Epidemiology and the Growing Epidemic of Food Allergy in Children and Adults Across the Globe

Oral exposure to nanoplastics and food allergy in mice fed a normal or high-fat diet

The global prevalence of food allergies, particularly IgE-mediated responses, is increasing at an alarming rate. This trend is likely driven by environmental factors such as nanoplastics (NPs) ingestion and the westernization of dietary and lifestyle habits. This study examines the impact of polystyrene nanoplastics (PS-NPs) on ovalbumin (OVA)-induced food allergies in mice subjected to either a normal diet (ND) or a high-fat diet (HFD). BALB/c mice were stratified into eight groups based on dietary regimen, NP exposure, and OVA sensitization. Food allergy was induced via OVA administration, and multiple physiological and immunological parameters were evaluated, including body weight, intestinal permeability, cytokine profiles, gut microbiota composition, and small intestinal gene expression. Mice in the HFD + OVA + NP group exhibited significant increases in intestinal permeability, diarrhea severity, and serum OVA-specific IgE levels compared to other groups. Flow cytometric analysis revealed an expansion of innate lymphoid cells (ILC2 and ILC1) within the lamina propria of the small intestine. Shotgun metagenomic sequencing demonstrated gut microbiota dysbiosis, characterized by a reduction in beneficial bacterial populations in the HFD + OVA + NP cohort. Weighted Gene Co-Expression Network Analysis (WGCNA) identified a negative correlation between NPs exposure or OVA sensitization and the expression of Slc1a1, Slc5a8, and Mep1a, while a positive correlation was observed with Aa467197 expression. These findings indicate that oral exposure to PS-NPs exacerbates OVA-induced food allergies, particularly in the context of an HFD, through mechanisms involving increased intestinal permeability, gut microbial dysbiosis, and gene expression modulation. This study highlights the potential health hazards posed by environmental microplastic contamination and its possible contribution to the escalating incidence of food allergies.

Use of the DEFASE score in research trials

PURPOSE OF REVIEW

To explore the potential applicability in clinical trials of the groundbreaking international consensus named DEFASE (DEfinition of Food Allergy SEverity) as the unique grading system for IgE-mediated food allergy (FA) severity embracing the different aspects of the disease in a holistic approach. Herein, we discuss its relevance in clinical trials and potential applications in research and clinical settings through a few clinical scenarios.

RECENT FINDINGS

The DEFASE score has been developed to be used in research settings as a comprehensive scoring system. Researchers are currently focusing on internal and external validation of the scoring system, targeting these models to various food allergenic sources, populations, and settings.

SUMMARY

Implementing the DEFASE score in clinical trials could improve patient stratification, guide therapeutic decisions, and support regulatory assessments. Future research will focus on its external validation and integration with biomarker data to refine its predictive accuracy and make this tool applicable in the near future.

Re-evaluating treatment success in trials of peanut oral-immunotherapy: impact of different definitions on efficacy outcomes

PURPOSE OF REVIEW

Allergen immunotherapy (AIT) is increasingly popular as a treatment strategy for food allergy. Unfortunately, there is significant heterogeneity in reported outcomes, specifically in the dose-thresholds selected for evaluation and the symptoms used to define a "tolerated dose". These considerations are often investigator-driven and do not consider patient perspectives.

RECENT FINDINGS

A systematic review by the EAACI CO-FAITH taskforce recently flagged the need to better standardize and harmonize outcomes used in clinical trials of food-AIT. Using less objective symptoms to define dose-limiting symptoms can underestimate the reaction threshold determined at baseline food challenge. As a consequence, this can overestimate the efficacy of food-AIT by 15%. In this review, we perform an individual patient data (IPD) meta-analysis using data from three randomized-controlled trials and one real-world registry, to evaluate how the definition of dose "tolerance" impacts upon reported desensitization rates.

SUMMARY

This analysis provides insight into how clinical efficacy rates for food-AIT are impacted by using different dose thresholds and definitions for when a dose might be consider tolerated. Using more patient-centric outcomes may be a more useful metric to harmonize reporting of outcomes and inform clinical practice, paving the way towards reaching a consensus on outcome reporting in trials of food-AIT.

Common data elements for food allergy clinical trials: an overview

PURPOSE OF REVIEW

Food allergy represents a major public health issue, affecting about 8% of children and 11% of adults in the United States. Research in the field has rapidly expanded but is limited by a lack of standardized data fields or common data elements (CDEs) to record food allergy data. The present review focuses on the need for developing CDEs for food allergy, and their anticipated impact, as well as describes the central tenets of CDEs.

