review, we report the recent development in research in gut-lung axis, with focus on the effects of targeting microbiota of infants and children at risk of or with progressive lung diseases. The basic concept is to exploit this approach in critical window to achieve the best results in the control of future health.

Prevention of allergies in childhood - where are we now?

Allergic diseases represent an increasing health problem for children worldwide. Along with allergic airway diseases, food allergy comes to the fore and herewith closely intertwined the hypothesis that an early allergic sensitization might occur via skin barrier defect(s). The importance of the skin barrier has been documented by several studies meanwhile. Not only genetic studies screen the associations between Filaggrin loss-of-function mutations, atopic dermatitis, allergic sensitization, food allergy and even airway diseases, but also epidemiological studies cast new light on the hypothesis of the atopic march. As another focus in context of the development of an allergic phenotype, the specific microbial exposure with all its diversities has been crystallized as it shapes the immune system in (early) infancy. Studies explored both, the role of human intestinal microbiota as well as the external microbial diversity. Unfortunately suitable markers for atopic predictors are still rare. New studies point out that specific IgE antibodies (e.g., IgE to Phl p 1) in children without allergic symptoms so far, might function as a pre-clinical biomarker, which may help to identify candidates for primary (allergen non-specific) or secondary (allergen-specific) prevention in terms of specific immunoprophylaxis. These manifold research activities document a complex increase in knowledge. Nevertheless new assumptions need to be substantively confirmed in order to finally generate the urgently needed preventive strategies for allergic diseases in childhood.

Postprandial metabolic response of breast-fed infants and infants fed lactose-free vs regular infant formula: A randomized controlled trial

Lactose intolerance is a major concern driving the growth of lactose-free foods including lactose-free infant formula. It is unknown what the metabolic consequence is of consumption of a formula where lactose has been replaced with corn syrup solids (CSS). Here, a randomized double-blinded intervention study was conducted where exclusively formula-fed infants were fed formula containing either lactose or CSS-based infant formula and compared with an equal number of exclusively breast-fed infants. Plasma metabolites and insulin were measured at baseline, 15, 30, 60, 90 and 120 min after feeding. Differences in plasma metabolite profiles for formula-fed infants included a rapid increase in circulating amino acids, creatinine and urea compared with breast-fed infants. At 120 min post-feeding, insulin was significantly elevated in formula-fed compared with breast-fed infants. Infants fed lactose-based formula had the highest levels of glucose at 120 min, and leucine, isoleucine, valine and proline at 90 and 120 min, whereas infants fed CSS-based formula had the lowest levels of non-esterified fatty acids at all time points, and glucose at 120 min. Overall, these differences highlight that changes in infant formula composition impact infant metabolism, and show that metabolomics is a powerful tool to help with development of improved infant formulas.

Mode of delivery and atopic phenotypes: Old questions new insights? A retrospective study

BACKGROUND

To date studies on the relation between mode of delivery and atopic diseases in are controversial.

OBJECTIVE

The aim of the study was to determine a possible relationship between mode of delivery and risk of atopic phenotypes and, to assess the critical role of some pre-and post-natal parameters as a link between mode of delivery and risk of atopy.

METHODS

1516 children were assessed by skin prick tests, serum total and specific IgE levels. Parental reports on demographic and clinical data were also recorded.

RESULTS

Of the 1516 children enrolled for the study, clinical and laboratory informations were obtained from 917 children. 460 children of them were born via CD and 457 via VD. Mode of delivery did not modify the prevalence of immune sensitization and/or allergic diseases. However, CD was associated with increased risk of atopy (p<0.001). Moreover, some parameters such as familiar history of atopy (p<0.001), habits smoking (p<0.05), exclusive artificial feeding (p<0.001); and breast-feeding time (<3months) (p<0.001) were associated with a major risk of atopy in CD group. Additionally, although our study confirmed that breast-feeding is associated to lower serum total IgE levels than artificial-feeding (p<0.001), it seems that the protective role of breast-feeding is negatively influenced from CD. Also in artificial-feeding subjects CD is related to a significant higher levels of IgE than VD (p<0.001).

CONCLUSIONS

Our findings suggest that CD influences only the risk of atopy but no prevalence of immune sensitization and allergic diseases.

