Multi-Perspective Observation on the Prevalence of Food Allergy in the General Chinese Population: A Meta-Analysis

Quantitative food allergen risk assessment: Evolving concepts, modern approaches, and industry implications

Food safety is crucially linked to the food system, ensuring safe production, handling, and distribution to protect public health. Food allergy has been considered as a public health and food safety issue. Despite being widely regarded as a prevailing strategy for managing food allergies, strict food avoidance faces challenges due to allergen cross-contact in the food supply chain and the potential for inaccurate allergen labeling. Hence, a scientific approach to assess allergen risk in this context is imperative. In this review, a novel approach to managing food allergies, referred to as quantitative food allergen risk assessment, is presented. This discussion covered the evolving concepts and modern analytical approaches. Moreover, this review delves into the current application of quantitative food allergen risk assessment. Finally, a valuable tool for food allergen risk assessment in the food industry, Voluntary Incidental Trace Allergen Labelling (VITAL), was introduced. The establishment of a globally harmonized and standardized quantitative food allergen risk assessment framework could facilitate the promotion of international harmonization of allergen labeling, support food allergic consumers in making safe food choices, and safeguard the health of allergic individuals across various regions and ethnicities. The implementation of food allergen risk assessment could ensure both food supply chain safety and guide the establishment of acceptable allergen cross-contact levels, enhancing food safety and bolstering the integrity and sustainability of the food system.

Oral exposure to ovalbumin alters glucose metabolism in sensitized mice: upregulation of HIF-1α-mediated glycolysis

Food allergies are pathological adverse reactions against harmless dietary proteins. While studies have shown the involvement of host metabolic changes (e.g., lipid metabolism and amino acid metabolism) in the development of food allergy (FA), the adaptive changes in glucose metabolism induced by food allergen exposure remain largely unclear. In this study, BALB/c mice were sensitized intraperitoneally with an ovalbumin (OVA)/aluminum adjuvant, followed by oral OVA challenges to induce anaphylaxis. Increased levels of serum OVA-specific IgE and MCPT-1, and Th2 response bias were also presented in FA mice. Subsequently, the intestinal untargeted metabolomic analysis revealed the signature enrichment of glycolysis, manifested by increases in glycolytic metabolites including glucose-6-phosphate, fructose-6-phosphate, 2-phosphoglycerate, and lactate in FA mice. Consistently, the serum lactate level was found to be significantly elevated in allergic mice. Oral administration of OVA also upregulated the expression of critical metabolic enzymes in glycolysis, namely hexokinase 2, phosphoglycerate mutase 1, and lactate dehydrogenase. Moreover, the hypoxia inducible factor-1 (HIF-1) signaling pathway was activated in FA mice, and the expression of HIF-1α, known as the upstream regulator of glycolysis, was increased after oral OVA challenges. In vitro inhibition of HIF-1α was found to impede mast cell inflammatory responses to allergens. In summary, this study demonstrated that OVA-induced FA exhibited a glucose metabolic feature of HIF-1α-mediated glycolysis upregulation, suggesting the potential of HIF-1α/glycolysis targeted strategies in the alleviation of FA.

Food Allergy in Children in China

The prevalence of food allergies in China seems to be increasing, but there are limited studies describing the pattern of food allergies across the country. This review highlights regional variations observed across China, with data indicating a higher prevalence in the more economically developed eastern and southern coastal regions compared to inland areas. Egg and milk are the most common allergies among children under 3 years old; for children above 3 years old, specific food allergens also show regional differences, with shellfish allergies being more common in southern and eastern coastal areas, while wheat and fruit allergies are more prevalent in northern regions. Emerging peanut and tree nut allergies have also been observed in China's megacities, although the prevalence remains relatively low compared to Western countries. These geographic and environmental influences highlight the complexity of the food allergy landscape in China and the need for a more nuanced understanding of the underlying drivers. Despite the growing burden of food allergies, significant gaps exist in effectively managing these conditions in China. Lack of standardised diagnostic tools, limited access to oral food challenges and a shortage of trained allergists pose major challenges. Another critical gap is the limited availability and affordability of epinephrine autoinjectors, essential for managing life-threatening anaphylactic reactions. Addressing these systemic deficiencies in China's food allergy management infrastructure will require concerted efforts from policymakers, healthcare systems and pharmaceutical companies. Investing in the development of standardised diagnostics, expanding the allergy speciality workforce and ensuring equitable access to emergency care and treatment options are crucial steps towards improving health outcomes for the millions of individuals affected by food allergies in China.

Precision risk assessment in wheat allergy: Leveraging advanced quantitative models for safer food consumption

Food allergy is a significant public health concern and food safety issue. Deriving from classical toxicology principle, the food allergen risk assessment has been considered a science-based strategy to identify, quantify, and manage the food allergy risks as such risk represent a significant food safety. Moreover, the implication of the precautionary allergen labeling in most jurisdictions is voluntary, resulting potential risk to allergic consumers. In this study, a quantitative risk assessment technique was employed to evaluate the risk of wheat allergy in prepackaged foods. The assessment utilized probabilistic models, including the lognormal, Weibull, Gamma distributions, and Bayesian model averaging. The predicted allergic reactions were determined to be 682, 854, 677, and 721 incidents per 10,000 eating occasions within wheat allergic population, respectively. The findings of this study revealed that the consumption of prepackaged foods containing gluten without wheat/gluten summary (i.e., ingredient) labeling would potentially pose the risk of allergic reactions to wheat allergic individuals. The utilization of quantitative risk assessment methodology at different points of the food system facilitates alleviating unnecessary concerns to stakeholders while maintaining a reasonable knowledge of allergy risk and providing valuable guidance in formulating effective management strategies to mitigate the risk of food allergies, thereby contributing to the overall safety of the sustainable food system.