RECENT FINDINGS

Standardization of data definitions and consistency in data collection within a study and across multiple studies is a fundamental principle of clinical research. Several NIH centers have been collaborating to support the development of CDEs, thereby promoting the FAIR principles for clinical research.

SUMMARY

The population health burden of food allergies continues to rise in the absence of a standardized language for documenting food allergy clinical research data. Development and implementation of food allergy CDEs is needed both nationally and globally, to better understand and reduce the burden of this immune-mediated disease. When adopted, these CDEs will not only improve data consistency and interoperability but also speed up and improve the quality of future food allergy clinical trials.

Is Zebrafish a Good Model for the Alpha-Gal Syndrome?

The alpha-Gal syndrome (AGS) is an underdiagnosed tick-borne allergy characterized by both immediate and delayed IgE-mediated anaphylactic reactions to the galactose-alpha-1,3-galactose (alpha-Gal) epitope. Common manifestations include gastrointestinal, cutaneous, and respiratory symptoms appearing 2-6 h after the consumption of mammalian meat or derived products. Zebrafish (Danio rerio) are emerging as essential animal models in biomedical studies, due to their anatomical, genetic, and physiological similarities to humans, with significant applications in toxicology, behavioral research, oncology, and inflammation studies. The mechanisms associated with AGS are sustained by studies in the humanized α1,3GalT-KO C57BL/6 mouse (Mus musculus) and zebrafish animal models for the production of anti-alpha-Gal antibodies in response to tick saliva, the development of allergic reactions in animals sensitized with tick protein extracts following mammalian meat consumption, and the identification of immune mechanisms. The immune mechanisms characterized in both models are associated with a skewed type 2 immune response, triggering Toll-Like receptor (TLR) signaling pathways, IL-4 production, and humoral activity. These results support the use of both models rather than a single one for a more comprehensive characterization of AGS-associated immune mechanisms. In this study, we focused on the use of zebrafish as a model for biomedicine research in immunity, infectious, and allergic diseases, with a particular emphasis on the AGS and the identification of candidate therapeutic interventions. Based on insights from multiple studies, we concluded that zebrafish is a suitable model for studying the AGS, considering the addressed limitations and in combination with the α1,3GalT-KO mouse model.

Are We Meeting the Needs? A Systematic Review of Nutritional Gaps and Growth Outcomes in Children with Multiple Food Allergies

BACKGROUND/OBJECTIVES

Food allergies represent a growing public health challenge, showing an alarming increase in prevalence over the past few decades. Children with multiple food allergies face not only allergic reaction risks but also nutritional gaps, affecting diet, nutrition, and growth. This review summarizes the impact on nutrient intake and growth, highlighting key challenges and strategies to improve clinical care.

METHODS

The literature search was conducted using a structured search strategy in PubMed up to 31 January, using MeSH terms with Boolean operators (AND, OR) to combine searches (food hypersensitivity AND growth, food hypersensitivity AND nutrition, food hypersensitivity AND micronutrient, food hypersensitivity AND vitamin, food hypersensitivity AND trace element, and soy hypersensitivity) for human studies meeting pre-defined PICOS criteria that simultaneously assessed the reproducibility and validity.

RESULTS

Nearly 2000 studies were identified in the literature search, with 31 articles selected for full-text evaluation and 11 articles included in the final review. Dietary restrictions imposed by the need to avoid multiple allergens can lead to a reduced intake of essential nutrients, particularly proteins, calcium, iron, zinc, iodine, folate, vitamin B12, and vitamin D. Children with multiple FAs appear to be at an increased risk of impaired growth, as evidenced by the lower height-for-age, weight-for-age, head-circumference, and weight-for-length Z-scores compared to non-allergic peers.

CONCLUSIONS

Evidence from the studies reviewed suggests that children with multiple FAs may be at increased risk for growth impairments and nutritional inadequacies, especially where dietary management does not adequately compensate for nutrient losses, and highlights that tailored dietary counseling is crucial.

Development of a novel parent-report measure of food allergy impact

AIM

The aim of this study was to develop an outcome measure for caregivers of children with food allergy.

METHODS

A community-informed measure development process was utilised to generate a novel parent-reported outcome tool for caregivers of children with food allergy. We conducted focus groups with parents and caregivers of food-allergic (n = 18) children, following which a team of coders identified themes and generated an initial set of candidate items. These items were reviewed by content-area experts (n = 10) using content validity indices. We then conducted a series of cognitive interviews with parents of children with food allergy (n = 12) validating the instrument draft.

