Decreased cord blood IL-4, IL-13, and CCR4 and increased TGF-β levels after fish oil supplementation of pregnant women

Impact of Climate Change on Dietary Nutritional Quality and Implications for Asthma and Allergy

Asthma and allergic disorders are common in childhood with genetic and environmental determinants of disease that include prenatal nutritional exposures such as long-chain polyunsaturated fatty acids and antioxidants. Global climate change is implicated in asthma and allergic disorder morbidity with potential mechanisms including perturbations of ecosystems. There is support that environmental and climatic changes such as increasing global temperate and carbon dioxide levels affect aquatic and agricultural ecosystems with subsequent alterations in long-chain polyunsaturated fatty acid availability and nutrient quality and antioxidant capacity of certain crops, respectively. This article discusses asthma epidemiology and the influence of global climate change.

Immunomodulatory effect of marine lipids on food allergy

Seafood is highly enriched in n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFAs), particularly eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3), in contrast to the ultra-processed foods included in the modern Western diet that have high levels of n-6 linoleic acid (LA, 18:2 n-6), precursor for the pro-inflammatory n-6 arachidonic acid (ARA, 20:4 n-6). The capacity of marine lipids to reduce plasmatic triglycerides and blood pressure have been well-described. Moreover, recent studies have also raised evidence of a potential regulatory action of marine lipids on inflammation, the immune system, and food allergy (FA). FA is considered one of the main concerns to become life threatening in food safety. The prevalence of this emerging global problem has been increasing during the last two decades, especially in industrialized countries. About a 6-8% of young children and 2-4% of adults is estimated to be affected by FA. The main objective of the current study is to update the existing knowledge, but also the limitations, on the potential impact of marine lipids and their lipid mediators in regulating immunity, inflammation, and ultimately, food allergies. In particular, the focus is on the effect of marine lipids in modulating the key factors that control the sensitization and effector phases of FA, including gut microbiota (GM), inflammation, and immune system response. Results in animal models highlight the positive effect that consuming marine lipids, whether as a supplement or through seafood consumption, may have a relevant role in improving gut dysbiosis and inflammation, and preventing or reducing the severity of FA. However, more systematic studies in humans are needed to optimize such beneficial actions to each particular FA, age, and medical condition to reach an effective clinical application of marine lipids to improve FAs and their outcomes.

Omega-3 long-chain polyunsaturated fatty acids: Metabolism and health implications

Recently, omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) have gained substantial interest due to their specific structure and biological functions. Humans cannot naturally produce these fatty acids (FAs), making it crucial to obtain them from our diet. This comprehensive review details n-3 LC-PUFAs and their role in promoting and maintaining optimal health. The article thoroughly analyses several sources of n-3 LC-PUFAs and their respective bioavailability, covering marine, microbial and plant-based sources. Furthermore, we provide an in-depth analysis of the biological impacts of n-3 LC-PUFAs on health conditions, with particular emphasis on cardiovascular disease (CVD), gastrointestinal (GI) cancer, diabetes, depression, arthritis, and cognition. In addition, we highlight the significance of fortification and supplementation of n-3 LC-PUFAs in both functional foods and dietary supplements. Additionally, we conducted a detailed analysis of the several kinds of n-3 LC-PUFAs supplements currently available in the market, including an assessment of their recommended intake, safety, and effectiveness. The dietary guidelines associated with n-3 LC-PUFAs are also highlighted, focusing on the significance of maintaining a well-balanced intake of n-3 PUFAs to enhance health benefits. Lastly, we highlight future directions for further research in this area and their potential implications for public health.

Maternal fish oil and/or probiotics intervention: Allergic diseases in children up to two years old

BACKGROUND

As n-3 long-chain polyunsaturated fatty acids and probiotics possess immunomodulatory properties, theoretically they could lower the risk of allergic diseases. But their effects remain controversial. We aimed to study the effects of fish oil and probiotics separately or in combination from early pregnancy onwards to lower the risk of allergic diseases in the infants.

METHODS

In this double-blind trial, women (n = 439) in early pregnancies were randomized into four intervention groups: fish oil + placebo, probiotics + placebo, fish oil + probiotics, and placebo + placebo. Fish oil (1.9 g docosahexaenoic acid and 0.22 g eicosapentaenoic acid) and probiotic (Lacticaseibacillus rhamnosus HN001 and Bifidobacterium animalis ssp. lactis 420, 1010 colony-forming units each) supplements were provided for daily consumption from randomization up to 6 months postpartum. All analyses were adjusted with pet ownership.

RESULTS

No difference between the infants in the four intervention groups were found regarding physician-diagnosed food allergy, atopic eczema, or atopy at the age of 12 or 24 months (all p > .05). The probiotic intervention was associated with lower odds of recurrent wheezing at 24 months (OR 0.39, 95% CI 0.18-0.84, p = .017), but not at 12 months.

CONCLUSIONS

The use of fish oil and/or probiotics from early pregnancy onwards did not lower the odds of childhood allergic diseases or atopy, with the exception of the probiotic intervention which decreased the risk of recurrent wheezing when the infants were two years old. This suggests that the incidence of asthma could also decrease later in childhood and thus these outcomes need to be clarified in further investigations.

Nutritional management of food allergies: Prevention and treatment

An individualized allergen avoidance plan is the cornerstone of the nutritional management of food allergy (FA). In pediatric age, the main objective is preventing the occurrence of acute and chronic symptoms by avoiding the offending food(s) and providing an adequate, nutritionally balanced and personalized diet at the same time. For this reason, the presence of a trained dietitian is recommended in order to meet nutritional needs of patients with FA and to provide a tailored nutritional plan, minimizing the impact of FA on quality of life and maintaining optimal growth.

Membrane fatty acid desaturase: biosynthesis, mechanism, and architecture

Fatty acid desaturase catalyzes the desaturation reactions by inserting double bonds into the fatty acyl chain, producing unsaturated fatty acids, which play a vital part in the synthesis of polyunsaturated fatty acids. Though soluble fatty acid desaturases have been described extensively in advanced organisms, there are very limited studies of membrane fatty acid desaturases due to their difficulties in producing a sufficient amount of recombinant desaturases. However, the advancement of technology has shown substantial progress towards the development of elucidating crystal structures of membrane fatty acid desaturase, thus, allowing modification of structure to be manipulated. Understanding the structure, mechanism, and biosynthesis of fatty acid desaturase lay a foundation for the potential production of various strategies associated with alteration and modifications of polyunsaturated fatty acids. This manuscript presents the current state of knowledge and understanding about the structure, mechanisms, and biosynthesis of fatty acid desaturase. In addition, the role of unsaturated fatty acid desaturases in health and diseases is also encompassed. This will be useful in understanding the molecular basis and structural protein of fatty acid desaturase that are significant for the advancement of therapeutic strategies associated with the improvement of health status. KEY POINTS: • Current state of knowledge and understanding about the biosynthesis, mechanisms, and structure of fatty acid desaturase. • The role of unsaturated fatty acid desaturase. • The molecular basis and structural protein elucidated the crystal structure of fatty acid desaturase.

Maternal diet during pregnancy and risk of allergic diseases in children up to 7-9 years old from Polish Mother and Child Cohort study

BACKGROUND

The impact of maternal diet during pregnancy on the risk of allergic diseases in childhood is an increasing scientific and public health concern. We evaluated the associations of maternal type of diet and essential elements and vitamins intake during pregnancy with offspring allergic and respiratory outcomes.

METHODS

The study population included 557 mother-child pairs from Polish Mother and Child Cohort (REPRO_PL). Based on the Food Frequency Questionnaire filled in between the 20th-24th week of pregnancy, overall maternal diet was evaluated as the difference between the Prudent Dietary Pattern (PDP) score and Western Dietary Pattern (WDP) score ((PDP-WDP) score) and maternal achievement of dietary recommendations (estimated average requirement, EAR) for essential elements and vitamins was assessed. Children's health examination at age of 1, 2, and 7-9 years covered the following symptoms: infections, wheezing/asthma, food allergy, allergic rhinitis, and atopic dermatitis. At age of 7-9 years, children underwent spirometry and skin-prick tests.

RESULTS

Children of the mothers who were not achieving adequate intake of vitamin C during pregnancy had a higher risk of wheezing and having more than two infections within the first two years of life comparing to those who met EAR (OR = 2.6, p = 0.05, and OR = 2.3, p = 0.04, respectively). Inadequate intake of vitamin E during pregnancy was related to a higher risk of atopic dermatitis (OR = 2.7, p = 0.04), whereas inadequate intake of magnesium during pregnancy was associated with the risk of wheezing in the offspring at age of two years (OR = 3.7, p = 0.03). A lower (PDP-WDP) score during pregnancy (indicating unhealthier diet) was associated with a higher risk of infections (OR = 1.5, p = 0.007) but a lower risk of atopic dermatitis (OR = 0.7, p = 0.02) at age of 7-9 years.

CONCLUSIONS

These results may contribute to the body of evidence for the impact of maternal diet during pregnancy for children's optimal health, however further studies are needed before drawing conclusions and recommendations for clinical practice.