Comparative analysis of human milk and infant formula derived peptides following in vitro digestion

It has long been recognised that there are differences between human milk and infant formulas which lead to differences in health and nutrition for the neonate. In this study we examine and compare the peptide profile of human milk and an exemplar infant formula. The study identifies both similarities and differences in the endogenous and postdigestion peptide profiles of human milk and infant formula. This includes differences in the protein source of these peptides but also with the region within the protein producing the dominant proteins. Clustering of similar peptides around regions of high sequence identity and known bioactivity was also observed. Together the data may explain some of the functional differences between human milk and infant formula, while identifying some aspects of conserved function between bovine and human milks which contribute to the effectiveness of modern infant formula as a substitute for human milk.

Effects of Breastfeeding on Respiratory Symptoms in Infancy

OBJECTIVE

To assess the impact of potential risk factors on the development of respiratory symptoms and their specific modification by breastfeeding in infants in the first year of life.

STUDY DESIGN

We prospectively studied 436 healthy term infants from the Bern-Basel Infant Lung Development cohort. The breastfeeding status, and incidence and severity of respiratory symptoms (score) were assessed weekly by telephone interview during the first year of life. Risk factors (eg, pre- and postnatal smoking exposure, mode of delivery, gestational age, maternal atopy, and number of older siblings) were obtained using standardized questionnaires. Weekly measurements of particulate matter <10 μg were provided by local monitoring stations. The associations were investigated using generalized additive mixed model with quasi Poisson distribution.

RESULTS

Breastfeeding reduced the incidence and severity of the respiratory symptom score mainly in the first 27 weeks of life (risk ratio 0.70; 95% CI 0.55-0.88). We found a protective effect of breastfeeding in girls but not in boys. During the first 27 weeks of life, breastfeeding attenuated the effects of maternal smoking during pregnancy, gestational age, and cesarean delivery on respiratory symptoms. There was no evidence for an interaction between breastfeeding and maternal atopy, number of older siblings, child care attendance, or particulate matter <10 μg.

CONCLUSIONS

This study shows the risk-specific effect of breastfeeding on respiratory symptoms in early life using the comprehensive time-series approach.

The Role of Lactoferrin in Gastrointestinal and Immune Development and Function: A Preclinical Perspective

The early postnatal period is a critical time for gastrointestinal (GI) and immune development. Neonates fed mother's milk have more rapid GI and immune development than fed-formula infants. In addition, clinical and epidemiologic data provide strong evidence that breastfeeding reduces the incidence and/or severity of infectious diseases. Lactoferrin is a 77 kDa, iron-binding glycoprotein that is present at high concentration in human milk compared with bovine milk and infant formula. It is a multifunctional protein that mediates many of the physiological processes in which breastfed infants have advantages over their formula-fed peers, including promoting GI and immune development, protection from infections, and improved cognitive development. Feeding bovine lactoferrin or recombinant human lactoferrin was well tolerated and stimulated intestinal cell proliferation and increased villus length and crypt depth in piglets. Lactoferrin also influenced both systemic and GI immune development by stimulating a balanced T-helper-1/T-helper-2 cytokine immune response. Further, there was a tendency for immune cells to secrete more anti-inflammatory cytokines in an unstimulated state, while being primed for a robust pro-inflammatory response when presented with a bacterial trigger in piglets fed lactoferrin. These findings support clinical studies demonstrating benefits of dietary lactoferrin in the prevention of infections, late onset sepsis, and necrotizing enterocolitis.

High fecal IgA is associated with reduced Clostridium difficile colonization in infants

Colonization of infants with Clostridium difficile is on the rise. Although better tolerated by infants than adults, it is a risk factor for future allergic disease. The present study describes associations between infant fecal immunoglobulin A (IgA) and colonization with C. difficile in 47 infants enrolled in the Canadian Healthy Infant Longitudinal Development (CHILD) study. C. difficile colonization was observed in over half (53%) of the infants. Median IgA was lower in infants colonized with C. difficile (10.9 μg versus 25.5 μg per g protein; p = 0.18). A smaller proportion of infants with IgA in the highest tertile were colonized with C. difficile compared to the other tertiles (31.3% versus 64.5%, p = 0.03). In unadjusted analysis, odds of colonization with C. difficile was reduced by 75% (OR 0.25 95% CI 0.07, 0.91 p = 0.04) among infants with IgA in the highest tertile compared to those in the other tertiles. Following adjustment for parity, birth mode and breastfeeding, this association was even stronger (aOR 0.17, 95% CI 0.03, 0.94, p = 0.04). Our study provides evidence that high fecal IgA, independent of breastfeeding, is associated with reduced likelihood of C. difficile colonization in infancy.

