How dietary advanced glycation end products could facilitate the occurrence of food allergy

Dietary advanced glycation end products may increase the incidence of allergic rhinitis depending on genetic susceptibility: a prospective cohort study

Background: Limited evidence exists for the relationship between dietary advanced glycation end product (AGE) intake and allergic rhinitis (AR). Herein, the association between dietary AGEs and the risk of developing AR and whether genetic susceptibility influences the effects of dietary AGEs on AR were explored. Methods: In total, 125 276 participants without AR at baseline and having completed at least two 24-hour dietary recalls from the UK Biobank (2006-2010) were included. Dietary AGEs, specifically Nε-(1-carboxyethyl)-L-lysine (CEL), Nε-(carboxymethyl) lysine (CML), and Nδ-(5-hydro-5-methyl-4-imidazolone-2-yl) ornithine (MG-H1), were quantified by coupling 24-hour food assessments with a validated dietary AGE database. The incidence of allergic rhinitis was determined through hospital admissions. Multivariate Cox regression models were used to calculate the hazard ratios (HR) and 95% confidence intervals (CI) of the association between dietary AGE intake and the risk of AR. Results: During a median follow-up period of 12.4 years, 1171 individuals developed AR. In the fully adjusted model, higher dietary AGEs (HR: 1.27; 95% CI: 1.07, 1.50; P-trend = 0.006) and MG-H1 intake (HR: 1.19; 95% CI: 1.01, 1.41; P-trend = 0.046), especially the dietary AGEs derived from baked foods (HR: 1.23; 95% CI: 1.03, 1.46; P-trend = 0.020) and from nuts and legumes (HR: 1.24; 95% CI: 1.05, 1.47; P-trend = 0.013) were associated with an increased risk of AR. Among participants with a low genetic risk of AR, the HRs (95% CI) of AR were 1.32 (1.01, 1.73) and 1.37 (1.05, 1.79) for dietary AGE and MG-H1 intake, respectively. Conclusions: Dietary AGE intake was associated with an increased risk of AR, which was modified through genetic predisposition.

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.

The Impact of Dietary Counseling on the Nutritional Status of Pediatric Patients with Non-IgE-Mediated Gastrointestinal Food Allergies: A Non-Randomized, Prospective Intervention Study

Background/Objectives: Pediatric patients with non-IgE-mediated gastrointestinal food allergies (non-IgE-GIFAs) may experience alterations of nutritional status. This non-randomized, prospective intervention study investigated the impact of dietary counseling on nutritional status in pediatric patients with non-IgE-GIFAs. Methods: Patients of both sexes aged 0-14 years newly diagnosed with non-IgE-GIFAs received dietary counseling provided by certified pediatric dietitians immediately after diagnosis. Nutritional status parameters were assessed to identify nutritional status alterations at baseline and after 12 months of intervention (T12). Results: The study included 100 patients (58% male, mean age 8.5 ± 8.8 months). Non-IgE-GIFAs phenotypes included food protein-induced enteropathy (FPE, 44%), food protein-induced enterocolitis syndrome (FPIES, 11%), food protein-induced allergic proctocolitis (FPIAP, 17%), and food protein-induced motility disorders (FPIMD, 28%). At diagnosis, 1% was affected by obesity (1 FPIAP), 5% were affected by overweight (2 FPE, 1 FPIAP, and 2 FPIMD), 7% were moderately underweight (5 FPE and 2 FPIMD), 1% was severely underweight (1 FPE), 7% were moderately stunted (4 FPE, 1 FPIAP, and 2 FPIMD), 16% were moderately wasted (11 FPE, 1 FPIES, 1 FPIAP, and 3 FPIMD), and 4% were severely wasted (2 FPE and 2 FPIMD). At T12, improvements in anthropometric parameters were observed, along with a reduction in the prevalence of malnutrition by excess (6% at diagnosis vs. 2% at T12) and a reduction in the undernutrition subtypes rate, including underweight, stunting, and wasting (26% at diagnosis vs. 3% at T12, p < 0.001). Conclusions: Non-IgE-GIFAs can negatively impact the nutritional status of pediatric patients. Thus, dietary counseling could be an effective strategy for preventing and managing nutritional alterations in these patients.