Mediterranean-Type Diets as a Protective Factor for Asthma and Atopy

We are currently riding the second wave of the allergy epidemic, which is ongoing in affluent societies, but now also affecting developing countries. This increase in the prevalence of atopy/asthma in the Western world has coincided with a rapid improvement in living conditions and radical changes in lifestyle, suggesting that this upward trend in allergic manifestations may be associated with cultural and environmental factors. Diet is a prominent environmental exposure that has undergone major changes, with a substantial increase in the consumption of processed foods, all across the globe. On this basis, the potential effects of dietary habits on atopy and asthma have been researched rigorously, but even with a considerable body of evidence, clear associations are far from established. Many factors converge to obscure the potential relationship, including methodological, pathophysiological and cultural differences. To date, the most commonly researched, and highly promising, candidate for exerting a protective effect is the so-called Mediterranean diet (MedDi). This dietary pattern has been the subject of investigation since the mid twentieth century, and the evidence regarding its beneficial health effects is overwhelming, although data on a correlation between MedDi and the incidence and severity of asthma and atopy are inconclusive. As the prevalence of asthma appears to be lower in some Mediterranean populations, it can be speculated that the MedDi dietary pattern could indeed have a place in a preventive strategy for asthma/atopy. This is a review of the current evidence of the associations between the constituents of the MedDi and asthma/atopy, with emphasis on the pathophysiological links between MedDi and disease outcomes and the research pitfalls and methodological caveats which may hinder identification of causality. MedDi, as a dietary pattern, rather than short-term supplementation or excessive focus on single nutrient effects, may be a rational option for preventive intervention against atopy and asthma.

[Immune system and allergies-An unholy alliance]

Various factors affect the maturation of the infantile immune system both prenatally and postnatally, including risk and protective factors from the environment, nutrition, genetics and epigenetics. The microbiome seems to play a substantial role. The complex interaction and regulation of all these factors is ultimately decisive for whether a child develops an allergy during the course of development of the immune system. The genetic components play a decisive role in the development of allergic diseases. The epigenetic regulation could represent a mechanism where environmental influences act upon the immune regulation in the emergence of allergic diseases. The main factors in the pathophysiology of allergic reactions are a dysregulation of various cells of the innate and acquired immune systems as well as their interaction. This review describes the role of various T helper cell types in allergic diseases. The incidence and duration of airway infections are clearly increased in allergic patients compared to nonallergic controls. In addition to functional aspects, the reason for the more frequent infections is an impairment of the immune defence by the allergy-related persisting inflammation of the mucous membranes. These mechanisms must be differentiated from a true immunodeficiency. Allergic rhinitis (AR) and bronchial asthma are nowadays no longer defined as separate diseases but as two forms of expression of an atopic entity with a similar pathology. Both diseases can be mediated by immunoglobulin E and be elicited by identical triggers. A bronchial hyperreactivity is detectable in the majority of patients with AR but without clinical asthma.

Long-Chain Polyunsaturated Fatty Acid Status at Birth and Development of Childhood Allergy: A Systematic Review

The associations of fetal fatty acids status to immune-related health parameters later in life are unclear. Our aim is to collect all available information on the relationship between fatty acid status at birth and allergy in childhood. Systematic literature search was performed on Ovid MEDLINE, Cochrane Library, and Embase. The search retrieved 897 articles without duplicates; 14 articles remained after excluding those that did not fit into our inclusion criteria. When the dichotomous parameter of suffering or not from allergic condition in childhood was analyzed, cord blood eicosapentaenoic acid (EPA) values proved to be significantly lower in allergic than non-allergic children in four comparisons from three studies. When the linear parameters of odds ratios and relative risks for allergy were taken into consideration, high cord blood EPA, but also high docosahexaenoic acid (DHA) and high total n-3 long-chain polyunsaturated fatty acid values were associated to clinically relevant reduction (at least 38%) in eight comparisons from five studies. Within the cord blood samples, higher EPA, docosapentaenoic acid, and DHA values were significantly and negatively associated in eight correlation analyses from three studies with laboratory parameters considered to reflect allergic trait. The data reported here may provide information for defining optimal fatty acid intakes for pregnant women.

Role of EPA in Inflammation: Mechanisms, Effects, and Clinical Relevance

Many chronic inflammatory processes are linked with the continuous release of inflammatory mediators and the activation of harmful signal-transduction pathways that are able to facilitate disease progression. In this context atherosclerosis represents the most common pathological substrate of coronary heart disease, and the characterization of the disease as a chronic low-grade inflammatory condition is now validated. The biomarkers of inflammation associated with clinical cardiovascular risk support the theory that targeted anti-inflammatory treatment appears to be a promising strategy in reducing residual cardiovascular risk. Several literature data highlight cardioprotective effects of the long-chain omega-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA). This PUFA lowers plasma triglyceride levels and has potential beneficial effects on atherosclerotic plaques. Preclinical studies reported that EPA reduces both pro-inflammatory cytokines and chemokines levels. Clinical studies in patients with coronary artery disease that receive pharmacological statin therapy suggest that EPA may decrease plaque vulnerability preventing plaque progression. This review aims to provide an overview of the links between inflammation and cardiovascular risk factors, importantly focusing on the role of diet, in particular examining the proposed role of EPA as well as the success or failure of standard pharmacological therapy for cardiovascular diseases.

Fetal lipidome and incident risk of food allergy: A prospective birth cohort study

BACKGROUND

Lipids are proposed to be important in developing adaptive immunity and allergy. However, studies to date reported inconsistent findings.

OBJECTIVE

To examine newborn lipidome (a comprehensive profiling of circulating lipid metabolites) on child's risk of developing food allergy (FA). The maternal-cord joint effects of lipid metabolites on FA development were also investigated.

METHODS

This study included 647 mother-child pairs from the Boston Birth Cohort and analyzed 202 lipid metabolites in cord plasma profiled by liquid chromatography tandem mass spectrometry. FA was defined based on standard clinical criteria. Logistic regression was applied to examine the relationships between individual metabolites and risk of FA.

RESULTS

Of the 647 children, 61 developed FA. Cord triacylglycerols of long carbon chains and multiple double bonds were significantly associated with decreased risk of FA. These associations were comparable across strata of pertinent maternal and child covariates, and were independent of maternal triacylglycerols when assessed simultaneously. Besides, cord and maternal triacylglycerols had an additive effect in association with risk of FA: Children having high (≥Median) C56:8 triacylglycerol levels in both cord and maternal plasma were at the lowest risk of developing FA (OR = 0.24, 95% CI = 0.10-0.56, p = .001), compared to those having low levels in both cord and maternal plasma.

CONCLUSION

This is the first birth cohort study to link altered cord plasma lipidome with future risk of development FA during childhood. It calls for further investigation on triacylglycerols of long carbon chains and multiple double bonds as potential novel predictive biomarkers and therapeutic targets for FA.

Potential Role of Omega-3 Polyunsaturated Fatty Acids in Pediatric Food Allergy

Polyunsaturated fatty acids (PUFAs) are involved both in immune system regulation and inflammation. In particular, within the PUFAs category, omega-3 (ω-3) may reduce inflammation, whereas omega-6 (ω-6) PUFAs are generally considered to have a proinflammatory effect. Recent evidence highlights an imbalance in the ω-3:ω-6 ratio with an increased intake of ω-6, as a consequence of the shift towards a westernized diet. In critical age groups such as infants, toddlers and young children, as well as pregnant and lactating women or fish allergic patients, ω-3 intake may be inadequate. This review aims to discuss the potential beneficial effects of PUFAs on pediatric food allergy prevention and treatment, both at prenatal and postnatal ages. Data from preclinical studies with PUFAs supplementation show encouraging effects in suppressing allergic response. Clinical studies results are still conflicting about the best timing and dosages of supplementation and which individuals are most likely to benefit; therefore, it is still not possible to draw firm conclusions. With regard to food-allergic children, it is still debated whether PUFAs could slow disease progression or not, since consistent data are lacking. In conclusion, more data on the effects of ω-3 PUFAs supplementation alone or in combination with other nutrients are warranted, both in the general and food allergic population.

Insight on Polyunsaturated Fatty Acids in Endometrial Receptivity

Endometrial receptivity plays a crucial role in fertilization as well as pregnancy outcome in patients faced with fertility challenges. The optimization of endometrial receptivity may help with normal implantation of the embryo, and endometrial receptivity may be affected by numerous factors. Recently, the role of lipids in pregnancy has been increasingly recognized. Fatty acids and their metabolites may be involved in all stages of pregnancy and play a role in supporting cell proliferation and development, participating in cell signaling and regulating cell function. Polyunsaturated fatty acids, in particular, are essential fatty acids for the human body that can affect the receptivity of the endometrium through in a variety of methods, such as producing prostaglandins, estrogen and progesterone, among others. Additionally, polyunsaturated fatty acids are also involved in immunity and the regulation of endometrial decidualization. Fatty acids are essential for fetal placental growth and development. The interrelationship of polyunsaturated fatty acids with these substances and how they may affect endometrial receptivity will be reviewed in this article.

Maternal FADS2 single nucleotide polymorphism modified the impact of prenatal docosahexaenoic acid (DHA) supplementation on child neurodevelopment at 5 years: Follow-up of a randomized clinical trial

BACKGROUND

Variability in the FADS2 gene, which codifies the Delta-6 Desaturases and modulates the conversion of essential n-3 and n-6 fatty acids into long-chain polyunsaturated fatty acids, might modify the impact of prenatal supplementation with n-3 docosahexaenoic acid (DHA) on neurodevelopment.