RESULTS

We describe the results of these development steps as well as future steps to produce the final, validated form of the measure. The resultant 91-item measure is intended for parents of children ages two to 12 years.

CONCLUSION

This measure fills a unique need in the field by leveraging key stakeholders' perspectives to develop and subsequently validate a novel parent-reported measure of parent and family food allergy impacts of children ages two to 12 years old.

The impact of neonatal antibiotic exposure on the development of childhood food allergies

Food allergies (FAs) in children have become increasingly prevalent. While early life factors such as gut microbiome disruptions have been implicated, the association between neonatal antibiotic exposure and subsequent FAs remains a topic of ongoing debate. This nationwide cohort study aimed to investigate the impact of neonatal antibiotic exposure on the development of childhood FA. This population-based retrospective cohort study analyzed data from Clalit-Healthcare-Services, Israel's largest state-mandated healthcare provider. The cohort included neonates (aged 0-60 days) admitted with fever between 2011 and 2018. Patients with confirmed infectious etiologies were excluded. The cohort was divided into two groups: those who received systemic antibiotics (Antibiotic ( +)) and those who did not (Antibiotic ( -)). FA cases were identified using ICD-9 codes up to age 6. Multivariate logistic regression and survival analysis models were utilized and adjusted for inflammatory markers, maternal atopy, and socioeconomic status. Among 2780 neonates, 1220 received antibiotics, while 1560 did not. The incidence of FAs was significantly higher in the Antibiotic ( +) group compared to the Antibiotic ( -) group (2.5% vs. 1.3%, P = 0.02). Adjusted analysis revealed that systemic antibiotic exposure during the neonatal period was associated with a threefold increased risk of FA up to age 6 (OR = 2.89, 95% CI = 1.34-6.92, P = 0.01). Conclusions: This study provides strong evidence linking neonatal antibiotic exposure to an increased risk of childhood FAs, particularly in the first 2 years of life. The findings highlight the importance of judicious antibiotic use in young infants.

Elucidation of Desensitization Mechanisms Induced by Oral Immunotherapy in a Rat Model of Ovalbumin Allergy

Oral immunotherapy (OIT) is a promising approach for treating food allergy. Here, we elucidated the mechanisms of desensitization induced by OIT in rats sensitized to ovalbumin (OVA). The desensitization was induced by ingestion of OVA three times per week after sensitization in rats. OIT suppressed the decrease in rectal temperature and increase in plasma histamine levels induced by OVA injection immediately and 4 weeks after OIT completion. Plasma OVA-specific IgE (sIgE) levels did not differ between the non-OIT and OIT groups, but OVA-specific IgG1 levels were higher in the OIT group than in the non-OIT group at both timepoints. To evaluate IgG's effect on IgE crosslinking with OVA, amplified luminescence proximity homogeneous assay involving crosslinking (AlphaCL) was performed. When IgG was removed using a Protein G column, the AlphaCL signal was significantly increased, especially in the OIT group, indicating that OIT-induced IgG inhibited the sIgE response. The proportions of cluster of differentiation (CD)4+ cells and CD4+CD25+FoxP3+ cells in mesenteric lymph nodes and spleen were similar between the two groups. These findings indicate that OIT attenuates systemic allergic responses by inhibiting sIgE binding to OVA through increased IgG. Our model is useful for understanding the mechanisms of OIT and optimizing therapeutic strategies for ameliorating food allergies.

Neonatal Food Protein-Induced Enterocolitis: Current Insights and Knowledge Gaps

Acute and chronic Food Protein-Induced Enterocolitis Syndrome (FPIES) has been well characterized in children; otherwise, neonatal FPIES (N-FPIES) remains poorly understood. In terms of pathophysiology, neonatal FPIES appears to have a more prevalent TH2 response and is characterized by specific clinical features that make the diagnosis challenging. Genetic and environmental risk factors may predispose to the development of FPIES. Recent evidence indicates that a characteristic microbiota signature may lead to barrier dysfunction, reduced regulatory T cells, and abnormal intestinal production of serotonin, responsible for the symptoms of FPIES. Regarding clinical presentation, newborns with FPIES may not fully meet the current guideline's diagnostic criteria at disease onset, being more similar to clinical entity specific of neonatal age than to acute FPIES in infants and children. Hence, differentiation from other neonatal medical and surgical conditions-particularly necrotizing enterocolitis (NEC)-remains a critical challenge for clinicians. This present review highlights our current understanding of N-FPIES, in term of pathophysiology, clinical presentation diagnosis, and treatment strategies. Refining diagnostic criteria for N-FPIES represents a clinical priority to help physicians in diagnosing and managing this challenging condition. Last, but not least, larger clinical trials are needed to optimize treatment practices in term and preterm newborns with FPIES.