Development of immunity in early life

The immune system in early life goes through rapid and radical changes. Early life is also the period with the highest risk of infections. The foetal immune system is programmed to coexist with foreign antigenic influences in utero, and postnatally to rapidly develop a functional system capable of distinguishing helpful microbes from harmful pathogens. Both host genetics and environmental influences shape this dramatic transition and direct the trajectory of the developing immune system into early childhood and beyond. Given the malleability of the immune system in early life, interventions aimed at modulating this trajectory thus have the potential to translate into considerable reductions in infectious disease burden with immediate as well as long-lasting benefit. However, an improved understanding of the underlying molecular drivers of early life immunity is prerequisite to optimise such interventions and transform the window of early life vulnerability into one of opportunity.

Difference in the breast milk proteome between allergic and non-allergic mothers

BACKGROUND

Breastfeeding has been linked to a reduction in the prevalence of allergy and asthma. However, studies on this relationship vary in outcome, which may partly be related to differences in breast milk composition. In particular breast milk composition may differ between allergic and non-allergic mothers. Important components that may be involved are breast milk proteins, as these are known to regulate immune development in the newborn. The objective of this study was therefore to explore differences in the proteins of breast milk from 20 allergic and non-allergic mothers. The results from this comparison may then be used to generate hypotheses on proteins associated with allergy in their offspring.

METHODS

Milk samples from allergic and non-allergic mothers were obtained from the PIAMA project, a prospective birth cohort study on incidence, risk factors, and prevention of asthma and inhalant allergy. Non-targeted proteomics technology, based on liquid chromatography and mass spectrometry, was used to compare breast milk from allergic and non-allergic mothers.

RESULTS

Nineteen proteins, out of a total of 364 proteins identified in both groups, differed significantly in concentration between the breast milk of allergic and non-allergic mothers. Protease inhibitors and apolipoproteins were present in much higher concentrations in breast milk of allergic than non-allergic mothers. These proteins have been suggested to be linked to allergy and asthma.

CONCLUSIONS

The non-targeted milk proteomic analysis employed has provided new targets for future studies on the relation between breast milk composition and allergy.

Interactions between innate immunity genes and early-life risk factors in allergic rhinitis

PURPOSE

Allergic rhinitis (AR) is a common chronic disease. Many factors could affect the development of AR. We investigated early-life factors, such as delivery mode, feeding method, and use of antibiotics during infancy, which could affect the development of AR. In addition, how interactions between these factors and innate gene polymorphisms influence the development of AR was investigated.

METHODS

A cross-sectional study of 1,828 children aged 9-12 years was conducted. Three early-life factors and AR were assessed by a questionnaire. Skin prick tests were done. Polymorphisms of TLR4 (rs1927911) and CD14 (rs2569190) were genotyped.

RESULTS

Use of antibiotics during infancy increased the risk of AR (aOR [95% CI] 1.511 [1.222-2.037]) and atopic AR (aOR [95% CI], 1.565 [1.078-2.272]). There were synergistic interactions between caesarean delivery, formula feeding, and use of antibiotics in the rate of atopic AR (aOR [95% CI], 3.038 [1.256-7.347]). Additional analyses revealed that the risk for the development of AR or atopic AR subjects with the TLR4 CC genotype were highest when all the 3 early-life factors were present (aOR [95% CI], 5.127 [1.265-20.780] for AR; 6.078 [1.499-24.649] for atopic AR). In addition, the risk for the development of AR or atopic AR in subjects with the CD14 TT genotype were highest when all the 3 early-life factors were present (aOR [95% CI], 5.960 [1.421-15.002] for AR; 6.714 [1.440-31.312] for atopic AR).

CONCLUSIONS

Delivery mode, feeding method, and use of antibiotics during infancy appeared to have synergistic interactions in the development of AR. Gene-environment interactions between polymorphism of innate genes and early- life risk factors might affect the development of AR.

Infections in infants fed formula supplemented with bovine milk fat globule membranes

OBJECTIVES

Observational studies have shown that even in high-income countries formula-fed infants have a higher incidence of acute otitis media (AOM), and gastrointestinal and respiratory tract infections during the first year of life compared with breast-fed infants. We hypothesized that components of the milk fat globule membrane (MFGM) may be responsible for some of these differences and that supplementation with bovine MFGM would decrease the infectious morbidity in formula-fed infants.

METHODS

In a double-blind randomized controlled trial, 160 formula-fed infants received experimental formula (EF) supplemented with bovine MFGM (EF) or unsupplemented standard formula (SF) from <2 months until 6 months of age. A breast-fed reference group consisted of 80 infants. Disease symptoms, health care contacts, and medication were recorded by the parents until 12 months of age. Serum immunoglobulin G for 10 pneumococcal serotypes was analyzed at 6 months of age.