OBJECTIVE

To assess if maternal FADS2 single nucleotide polymorphisms (SNPs) modified the effect of prenatal DHA on offspring development at 5 years.

DESIGN

We conducted a post-hoc interaction analysis of the POSGRAD randomized controlled trial (NCT00646360) of prenatal supplementation with algal-DHA where 1094 pregnant women originally randomized to 400 mg/day of preformed algal DHA or a placebo from gestation week 18-22 through delivery. In this analysis, we included offspring with information on maternal genotype and neurodevelopment at 5 years (DHA = 316; Control = 306) and used generalized linear models to assess interactions between FADS2 SNPs rs174602 or rs174575 and prenatal DHA on neurodevelopment at 5 years measured with McCarthy Scales of Children's Abilities (MSCA).

RESULTS

Maternal and offspring characteristics were similar between groups. At baseline, mean (±standard deviation) maternal age was 26 ± 5 years and schooling was 12 ± 4 years. Forty-six percent (46%) of the children were female. Maternal minor allele frequencies were 0.37 and 0.33 for SNPs rs174602 and rs174575, respectively. There were significant variations by SNP rs174602 and intervention group (p for interactions <0.05) where children in the intervention group had higher MSCA scores on the quantitative (DHA: mean ± SEM = 22.6 ± 0.9 vs. Control = 19.1 ± 0.9, mean difference (Δ) = 3.45; p = 0.01) and memory (DHA = 27.9 ± 1.1 vs. Control = 23.7 ± 1.1, Δ = 4.26; p = 0.02) scales only among offspring of TT (minor allele homozygotes).

CONCLUSIONS

Maternal FADS2 SNP rs174602 modified the effect of prenatal DHA on cognitive development at 5 years. Variations in the genetic make-up of target populations could be an important factor to consider for prenatal DHA supplementation interventions.

Maternal Nutritional Status and Development of Atopic Dermatitis in Their Offspring

Atopic dermatitis (AD) is the leading chronic skin inflammatory disease and the initial manifestation of atopic march. Available evidence supports the notion that primary prevention early in life leads to a decreased incidence of AD, thus possibly decreasing the subsequent occurrence of atopic march. Nutritional status is essential to a proper functioning immune system and is valued for its important role in AD. Essential nutrients, which include carbohydrates, proteins, lipids, vitamins, and minerals, are transferred from the mother to the fetus through the placenta during gestation. Various nutrients, such as polyunsaturated fatty acids (PUFAs) and vitamin D, were studied in relation to maternal status and offspring allergy. However, no strong evidence indicates that a single nutrient or food in mothers' diet significantly affects the risk of childhood AD. In the light of current evidence, mothers should not either increase nor avoid consuming these nutrients to prevent or ameliorate allergic diseases in their offspring. Each essential nutrient has an important role in fetal development, and current government recommendations suggest specific intake amounts for pregnant women. This review discusses evidence on how various nutrients, including lipids (monounsaturated fatty acids, PUFAs, saturated fatty acids, and short-chain fatty acids), carbohydrates (oligosaccharides and polysaccharides), proteins, vitamins (A, B, C, D, and E), and trace minerals (magnesium, iron, zinc, copper, selenium, and strontium) in maternal status are associated with the development of AD and their possible mechanisms.

Improving Cognition with Nutraceuticals Targeting TGF-β1 Signaling

Rescue of cognitive function represents an unmet need in the treatment of neurodegenerative disorders such as Alzheimer's disease (AD). Nutraceuticals deliver a concentrated form of a presumed bioactive(s) agent(s) that can improve cognitive function alone or in combination with current approved drugs for the treatment of cognitive disorders. Nutraceuticals include different natural compounds such as flavonoids and their subclasses (flavan-3-ols, catechins, anthocyanins, and flavonols), omega-3, and carnosine that can improve synaptic plasticity and rescue cognitive deficits through multiple molecular mechanisms. A deficit of transforming growth factor-β1 (TGF-β1) pathway is an early event in the pathophysiology of cognitive impairment in different neuropsychiatric disorders, from depression to AD. In the present review, we provide evidence that different nutraceuticals, such as Hypericum perforatum (hypericin and hyperforin), flavonoids such as hesperidin, omega-3, and carnosine, can target TGF-β1 signaling and increase TGF-β1 production in the central nervous system as well as cognitive function. The bioavailability of these nutraceuticals, in particular carnosine, can be significantly improved with novel formulations (nanoparticulate systems, nanoliposomes) that increase the efficacy and stability of this peptide. Overall, these studies suggest that the synergism between nutraceuticals targeting the TGF-β1 pathway and current approved drugs might represent a novel pharmacological approach for reverting cognitive deficits in AD patients.

Combined prenatal Lactobacillus reuteri and ω-3 supplementation synergistically modulates DNA methylation in neonatal T helper cells

Background

Environmental exposures may alter DNA methylation patterns of T helper cells. As T helper cells are instrumental for allergy development, changes in methylation patterns may constitute a mechanism of action for allergy preventive interventions. While epigenetic effects of separate perinatal probiotic or ω-3 fatty acid supplementation have been studied previously, the combined treatment has not been assessed. We aimed to investigate epigenome-wide DNA methylation patterns from a sub-group of children in an on-going randomised double-blind placebo-controlled allergy prevention trial using pre- and postnatal combined Lactobacillus reuteri and ω-3 fatty acid treatment. To this end, > 866000 CpG sites (MethylationEPIC 850K array) in cord blood CD4+ T cells were examined in samples from all four study arms (double-treatment: n = 18, single treatments: probiotics n = 16, ω-3 n = 15, and double placebo: n = 14). Statistical and bioinformatic analyses identified treatment-associated differentially methylated CpGs and genes, which were used to identify putatively treatment-induced network modules. Pathway analyses inferred biological relevance, and comparisons were made to an independent allergy data set.

Results

Comparing the active treatments to the double placebo group, most differentially methylated CpGs and genes were hypermethylated, possibly suggesting induction of transcriptional inhibition. The double-treated group showed the largest number of differentially methylated CpGs, of which many were unique, suggesting synergy between interventions. Clusters within the double-treated network module consisted of immune-related pathways, including T cell receptor signalling, and antigen processing and presentation, with similar pathways revealed for the single-treatment modules. CpGs derived from differential methylation and network module analyses were enriched in an independent allergy data set, particularly in the double-treatment group, proposing treatment-induced DNA methylation changes as relevant for allergy development.

Conclusion

Prenatal L. reuteri and/or ω-3 fatty acid treatment results in hypermethylation and affects immune- and allergy-related pathways in neonatal T helper cells, with potentially synergistic effects between the interventions and relevance for allergic disease. Further studies need to address these findings on a transcriptional level, and whether the results associate to allergy development in the children. Understanding the role of DNA methylation in regulating effects of perinatal probiotic and ω-3 interventions may provide essential knowledge in the development of efficacious allergy preventive strategies.

Trial registration ClinicalTrials.gov, ClinicalTrials.gov-ID: NCT01542970. Registered 27th of February 2012—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT01542970.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01115-4.

Strategies and Future Opportunities for the Prevention, Diagnosis, and Management of Cow Milk Allergy

The prevalence of food allergy has increased over the last 20-30 years, including cow milk allergy (CMA) which is one of the most common causes of infant food allergy. International allergy experts met in 2019 to discuss broad topics in allergy prevention and management of CMA including current challenges and future opportunities. The highlights of the meeting combined with recently published developments are presented here. Primary prevention of CMA should start from pre-pregnancy with a focus on a healthy lifestyle and food diversity to ensure adequate transfer of inhibitory IgG- allergen immune complexes across the placenta especially in mothers with a history of allergic diseases and planned c-section delivery. For non-breastfed infants, there is controversy about the preventive role of partially hydrolyzed formulae (pHF) despite some evidence of health economic benefits among those with a family history of allergy. Clinical management of CMA consists of secondary prevention with a focus on the development of early oral tolerance. The use of extensive Hydrolysate Formulae (eHF) is the nutrition of choice for the majority of non-breastfed infants with CMA; potentially with pre-, probiotics and LCPUFA to support early oral tolerance induction. Future opportunities are, among others, pre- and probiotics supplementation for mothers and high-risk infants for the primary prevention of CMA. A controlled prospective study implementing a step-down milk formulae ladder with various degrees of hydrolysate is proposed for food challenges and early development of oral tolerance. This provides a more precise gradation of milk protein exposure than those currently recommended.

Examining Associations Between Dietary Inflammatory Index in Pregnancy, Pro-inflammatory Cytokine and Chemokine Levels at Birth, and Offspring Asthma and/or Wheeze by Age 4 Years

BACKGROUND

Few studies have demonstrated associations between maternal dietary inflammatory index (DII) during pregnancy and offspring asthma and/or wheeze.

OBJECTIVE

The study aimed to assess associations between maternal DII during pregnancy and 1) offspring cord sera pro-inflammatory cytokines (interleukin [IL]-1β, IL-4, IL-6, IL-10, tumor necrosis factor-α) and chemokines (IL-8, monocyte chemoattractant protein-1) at birth and 2) offspring asthma and/or wheeze at age 4 years.