Food additives and their impact on human health

Increasing evidence suggests that high consumption of ultra-processed foods (UPF) is associated with an increase in noncommunicable diseases, overweight, and obesity. This review aimed to verify the association of UPF with inflammatory diseases, especially allergic diseases. To identify relevant articles, an extensive literature search was conducted using the two most important search sites - PubMed and Google Scholar. Specific Medical Subject Headings (MeSHes) such as "food additives and health," "food additives and immune system," and "food additives and diseases" were used to conduct an advanced search. Emulsifiers have been, particularly, implicated in disrupting intestinal barrier function, modifying gut microbiota, and promoting inflammation, which may contribute to the development of food allergies and inflammatory diseases. While food additives serve various functions in the food industry, concerns regarding their impact on health, particularly in systemic autoimmune and metabolic conditions, have been raised. Common additives have been associated with allergic reactions, intolerances, and sensitivities.

The Etiology of IgE-Mediated Food Allergy: Potential Therapeutics and Challenges

Immunoglobulin E (IgE)-mediated food allergy has been dramatically increasing in incidence over the last few decades. The combinations of both genetic and environmental factors that affect the microbiome and immune system have demonstrated significant roles in its pathogenesis. The morbidity, and at times mortality, that occurs as the result of this specific, reproducible, but impaired immune response is due to the nature of the shift from a regulatory T (Treg) cellular response to a T helper 2 (Th2) cellular response. This imbalance caused by food allergens results in an interleukin (IL)-4 and IL-13 dominant environment that drives B cell activation and differentiation into IgE-producing plasma cells. The resulting symptoms can range from mild to more severe anaphylaxis, and even death. Current therapeutic strategies involve avoidance and broad symptom management upon accidental exposure; however, no definitive cure exists. This narrative review highlights how the elucidation of the pathogenesis of IgE-mediated food allergy resulted in the development of therapeutics that are more specific to these individual receptors and molecules which have been relatively successful in mitigating this potentially life-threatening allergic response. However, potential adverse effects and re-sensitization following the conclusion of treatment has urged the need for improved therapeutic methods. Therefore, given the understanding of their mechanism of action and the overlap with the mechanism of IgE-mediated food allergies, probiotics and small molecule natural compounds may provide novel therapeutic and preventative strategies. This is compelling, as they have demonstrated success in clinical trials and may provide hope to improve quality of life in allergy patients.

Intestinal permeability, food antigens and the microbiome: a multifaceted perspective

The gut barrier encompasses several interactive, physical, and functional components, such as the gut microbiota, the mucus layer, the epithelial layer and the gut mucosal immunity. All these contribute to homeostasis in a well-regulated manner. Nevertheless, this frail balance might be disrupted for instance by westernized dietary habits, infections, pollution or exposure to antibiotics, thus diminishing protective immunity and leading to the onset of chronic diseases. Several gaps of knowledge still exist as regards this multi-level interaction. In this review we aim to summarize current evidence linking food antigens, microbiota and gut permeability interference in diverse disease conditions such as celiac disease (CeD), non-celiac wheat sensitivity (NCWS), food allergies (FA), eosinophilic gastrointestinal disorder (EOGID) and irritable bowel syndrome (IBS). Specific food elimination diets are recommended for CeD, NCWS, FA and in some cases for EOGID. Undoubtfully, each of these conditions is very different and quite unique, albeit food antigens/compounds, intestinal permeability and specific microbiota signatures orchestrate immune response and decide clinical outcomes for all of them.

Adverse food reactions and alterations in nutritional status in children with autism spectrum disorders: results of the NAFRA project

BACKGROUND

To assess the adverse food reactions (AFR) prevalence in children with autism spectrum disorder (ASD) and in non-ASD healthy controls (NASD). Nutritional status alterations, food selectivity and adherence to Mediterranean Diet (MD) were also evaluated.

