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

Vitamin D binding protein correlate with estrogen increase after administration of human chorionic gonadotropin but do not affect ovulation, embryo, or pregnancy outcomes

Background

Vitamin D binding protein (DBP) might increase substantially after ovarian stimulation and hence could be associated with IVF/ICSI outcomes because it determines the fraction of free bioavailable 25(OH) vitamin D. In this study, we aim to determine whether DBP is associated with E2 level after ovarian stimulation and IVF/ICSI outcomes.

Design

Post-hoc analysis of a prospective observational cohort.

Setting

Single-center study.

Participants

2569 women receiving embryo transfer.

Intervention

None.

Main outcome measures

The main outcomes were oocyte and embryo quality as well as pregnancy outcomes.

Results

DBP concentration correlates with E2 on hCG day (=day of inducing ovulation with hCG; correlation coefficient r = 0.118, P<0.001) and E2 x-fold change to baseline level (r = 0.108, P<0.001). DBP is also positively correlated with total 25(OH)D (r = 0.689, R2 = 0.475, P<0.001) and inversely with free 25(OH)D (r=-0.424, R2=0.179, P<0.001), meaning that E2-stimulated DBP synthesis results in a decrease of free 25(OH)D during ovarian stimulation. However, such alteration does not affect IVF/ICSI outcomes when considering confounding factors, such as the number and quality of oocytes nor embryo quality as well as pregnancy outcomes.

Conclusion

DBP concentration correlates with the degree of E2 increase after ovarian stimulation. DBP is also positively correlated with total 25(OH)D and inversely with free 25(OH)D, suggesting that the proportion of free 25(OH)D decreases during ovarian stimulation caused by E2-stimulated DBP synthesis. However, such alteration does not affect clinical IVF/ICSI outcomes.

Primary Prevention of Allergy - Is It Feasible?

The allergy epidemic has been attributed to environmental influences related to urbanization and the modern lifestyle. In this regard, various theories exploring the role of microbes (hygiene, old friends, microbiota, and biodiversity hypotheses), and the epithelial barrier (epithelial, dual allergen exposure and vitamin D hypotheses) have been proposed. These hypotheses have guided clinical studies that led to the formulation of intervention strategies during the proposed window of opportunity dubbed as the "first thousand days." The most significant intervention is a paradigm shift from allergen avoidance to early introduction of allergenic foods, particularly egg and peanut, around 6 months of age for the prevention of food allergy. This recommendation has been adopted globally and included in allergy prevention guidelines. Other strategies with less robust clinical evidence include: encouraging a healthy balanced diet, rich in fish, during pregnancy; continuing allergenic food intake during pregnancy and lactation; vitamin D supplementation in pregnant women with asthma; discouraging social indications for caesarean section delivery; judicious use of antibiotics in early childhood; daily emollient use from birth in high risk babies; and avoiding cow's milk formula use in the first week of life. However, if early supplementation with cow's milk formula is required, continuing at least 10 mL of formula daily until age 2 months may be considered. Translating these strategies to public health and clinical practice is still a work in progress. Long-term population studies are crucial to assess the feasibility of these measures on allergy prevention.

A systematic review of quality and consistency of clinical practice guidelines on the primary prevention of food allergy and atopic dermatitis

Background and aims

With an increasing number of Clinical Practice Guidelines (CPGs) addressing primary prevention of food allergy and atopic dermatitis, it is timely to undertake a comprehensive assessment of the quality and consistency of recommendations and evaluation of their implementability in different geographical settings.

Methods

We systematically reviewed CPGs from 8 international databases and extensive website searches. Seven reviewers screened records in any language and then used the AGREE II and AGREE REX instruments to critically appraise CPGs published between January 2011 and April 2022.