Patterns and Prevalence of Food Allergen Cross-Reactivity: A Cross-Sectional Study of Food-Allergic Adults in the Makkah Region, Saudi Arabia

BACKGROUND AND OBJECTIVES

Food allergies are a growing public health concern, with cross-reactivity complicating diagnosis and management. Cross-reactivity occurs when immune responses to one allergen trigger reactions to similar proteins in other allergens. There is a lack of regional data on the prevalence and patterns of food allergen cross-reactivity in Saudi Arabia, particularly in the Makkah region. This study investigates the prevalence and patterns of food allergen cross-reactivity among adults in Makkah, considering gender- and age-related differences.

METHODS

A cross-sectional survey was conducted between July and October 2021 among 93 adults aged 18 years or older residing in the Makkah region who self-reported doctor-diagnosed food allergies. Participants were recruited through an online questionnaire distributed via social media. The survey, validated by expert reviewers and pretested for clarity, collected demographic information, allergen types, and cross-reactivity data. Descriptive statistics, chi-square tests, and a cross-reactivity matrix were used to assess allergen co-sensitization patterns and demographic associations.

RESULTS

The study identified high rates of nut, egg, and fruit allergies, with significant cross-reactivity, particularly among participants allergic to nuts. Females reported higher allergy prevalence of cross-reactivity (65.6%) compared to males (34.4%), aligning with global trends. Middle-aged females exhibited the highest rates of allergen cross-reactivity. The most frequent cross-reactivity was observed in participants with nut (100%), egg (90.7%), and fruit (89.2%) allergies. Specifically, 90.9% of individuals allergic to nuts experienced cross-reactivity with more than two other allergens. The cross-reactivity matrix revealed both expected (e.g., between tree nuts and peanuts) and unexpected patterns (e.g., between fruits and seafood), suggesting the possible influence of panallergens, co-sensitization, or regional dietary factors.

CONCLUSIONS

This study highlights a high prevalence of food allergen cross-reactivity among adults in the Makkah region, with significant gender- and age-related trends. The findings underscore the need for clinician awareness of atypical and panallergen-driven cross-reactivity to support tailored patient counseling and management strategies. Region-specific screening protocols and culturally informed public health campaigns are recommended to address local dietary practices and improve allergy awareness. Future longitudinal and interventional studies incorporating objective diagnostic tools are essential to validate these findings and assess the effectiveness of targeted interventions. These insights can inform clinical guidelines and national health policies to improve diagnosis, treatment, and patient education in Saudi Arabia.

Dietary AGEs and food allergy: insights into the mechanisms of AGEs-induced food allergy and mitigation strategies

Food allergy (FA) is a significant public health concern, with over one billion individuals globally affected, and its prevalence continues to rise. Advanced glycation end products (AGEs) are common hazards in various diet. Recent investigations have shown that AGEs could influence the pathogenesis of FA by interacting with AGEs receptors. This paper provides a comprehensive review of recent advances on diet AGEs, summarized the mechanisms of AGEs in regulating food allergy and mitigation strategies, analyzed the limitations of current research on AGEs and prospected the future research. AGEs could combine with the receptors for AGEs (RAGE) to induce oxidative stress, inflammation and allergic signaling pathways. AGEs can affect allergen epitopes and conformation and regulate intestinal flora in a non-receptor-dependent manner, as well as affect the intestinal barrier and Th1/Th2 immune balance through receptor-dependent pathways to regulate food allergy. Currently, the approaches to reduce the AGEs-induced food allergy mainly depended on improving food processing methods (e.g., low temperature, short time, low pH and non-thermal processing methods), natural AGEs inhibitors and RAGE inhibitors. This review elucidates the influences of AGEs on food allergy and mitigation strategies, which could provide novel insights into reducing food allergy induced by diet AGEs.