METHODS

The NAFRA (Nutritional status and Adverse Food Reactions in children with Autism Spectrum Disorder) project was an observational, case-control, comparative study conducted at a tertriary center for pediatrics involving Caucasian patients of both sexes, aged 18 months-7 years, with a diagnosis of ASD, and matched NASD controls.

RESULTS

From October 2017 to December 2023, 100 ASD patients [79 male, mean (± SD) age 49.9 months (± 15.4)] and 100 NASD controls [75 male, mean (± SD) age 49.8 months (± 17.7)] were enrolled at the Pediatric Section of the Department of Translational Medical Science of the University of Naples Federico II. A significantly higher prevalence of AFR was observed in ASD patients if compared with NASD (16% vs. 2%, p = 0.001), mainly due to a higher prevalence of food allergy (7% vs. 1%, p = 0.03). A significantly higher prevalence of food intolerance and celiac disease was also observed in ASD children. The rate of obesity was significantly higher in ASD patients compared to NASD. Food selectivity and low MD-adherence were more frequent in ASD children (26% vs. 2%, p < 0.0001 and 28% vs. 16%, p = 0.041, respectively).

CONCLUSIONS

The high rate of AFR, obesity and unhealthy dietary habits observed in ASD children strongly suggest the importance of a multidisciplinary approach, providing early diagnosis of AFR and appropriate nutritional management to improve core and associated ASD-related conditions.

TRIAL REGISTRATION

The NAFRA Project was registered on https://clinicaltrials.gov/ with the identifier NCT04719923. Registered 18 January 2021. https://clinicaltrials.gov/study/NCT04719923 .

Advanced glycation end products (AGEs) impair the intestinal epithelial barrier via STAT3 activation mediated by macrophages

Advanced glycation end products (AGEs) are a spectrum of complex compounds widely found in processed foods and frequently consumed by humans. AGEs are implicated in impairing the intestinal barrier, but the underlying mechanisms remain unclear. This study investigated the effects of three types of AGEs on gene expression of tight junctions (TJs) in colorectal epithelial HT-29 cells, and observed minimal alterations in TJs expression. Given the important role of subepithelial macrophages in regulating the intestinal barrier, we explored whether AGEs affect the intestinal barrier via the involvement of macrophages. Notably, a significant downregulation of TJs expression was observed when supernatants from AGEs-treated RAW264.7 macrophage cells were transferred to HT-29 cells. Further investigations indicated that AGEs increased IL-6 levels in RAW264.7 cells, subsequently triggering STAT3 activation and suppressing TJs expression in HT-29 cells. The role of STAT3 activation was confirmed by observing enhanced TJs expression in HT-29 cells following pretreatment with an inhibitor of STAT3 activation prior to the transfer of the conditioned medium. These findings demonstrated that AGEs impaired the intestinal barrier via macrophage-mediated STAT3 activation, shedding light on the mechanisms underlying AGEs-induced intestinal barrier injury and related food safety risks.

Ultra-processed foods, allergy outcomes and underlying mechanisms in children: An EAACI task force report

BACKGROUND

Consumption of ultra-processed foods [UPFs] may be associated with negative health outcomes. Limited data exist regarding the potential role of UPFs in the occurrence of allergic diseases. The underlying mechanisms underpinning any such associations are also poorly elucidated.

METHODS

We performed a systematic review and narrative evidence synthesis of the available literature to assess associations between UPF consumption and pediatric allergy outcomes (n = 26 papers), including data on the association seen with the gut microbiome (n = 16 papers) or immune system (n = 3 papers) structure and function following PRISMA guidelines.

RESULTS

Dietary exposure to fructose, carbonated soft drinks, and sugar intake was associated with an increased risk of asthma, allergic rhinitis, and food allergies in children. Commercial baby food intake was associated with childhood food allergy. Childhood intake of fructose, fruit juices, sugar-sweetened beverages, high carbohydrate UPFs, monosodium glutamate, UPFs, and advanced glycated end-products (AGEs) was associated with the occurrence of allergic diseases. Exposure to UPFs and common ingredients in UPFs seem to be associated with increased occurrence of allergic diseases such as asthma, wheezing, food allergies, atopic dermatitis, and allergic rhinitis, in many, but not all studies.