RESULTS

The cumulative incidence of AOM during the intervention was lower in the EF group than in the SF group (1% vs 9%, P = 0.034), and did not differ from the breast-fed reference group (0%, P = 1.0). The incidence (25% vs 43%, P = 0.021) and longitudinal prevalence (P = 0.012) of antipyretic use were significantly lower in the EF group than in the SF group. Serum immunoglobulin G concentrations against pneumococcal serotypes 1, 5, and 14 were lower in the EF group than in the SF group.

CONCLUSIONS

Supplementation of formula with bovine MFGM reduces the risk of AOM, decreases antipyretics use in formula-fed infants, and has immunomodulatory effects on humoral response against pneumococcus vaccine.

Recent advances in epidemiology and prevention of atopic eczema

Atopic dermatitis (AD), named also atopic eczema, is a chronic relapsing inflammatory skin disease with a considerable social and economic burden. The primum movens of AD is in most cases a genetic and/or immune-supported defect of the skin barrier, facilitating penetration and sensitization to food or airborne allergens, as well as infections by Staphylococcus aureus, herpes simplex virus, or other microbes. New pathogenetic concepts have generated new approaches to prevention and therapy of AD. In particular, the daily use of emollients in newborns at high risk of AD has shown interesting results, with a reduction in the cumulative incidence of AD ranging from 32% to 50% of the treated infants. On the other hand, the AD preventive efficacy of food and/or inhalant allergen avoidance has been questioned, and supplementation strategies (vitamin D, probiotics, or other compounds) need to be further investigated.

Cardiovascular risk markers until 12 mo of age in infants fed a formula supplemented with bovine milk fat globule membranes

BACKGROUND

Some of the health advantages of breast-fed as compared to formula-fed infants have been suggested to be due to metabolic programming effects resulting from early nutrition.

METHODS

In a prospective double-blinded randomized trial, 160 infants <2 mo of age were randomized to experimental formula (EF) with added milk fat globule membrane (MFGM) or standard formula (SF) until 6 mo of age. A breast-fed reference (BFR) group consisted of 80 infants. Measurements were made at inclusion and at 4, 6, and 12 mo of age.

RESULTS

During the intervention, the EF group had higher total serum cholesterol concentration than the SF group, reaching the level of the BFR group. The EF group had a low-density lipoprotein to high-density lipoprotein ratio not significantly different from the SF group but lower than the BFR group.

CONCLUSION

Supplementation of infant formula with MFGM modified the fat composition of the formula and narrowed the gap between breast-fed and formula-fed infants with regard to serum lipid status at 12 mo.

Single-cell analysis of innate cytokine responses to pattern recognition receptor stimulation in children across four continents

Innate immunity instructs adaptive immunity, and suppression of innate immunity is associated with an increased risk for infection. We showed previously that whole-blood cellular components from a cohort of South African children secreted significantly lower levels of most cytokines following stimulation of pattern recognition receptors compared with whole blood from cohorts of Ecuadorian, Belgian, or Canadian children. To begin dissecting the responsible molecular mechanisms, we set out to identify the relevant cellular source of these differences. Across the four cohorts represented in our study, we identified significant variation in the cellular composition of whole blood; however, a significant reduction in the intracellular cytokine production on the single-cell level was only detected in South African children's monocytes, conventional dendritic cells, and plasmacytoid dendritic cells. We also uncovered a marked reduction in polyfunctionality for each of these cellular compartments in South African children compared with children from the other continents. Together, our data identify differences in cell composition, as well as profoundly lower functional responses of innate cells, in our cohort of South African children. A possible link between altered innate immunity and increased risk for infection or lower response to vaccines in South African infants needs to be explored.

Toll-like receptor signaling in neonatal sepsis and inflammation: a matter of orchestration and conditioning

Altered neonatal Toll-like receptor (TLR) function is hypothesized to contribute to the heightened susceptibility to infection and perpetuated inflammation in term and preterm neonates, clinically evident in neonatal sepsis and increased rates of inflammatory disorders. Current data indicate that basal TLR expression in term neonates equals adult expression patterns, while expression in preterm infants seems to increase, depending on gestational age. Regarding TLR signaling, some studies suggest TLR incompetence in neonates associated with impaired pro-inflammatory responses, others describe neonatal TLR function well developed and allude to its hyper-inflammation tendency. We discuss the competing positions and considerable limitations of research approaches and conclude that neonatal innate immunity is not generally less able to respond to TLR stimulation. Moreover, we describe pre-conditioning factors other than immaturity having a comparable impact. In the long term, better understanding of the complex interplay of pre- and postnatal conditions and maturation-dependent neonatal TLR function may provide new therapeutic approaches.