Unraveling the Biological Properties of Whey Peptides and Their Role as Emerging Therapeutics in Immune Tolerance

Whey is a natural by-product of the cheese-making process and represents a valuable source of nutrients, including vitamins, all essential amino acids and proteins with high quality and digestibility characteristics. Thanks to its different techno-functional characteristics, such as solubility, emulsification, gelling and foaming, it has been widely exploited in food manufacturing. Also, advances in processing technologies have enabled the industrial production of a variety of whey-based products exerting biological activities. The beneficial properties of whey proteins (WPs) include their documented effects on cardiovascular, digestive, endocrine, immune and nervous systems, and their putative role in the prevention and treatment of non-communicable diseases (NCDs). In this regard, research on their application for health enhancement, based on the optimization of product formulation and the development of pharmaceuticals, is highly relevant. Beyond the health and nutritionally relevant effects as in in vivo animal studies, the allergenicity of WPs and WP hydrolysates is also herein tackled and discussed, as well as their potential role as therapeutics for immune tolerance and so-called tolerogenic effects. Grounded on the WPs' health-promoting functions, this paper presents the latest research showing the potential of whey-derived peptides as an alternative strategy in NCD treatment. This work also reports a careful analysis of their current use, also revealing which obstacles limit their full exploitation, thus highlighting the future challenges in the field. Concluding, safety considerations, encompassing WP allergenicity, are also discussed, providing some insights on the role of WPs and peptides in milk allergen immunotolerance.

US general population food allergy treatment preferences: a discrete choice experiment

OBJECTIVE

To quantify treatment preferences for food allergy management options (oral immunotherapy, biologic therapy, and allergen avoidance), overall and by sociodemographic strata.

METHODS

A US general population (≥13 years) discrete choice experiment (DCE) was conducted, including the Intolerance of Uncertainty-12 Scale and clinical/demographic questions. Conditional logistic regression analyses were conducted overall and by sociodemographic factors. DCE results were presented as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Participants (n = 294) mean (standard deviation) age was 47 (19.7) years; 48.6% were male. A 1% reduction in risk of having an exposure resulting in a moderate-to-severe reaction was statistically significantly associated with treatment preference (OR: 1.10; CI:1.04-1.16; p < 0.01). Features significantly associated with reduced preference included: a 1% increase in risk of treatment-related, severe anaphylaxis (0.85; 0.74-0.97; p=0.02); a 1% increase in risk of gastrointestinal symptoms (0.99; 0.99-0.99; p < 0.01); daily treatment (vs. every 2-4 weeks; 0.81; 0.72-0.91; p < 0.01); in-clinic administration (vs. at-home; 0.76; 0.66-0.87; p < 0.01); subcutaneous administration (vs. oral; 0.69; 0.61-0.78; p < 0.01); three-hour post-treatment physical activity limitation (0.84; 0.77-0.93; p < 0.01); and one-year life expectancy reduction (0.87; 0.85-0.89; p < 0.01). Rural dwellers favoured at-home use and no activity limits; lower-income respondents preferred convenience (oral, less frequent, and at-home administration). Teens strongly preferred being bite-safe (vs. fully allergic; 2.75; 1.09-6.90; p = 0.03).

CONCLUSION

When making food allergy management decisions, US general population respondents had strong preferences for features related to safety and convenience; however, the magnitude of preferences varied by sociodemographic factors. These findings may be pertinent for population-level health decision makers.

Extracellular adenosine triphosphate: A new gateway for food allergy mechanism research?

Although various studies have been conducted, the detailed mechanisms of food allergy remain a topic of ongoing debate. Recently, researchers have reported that extracellular adenosine triphosphate (eATP), a member of damage-associated molecular patterns secreted by stressed cells, plays a critical role in the progression of asthma and atopic dermatitis. These studies suggest that dysregulated eATP significantly influences various aspects of disease progression, from bodily sensitization to the emergence of clinical manifestations. Given the shared pathogenic mechanisms among asthma, atopic dermatitis, and food allergies, we hypothesize that eATP may also serve as a crucial regulator in the development of food allergies. To elucidate this hypothesis, we first summarize the evidence and limitations of food allergy theories, then discuss the roles of eATP in allergic diseases. We conclude with speculative insights into the potential influence of eATP on food allergy development, aiming to inspire further investigation into the molecular mechanisms of food allergies.

The Current State of Data to Estimate Prevalence and Severity of Food Allergies in the United States

Currently, in the United States, there is no comprehensive surveillance system to collect data on food allergies; however, prevalence and severity data are critical to quantify the burden of food allergies, develop evidence-based control measures, detect emerging issues, and monitor trends. To address this gap, we conducted a literature search, and expert interviews to identify surveillance systems and datasets that could be used to estimate the prevalence and severity of food allergies in the United States overall and for specific foods. Inclusion and exclusion criteria were developed and used to screen each data source. Selected articles were evaluated according to quality parameters to identify the most appropriate studies. Most studies estimated the prevalence of food allergies in children, investigated multiple foods, and used surveys to collect self-reported data. Despite the high quality, robust study designs, and comprehensive survey instruments that currently exist, the studies identified do not provide sufficiently recent data to estimate the current burden of food allergies in the country. Studies lack consistencies across the years making the analysis of trends over time a challenge. National surveys conducted by Northwestern University in 2009/2010 and 2015/2016 represented the best available data; however, these data are likely outdated and are limited in assessing temporal food allergy trends. Data to accurately estimate the current prevalence and severity of food allergies and related trends are lacking. U.S. public health agencies should explore the development of a comprehensive surveillance program to address this gap and help inform evidence-based policies in food allergy management and prevention.