DESIGN

The Healthy Start study is a prospective prebirth longitudinal study that recruited pregnant women in Denver, Colorado and tracked their offspring.

PARTICIPANTS AND SETTING

This study used data from 1228 mother-child dyads enrolled in the Healthy Start study. Pregnant women were recruited in Denver, Colorado, between 2009 and 2014, and offspring tracked until age 4 years.

MAIN OUTCOME MEASURES

Cord sera cytokines and chemokines were analyzed with multiplex panel immunoassays. Offspring diagnosis of asthma and/or wheeze by age 4 years was extracted from electronic medical records.

STATISTICAL ANALYSES PERFORMED

Unadjusted and adjusted linear and logistic regression models were used to assess associations. Covariates included factors such as nulliparity, race/ethnicity, gestational smoking, and maternal history of asthma.

RESULTS

Unadjusted analysis showed that increasing maternal DII scores were associated with increased odds of child asthma and/or wheeze by 4 years (odds ratio = 1.17; 95% CI: 1.07-1.27), but the association was attenuated and no longer statistically significant in the adjusted model (odds ratio = 1.15; 95% CI: 0.99-1.33). There were no significant associations between DII scores and cord sera cytokine or chemokine levels.

CONCLUSIONS

The study showed that the inflammatory profile of the maternal diet was not associated with cytokines and chemokine levels at birth. The results suggested that a more inflammatory maternal diet was associated with increased odds of offspring asthma and/or wheeze by age 4 years, which could be considered of clinical relevance but the finding was not statistically significant at the .05 level.

Perinatal and Early-Life Nutrition, Epigenetics, and Allergy

Epidemiological studies have shown a dramatic increase in the incidence and the prevalence of allergic diseases over the last several decades. Environmental triggers including risk factors (e.g., pollution), the loss of rural living conditions (e.g., farming conditions), and nutritional status (e.g., maternal, breastfeeding) are considered major contributors to this increase. The influences of these environmental factors are thought to be mediated by epigenetic mechanisms which are heritable, reversible, and biologically relevant biochemical modifications of the chromatin carrying the genetic information without changing the nucleotide sequence of the genome. An important feature characterizing epigenetically-mediated processes is the existence of a time frame where the induced effects are the strongest and therefore most crucial. This period between conception, pregnancy, and the first years of life (e.g., first 1000 days) is considered the optimal time for environmental factors, such as nutrition, to exert their beneficial epigenetic effects. In the current review, we discussed the impact of the exposure to bacteria, viruses, parasites, fungal components, microbiome metabolites, and specific nutritional components (e.g., polyunsaturated fatty acids (PUFA), vitamins, plant- and animal-derived microRNAs, breast milk) on the epigenetic patterns related to allergic manifestations. We gave insight into the epigenetic signature of bioactive milk components and the effects of specific nutrition on neonatal T cell development. Several lines of evidence suggest that atypical metabolic reprogramming induced by extrinsic factors such as allergens, viruses, pollutants, diet, or microbiome might drive cellular metabolic dysfunctions and defective immune responses in allergic disease. Therefore, we described the current knowledge on the relationship between immunometabolism and allergy mediated by epigenetic mechanisms. The knowledge as presented will give insight into epigenetic changes and the potential of maternal and post-natal nutrition on the development of allergic disease.

Long-Chain Polyunsaturated Fatty Acids (LCPUFAs) and the Developing Immune System: A Narrative Review

The immune system is complex: it involves many cell types and numerous chemical mediators. An immature immune response increases susceptibility to infection, whilst imbalances amongst immune components leading to loss of tolerance can result in immune-mediated diseases including food allergies. Babies are born with an immature immune response. The immune system develops in early life and breast feeding promotes immune maturation and protects against infections and may protect against allergies. The long-chain polyunsaturated fatty acids (LCPUFAs) arachidonic acid (AA) and docosahexaenoic acid (DHA) are considered to be important components of breast milk. AA, eicosapentaenoic acid (EPA) and DHA are also present in the membranes of cells of the immune system and act through multiple interacting mechanisms to influence immune function. The effects of AA and of mediators derived from AA are often different from the effects of the n-3 LCPUFAs (i.e., EPA and DHA) and of mediators derived from them. Studies of supplemental n-3 LCPUFAs in pregnant women show some effects on cord blood immune cells and their responses. These studies also demonstrate reduced sensitisation of infants to egg, reduced risk and severity of atopic dermatitis in the first year of life, and reduced persistent wheeze and asthma at ages 3 to 5 years, especially in children of mothers with low habitual intake of n-3 LCPUFAs. Immune markers in preterm and term infants fed formula with AA and DHA were similar to those in infants fed human milk, whereas those in infants fed formula without LCPUFAs were not. Infants who received formula plus LCPUFAs (both AA and DHA) showed a reduced risk of allergic disease and respiratory illness than infants who received standard formula. Studies in which infants received n-3 LCPUFAs report immune differences from controls that suggest better immune maturation and they show lower risk of allergic disease and respiratory illness over the first years of life. Taken together, these findings suggest that LCPUFAs play a role in immune development that is of clinical significance, particularly with regard to allergic sensitisation and allergic manifestations including wheeze and asthma.

The Impacts of Fish Oil and/or Probiotic Intervention on Low-Grade Inflammation, IGFBP-1 and MMP-8 in Pregnancy: A Randomized, Placebo-Controlled, Double-Blind Clinical Trial

Background: We investigated the impact of fish oil and/or probiotics on serum and vaginal inflammatory and metabolic proteins and their relation to the onset of gestational diabetes mellitus (GDM). Methods: Overweight/obese pregnant women received fish oil + placebo, probiotics + placebo, fish oil + probiotics or placebo + placebo from early pregnancy until six months postpartum (fish oil: 1.9 g docosahexaenoic acid and 0.22 g eicosapentaenoic acid; probiotics: Lactobacillus rhamnosus HN001 and Bifidobacterium animalis ssp. lactis 420, 10¹⁰ colony-forming units each). Serum high sensitivity C-reactive protein (hsCRP) and serum/vaginal (s/v) phosphorylated insulin-like growth factor binding-protein-1 (phIGFBP-1), IGFBP-1 and matrix metalloproteinase 8 (MMP-8) were analyzed. GDM was diagnosed according to 2 h 75 g OGTT. Results: The intervention had no impact on the change in proteins during pregnancy. Nevertheless, s-MMP-8 decreased and s-IGFBP-1 increased more in obese than in overweight women in the fish oil + probiotics group, while a decrease in s-MMP-8 was seen in obese women and an increase was seen in overweight women in the probiotics + placebo group. The late pregnancy s-phIGFBP-1 was higher in women who developed GDM in fish oil + probiotics-group compared to fish oil + placebo-group. The concentrations of s-phIGFBP-1 (635.9 ± 315.3 ng/mL vs. 753.2 ± 335.1 ng/mL, p = 0.005) and s-IGFBP-1 (3.78 ± 0.72 ng/mL vs. 3.96 ± 0.69 ng/mL, p = 0.042) were lower in early pregnancy in women who developed GDM than in women remaining healthy. Conclusions: The intervention per se had no impact on the proteins, but obesity and GDM may modify the effect. IGFBPs may affect the development of GDM.

Allergy Modulation by N-3 Long Chain Polyunsaturated Fatty Acids and Fat Soluble Nutrients of the Mediterranean Diet

The Mediterranean diet, containing valuable nutrients such as n-3 long chain poly-unsaturated fatty acids (LCPUFAs) and other fat-soluble micronutrients, is known for its health promoting and anti-inflammatory effects. Its valuable elements might help in the battle against the rising prevalence of non-communicable diseases (NCD), including the development of allergic diseases and other (chronic) inflammatory diseases. The fat fraction of the Mediterranean diet contains bioactive fatty acids but can also serve as a matrix to dissolve and increase the uptake of fat-soluble vitamins and phytochemicals, such as luteolin, quercetin, resveratrol and lycopene with known immunomodulatory and anti-inflammatory capacities. Especially n-3 LCPUFAs such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) derived from marine oils can target specific receptors or signaling cascades, act as eicosanoid precursors and/or alter membrane fluidity and lipid raft formation, hereby exhibiting anti-inflammatory properties. Beyond n-3 LCPUFAs, fat-soluble vitamins A, D, E, and K1/2 have the potential to affect pro-inflammatory signaling cascades by interacting with receptors or activating/inhibiting signaling proteins or phosphorylation in immune cells (DCs, T-cells, mast cells) involved in allergic sensitization or the elicitation/effector phase of allergic reactions. Moreover, fat-soluble plant-derived phytochemicals can manipulate signaling cascades, mostly by interacting with other receptors or signaling proteins compared to those modified by fat-soluble vitamins, suggesting potential additive or synergistic actions by applying a combination of these nutrients which are all part of the regular Mediterranean diet. Research concerning the effects of phytochemicals such as polyphenols has been hampered due to their poor bio-availability. However, their solubility and uptake are improved by applying them within the dietary fat matrix. Alternatively, they can be prepared for targeted delivery by means of pharmaceutical approaches such as encapsulation within liposomes or even unique nanoparticles. This review illuminates the molecular mechanisms of action and possible immunomodulatory effects of n-3 LCPUFAs and fat-soluble micronutrients from the Mediterranean diet in allergic disease development and allergic inflammation. This will enable us to further appreciate how to make use of the beneficial effects of n-3 LCPUFAs, fat-soluble vitamins and a selection of phytochemicals as active biological components in allergy prevention and/or symptom reduction.