Association between child cortisol levels in saliva and neuropsychological development during the second year of life

Exposure to highly elevated levels of cortisol has been linked with impairments in cognitive capacities in both children and adults. By contrast, moderate levels of cortisol may engender beneficial effects. The main aim of this study was to assess the association between child cortisol levels and neuropsychological development during the second year of life. A population-based birth cohort was established in the city of Sabadell (Catalonia, Spain) as part of the INMA (Environment and Childhood) Project. We assessed the cognitive and psychomotor development at the age of 14 months using the Bayley Scales of Infant Development (BSID). We included 302 children assessed during their second year of life for whom we had information on neuropsychological assessment and measurements of cortisol in saliva. Higher levels of cortisol were associated with better scores in BSID's mental scale. There was no association between cortisol levels and psychomotor test scores. We found a small positive association between duration of breastfeeding and child cortisol levels. This association was only found in boys. The results of this study suggest that moderate levels of cortisol in children could have small beneficial effects on their early neuropsychological development.

Dietary bovine lactoferrin alters mucosal and systemic immune cell responses in neonatal piglets

Lactoferrin (LF) is a multifunctional immune protein found at high concentrations in human milk. Herein, the effect of dietary bovine LF (bLF) on mucosal and systemic immune development was investigated. Colostrum-deprived piglets were fed formula containing 130 [control (Ctrl)], 367 (LF1), or 1300 (LF3) mg of bLF/(kg body weight · d). To provide passive immunity, sow serum was provided orally during the first 36 h of life. Blood, spleen, mesenteric lymph node (MLN), and ascending colon (Asc) contents were collected on day 7 (n = 10-14/group) and day 14 (n = 10-12/group). Immune cell populations were quantified by flow cytometry and immunoglobulins (Igs) were measured by ELISA. Additionally, immune cells were isolated from spleen and MLNs (n = 7/group) on day 7 and stimulated ex vivo with phytohemagglutinin or lipopolysaccharide (LPS) ± LF for 72 h. Secreted cytokine concentrations were quantified by multiplex assay. Lymphocyte populations [cluster determinant (CD)4, CD8, and natural killer cells] developed normally and were unaffected by dietary bLF. LF3 piglets tended to have 1.4 to 2 times more serum IgG than Ctrl piglets (P = 0.07) or LF1 piglets (P = 0.03), but IgA in Asc contents was unaffected by bLF. Asc IgA was 4 times higher on day 14 than day 7. Spleen cells from LF3 piglets produced 2 times more interleukin (IL)-10 and tumor necrosis factor (TNF)-α ex vivo than those from Ctrl or LF1 piglets. MLN cells from LF1 and LF3 piglets produced 40% more IL-10 and tended to produce 40% more IL-6 (P = 0.05) than those from Ctrl piglets. However, ex vivo bLF did not affect the cytokine response of spleen or MLN cells to LPS. In summary, dietary bLF alters the capacity of MLN and spleen immune cells to respond to stimulation, supporting a role for LF in the initiation of protective immune responses in these immunologically challenged neonates.

Zinc as an adjunct to the treatment of severe pneumonia in Ecuadorian children: a randomized controlled trial

BACKGROUND

Studies of zinc as an adjunct to treatment of severe pneumonia in children have shown mixed results, possibly because of poor information on zinc status and respiratory pathogens.

OBJECTIVE

We evaluated the effect of zinc given with standard antimicrobial treatment on the duration of respiratory signs in children with severe pneumonia. Zinc status and pathogens were assessed.

DESIGN

Children aged 2-59 mo with severe pneumonia who were admitted to the main children's hospital in Quito, Ecuador, were given standard antibiotics and randomly allocated to receive zinc supplements twice daily or a placebo. Measurements included anthropometric variables, breastfeeding, hemoglobin, plasma zinc, and common bacteria/viral respiratory pathogens. The primary outcome was time to resolution of respiratory signs. The secondary outcome was treatment failure.

RESULTS

We enrolled 225 children in each group. There was no difference between groups in time to resolution of respiratory signs or treatment failure; pathogens were not associated with outcomes. Tachypnea and hypoxemia resolved faster in older children (P = 0.0001) than in younger ones. Higher basal zinc concentration (P = 0.011) and better height-for-age z score (HAZ) (P = 0.044) were associated with faster resolution of chest indrawing. Better weight-for-height z score (WHZ) (P = 0.031) and HAZ (P = 0.048) were associated with faster resolution of tachypnea. Increased C-reactive protein was associated with a longer duration of tachypnea (P = 0.044).