Anti-IgE and food allergy

Food allergy is a growing problem that can have a significant impact on both the individual, the family, and society. We are entering a new era of food allergy management with the recent US Food and Drug Administration approvals of 2 therapies for food allergy. IgE is now known to play a critical role in allergic diseases, including food allergy. Ant-IgE therapy has been under investigation for decades and is now approved for asthma, urticaria, nasal polyps, and most recently, IgE-mediated food allergy. Here, we evaluate what is known about the safety and efficacy of anti-IgE therapy as monotherapy and in combination with oral immunotherapy. In addition, we will highlight important practical considerations and key knowledge gaps.

Understanding Experiences, Barriers, and Facilitators of Safe Airline Travel: A Global Survey of Food Allergy Patients and Caregivers

BACKGROUND

The global prevalence of food allergy (FA) has increased markedly across recent decades, with millions of patients engaging in airline travel each year. However, air travel can pose specific challenges to FA management.

OBJECTIVE

To collect global data about patients' and families' FA-related airline travel experiences, attitudes, and behaviors.

METHODS

An electronic survey was developed and refined by global FA stakeholders, which was administered between October 2022 and January 2023 to patients with FA and caregivers recruited via 45 FA patient advocacy organizations and research institutions.

RESULTS

Most of the 4704 survey respondents self-reported as female (88.4%), aged between 40 and 59 years (67.7%), and non-Hispanic White race (75.8%), and resided in the United States (79.6%). A history of 1 or more in-flight food-allergic reaction was reported by 8.5% of participants, with peanut (3.9%), tree nuts (2.4%), and milk (0.6%) the most reported triggers. Epinephrine was administered in 15.1% of reactions and was most often self-carried (91.7% of events). Only 57.4% of in-flight reactions were reported to either the flight crew in the air or the airline on landing. Many preventive measures were reportedly taken by respondents to avoid adverse FA outcomes during air travel, including specific requests for accommodation, which were often not provided as assured. Respondents generally reported high levels of anxiety managing FA during air travel and that FA-related policies and other related factors were primary drivers of travel-related decision making.

CONCLUSIONS

Air travel presents numerous challenges to optimal FA management, many of which can be at least partially mitigated though consistent implementation of appropriate FA-related policies.

Epithelial barrier theory in the context of nutrition and environmental exposure in athletes

Exposure to toxic substances, introduced into our daily lives during industrialization and modernization, can disrupt the epithelial barriers in the skin, respiratory, and gastrointestinal systems, leading to microbial dysbiosis and inflammation. Athletes and physically active individuals are at increased risk of exposure to agents that damage the epithelial barriers and microbiome, and their extreme physical exercise exerts stress on many organs, resulting in tissue damage and inflammation. Epithelial barrier-damaging substances include surfactants and enzymes in cleaning products, laundry and dishwasher detergents, chlorine in swimming pools, microplastics, air pollutants such as ozone, particulate matter, and diesel exhaust. Athletes' high-calorie diet often relies on processed foods that may contain food emulsifiers and other additives that may cause epithelial barrier dysfunction and microbial dysbiosis. The type of the material used in the sport equipment and clothing and their extensive exposure may increase the inflammatory effects. Excessive travel-related stress, sleep disturbances and different food and microbe exposure may represent additional factors. Here, we review the detrimental impact of toxic agents on epithelial barriers and microbiome; bring a new perspective on the factors affecting the health and performance of athletes and physically active individuals.

Maternal influences on offspring food allergy

The prevalence of allergies has been globally escalating. While allergies could appear at any age, they often develop in early life. However, the significant knowledge gap in the field is the mechanisms by which allergies affect certain people but not others. Investigating early factors and events in neonatal life that have a lasting impact on determining the susceptibilities of children to develop allergies is a significant area of the investigation as it promotes the understanding of neonatal immune system that mediates tolerance versus allergies. This review focuses on the research over the recent 10 years regarding the potential maternal factors that influence offspring allergies with a view to food allergy, a potentially life-threatening cause of anaphylaxis. The role of breast milk, maternal diet, maternal antibodies, and microbiota that have been suggested as key maternal factors regulating offspring allergies are discussed here. We also suggest future research area to expand our knowledge of maternal-offspring interactions on the pathogenesis of food allergy.