CONCLUSION

More preclinical and clinical studies are required to better define the link between UPF consumption and the risk of allergies and asthma. These observational studies ideally require supporting data with clearly defined UPF consumption, validated dietary measures, and mechanistic assessments to definitively link UPFs with the risk of allergies and asthma.

The potential of orally exposed risk factors and constituents aggravating food allergy: Possible mechanism and target cells

Food allergy is a significant concern for the health of humans worldwide. In addition to dietary exposure of food allergens, genetic and environmental factors also play an important role in the development of food allergy. However, only the tip of the iceberg of risk factors in food allergy has been identified. The importance of food allergy caused by orally exposed risk factors and constituents, including veterinary drugs, pesticides, processed foods/derivatives, nanoparticles, microplastics, pathogens, toxins, food additives, dietary intake of salt/sugar/total fat, vitamin D, and therapeutic drugs, are highlighted and discussed in this review. Moreover, the epithelial barrier hypothesis, which is closely associated with the occurrence of food allergy, is also introduced. Additionally, several orally exposed risk factors and constituents that have been reported to disrupt the epithelial barrier are elucidated. Finally, the possible mechanisms and key immune cells of orally exposed risk factors and constituents in aggravating food allergy are overviewed. Further work should be conducted to define the specific mechanism by which these risk factors and constituents are driving food allergy, which will be of central importance to the targeted therapy of food allergy.

The journey toward disease modification in cow milk protein allergy

Cow milk protein allergy (CMPA) is one of the most common food allergies in the pediatric age worldwide. Prevalence, persistence, and severity of this condition are on the rise, with a negative impact on the health-related quality of life of the patients and families and on the costs related to its management. Another relevant issue is that CMPA in early life may be the first stage of the "allergic march," leading to the occurrence of other atopic manifestations later in life, especially asthma, atopic eczema, urticaria, and rhinoconjunctivitis. Thus, "disease modification" options that are able to modulate the disease course of pediatric patients affected by CMPA would be very welcomed by affected families and healthcare systems. In this review, we report the most relevant progress on this topic.

Atopic dermatitis and IgE-mediated food allergy: Common biologic targets for therapy and prevention

OBJECTIVE

To highlight common mechanistic targets for the treatment of atopic dermatitis (AD) and IgE-mediated food allergy (IgE-FA) with potential to be effective for both diseases and prevent atopic progression.

DATA SOURCES

Data sources were PubMed searches or National Clinical Trials (NCT)-registered clinical trials related to AD, IgE-FA, and other atopic conditions, especially focused on the pediatric population.

STUDY SELECTIONS

Human seminal studies and/or articles published in the past decade were emphasized with reference to preclinical models when relevant. NCT-registered clinical trials were filtered by inclusion of pediatric subjects younger than 18 years with special focus on children younger than 12 years as a critical period when AD and IgE-FA diseases may often be concurrent.

RESULTS

AD and IgE-FA share several pathophysiologic features, including epithelial barrier dysfunction, innate and adaptive immune abnormalities, and microbial dysbiosis, which may be critical for the clinical progression between these diseases. Revolutionary advances in targeted biologic therapies have shown the benefit of inhibiting type 2 immune responses, using dupilumab (anti-interleukin-4Rα) or omalizumab (anti-IgE), to potentially reduce symptom burden for both diseases in pediatric populations. Although the potential for biologics to promote disease remission (AD) or sustained unresponsiveness (IgE-FA) remains unclear, the refinement of biomarkers to predict infants at risk for atopic disorders provides promise for prevention through timely intervention.

CONCLUSION

AD and IgE-FA exhibit common features that may be leveraged to develop biologic therapeutic strategies to treat both conditions and even prevent atopic progression. Future studies should be designed with consistent age stratification in the pediatric population and standardized regimens of adjuvant oral immunotherapy or dose escalation (IgE-FA) to improve cross-study interpretation.