CONCLUSIONS

Zinc did not affect time to pneumonia resolution or treatment failure, nor did type of respiratory pathogens affect outcomes. Higher basal zinc and better HAZ and WHZ were associated with reduced time to resolution of respiratory signs. These results suggest the need for prevention of chronic zinc deficiency and improvement of general nutritional status among Ecuadorian children.

Maternal concentrations of persistent organochlorine pollutants and the risk of asthma in offspring: results from a prospective cohort with 20 years of follow-up

BACKGROUND

Previous findings suggest that developmental exposures to persistent organochlorine pollutants (POPs) may be detrimental for the development of the immune system in the offspring. Whether these suspected immunoregulatory effects persist beyond early childhood remains unclear.

OBJECTIVES

The objective of this study was to evaluate the association between maternal serum concentrations of POPs and the risk of asthma in offspring after 20 years of follow-up.

METHODS

A birth cohort with 965 women was formed in 1988-1989 in Aarhus, Denmark. Concentrations of six polychlorinated biphenyls (PCBs) (congeners 118, 138, 153, 156, 170, 180), hexachlorobenzene (HCB), and dichlorodiphenyldichloroethylene (p,p´-DDE) were quantified in maternal serum (n=872) collected in gestation week 30. Information about offspring use of asthma medications was obtained from the Danish Registry of Medicinal Product Statistics.

RESULTS

Maternal serum concentrations of HCB and dioxin-like PCB-118 were positively associated with offspring asthma medication use after 20 years of follow-up (p for trend<0.05). Compared with subjects in the first tertile of maternal concentration, those in the third tertile of PCB-118 had an adjusted hazard ratio (HR) of 1.90 (95% CI: 1.12, 3.23). For HCB the HR for the third versus the first tertile of maternal concentration was 1.92 (95% CI: 1.15, 3.21). Weak positive associations were also estimated for PCB-156 and the non-dioxin-like PCBs (PCBs 138, 153, 170, 180). No associations were found for p,p´-DDE.

CONCLUSIONS

Maternal concentrations of PCB-118 and HCB were associated with increased risk of asthma in offspring followed through 20 years of age.

Breastfeeding and wheeze prevalence in pre-schoolers and pre-adolescents: the Genesis and Healthy Growth studies

BACKGROUND

To date, extensive research has been undertaken on a potential link of breastfeeding (BF) to wheezing illnesses. Nevertheless, an association remains to be established, partly due to age-dependent discrepancies and different definitions of exposures/outcomes across studies. We thus investigated the relation of diverse infantile feeding patterns with wheeze/asthma prevalence in two cohorts of children of different ages (preschool and preadolescent).

METHODS

Wheeze ever/in the last 12 months (current) and doctor-diagnosed asthma were retrospectively reported by parents of the participants of two cross-sectional studies: the Genesis study (1871 children aged 1-5) and the Healthy Growth study (1884 children aged 9-13). Information on feeding practices (exclusive breastfeeding vs. mixed vs. formula feeding) and their duration (2 vs. 4 vs. 6 months) was recorded. Perinatal and anthorpometric data were also collected.

RESULTS

In pre-schoolers, regimes that did not entail exclusive BF were positively correlated to current/ever wheeze, both before and after adjustment for confounders. No differences between the associations of regimes with 2, 4 or 6 months of exclusive BF with current/ever wheeze were shown. Furthermore, there was no consistent correlation of feeding practices with physician-diagnosed asthma. In pre-adolescents, no association of infantile feeding patterns with the wheeze/asthma outcomes was observed.

CONCLUSIONS

Exclusive BF is associated with reduced prevalence of current/ever wheeze in pre-schoolers; however, this appears to wane in older children. The association of a period of exclusive BF as low as 2 months with pre-school wheeze prevalence, appeared to be comparable with that of 6 months of exclusivity.

