Comparative studies on allergic ability, gut microbiota and metabolic pathways of fish parvalbumin, shrimp tropomyosin, egg ovalbumin and milk β-lactoglobulin to mice

The present article aims to perform a comparative study whether the allergic ability of fish parvalbumin, shrimp tropomyosin, egg ovalbumin and milk β-lactoglobulin to BALB/c mice was associated with gut microbiota-sera metabolism. BALB/c mice were given the same amount of four allergens to establish an allergic model, and four allergens presented different allergic abilities to mice, which resulted in increased of IgE, IgG and IgG₁ levels, allergy symptom scores, spleen and thymus index. Meanwhile, these allergens reduced the relative abundance of allergy-associated gut microbiota, such as Lachnospiraceae_NK4A136_group, Lachnospiraceae, Blautia, Roseburia and Oscillibacter. Four allergens also downregulated the serotonin metabolic pathway, upregulated the indole and kynurenine pathways, and significantly affected the glycerophospholipid metabolic pathway. Overall, the disruption of the allergy-associated gut microbiota and regulating tryptophan and glycerophospholipid metabolic pathway were responsible for increasing the allergic ability of four allergens, which have different antigenic epitopes resulting in different allergic abilities.