This study is the first investigation of the effects of polysaccharide extracted from rice bran (RBP) on ovalbumin (OVA)-induced allergy and the gut microbiota, which hasn't been reported previously. RBP in the medium-dose was found to significantly reduce the symptoms of food allergy  (FA) in mice, lower the levels of histamine and allergen-specific (IgE), and attenuate intestinal inflammation. Further studies demonstrated that RBP decreased allergy-associated responses in intestinal epithelial cells and Th2 cells while regulating Th1/Th2 differentiation to reach a dynamic equilibrium and downregulating Th2 polarization caused by allergies.  Short-chain fatty acid (SCFAs) content and 16S rRNA sequencing revealed that RBP enhanced the abundance and diversity of the gut microflora and raised the content of SCFAs. These results suggest that RBP may mitigate FA by modulating the gut microbiota. This study revealed the effective use of rice bran and served as a basis for the development of innovative functional foods with anti-allergic properties.

Studies showed that complexation of polyphenols with milk allergens reduced their immunogenic potential. However, the relationship between structures of polyphenols and their hypoallergenic effects on milk allergens in association with physiological and conformational changes of the complexes remain unclear. In this study, polyphenols from eight botanical sources were extracted to prepare non-covalent complexes with β-lactoglobulin (β-LG), a major allergen in milk. The dominant phenolic compounds bound to β-LG with a diminished allergenicity were identified to investigate their respective role on the structural and allergenic properties of β-LG. Extracts from Vaccinium fruits and black soybeans were found to have great inhibitory effects on the IgE-and IgG-binding abilities of β-LG. Among the fourteen structure-related phenolic compounds, flavonoids and tannins with larger MWs and multi-hydroxyl substituents, notably rutin, EGCG, and ellagitannins were more potent to elicit changes on the conformational structures of β-LG to decrease the allergenicity of complexed β-LG. Correlation analysis further demonstrated that a destabilized secondary structure and protein depolymerization caused by polyphenol-binding were closely related to the allergenicity property of formed complexes. This study provides insights into the understanding of structure-allergenicity relationship of β-LG-polyphenol interactions and would benefit the development of polyphenol-fortified matrices with hypoallergenic potential.

Advanced glycation end-products (AGEs) are a group of heterogeneous compounds formed in heat-processed foods and are proven to be detrimental to human health. Currently, there is no comprehensive database for AGEs in foods that covers the entire range of food categories, which limits the accurate risk assessment of dietary AGEs in human diseases. In this study, we first established an isotope dilution UHPLC-QqQ-MS/MS-based method for simultaneous quantification of 10 major AGEs in foods. The contents of these AGEs were detected in 334 foods covering all main groups consumed in Western and Chinese populations. N^ε-Carboxymethyllysine, methylglyoxal-derived hydroimidazolone isomers, and glyoxal-derived hydroimidazolone-1 are predominant AGEs found in most foodstuffs. Total amounts of AGEs were high in processed nuts, bakery products, and certain types of cereals and meats (> 150 mg/kg), while low in dairy products, vegetables, fruits, and beverages (< 40 mg/kg). Assessment of estimated daily intake implied that the contribution of food groups to daily AGE intake varied a lot under different eating patterns, and selection of high-AGE foods leads to up to a 2.7-fold higher intake of AGEs through daily meals. The presented AGE database allows accurate assessment of dietary exposure to these glycotoxins to explore their physiological impacts on human health.

Cutaneous exposure to food allergens through a disrupted skin barrier is recognized as an important cause of food allergy, and the cutaneous sensitized mouse model has been established to investigate relevant allergic disorders. However, the role of different genetic backgrounds of mice on immune responses to food allergens upon epicutaneous sensitization is largely unknown. In this study, two strains of mice, i.e., the BALB/c and C57BL/6 mice, were epicutaneously sensitized with ovalbumin on atopic dermatitis (AD)-like skin lesions, followed by intragastric challenge to induce IgE-mediated food allergy. Allergic outcomes were measured as clinical signs, specific antibodies and cytokines, and immune cell subpopulations, as well as changes in intestinal barrier function and gut microbiota. Results showed that both strains of mice exhibited typical food-allergic symptoms with a Th2-skewed response. The C57BL/6 mice, rather than the BALB/c mice, were fitter for establishing an epicutaneously sensitized model of food allergy since a stronger Th2-biased response and severer disruptions in the intestinal barrier and gut homeostasis were observed. This study provides knowledge for selecting an appropriate mouse model to study food-allergic responses associated with AD-like skin lesions and highlights the role of genetic variations in the immune mechanism underlying pathogenesis of food allergy.

As one of the most important cereals, wheat (Triticum aestivum) has high nutritional value and is widely cultivated in China. However, wheat can cause severe allergic reactions, and a growing number of people are developing allergies to Chinese wheat. Low molecular weight glutenin (LMW-GS), an important allergen in susceptible populations, is responsible for celiac disease and wheat contacts dermatitis. In this study, LMW-GS was highly purified from Chinese wheat (Xiaoyan 6) and further identified and characterized. In addition, 8 peptides were predicted efficiently by 5 immunological tools, among which five peptides showed significant immunoglobulin E (IgE) binding abilities. Two specific epitopes were found to be in the non-conserved region of the amino acid sequence of LMW-GS, which was speculated to be the specific epitope of Chinese wheat. This systematic research of LMW-GS may provide new insights into the prevention of wheat allergy and development of hypoallergenic wheat products.

Food allergy is one of the most important food safety problems that has attracted increasing attention. The food allergy experimental models provide not only the accurate allergen detection and evaluation methods but also the powerful approaches for mechanism investigations. In this paper, we reviewed the common food allergy cell models including mast cell, basophil granulocyte and basophil, as well as the animal models of BALB/c mouse, C3H/HeJ mouse, and BN rat. We also introduced zebrafish, a promising model organism for investigating immunity though lacking direct applications in food allergy to date, and focused on traumatic inflammation, bacterial infection and viral infection models. In addition, we also summarized the clinical diagnostic research methods for food allergy. The elucidation of these topics will help researchers to understand the characteristics and mechanisms of various models and thus select the proper models for particular study, so as to support further investigations of food allergy.