Maternal dietary inflammatory potential and quality are associated with offspring asthma risk over 10-year follow-up: the Lifeways Cross-Generation Cohort Study

BACKGROUND

Asthma is the most common childhood chronic health condition. Maternal antenatal diet has been associated with offspring asthma risk, but studies investigating maternal whole diet quality and inflammatory potential with long-term offspring follow-up (>5 y) are rare.

OBJECTIVES

We aimed to elucidate these associations in a prospective cohort study in Ireland.

METHODS

Early pregnancy diets were assessed using a validated FFQ from which energy-adjusted Dietary Inflammatory Index (E-DII) and Healthy Eating Index (HEI)-2015 scores were computed. Doctor-diagnosed offspring asthma status (general practitioner or parent reports) for the first 10 y of life was collected at 3-y, 5-y, and 9-y follow-up. A total of 862 mother-child pairs with information on maternal diet and ≥1 offspring asthma data points were included. The longitudinal associations between maternal E-DII and HEI scores and offspring asthma status were assessed using generalized estimating equations.

RESULTS

Cumulative offspring asthma incidence was 21% over the 10-y period. In the main models, adjusted for maternal lifestyle and sociodemographic factors, a higher E-DII score, indicating a more proinflammatory diet, was associated with higher risk of offspring asthma (OR: 1.35; 95% CI: 1.10, 1.65; per 1-SD score increment), whereas a higher HEI-2015 score, indicating better dietary quality, was associated with lower risk (OR: 0.77; 95% CI: 0.64, 0.93) (both P < 0.01). Results persisted with further adjustment for childhood factors (e.g., breastfeeding, diet, and childcare attendance) and parental asthma history. Similar associations were observed when E-DII and HEI-2015 scores were modeled in quartiles (both P-trend < 0.05). Associations for HEI-2015 were attenuated after adjustment for E-DII, suggesting the importance of anti-inflammatory pathways.

CONCLUSIONS

Our results suggest that a proinflammatory and low-quality diet during pregnancy is associated with a higher risk of offspring asthma. Pending confirmation from other studies, optimizing these aspects of maternal diet can be a promising strategy for reducing childhood asthma risk. This prospective observational study was registered at the ISRCTN Registry as ISRCTN16537904.

Associations of Breast Milk Microbiota, Immune Factors, and Fatty Acids in the Rat Mother-Offspring Pair

The present study aimed to analyze the rat breast milk profile of fatty acids (FA), immunoglobulins (Ig), microbiota, and their relationship, and to further assess their associations in the mother–offspring pair. Dams were monitored during the three weeks of gestation, allowed to deliver at term, and followed during two weeks of lactation. At the end of the study, milk was obtained from the dams for the analysis of fatty acids, microbiota composition, immunoglobulins, and cytokines. Moreover, the cecal content and plasma were obtained from both the dams and pups to study the cecal microbiota composition and the plasmatic levels of fatty acids, immunoglobulins, and cytokines. Rat breast milk lipid composition was ~65% saturated FA, ~15% monounsaturated FA, and ~20% polyunsaturated FA. Moreover, the proportions of IgM, IgG, and IgA were ~2%, ~88%, and ~10%, respectively. Breast milk was dominated by members of Proteobacteria, Firmicutes, and Bacteroidetes phyla. In addition, forty genera were shared between the milk and cecal content of dams and pups. The correlations performed between variables showed, for example, that all IgGs subtypes correlated between the three compartments, evidencing their association in the mother-milk-pup line. We established the profile of FA, Ig, and the microbiota composition of rat breast milk. Several correlations in these variables evidenced their association through the mother-milk-pup line. Therefore, it would be interesting to perform dietary interventions during pregnancy and/or lactation that influence the quality of breast milk and have an impact on the offspring.

NCM 1921, a Mixture of Several Ingredients, Including Fatty Acids and Choline, Attenuates Atopic Dermatitis in 1-Chloro-2,4-Dinitrobenzene-Treated NC/Nga Mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease in humans. In this study, we evaluated the effects of a mixture (NCM 1921) of omega-3 butter, omega-3 beef tallow oil, omega-3 lard oil, caprylic acid, lauric acid, choline, and Fe on AD in 1-chloro-2,4-dinitrobenzene (DNCB)-treated NC/Nga mice. NCM 1921 significantly ameliorated the macroscopic and microscopic signs and reduced skin thickness and mast cell incorporation in the skin lesions of mice with DNCB-induced AD. Furthermore, it reduced serum immunoglobulin E levels; reduced the number of IgE-producing B cells, peripheral blood mononuclear cells, white blood cells, and differential white blood cells; and increased the number of lymphocytes. NCM 1921 normalized the total cell number in dorsal skin tissue, the axillary lymph node, and spleen following DNCB exposure and reduced the number of CD23+/B220+ cells in the axillary lymph node and CD3+ cells in dorsal skin tissue. Moreover, it reduced the levels of interleukin (IL)-4 and IL-13 but increased the levels of interferon-γ in anti-CD3–stimulated splenocytes. Immunohistofluorescence staining showed that NCM 1921 treatment significantly increased claudin1, filaggrin, and Sirt1 protein expressions in AD skin lesions. These results suggest that NCM 1921 could be a valuable remedy for the treatment of AD.

Prenatal oxidative balance and risk of asthma and allergic disease in adolescence

BACKGROUND

Fetal oxidative balance (achieved when protective prenatal factors counteract sources of oxidative stress) might be critical for preventing asthma and allergic disease.

OBJECTIVE

We examined prenatal intakes of hypothesized protective nutrients (including antioxidants) in conjunction with potential sources of oxidative stress in models of adolescent asthma and allergic disease.

METHODS

We used data from 996 mother-child pairs in Project Viva. Exposures of interest were maternal prepregnancy body mass index and prenatal nutrients (energy-adjusted intakes of vitamins D, C, and E; β-carotene; folate; choline; and n-3 and n-6 polyunsaturated fatty acids [PUFAs]), air pollutant exposures (residence-specific third-trimester black carbon or particulate matter with a diameter of less than 2.5 μm [PM2.5]), acetaminophen, and smoking. Outcomes were offspring's current asthma, allergic rhinitis, and allergen sensitization at a median age of 12.9 years. We performed logistic regression. Continuous exposures were log-transformed and modeled as z scores.

RESULTS

We observed protective associations for vitamin D (odds ratio [OR], 0.69 [95% CI, 0.53-0.89] for allergic rhinitis), the sum of the n-3 PUFAs eicosapentaenoic acid and docosahexaenoic acid (OR, 0.81 [95% CI, 0.66-0.99] for current asthma), and the n-3 PUFA α-linolenic acid (OR, 0.78 [95% CI, 0.64-0.95] for allergen sensitization and OR, 0.80 [95% CI 0.65-0.99] for current asthma). Black carbon and PM2.5 were associated with an approximately 30% increased risk for allergen sensitization. No multiplicative interactions were observed for protective nutrient intakes with sources of oxidative stress.

CONCLUSIONS

We identified potential protective prenatal nutrients (vitamin D and n-3 PUFAs), as well as adverse prenatal pro-oxidant exposures that might alter the risk of asthma and allergic disease into adolescence.

Elevated Gestational IL-13 During Fetal Development Is Associated With Hyperactivity and Inattention in Eight-Year-Old Children

Maternal immune activation (MIA) during fetal development leads to behavioral and psychological disorders in the offspring. Concomitantly, insufficient supply of polyunsaturated fatty acids (PUFAs) is suspected to contribute to early neuronal maldevelopment due to the immune modulatory capabilities of PUFAs. However, human data are missing considering both of these aspects and their impact on children's behavioral outcomes. In line, this study aimed to elucidate the influence of gestational cytokines and PUFA-containing lipids during late pregnancy on behavioral sequelae in childhood, particularly focusing on an immune activation shaped by a history of maternal atopic diseases instead of a pathogen-mediated immune response. Based on the prospective mother-child cohort LINA we assessed the unstimulated blood cytokine profiles and concentrations of PUFA-containing lipids of 293 mothers at the 34th week of pregnancy. Maternal history of atopic diseases was obtained from questionnaires and behavior in eight-year-old children was assessed by the standardized Strength and Difficulties Questionnaires (SDQ) generating scores for hyperactivity/inattention, emotional symptoms, conduct problems, and peer relationship problems. Elevated IL-13 increased the risk for the child to show behavioral difficulties, in particular, hyperactive/inattentive behavior [adj. OR (95% CI): 2.47 (1.51-4.02), n = 255 vs. 38] at the age of eight years. Although the presence of maternal atopic dermatitis (AD) was associated with increased gestational IL-13 concentrations [adj. MR (95% CI): 1.17 (1.04-1.32)], no effect on children's behavioral difficulties was observed. However, a decrease in the PUFA containing lipid species PC aa C38:6 was not only associated with an increased gestational IL-13 concentration but also mediated the indirect effect of low PC aa C38:6 concentrations on children's abnormal behavior independent of maternal AD. We additionally assessed whether maternal IL-13 and PC aa C38:6 concentrations translate their effect by altering children's cord blood PC aa C38:6 and IL-13. While also the children's cord blood IL-13 was related to children's behavior, no effect of children's PC aa C38:6 was observed. This is the first study demonstrating that elevated gestational IL-13 increases the risk for children to develop behavioral difficulties. Analyses suggest that a reduced supply of gestational PC aa C38:6 contributes to elevated gestational IL-13 leading to behavioral sequelae in the offspring.