Select human milk oligosaccharides directly modulate peripheral blood mononuclear cells isolated from 10-d-old pigs

Infant formulas lack the complex mixture of oligosaccharides found in human milk. These human milk oligosaccharides (HMO) may be pivotal to the development of the neonatal immune system. Few comprehensive analyses of the effects of HMO on immune cells from neonates have been undertaken. Herein, the direct effects of HMO on immune cells were analysed ex vivo. Peripheral blood mononuclear cells (PBMC) isolated from 10-d-old sow-reared (SR) or colostrum-deprived formula-fed (FF) pigs were stimulated for 72 h with single HMO, mixtures of single HMO or a complex mixture of HMO isolated from human milk (iHMO). T-cell phenotype, cytokine production and proliferation were measured by flow cytometry, immunoassay and [³H]thymidine incorporation, respectively. Stimulation with HMO had direct effects on PBMC. For instance, cells stimulated with iHMO produced more IL-10 than unstimulated cells, and cells stimulated with fucosylated HMO tended to proliferate less than unstimulated cells. Additionally, co-stimulation with HMO mixtures or single HMO altered PBMC responses to phytohaemagglutinin (PHA) or lipopolysaccharide (LPS) stimulation. Compared with PBMC stimulated with PHA alone, cells co-stimulated with iHMO and PHA proliferated more and had fewer detectable CD4⁺CD8⁺ T cells. Compared with PBMC stimulated by LPS alone, cells co-stimulated with a mixture of sialylated HMO and LPS proliferated more and tended to have fewer detectable CD4⁺ T cells. Differences in the baseline responses of PBMC isolated from the SR or FF pigs were observed. In summary, HMO directly affected PBMC populations and functions. Additionally, ex vivo measurements of PBMC phenotype, cytokine production and proliferation were influenced by the neonate's diet.

Black currant seed oil supplementation of mothers enhances IFN-γ and suppresses IL-4 production in breast milk

BACKGROUND

The first year of infancy is crucial for the development of atopic immune response. Inadequate early Th1 and Treg responses and increased production of Th2 cytokines are associated with atopy. Breast milk contains several immunomodulatory cytokines and other factors that might influence the maturation of the infant's immune system. We assessed the cytokines in breast milk of mother of newborn infants and their associations with black currant seed oil (BCSO) supplementation during pregnancy, mother's atopic status and the development of infant's atopic dermatitis.

METHODS

Mothers and infants from an intervention study by black currant seed oil (n = 31) or olive oil as placebo (n = 30) were included in the study. Breast milk samples were collected during the first 3 months of breastfeeding. Breast milk levels of IL-4, IL-5, IL-10, IL-12, IFN-γ and TNF were measured by Luminex technology.

RESULTS

BCSO intervention group had decreased level of IL-4 (p = 0.044) and elevated level of IFN-γ (p = 0.014) in breast milk as compared to olive oil group. No significant differences were observed in IL-5, IL-10, IL-12 and TNF levels between the BCSO and olive oil groups. Mothers who had atopic dermatitis had significantly decreased levels of IL-10 (p = 0.044) in breast milk. Breast milk of the mothers of the children who developed atopic dermatitis had lower levels of IFN-γ (p = 0.039) as compared to the breast milk of the mothers of the children without dermatitis.

CONCLUSION

Dietary intervention with BCSO had immunomodulatory effects on breast milk cytokine production towards Th2 to Th1 immunodeviation.

The nutritive and immunoprotective quality of human milk beyond 1 year postpartum: are lactation-duration-based donor exclusions justified?

Donor human milk is critical for the fragile preterm infant who does not have access to his or her mother's milk, improving survival rates and quality of survival and decreasing hospital stay. Despite the opening of donor milk banks around the world, shortages continue as demand for donor milk exceeds supply. One potential means of increasing supply is by reducing exclusion criteria that prohibit mothers from donating milk based on duration of lactation. Minimal research has been done on the composition of human milk during the second year of lactation, with most research focusing on the nutritive compounds and not the immunoprotective compounds. Several immunoprotective compounds, including lysozyme, lactoferrin, secretory immunoglobulin A, and oligosaccharides, are abundant in human milk compared to bovine-based infant formula and are partially or fully retained during Holder pasteurization, making them an important differentiating feature of donor milk. A PubMed search was conducted to review studies in human milk composition during the second year of lactation. Limitations of existing research include sample collection protocols, small study sizes, and use of populations that may have been at risk for nutritional deficiencies. Stable concentrations of several components were reported including protein, lactose, iron, copper, lactoferrin, and secretory immunoglobulin A. Lysozyme concentration increased during extended lactation, while zinc and calcium concentrations declined into the second year. Conflicting findings were reported on fat content, and no information was available regarding oligosaccharide content. More research is needed to create evidence-based guidelines regarding the nutritive and immunoprotective value of donor milk throughout the course of lactation.

Early life response to infection

PURPOSE OF REVIEW

Sepsis is a serious complication in preterm and term infants, yet our understanding of how neonates respond to infection remains poorly defined.

