Oral exposure to nano- and microplastics: Potential effects in food allergies?

Food allergies (FA) is an inappropriate immune response to dietary antigens and ranks among the most common chronic diseases globally, with a rising incidence. Environmental exposure significantly influences the development of FA. In modern life, hundreds of thousands of novel environmental contaminants have been introduced, including nano- and microplastics (NMPs). The recently introduced 'Epithelial Barrier Theory' suggests that NMPs damage the epithelium of our skin, lungs and gastrointestinal system. And studies also have shown a correlation between NMPs exposure and allergic diseases, such as allergic asthma and rhinitis. However, the relationship between NMPs and FA remains unclear. There is a possibility that high concentrations of NMPs in the diet and environment could increase the prevalence or severity of FA. This review aimed to provide relevant information on the possible effects of NMPs exposure on FA. Contaminating NMPs can interact with food allergens in the food matrix, potentially binding to and altering their structure. Moreover, NMPs might decrease the gastrointestinal digestibility of food allergens, increase intestinal permeability, promote an intestinal inflammatory environment in the intestines, cause intestinal dysbiosis or interfere with immune systems-all of which might enhance sensitivity to food allergens. Given the limited information on the impacts of NMPs exposure regarding to the risk of FA development, further research is needed to determine whether NMPs could amplify the risk of allergic sensitization to food proteins.