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.

Systematic review and meta-analyses on the accuracy of diagnostic tests for IgE-mediated food allergy

The European Academy of Allergy and Clinical Immunology (EAACI) is updating the Guidelines on Food Allergy Diagnosis. We aimed to undertake a systematic review of the literature with meta-analyses to assess the accuracy of diagnostic tests for IgE-mediated food allergy. We searched three databases (Cochrane CENTRAL (Trials), MEDLINE (OVID) and Embase (OVID)) for diagnostic test accuracy studies published between 1 October 2012 and 30 June 2021 according to a previously published protocol (CRD42021259186). We independently screened abstracts, extracted data from full texts and assessed risk of bias with QUADRAS 2 tool in duplicate. Meta-analyses were undertaken for food-test combinations for which three or more studies were available. A total of 149 studies comprising 24,489 patients met the inclusion criteria and they were generally heterogeneous. 60.4% of studies were in children ≤12 years of age, 54.3% were undertaken in Europe, ≥95% were conducted in a specialized paediatric or allergy clinical setting and all included oral food challenge in at least a percentage of enrolled patients, in 21.5% double-blind placebo-controlled food challenges. Skin prick test (SPT) with fresh cow's milk and raw egg had high sensitivity (90% and 94%) for milk and cooked egg allergies. Specific IgE (sIgE) to individual components had high specificity: Ara h 2-sIgE had 92%, Cor a 14-sIgE 95%, Ana o 3-sIgE 94%, casein-sIgE 93%, ovomucoid-sIgE 92/91% for the diagnosis of peanut, hazelnut, cashew, cow's milk and raw/cooked egg allergies, respectively. The basophil activation test (BAT) was highly specific for the diagnosis of peanut (90%) and sesame (93%) allergies. In conclusion, SPT and specific IgE to extracts had high sensitivity whereas specific IgE to components and BAT had high specificity to support the diagnosis of individual food allergies.

Large-scale automatic extraction of agricultural greenhouses based on high-resolution remote sensing and deep learning technologies

Widely used agricultural greenhouses are critical in the development of facility agriculture because of not only their huge capacity in food and vegetable supplies, but also their environmental and climatic effects. Therefore, it is important to obtain the spatial distribution of agricultural greenhouses for agricultural production, policy making, and even environmental protection. Remote sensing technologies have been widely used in greenhouse extraction mainly in small or local regions, while large-scale and high-resolution (~ 1-m) greenhouse extraction is still lacking. In this study, agricultural greenhouses in an important agricultural province (Shandong, China) are extracted by the combination of high-resolution remote sensing images from Google Earth and deep learning algorithm with high accuracy (94.04% for mean intersection over union over test set). The results demonstrated that the agricultural greenhouses cover an area of 1755.3 km2, accounting for 1.11% of the total province and 2.31% of total cultivated land. The spatial density map of agricultural greenhouses also suggested that the facility agriculture in Shandong has obviously regional aggregation characteristics, which is vulnerable in both environment and economy. The results of this study are useful and meaningful for future agriculture planning and environmental management.

Positive rate of wheat allergens in the Chinese allergic population: a systematic review and meta-analysis

In recent years, the prevalence of allergic diseases has increased significantly, causing great concern, and wheat, as one of the top 8 food allergens, is a common allergy trigger. Nevertheless, reliable estimates of the positivity rate of wheat allergens in the allergic population in China are still lacking. The systematic review and meta-analysis aims to evaluate the positive detection rate of wheat allergens in the Chinese allergic population and further provide a reference for the prevention of allergy. CNKI, CQVIP, WAN-FANG DATA, Sino Med, PubMed, Web of Science, Cochrane Library, and Embase databases were retrieved. Related research and case reports about the positive rate of wheat allergen in the Chinese allergic population published from inception to June 30, 2022, were searched, and meta-analysis was performed using Stata software. The pooled positive rate of wheat allergens and 95% confidence interval were calculated by random effect models, and the publication bias was evaluated using Egger's test. A total of 13 articles were included for the final meta-analysis, in which wheat allergen detection methods involved only serum sIgE testing and SPT assessment. The results showed that the wheat allergen positivity detection rate in Chinese allergic patients was 7.30% (95% CI 5.68-8.92%). Subgroup analysis showed that the positivity rate of wheat allergens was influenced by region, but hardly by age and assessment method. The positive rates of wheat allergy in the population with allergic diseases were 2.74% (95% CI 0.90-4.58%) and 11.47% (95% CI 7.08-15.87%) in southern and northern China, respectively. In particular, the positive rates of wheat allergens were greater than 10% in Shaanxi, Henan and Nei Mongol, all of which belong to the northern region. These results suggest that wheat allergens are an important cause of sensitization in allergic populations from northern China, and therefore attention should be paid to early prevention in high-risk populations.