Results

Our search identified 2138 relevant articles, of which 30 CPGs were eventually included. Eight (27%) CPGs were shortlisted based on our predefined quality criteria of achieving scores >70% in the "Scope and Purpose" and "Rigour of Development" domains of the AGREE II instrument. Among the shortlisted CPGs, scores on the "Applicability" domain were generally low, and only 3 CPGs rated highly in the "Implementability" domain of AGREE-REX, suggesting that the majority of CPGs fared poorly on global applicability. Recommendations on maternal diet and complementary feeding in infants were mostly consistent, but recommendations on use of hydrolysed formula and supplements varied considerably.

Conclusion

The overall quality of a CPG for Food Allergy and Atopic Dermatitis prevention did not correlate well with its global applicability. It is imperative that CPG developers consider stakeholders' preferences, local applicability, and adapt existing recommendations to each individual population and healthcare system to ensure successful implementation. There is a need for development of high-quality CPGs for allergy prevention outside of North America and Europe.

PROSPERO registration number

CRD42021265689.

Role of dietary fiber in promoting immune health-An EAACI position paper

Microbial metabolism of specific dietary components, such as fiber, contributes to the sophisticated inter-kingdom dialogue in the gut that maintains a stable environment with important beneficial physiological, metabolic, and immunological effects on the host. Historical changes in fiber intake may be contributing to the increase of allergic and hypersensitivity disorders as fiber-derived metabolites are evolutionarily hardwired into the molecular circuitry governing immune cell decision-making processes. In this review, we highlight the importance of fiber as a dietary ingredient, its effects on the microbiome, its effects on immune regulation, the importance of appropriate timing of intervention to target any potential window of opportunity, and potential mechanisms for dietary fibers in the prevention and management of allergic diseases. In addition, we review the human studies examining fiber or prebiotic interventions on asthma and respiratory outcomes, allergic rhinitis, atopic dermatitis, and overall risk of atopic disorders. While exposures, interventions, and outcomes were too heterogeneous for meta-analysis, there is significant potential for using fiber in targeted manipulations of the gut microbiome and its metabolic functions in promoting immune health.

Nip allergies in the Bub: a qualitative study for a public health approach to infant feeding for allergy prevention

OBJECTIVE

To identify a brand, key messages and resources to underpin a public health approach to food allergy prevention.

METHODS

A focus group design was used to explore perceptions and opinions of potential brands, infant feeding messages and resources for providing standardised food allergy prevention information. Focus groups were conducted in February 2018 using interview guides and were transcribed verbatim. A content analysis of the transcripts was undertaken using thematic analysis software. The University of Western Australia provided ethics approval: RA/4/20/4280.

RESULTS

Seven focus groups with 39 participants were conducted. Four slogans and styles of imagery were considered. 'Nip Allergies in the Bub' was the most favoured slogan and images of babies with food were most favoured. Participant feedback was sought regarding messages and supporting messages were considered important. Participants were consulted about useful resources and a website was identified.

CONCLUSIONS

Conducting focus groups assisted the selection of a brand, messages and resources to underpin a public health approach to implementing allergy prevention guidelines.

IMPLICATIONS FOR PUBLIC HEALTH

This is the first focus group research undertaken for food allergy prevention. Identification of a meaningful brand, key messages and resources will support a public health approach to implementing allergy prevention guidelines.

A new partially hydrolyzed whey-based follow-on formula with age-adapted protein content supports healthy growth during the first year of life

BACKGROUND

Standard infant formulae often have higher protein content than breastmilk in order to compensate for potentially lower digestibility; excess protein intake may promote adverse effects later in life. A new partially hydrolyzed whey-based (pHF-W) follow-on formula (FoF) with age-adapted protein content was evaluated for growth and gastrointestinal (GI) tolerance in healthy infants.

METHODS

Formula-fed (FF) infants (n = 108) received standard pHF-W formula (1.9 g protein/100 kcal) from enrollment (age ≤ 30 days) until age 120 days followed by new pHF-W FoF (1.6 g protein/100 kcal) until 360 days. Weight gain velocity (WGV) (mean daily WG from enrollment to age 180 days) was compared to WHO growth standards and a breastfed (BF) reference group (n = 86) (non-inferiority margin -3 g/day). GI tolerance was assessed using a validated questionnaire (scale range 13-65).