All roads lead to IgA: Mapping the many pathways of IgA induction in the gut

The increasing prevalence of food allergy and related pathologies in recent years has underscored the need to understand the factors affecting adverse reactions to food. Food allergy is caused when food-specific IgE triggers the release of histamine from mast cells. However, other food-specific antibody isotypes exist as well, including IgG and IgA. IgA is the main antibody isotype in the gut and mediates noninflammatory reactions to toxins, commensal bacteria, and food antigens. It has also been thought to induce tolerance to food, thus antagonizing the role of food-specific IgE. However, this has remained unclear as food-specific IgA generation is poorly understood. Particularly, the location of IgA induction, the role of T cell help, and the fates of food-specific B cells remain elusive. In this review, we outline what is known about food-specific IgA induction and highlight areas requiring further study. We also explore how knowledge of food-specific IgA induction can be informed by and subsequently contribute to our overall knowledge of gut immunity.

Management of Infant Atopic Eczema to Prevent Severe Eczema and Food Allergy

Early intervention and active management of infant atopic eczema may play a crucial role in limiting eczema severity and preventing the onset of immediate-type food allergy. Eczema management involves education, skincare and medications targeting skin inflammation and barrier repair. Topical corticosteroids are the mainstay of anti-inflammatory therapy, with nonsteroidal options available for some infants. Proactive therapy, addressing subclinical inflammation, is useful for preventing eczema flares, especially in infants with recurrent eczema flares despite reactive therapy. In clinical practice, holistic consideration of overall infant and family health is essential. Providing advice on maternal stress management, nutritional guidance and recommendations for proper sleep and lifestyle is crucial for the well-being of children and their families, not limited to eczema treatment alone.

Regulation of immune responses to food by commensal microbes

The increasing prevalence of immune-mediated non-communicable chronic diseases, such as food allergies, has prompted a deeper investigation into the role of the gut microbiome in modulating immune responses. Here, we explore the complex interactions between commensal microbes and the host immune system, highlighting the critical role of gut bacteria in maintaining immune homeostasis. We examine how modern lifestyle practices and environmental factors have disrupted co-evolved host-microbe interactions and discuss how changes in microbiome composition impact epithelial barrier function, responses to food allergens, and susceptibility to allergic diseases. Finally, we examine the potential of bioengineered microbiome-based therapies, and live biotherapeutic products, for reestablishing immune homeostasis to prevent or treat food allergies.

Current perspective on allergen immunotherapy for food allergies

Food allergies are an increasing global problem and societal issue. In addition to the potential for severe allergic reactions from accidental ingestion, food allergies impose a significant burden on the quality of life, nutrition, cost of living, and social activities of both those afflicted and their caregivers. Strict avoidance of allergens and use of emergency medications to treat allergic reactions are the traditional management and treatment strategies; however, significant progress has been made in recent years toward better treatment of food allergies. Many clinical trials on food allergen immunotherapy (oral, epicutaneous, and sublingual) have revealed its efficacy in increasing reaction thresholds and desensitization. These positive results led to the first FDA approval of peanut oral immunotherapy (OIT). However, safer and more effective approaches are required, and adjunct treatments and allergen modifications are being considered. More than 100 facilities in Japan conduct OIT, and numerous studies on it have been reported. Unlike in Europe and the US, stepwise oral food challenges with dietary guidance are conducted separately from the OIT. This review describes the current perspectives on allergen immunotherapy for the treatment of food allergies, focusing on evidence from Japan.

Triggers for eosinophilic esophagitis (EoE): The intersection of food allergy and EoE

Eosinophilic esophagitis and IgE-mediated food allergy are both food-triggered diseases that are increasing in prevalence. They share many clinical links, including significant comorbidity and similar food triggers, and as atopic diseases, they likely share upstream mechanisms related to barrier function and signals leading to TH2 skewing. In this review, we focus on links between eosinophilic esophagitis and IgE-mediated food allergy with an emphasis on what insights may be derived from overlapping food triggers and immune phenotypes. Through further investigation of these connections, we may be able to better understand not only IgE-mediated food allergy and eosinophilic esophagitis but also general atopic response to food proteins and evolution of allergic response to food.

Understanding the burden of food allergy among urban and rural school children from north India

Background

There is paucity of reliable epidemiological data regarding the burden of food allergy in most developing countries, including India.

