Insect Protein-Based Diet as Potential Risk of Allergy in Dogs

SIMPLE SUMMARY: There is growing interest in the use of edible insects as an alternative source of protein and fat in food/feed formulations. Yellow mealworm (Tenebrio molitor) larvae are rich in protein and other nutrients. Since insects are related to mites, a common allergenic species in dogs, we investigated the interaction between mealworm proteins and the immune system of allergic dogs sensitised to storage mites in this study. Using Western blot analysis, we confirmed the binding of IgEs from canine sera to mealworm proteins. With mass spectrometry analysis, we identified several T. molitor proteins, which are known as human allergens. The results of our study raised the possibility that dogs allergic to mites clinically show cross-reactivity to mealworm proteins. ABSTRACT: Before insects can be used widely as an alternative source of dietary protein, their allerginicity should be investigated. Therefore, the aim of our study was to assess the potential adverse reactions of the immune system of dogs against Tenebrio molitor proteins. Dogs sensitised to storage mites T. putrescentiae and A. siro were included. Clinically healthy and clinically allergic dogs were compared. Proteins were extracted from mealworm larvae and their digestibility determined by in vitro incubation with digestive proteases. Mealworm protein extracts and digests were analysed by SDS–PAGE. Canine sera tested for the presence of mite-specific IgEs were used for subsequent Western blotting. LC-MS/MS analysis was used to identify mealworm proteins and their allergenic potential was predicted with the AllermatchTM tool. The binding of canine sera IgEs to mealworm proteins was confirmed; however, the differences between the two groups of dogs were not significant. Moreover, no clear correlation was found between sensitisation to storage mites and clinical status of the dogs. Altogether, 17 different proteins were identified, including tropomyosin, α-amylase, and Tm-E1a cuticular protein that are known cross-reacting IgE-binding allergens. Our results suggest that dogs allergic to mites may clinically express also the cross-reactivity with mealworm proteins.