RESULTS

WGV in FF infants (mean ± SD 24.0 ± 4.4 g/day) was non-inferior to BF (23.7 ± 3.9 g/day) and WHO standards (all p ≤ 0.013). Weight-for-age, length-for-age, weight-for-length, and head circumference-for-age z-scores of FF infants were not significantly different from BF at any timepoint. Symptoms of GI intolerance were low (≤23) at all timepoints and similar between groups.

CONCLUSION

A new pHF-W FoF with age-adapted protein content fed sequentially after standard pHF-W infant formula is safe, well-tolerated, and promotes a healthy growth pattern consistent with BF infants and WHO standards during the first year of life.

CLINICAL TRIAL REGISTRATION

[https://clinicaltrials.gov/], identifier [NCT03276663].

Food allergy across the globe

The prevalence of food allergy (FA) is increasing in some areas of the globe, highlighting the need for better strategies for prevention, diagnosis, and therapy. In the last few decades, we have made great strides in understanding the causes and mechanisms underlying FAs, prompting guideline updates. Earlier guidelines recommended avoidance of common food allergens during pregnancy and lactation and delaying the introduction of allergenic foods in children aged between 1 and 3 years. Recent guidelines for allergy prevention recommend consumption of a healthy and diverse diet without eliminating or increasing the consumption of allergenic foods during pregnancy or breast-feeding. Early introduction of allergenic foods is recommended by most guidelines for allergy prevention after a period of exclusive breast-feedng (6 months [World Health Organization] or 4 months [European Academy of Allergy and Clinical Immunology]). New diagnostics for FA have been developed with varied availability of these tests in different countries. Finally, the first oral immunotherapy drug for FA was approved by the US Food and Drug Administration and European Medicines Agency in 2020. In this review, we will address the global prevalence of FA, our current understanding of the causes of FA, and the latest guidelines for preventing, diagnosing, and treating FA. We will also discuss similarities and differences between FA guidelines.

A systematic review of infant feeding food allergy prevention guidelines - can we AGREE?

Food allergy is a significant issue worldwide, particularly in Westernised countries. There is no clear explanation why food allergy appears to have increased so rapidly in recent years, particularly in young children, hence ongoing research to identify effective primary prevention strategies. Food allergy prevention guidelines for health professionals have been developed based on existing clinical trial evidence for effective translation and implementation. As these guidelines underpin clinical practice, it is important to ensure robust processes of development. We conducted a systematic review to identify food allergy prevention guidelines for health professional use; to compare the recommendations made by the identified guideline documents; and to assess the quality of the identified guideline documents. We searched Medline, EMBASE, CINAHL, Scopus, Global Health and Guidelines International Network for the period 1990 to 13 August 2019, to identify articles referring to English-language food allergy prevention guidelines or the guidelines themselves. A grey literature search of Google Scholar and reference checking was also undertaken. The guidelines were compared for recommendation similarities and differences. An Appraisal Guidelines for Research and Evaluation (AGREE II) appraisal was undertaken to assess guideline quality. The electronic database search yielded 1121 publications and reference checking identified an additional 16 publications. After title, abstract and full text screening, data extraction was undertaken on 156 publications and with additional reference checking, 28 food allergy prevention guidelines and advice documents were identified. Comparison of the recommendations within the guidelines and advice documents indicated the greatest variation in recommendations related to exclusive breastfeeding and timing of solid food introduction. Eight of the 10 guidelines and none of the 18 advice documents met the quality threshold set by the reviewers. Overall, documents specifically termed "guidelines" scored better than advice documents when assessed using the AGREE II tool. Variation in recommendations may create confusion for health professionals and result in inconsistent advice being provided to parents, and less translation of the evidence into actual food allergy reduction in the population. Appraisal using the AGREE II tool identified that there is considerable room for improvement in the development of guidelines and advice documents for food allergy prevention. The AGREE II appraisal identified common areas of poorer quality development and/or documentation of processes to inform future guideline development. Based on this study, we recommend the use of validated guideline development tools, to direct food allergy prevention guideline review or development. Use of the AGREE II tool, to direct the review and development of guidelines, is very likely to improve guideline quality.