Association of Soda Drinks and Fast Food with Allergic Diseases in Korean Adolescents: A Nationwide Representative Study

INTRODUCTION

A high consumption of carbonated soft drinks (i.e., soda drinks) and fast food is potentially associated with the observed global rise in adolescent allergic diseases. Thus, our study aimed to examine the potential associations between the consumption of soda drinks and fast food and allergic conditions, identifying specific relationships across subgroups and each allergic condition (asthma, allergic rhinitis, and atopic dermatitis).

METHODS

This study uses large-scale data from the Korea Youth Risk Behavior Web-Based Survey (total n = 865,614). Soda drinks and fast food were defined by a self-reported questionnaire and allergic conditions by physician-diagnosed within 1 year. Multivariable logistic regression was used to analyze the weighted odds ratios (ORs), along with 95% confidence intervals (CIs), for allergic diseases associated with the intake of soda drinks and fast food.

RESULTS

Among 865,614 adolescents in grades 7-12 (male, 51.40%), patients with asthma, allergic rhinitis, and atopic dermatitis were 18,568 (2.15%), 153,536 (17.74%), and 59,014 (6.82%), respectively. Current asthma was associated with soda drinks (OR, 1.07; 95% CI, 1.03-1.12) and fast food consumption (1.25; 1.17-1.33). Interestingly, stronger associations were observed for female high schoolers, compared to male high schoolers and middle schoolers, in relation to the consumption of soda drinks (1.31; 1.19-1.44) and fast food (1.46; 1.26-1.69) with asthma. Current allergic rhinitis and atopic dermatitis had no significant association with fast food consumption and soda drinks.

CONCLUSION

This first large-scale study suggests that fast food and soda drinks consumption are potentially associated with current asthma, with stronger associations observed in females than males, underscoring the need for sex-specific allergy prevention programs.

Metabolomics in Children Cow's Milk Protein Allergy: Possible Contribution from a System Biology Approach?

One of the most frequent triggers of food anaphylaxis in pediatric age but also among the most common, early, and complex causes of childhood food allergy is cow's milk protein allergy (CMPA). The diagnostic course and management of this allergy is defined in a complex clinical picture due to several factors. First of all, the epidemiological data are not uniform, mainly as a consequence of the diagnostic methodology used in the various studies and the different age ranges covered. In addition, there is the complexity of terminology, since although CMPA traditionally refers to immune-mediated reactions to cow's milk, it is a term encompassing numerous clinical features with different symptoms and the requirement for specific treatments. Moreover, the differential diagnosis with other very frequent diseases, especially in the first year of life, such as gastro-esophageal reflux disease or colic, is still complex. This can result in misdiagnosis and incorrect treatment, with harmful health consequences and significant economic repercussions. In this context, the combination of several omics sciences together, which have already proved useful in clarifying the allergenicity of cow's milk proteins with greater precision, could improve the diagnostic tests currently in use through the identification of new, more specific, and precise biomarkers that make it possible to improve diagnostic accuracy and predict the patient's response to the various available treatments for the recovery of tolerance.

The Role of Gut Microbiota and Leaky Gut in the Pathogenesis of Food Allergy

Food allergy (FA) is a growing public health concern, with an increasing prevalence in Western countries. Increasing evidence suggests that the balance of human gut microbiota and the integrity of our intestinal barrier may play roles in the development of FA. Environmental factors, including industrialization and consumption of highly processed food, can contribute to altering the gut microbiota and the intestinal barrier, increasing the susceptibility to allergic sensitization. Compositional and functional alterations to the gut microbiome have also been associated with FA. In addition, increased permeability of the gut barrier allows the translocation of allergenic molecules, triggering Th2 immune responses. Preclinical and clinical studies have highlighted the potential of probiotics, prebiotics, and postbiotics in the prevention and treatment of FA through enhancing gut barrier function and promoting the restoration of healthy gut microbiota. Finally, fecal microbiota transplantation (FMT) is now being explored as a promising therapeutic strategy to prevent FA in both experimental and clinical studies. In this review article, we aim to explore the complex interplay between intestinal permeability and gut microbiota in the development of FA, as well as depict potential therapeutic strategies.