Objective

To provide current estimates of the prevalence and distribution of food allergy among urban and rural school children aged 6-14 years in Delhi and the National Capital Region (NCR) of Khekra in India.

Methods

A cross-sectional study was conducted from January 2022 to February 2023 to enroll school children, 6-14 years, from select urban and rural schools in Delhi and NCR. A questionnaire consisting of questions focused on household environment, early life factors, and pediatric food allergy characteristics was administered by a trained medical researcher to collect parent-proxy data. Univariate statistics were used to describe frequencies, percentages, and 95% confidence intervals for survey items.

Results

The estimated prevalence of parent-reported food allergy was 0.8% (95% CI: 0.4-1.5; urban: 0.4%, 95% CI: 0.1-1.1; rural: 1.7%, 95% CI: 0.7-3.5). Fruits such as mango (0.3%, 95% CI: 0.1-0.9), strawberry (0.1%, 95% CI: 0.0-0.7), orange (0.1%, 95% CI: 0.0-0.7), and custard apple (0.1%, 95% CI: 0.0-0.7) were reported only by urban children, while rural children reported yogurt (0.6%, 95% CI: 0.1-1.8) and wheat (0.3%, 95% CI: 0.0-1.3). Both groups reported brinjal (also known as eggplant) and banana, 0.1% (95% CI: 0.0-0.7) of urban and 0.3% (95% CI: 0.0-1.3) of rural, respectively. Overall, commonly reported clinical symptoms were diarrhea and/or vomiting (100%, 95% CI: 76.2-100), abdominal pain (88.9%, 95% CI: 58.6-98.8), and rash/itchy skin (66.7%, 95% CI: 34.8-89.6). Among children with parent reported food allergy, 66.7% (95% CI: 34.8-89.6) of food allergies were physician diagnosed, of which 33.3% were diagnosed via history alone (95% CI:7.7-71.4) while 66.7% (95% CI: 28.6-92.3) were confirmed via skin prick test and/or blood test.

Conclusion

The overall prevalence of food allergy is very low in Delhi and Khekra, India. Future work should focus on elucidating the complex interplay of early-life, environmental, genetic, and lifestyle factors to understand the reasons for India's low food allergy burden and improve epidemiological clues to prevention for the nations with higher disease burden.

Can diet change the natural history of gastrointestinal diseases?

Belatedly, gastroenterologists have begun to pay attention to the role of diet in the exacerbation of gastrointestinal symptoms in many digestive disorders-a recognition that has spurred both high-quality clinical trials and translational research into this area. It has become clear that multiple mechanisms acting either in isolation or together can induce gut symptoms and that appropriate interventions can lead to significant relief. What this review will explore is not the role of diet in the production of certain symptoms or symptom clusters, but rather whether a dietary intervention can beneficially alter the natural history of a gastrointestinal disease-a much more demanding expectation. Yet there are examples of where a diet, if sustained, can have a long-term impact on at least some of those affected by conditions such as eosinophilic esophagitis, celiac disease, food allergy, and constipation.

Oral administration of egg ovalbumin allergen induces dysregulation of tryptophan metabolism in sensitized BALB/c mice

Food allergy (FA), triggered by specific dietary allergens, has emerged as a substantial global concern for food safety and public health. While studies have elucidated changes in immune cells and cytokines associated with allergen exposure, a comprehensive analysis of the host's metabolic features and the interaction between metabolites and the gut microbiota has not been conducted. In this study, egg allergen ovalbumin (OVA) was administered by the oral route to sensitized BALB/c mice to faithfully replicate key aspects of human FA, including severe allergic diarrhea, mast cell infiltration, and elevated levels of serum IgE, mMCPT-1, and Th2 cell hallmark cytokines (such as IL-4, IL-5, and IL-13). Furthermore, the untargeted and targeted metabolomic analyses indicated that FA in mice precipitated a substantial decrease in the tryptophan metabolites indole-3-acrylic acid (IA) and indole-3-lactic acid (ILA). The integration of shotgun metagenome and metabolome data further unveiled that the dysregulation of indole metabolism is related to a decline in the abundance of beneficial bacteria such as Lactobacillus and Bifidobacterium. Additionally, disruption of the tryptophan indole derivative pathway compromises the maintenance of intestinal mucosal function through the AHR signaling pathway, manifested by decreased expression of Reg3g and IL22. Taken together, this study demonstrated that the anaphylaxis triggered by oral ingestion of food allergens can lead to disruptions in tryptophan metabolism, consequently impairing intestinal immune homeostasis.