Effects on Animal Health and Immune Function

The concept of developmental programming was established using epidemiologic studies that investigated chronic illnesses in humans, such as coronary heart disease and hypertension. In livestock species, the impacts of developmental programming are important for production and welfare reasons and are used as research models for human and other animal species. Dams should be in adequate nutritional status to ensure optimal nutrient supply for fetal growth, including development of their immune system. Beef and dairy cows with insufficient nutrient intake during gestation produce calves with reduced immunity against diseases, such as scours, respiratory disease, and mastitis.

[Reasons for the development of allergies in children]

Allergies are one of the most common chronic diseases in childhood, contributing to a tremendous medical and economical burden in health care systems of most industrialized countries. The development of allergies is dependent on a complex interaction of-among others-environmental factors, nutrition, genetic and epigenetic mechanisms as well as the microbiome. These diverse factors can influence early life immune regulation including innate and adaptive immune mechanisms in a complex fashion. In case of any Childhood allergies have increased significantly in past decades. In addition to environmental factors and nutrition, genetic and epigenetic mechanisms as well as the microbiome of children play an important role. Of relevance is the way in which these diverse factors influence early immune development of the innate and adaptive immune systems of children. Their complex regulation is decisive for whether or not a child develops an allergy that manifests in most cases as atopic dermatitis, bronchial asthma, or allergic rhino conjunctivitis, or whether a child develops an immune tolerance. These influences can begin prenatally, already setting the course for later immune system development and occurrence of disease.

Role of dietary lipids in food allergy

The prevalence of food allergy is raising in industrialized countries, but the mechanisms behind this increased incidence are not fully understood. Environmental factors are believed to play a role in allergic diseases, including lifestyle influences, such as diet. There is a close relationship between allergens and lipids, with many allergenic proteins having the ability to bind lipids. Dietary lipids exert pro-inflammatory or anti-inflammatory functions on cells of the innate immunity and influence antigen presentation to cells of the adaptive immunity. In addition to modifying the immunostimulating properties of proteins, lipids also alter their digestibility and intestinal absorption, changing allergen bioavailability. This study provides an overview of the role of dietary lipids in food allergy, taking into account epidemiological information, as well as results of mechanistic investigations using in vivo, ex vivo and in vitro models. The emerging link among high-fat diets, obesity, and allergy is also discussed.

Maternal triacylglycerol signature and risk of food allergy in offspring

BACKGROUND

The prevalence of IgE-mediated food allergy (FA) is increasing worldwide, but the underlying mechanisms are poorly understood.

OBJECTIVE

We sought to examine the role of maternal lipidomic profiles in risk of FA development in offspring and to investigate the potential modification effects by timing of first solid-food introduction.

METHODS

This report included 1068 mother-child dyads from the Boston Birth Cohort. Maternal lipid metabolites in plasma were assessed by using liquid chromatography tandem mass spectrometry. Food sensitization (FS) was defined as a specific IgE level of 0.35 kU/L or greater to any of the 8 common food allergens determined by using ImmunoCAP. FA was defined based on FS, clinical symptoms, and food avoidance. Logistic regression was applied to analyze associations between maternal metabolites and risk of FS and FA in offspring and to explore potential effect modifications.

RESULTS

Of the 1068 children, 411 had FS, and 132 had FA. Among the 209 metabolites, maternal triacylglycerols (TAGs) of shorter carbon chains and fewer double bonds were associated with greater risk of FA, whereas TAGs of longer carbon chains and more double bonds were significantly associated with lower risk of FA in offspring. These associations were stronger in children with delayed solid-food introduction (≥7 months of age) than those with earlier solid-food introduction (P = .010 for interaction between the maternal TAG score and timing of solid-food introduction). No significant association was found for FS.

CONCLUSION

This is the first study to demonstrate a link between maternal TAGs and risk of FA in offspring and potential risk modification by timing of solid-food introduction.

Omega-3 fatty acid addition during pregnancy

BACKGROUND

Higher intakes of foods containing omega-3 long-chain polyunsaturated fatty acids (LCPUFA), such as fish, during pregnancy have been associated with longer gestations and improved perinatal outcomes. This is an update of a review that was first published in 2006.

OBJECTIVES

To assess the effects of omega-3 LCPUFA, as supplements or as dietary additions, during pregnancy on maternal, perinatal, and neonatal outcomes and longer-term outcomes for mother and child.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (16 August 2018), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing omega-3 fatty acids (as supplements or as foods, stand-alone interventions, or with a co-intervention) during pregnancy with placebo or no omega-3, and studies or study arms directly comparing omega-3 LCPUFA doses or types. Trials published in abstract form were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data, assessed risk of bias in trials and assessed quality of evidence for prespecified birth/infant, maternal, child/adult and health service outcomes using the GRADE approach.

MAIN RESULTS

In this update, we included 70 RCTs (involving 19,927 women at low, mixed or high risk of poor pregnancy outcomes) which compared omega-3 LCPUFA interventions (supplements and food) compared with placebo or no omega-3. Overall study-level risk of bias was mixed, with selection and performance bias mostly at low risk, but there was high risk of attrition bias in some trials. Most trials were conducted in upper-middle or high-income countries; and nearly half the trials included women at increased/high risk for factors which might increase the risk of adverse maternal and birth outcomes.Preterm birth < 37 weeks (13.4% versus 11.9%; risk ratio (RR) 0.89, 95% confidence interval (CI) 0.81 to 0.97; 26 RCTs, 10,304 participants; high-quality evidence) and early preterm birth < 34 weeks (4.6% versus 2.7%; RR 0.58, 95% CI 0.44 to 0.77; 9 RCTs, 5204 participants; high-quality evidence) were both lower in women who received omega-3 LCPUFA compared with no omega-3. Prolonged gestation > 42 weeks was probably increased from 1.6% to 2.6% in women who received omega-3 LCPUFA compared with no omega-3 (RR 1.61 95% CI 1.11 to 2.33; 5141 participants; 6 RCTs; moderate-quality evidence).For infants, there was a possibly reduced risk of perinatal death (RR 0.75, 95% CI 0.54 to 1.03; 10 RCTs, 7416 participants; moderate-quality evidence: 62/3715 versus 83/3701 infants) and possibly fewer neonatal care admissions (RR 0.92, 95% CI 0.83 to 1.03; 9 RCTs, 6920 participants; moderate-quality evidence - 483/3475 infants versus 519/3445 infants). There was a reduced risk of low birthweight (LBW) babies (15.6% versus 14%; RR 0.90, 95% CI 0.82 to 0.99; 15 trials, 8449 participants; high-quality evidence); but a possible small increase in large-for-gestational age (LGA) babies (RR 1.15, 95% CI 0.97 to 1.36; 6 RCTs, 3722 participants; moderate-quality evidence, for omega-3 LCPUFA compared with no omega-3. Little or no difference in small-for-gestational age or intrauterine growth restriction (RR 1.01, 95% CI 0.90 to 1.13; 8 RCTs, 6907 participants; moderate-quality evidence) was seen.For the maternal outcomes, there is insufficient evidence to determine the effects of omega-3 on induction post-term (average RR 0.82, 95% CI 0.22 to 2.98; 3 trials, 2900 participants; low-quality evidence), maternal serious adverse events (RR 1.04, 95% CI 0.40 to 2.72; 2 trials, 2690 participants; low-quality evidence), maternal admission to intensive care (RR 0.56, 95% CI 0.12 to 2.63; 2 trials, 2458 participants; low-quality evidence), or postnatal depression (average RR 0.99, 95% CI 0.56 to 1.77; 2 trials, 2431 participants; low-quality evidence). Mean gestational length was greater in women who received omega-3 LCPUFA (mean difference (MD) 1.67 days, 95% CI 0.95 to 2.39; 41 trials, 12,517 participants; moderate-quality evidence), and pre-eclampsia may possibly be reduced with omega-3 LCPUFA (RR 0.84, 95% CI 0.69 to 1.01; 20 trials, 8306 participants; low-quality evidence).For the child/adult outcomes, very few differences between antenatal omega-3 LCPUFA supplementation and no omega-3 were observed in cognition, IQ, vision, other neurodevelopment and growth outcomes, language and behaviour (mostly low-quality to very low-quality evidence). The effect of omega-3 LCPUFA on body mass index at 19 years (MD 0, 95% CI -0.83 to 0.83; 1 trial, 243 participants; very low-quality evidence) was uncertain. No data were reported for development of diabetes in the children of study participants.