RECENT FINDINGS

We describe our current clinical, cellular and molecular understanding of the neonatal host systemic response to infection. We find that host resilience essentially relies on innate immune mechanisms despite there being a complete repertoire of cellular components of the adaptive immune arm. The functional interplay between metabolism, immunity and microbiome further suggests that neonatal vulnerability to infection is not simply due to immaturity of the immune system but how immune homeostasis is regulated. Further research is required for exploring regulatory homeostatic mechanisms between innate and adaptive responses and microbiome colonization at birth, but which can impart an adverse trajectory to infection.

SUMMARY

The vulnerability and resilience against infection in neonates, including extreme preterm infants, still remains poorly understood. We advance the view that greater consideration should be given to understanding the set point in the regulation of homeostatic control of innate and adaptive immunity and its interplay with metabolism and the newly acquired microbiome.

Variation between Populations in the Innate Immune Response to Vaccine Adjuvants

The success of the World Health Organization recommended “Expanded Program of Immunization” (EPI) and similar regional or national programs has been astounding. However, infectious threats currently not covered by these programs continue to infect millions of infants around the world. Furthermore, many infants do not receive existing vaccines either on time or for the required number of doses to provide optimal protection. Nor do all infants around the world develop the same protective immune response to the same vaccine. As a result approximately three million infants die every year from vaccine preventable infections. To tackle these issues, new vaccines need to be developed as well as existing ones made easier to administer. This requires identification of age-optimized vaccine schedules and formulations. In order to be most effective this approach will need to take population-based differences in response to vaccines and adjuvants into account. This review summarizes what is currently known about differences between populations around the world in the innate immune response to existing as well as new and promising vaccine adjuvants.

Plasma-mediated immune suppression: a neonatal perspective

Plasma is a rich mixture of immune regulatory factors that shape immune cell function. This immunomodulatory role of plasma is especially important in neonates. To maintain in utero feto-maternal tolerance and to allow for microbial colonization after birth, the neonatal immune system is biased against pro-inflammatory responses while favoring immune suppression. Therefore, the neonatal period provides a unique opportunity to study the physiologic mechanisms regulating the immune system. Several recent studies in neonates have identified plasma factors that play a key role in immune regulation. Insight into immune regulation by neonatal and adult plasma may have clinical implications, because plasma is easily accessible, affordable, and widely available. Herein, we review plasma-mediated immune regulation, with specific focus on neonatal plasma. We discuss how immune suppression is a key function of plasma and provide a systematic overview of the published literature regarding plasma-derived immune suppressive proteins, lipids, purines, and sugars. Finally, we outline how immune regulation by these factors, which are particularly abundant in neonatal plasma, may eventually be used to treat immune-mediated diseases, such as autoimmune, allergic, and inflammatory diseases.

Innate immune function by Toll-like receptors: distinct responses in newborns and the elderly

Given the "inborn" nature of the innate immune system, it is surprising to find that innate immune function does in fact change with age. Similar patterns of distinct Toll-like-receptor-mediated immune responses come to light when one contrasts innate immune development at the beginning of life with that toward the end of life. Importantly, these developmental patterns of innate cytokine responses correlate with clinical patterns of susceptibility to disease: A heightened risk of suffering from excessive inflammation is often detected in prematurely born infants, disappears over the first few months of life, and reappears toward the end of life. In addition, risk periods for particular infections in early life reemerge in older adults. The near-mirror-image patterns that emerge in contrasts of early versus late innate immune ontogeny emphasize changes in host-environment interactions as the underlying molecular and teleologic drivers.

Allergic airway diseases in childhood - marching from epidemiology to novel concepts of prevention

In the past years, a wide range of epidemiological, clinical, and experimental studies have produced remarkable advances in the field of respiratory allergies in childhood. By the recent investigations on epidemiological trends, risk factors, and prevention of asthma and allergic rhinitis, various exiting concepts have been challenged, and novel innovative approaches have been developed. Pediatric Allergy and Immunology (PAI), with a number of highly relevant contributions between 2010 and 2012, has become an important forum in this area. The prevalence of asthma in some developed countries may have reached a plateau, while in developing countries, where the prevalence was previously low, allergic diseases are still on the increase. A wide array of risk and protective factors, including hygiene, infections, outdoor and indoor air pollution, allergen exposure, breast-feeding practices, nutrition, and obesity, play a multifaceted role in shaping the observed worldwide trends of respiratory allergies. Under the guidance of recent research, prediction and prevention strategies in the clinical practice are progressively changing, the focus moving away from avoidance of allergen exposure and toward tolerance induction.