Tuna Oil Attenuates Crab Tropomyosin-Induced Food Allergy in Mice via Modulation of Intestinal Immunity, Microbiota, and Proteome

Food allergies, particularly to crustaceans, are a growing health concern with limited management options. We heterologously expressed and purified crab tropomyosin and then evaluated the beneficial effects of tuna oil on crab TM-induced food allergy in mice. The results demonstrated that tuna oil dose-dependently alleviated allergic symptoms and reduced serum levels of TM-specific IgE, histamine, and cytokines. It also improved intestinal dendritic cell imbalance by reducing CD11c+CD80+/CD86+ cells and restoring CD103+ subsets. In addition, tuna oil enhanced the richness and diversity of gut microbiota, increased beneficial Ligilactobacillus, and decreased allergy-associated taxa. Proteomics further revealed that tuna oil partially reversed TM-induced colonic proteomic alterations, including the downregulation of Tpsab1 and the modulation of lipid metabolism pathways. In conclusion, tuna oil alleviates crab TM-induced allergy through integrated regulation of intestinal immunity, gut microbiota, and colonic proteome, supporting its potential as a dietary strategy against crustacean allergy.