AUTHORS' CONCLUSIONS

In the overall analysis, preterm birth < 37 weeks and early preterm birth < 34 weeks were reduced in women receiving omega-3 LCPUFA compared with no omega-3. There was a possibly reduced risk of perinatal death and of neonatal care admission, a reduced risk of LBW babies; and possibly a small increased risk of LGA babies with omega-3 LCPUFA.For our GRADE quality assessments, we assessed most of the important perinatal outcomes as high-quality (e.g. preterm birth) or moderate-quality evidence (e.g. perinatal death). For the other outcome domains (maternal, child/adult and health service outcomes) GRADE ratings ranged from moderate to very low, with over half rated as low. Reasons for downgrading across the domain were mostly due to design limitations and imprecision.Omega-3 LCPUFA supplementation during pregnancy is an effective strategy for reducing the incidence of preterm birth, although it probably increases the incidence of post-term pregnancies. More studies comparing omega-3 LCPUFA and placebo (to establish causality in relation to preterm birth) are not needed at this stage. A further 23 ongoing trials are still to report on over 5000 women, so no more RCTs are needed that compare omega-3 LCPUFA against placebo or no intervention. However, further follow-up of completed trials is needed to assess longer-term outcomes for mother and child, to improve understanding of metabolic, growth and neurodevelopment pathways in particular, and to establish if, and how, outcomes vary by different types of omega-3 LCPUFA, timing and doses; or by characteristics of women.

The impact of omega-3 fatty acid supplementation on glycemic control in patients with gestational diabetes: a systematic review and meta-analysis of randomized controlled studies

Background: Omega-3 fatty acid supplementation shows some treatment efficacy for gestational diabetes. This systematic review and meta-analysis is conducted to investigate the efficacy of omega-3 fatty acid supplementation for glycemic control in patients with gestational diabetes.Methods: The databases including PubMed, Embase, Web of science, EBSCO, and Cochrane Library databases are systematically searched for collecting the randomized controlled trials (RCTs) regarding the efficacy of omega-3 fatty acid versus placebo for gestational diabetes.Results: This meta-analysis has included seven RCTs. Compared with placebo group in patients with gestational diabetes, omega-3 fatty acids supplementation results in remarkably reduced fasting plasma glucose (FPG) (standard mean difference (std. MD) = -0.56; 95% confidence interval (CI) = -0.87 to -0.24; p = .0005), homeostatic model of assessment for insulin resistance (HOMA-IR) (std. MD = -0.52; 95% CI = -0.83 to -0.21; p = .001), but has no statistical impact on macrosomia (risk ratio (RR) = 0.48; 95% CI = 0.22-1.02; p = .06), newborns' hyperbilirubinemia (RR = 0.46; 95% CI = 0.19-1.10; p = .08), nitric oxide (NO) (std. MD = 0.17; 95% CI = -0.64-0.98; p = .68), preterm delivery (RR = 1.75; 95% CI = 0.08-3.80; p=.16) and preeclampsia (RR =0.74; 95% CI = 0.26-2.16; p = .59). However, notably decreased high sensitivity C-reactive protein (hs-CRP) is revealed after omega-3 fatty acids supplementation (std. MD = -1.14; 95% CI = -2.0 to -0.29; p = .009).Conclusions: Omega-3 fatty acids supplementation can provide substantially beneficial effects on glycemic control and inflammatory response for gestational diabetes.

Effects of supplementation with omega-3 fatty acids during pregnancy on asthma or wheeze of children: a systematic review and meta-analysis

Objective: To evaluate the effects of omega-3 fatty acids during pregnancy on the incidence of wheeze and asthma of children.Methods: A search was conducted in PubMed, Embase and CENTRAL until September 2017. Randomized controlled trials (RCTs) assessing the effects of omega-3 fatty acids during pregnancy on wheeze/asthma of children were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. Outcomes of relative risks were pooled. Subgroup analyses were conducted.Results: Seven RCTs involving 2047 children were included. The pooled data revealed the supplementation during pregnancy reduced the incidence of wheeze/asthma (risk ratio (RR) 0.81; 95% CI 0.66-0.99; p .04), but the incidence of childhood asthma was not significantly reduced (RR 0.89; 95% CI 0.67-1.17; p .40). Subgroup analyses indicated that the risk of childhood wheeze/asthma was significantly decreased (1) in studies located in Europe (RR 0.67 95% CI 0.51- 0.88), (2) in children whose first-degree relatives were diagnosed with allergic disease (RR 0.65 95% CI 0.49-0.85), (3) when a dose of omega -3 fatty acids ≥2000 mg/d was applied (RR 0.61 95% CI 0.45-0.81), (4) in wheeze/asthma without sensitivity (RR 0.71 95% CI 0.54-0.94).Conclusion: The available low-quality evidence indicated that omega-3 fatty acids supplementation during pregnancy may reduce the incidence of wheeze/asthma of children, but incidence of asthma was not reduced after omega-3 fatty acids supplementation during pregnancy. More well-designed RCTs with large sample sizes need to be conducted to better understand the effectiveness of omega-3 fatty acids supplementation during pregnancy with asthma in childhood.

As You Eat It: Effects of Prenatal Nutrition on Asthma

Asthma most frequently develops early in life, and increased recognition of the role of lifestyle and environmental factors in asthma susceptibility raises the possibility that dietary exposures during pregnancy may influence the risk of asthma in offspring. This review discusses the latest evidence with regard to the effect of diet during pregnancy on childhood asthma risk, including potential mechanisms, outcomes of randomized clinical trials, and results from observational studies. Vitamin D and polyunsaturated fatty acid intake during pregnancy are highlighted as areas with large and growing bodies of literature to support a potential role in prenatal modulation of subsequent asthma risk. Several other nutritional interventions are under active investigation, and recommendations regarding dietary modifications during pregnancy will likely need to be personalized based on factors such as maternal smoking and genetic variants. Although nutrition during pregnancy is uniquely challenging to investigate, and definitive recommendations cannot be made without additional high-quality evidence and knowledge regarding long-term effects of interventions, the modifiable nature of the diet and sizeable potential reduction of morbidity supports ongoing research to determine how to optimize nutrition during pregnancy to prevent asthma in offspring.

Can Early Omega-3 Fatty Acid Exposure Reduce Risk of Childhood Allergic Disease?

A causal link between increased intake of omega-6 (n-6) polyunsaturated fatty acids (PUFAs) and increased incidence of allergic disease has been suggested. This is supported by biologically plausible mechanisms, related to the roles of eicosanoid mediators produced from the n-6 PUFA arachidonic acid. Fish and fish oils are sources of long chain omega-3 (n-3) PUFAs. These fatty acids act to oppose the actions of n-6 PUFAs particularly with regard to eicosanoid synthesis. Thus, n-3 PUFAs may protect against allergic sensitisation and allergic manifestations. Epidemiological studies investigating the association between maternal fish intake during pregnancy and allergic outcomes in infants/children of those pregnancies suggest protective associations, but the findings are inconsistent. Fish oil provision to pregnant women is associated with immunologic changes in cord blood. Studies performed to date indicate that provision of fish oil during pregnancy may reduce sensitisation to common food allergens and reduce prevalence and severity of atopic eczema in the first year of life, with a possible persistence until adolescence. A recent study reported that fish oil consumption in pregnancy reduces persistent wheeze and asthma in the offspring at ages 3 to 5 years. Eating oily fish or fish oil supplementation in pregnancy may be a strategy to prevent infant and childhood allergic disease.

Dietary primary prevention of allergic diseases in children: the Philippine guidelines

Allergic diseases, such as asthma, allergic rhinitis, eczema, and food allergy, are preventable diseases. Primary prevention strategies of allergic diseases have been in scrutiny. Effective prevention strategies maybe started prenatally, postnatally, during infancy, and even during childhood. These guidelines have been prepared by the Philippine Society of Allergy, Asthma and Immunology and the Philippine Society for Pediatric Gastroenterology, Hepatology and Nutrition. They aim to provide evidence-based recommendations for the dietary primary prevention of allergic diseases in children. The primary audience of these guidelines is all healthcare practitioners who manage patients with potential allergic conditions. These guidelines are based on an exhaustive review of evidences, mostly systematic reviews, randomized controlled trials, and cohort studies. However, there are still many gaps in the evidence of dietary primary prevention of allergic diseases.

Emerging Clinical Benefits of New-Generation Fat Emulsions in Preterm Neonates

Soybean oil-based intravenous fat emulsions (IVFEs) have been the predominant parenteral nutrition IVFE used in the United States for neonates over the past 45 years. Even though this emulsion has proven useful in supplying infants with energy for growth and essential fatty acids, there have been concerns over its composition in the development of several morbidities, ranging from sepsis to liver disease, bronchopulmonary dysplasia, and impaired neurodevelopment and growth. The exact mechanisms that drive these morbidities in preterm infants are multifactorial, but potential contributors include high ω-6 (n-6) fatty acid composition, low docosahexaenoic acid and antioxidant supplementation, and the presence of potentially harmful nonnutritive components (eg, phytosterols). To address these issues, new-generation IVFEs with various types and amounts of fat have been developed containing greater amounts of the medium-chain fatty acids, long-chain polyunsaturated fatty acid, docosahexaenoic acid, lower concentrations of ω-6 polyunsaturated fatty acids, supplemental vitamin E, and low or negligible amounts of phytosterols. This review examines the clinical outcomes associated with different morbidities of parenteral nutrition in neonates who have received either soybean oil-based or new-generation IVFEs and addresses whether the proposed benefits of new-generation IVFEs have improved outcomes in the neonatal population.