A perspective on partially hydrolyzed protein infant formula in nonexclusively breastfed infants

The World Health Organization recommends that infants should be exclusively breastfed for the first 6 months of life to provide optimal nutrition in this critical period of life. After this, infants should receive nutritionally adequate and safe complementary foods while breastfeeding continues for up to 2 years of age or beyond. For nonbreastfed infants, infant formula is an available option to provide the nutrition needed. Infant formula is usually prepared from industrially modified cow’s milk and processed to adjust for the nutritional needs of infants. However, cow’s milk is one of the most common causes of food allergy, affecting 2%–5% of all formula-fed infants during their first year of life. One strategy to prevent cow’s milk allergy in nonbreastfed infants is the use of partially hydrolyzed formula (pHF) in high-risk infants, which are infants born in families with atopic disease. However, based on an epidemiological study, approximately half of the infants who develop allergy are not part of the at-risk group. This is because the non-at-risk group is significantly larger than the at-risk group and the non-at-risk infants have approximately 15% risk of developing allergies. This study aimed to evaluate the effects of partially hydrolyzed whey formula (pHF-W) in nonbreastfed infants and determine whether pHF-W can prevent atopic disease in high-risk infants and can be used as routine starter formula regardless of the allergy risk status.

Discovery and Quantification of Nonhuman Proteins in Human Milk

The question whether and which nonhuman peptides or proteins are present in human milk was raised many decades ago. However, due to cross-reactivity or nonspecific antibody recognition, the accuracy of detection by immunochemical methods has been a concern. Additionally, the relative low-abundance of nonhuman peptides/proteins in the complex milk sample makes them a challenging target to detect. Here, by deep proteome profiling, we detected several nonhuman peptides, which could be grouped as nonhuman proteins. We next estimated their concentration in human milk by combining data-dependent shotgun proteomics and parallel reaction monitoring. First, we fractionated human milk at the protein level and were able to detect 1577 human proteins. Additionally, we identified 109 nonhuman peptides, of which 71 were grouped into 36 nonhuman proteins. In the next step, we targeted 37 nonhuman peptides and nine of them could be repeatedly quantified in human milk samples. Peptides/proteins originating from bovine milk products were the dominant nonhuman proteins observed, notably bovine caseins (α-S1-, α-S2-, β-, κ-caseins) and β-lactoglobulin. The method we present here can be expanded to investigate more about nonhuman peptides and proteins in human milk and give a better understanding of how human milk plays a role in allergy prevention.

Early introduction of allergenic foods for the prevention of food allergy from an Asian perspective-An Asia Pacific Association of Pediatric Allergy, Respirology & Immunology (APAPARI) consensus statement

Emerging evidence for the early introduction of allergenic foods for the prevention of food allergies, such as peanut allergy in Western populations, has led to the recent publication of guidelines in the USA and Europe recommending early peanut introduction for high-risk infants with severe eczema or egg allergy. Peanut allergy is, however, much less prevalent in Asia compared to the West. Varying patterns of food allergy are seen even within Asian countries-such as a predominance of wheat allergy in Japan and Thailand and shellfish allergy in Singapore and the Philippines. Customs and traditions, such as diet and infant feeding practices, also differ between Asian populations. Hence, there are unique challenges in adapting guidelines on early allergenic food introduction to the Asian setting. In this paper, we review the evidence and discuss the possible approaches to guide the timely introduction of allergenic food in high-risk infants in Asia.