A Randomized Controlled Clinical Trial Investigating the Effects of Omega-3 Fatty Acids and Vitamin E Co-Supplementation on Biomarkers of Oxidative Stress, Inflammation and Pregnancy Outcomes in Gestational Diabetes

OBJECTIVES

Limited data are available for assessing the effects of omega-3 fatty acids and vitamin E co-supplementation on metabolic profiles and pregnancy outcomes in gestational diabetes (GDM). This study was designed to determine the effects of omega-3 fatty acids and vitamin E co-supplementation on biomarkers of oxidative stress, inflammation and pregnancy outcomes in women with GDM.

METHODS

This randomized, double-blind, placebo-controlled clinical trial was conducted in 60 patients with GDM who were not taking oral hypoglycemic agents. Patients were randomly allocated to intake either 1000 mg omega-3 fatty acids from flaxseed oil plus 400 IU vitamin E supplements (n=30) or placebo (n=30) for 6 weeks. Fasting blood samples were obtained from the women at the beginning of the study and after the 6-week intervention to quantify related markers.

RESULTS

After 6 weeks of intervention, omega-3 fatty acids and vitamin E co-supplementation, compared with the placebo, resulted in a significant rise in total antioxidant capacity (TAC) (+187.5±224.9 vs. -32.5±136.1 mmol/L; p<0.001); nitric oxide (NO) (+5.0±7.7 vs. -12.0±28.0 µmol/L; p=0.002) and a significant decrease in plasma malondialdehyde (MDA) concentrations (-0.1±0.9 vs. +0.6±1.4 µmol/L; p=0.03). Co-supplementation with omega-3 fatty acids and vitamin E showed no detectable changes in plasma glutathione and serum high-sensitivity C-reactive protein levels. Joint omega-3 fatty acids and vitamin E supplementation resulted in lower incidences of hyperbilirubinemia in newborns (10.3% vs. 33.3%; p=0.03).

CONCLUSIONS

Overall, omega-3 fatty acids and vitamin E co-supplementation for 6 weeks in women with GDM had beneficial effects on plasma TAC, MDA and NO and on the incidence of the newborns' hyperbilirubinemia.

The effect of n-3 LCPUFA supplementation on oxidative stress and inflammation in the placenta and maternal plasma during pregnancy

Pregnancy represents a state of heightened oxidative stress and inflammation, and these processes are further increased in pregnancy complications. The quality of the maternal diet is directly associated with maternal health and wellbeing, pregnancy and fetal outcomes, as well as the risk of pregnancy complications. Long chain polyunsaturated fatty acids (LCPUFAs) have significant potential to modify placental and fetal lipid environments and thereby modulate health outcomes. The omega-3 (n-3) LCPUFA in particular have been shown to exhibit both antioxidant and anti-inflammatory properties, and have potential therapeutic applications in reducing oxidative damage and inflammation during pregnancy. The purpose of this review is to provide an overview of our current understanding of the impact of maternal n-3 LCPUFA supplementation on oxidative stress and inflammation during pregnancy, with a particular focus on effects on the mother and the placenta.

Pregnancy and Infants' Outcome: Nutritional and Metabolic Implications

Pregnancy is a complex period of human growth, development, and imprinting. Nutrition and metabolism play a crucial role for the health and well-being of both mother and fetus, as well as for the long-term health of the offspring. Nevertheless, several biological and physiological mechanisms related to nutritive requirements together with their transfer and utilization across the placenta are still poorly understood. In February 2009, the Child Health Foundation invited leading experts of this field to a workshop to critically review and discuss current knowledge, with the aim to highlight priorities for future research. This paper summarizes our main conclusions with regards to maternal preconceptional body mass index, gestational weight gain, placental and fetal requirements in relation to adverse pregnancy and long-term outcomes of the fetus (nutritional programming). We conclude that there is an urgent need to develop further human investigations aimed at better understanding of the basis of biochemical mechanisms and pathophysiological events related to maternal-fetal nutrition and offspring health. An improved knowledge would help to optimize nutritional recommendations for pregnancy.

Fish oil supplementation during pregnancy and allergic respiratory disease in the adult offspring

BACKGROUND

Maternal supplementation with long-chain n-3 polyunsaturated fatty acids can have immunologic effects on the developing fetus through several anti-inflammatory pathways. However, there is limited knowledge of the long-term programming effects.

OBJECTIVE

In a randomized controlled trial from 1990 with 24 years of follow-up, our aim was to determine whether supplementation with 2.7 g of long-chain n-3 polyunsaturated fatty acids in pregnancy can reduce the risk of asthma in offspring and allergic respiratory disease.

METHODS

The randomized controlled trial included 533 women who were randomly assigned to receive fish oil during the third trimester of pregnancy, olive oil, or no oil in the ratio 2:1:1. The offspring were followed in a mandatory national prescription register, with complete follow-up for prescriptions related to the treatment of asthma and allergic rhinitis as primary outcomes. Furthermore, the offspring were invited to complete a questionnaire (74% participated) and attend a clinical examination (47% participated) at age 18 to 19 years.

RESULTS

In intention-to-treat analyses the probability of having had asthma medication prescribed was significantly reduced in the fish oil group compared with the olive oil group (hazard ratio, 0.54, 95% CI, 0.32-0.90; P = .02). The probability of having had allergic rhinitis medication prescribed was also reduced in the fish oil group compared with the olive oil group (hazard ratio, 0.70, 95% CI, 0.47-1.05; P = .09), but the difference was not statistically significant. Self-reported information collected at age 18 to 19 years supported these findings. No associations were detected with respect to lung function outcomes or allergic sensitization at 18 to 19 years of age.

CONCLUSION

Maternal supplementation with fish oil might have prophylactic potential for long-term prevention of asthma in offspring.

Nutritional control of immunity: Balancing the metabolic requirements with an appropriate immune function

The immune system is a highly integrated network of cells sensitive to a number of environmental factors. Interestingly, recent years have seen a dramatic increase in our understanding of how diet makes a crucial contribution to human health, affecting the immune system, secretion of adipocytokines and metabolic pathways. Recent experimental evidence indicates that diet and its components are able to profoundly influence immune responses, thus affecting the development of inflammatory and autoimmune diseases. This review aims to discuss some of the main topics concerning the impact of nutrients and their relative composition on immune cell development and function that may be particularly important for regulating the balance between inflammatory and tolerogenic processes. We also highlight the effects of diet on commensal bacteria and how changes in the composition of the microbiota alter intestinal and systemic immune homeostasis. Finally, we summarize the effects of dietary compounds on epigenetic mechanisms involved in the regulation of several immune related genes.

Maternal diet and its influence on the development of allergic disease

The early presentation of childhood allergies and the rise in their prevalence suggest that changes in early-life exposures may increase the predisposition. Very early-life exposures may act upon the developing foetal immune system and include infection, environmental tobacco smoke, other pollutants and nutrients provided via the mother. Three nutrients have come under close scrutiny: vitamin D, omega 3 polyunsaturated fatty acids (PUFAs) and folate (or the synthetic form, folic acid). Much of the data on these nutrients are observational although some randomised, placebo-controlled trials have been conducted with omega 3 PUFAs and one with vitamin D. Some studies with omega 3 PUFA supplements in pregnancy have demonstrated immunomodulatory effects on the neonate and a reduction in risk of early sensitisation to allergens. A few studies with omega 3 polyunsaturated fatty acid supplements in pregnancy have shown a reduction in proportion of children affected by allergic symptoms (food allergy) or in symptom severity (atopic dermatitis). Observational studies investigating the association of maternal vitamin D intake or maternal or neonatal vitamin D status have been inconsistent. One randomised, controlled trial of vitamin D supplementation during pregnancy did not show any significant effect on allergic outcome in the offspring. Studies investigating the association between maternal folic acid or folate intake or maternal or neonatal folate status and offspring risk of allergic disease have been equivocal. Further evidence is required to clarify whether increased intake of these nutrients during pregnancy influences allergic disease in the offspring. In the light of current evidence, mothers should not either increase or avoid consuming these nutrients to prevent or ameliorate allergic disease in their offspring. However, these essential nutrients each have important roles in foetal development. This is reflected in current government recommendations for intake of these nutrients by pregnant women.

Does allergy begin in utero?

It has been recognized for centuries that allergic disease runs in families, implying a role for genetic factors in determining individual susceptibility. More recently, a range of evidence shows that many of these genetic factors, together with in utero environmental exposures, lead to the development of allergic disease through altered immune and organ development. Environmental exposures during pregnancy including diet, nutrient intake and toxin exposures can alter the epigenome and interact with inherited genetic and epigenetic risk factors to directly and indirectly influence organ development and immune programming. Understanding of these factors will be essential in identifying at-risk individuals and possible development of therapeutic interventions for the primary prevention of allergic disease. In this review, we summarize the evidence that suggests allergic disease begins in utero, together with possible mechanisms for the effect of environmental exposures during pregnancy on allergic disease risk, including epigenetics.