Compositional Analysis of Black-Bone Chicken Egg Yolk Oil and Its Mechanism of Action in Alleviating Allergic Response in β-Lactoglobulin-Sensitized Mice

Objective: To investigate the major components of black-bone chicken egg yolk oil (BYO) and its ability to promote the digestion of allergenic proteins and to elucidate its mechanism of action in alleviating β-lactoglobulin (β-LG)-induced allergic responses in mice. Methods: The fatty acid composition of BYO and normal Huainan partridge egg yolk oil (NYO) was analyzed using gas chromatography-tandem mass spectrometry (GC-MS/MS). In vitro simulated adult and infant digestion models were employed to evaluate their effects on the hydrolysis degree of milk powder, casein, and β-LG, as well as the binding capacity to immunoglobulin E (IgE). A β-LG-sensitized BALB/c mouse model was established and four groups of mice were set up: control, model, low-dose BYO (OL, 3 g/kg), and high-dose BYO (OH, 6 g/kg). Growth performance, serum immune factors including IgG, IgE, and histamine (His), spleen and jejunum histopathology, and T helper 1 cells (Th1)/T helper 2 cells (Th2) immune balance were assessed. Results: BYO contained significantly higher levels of ω-3 polyunsaturated fatty acids (e.g., α-linolenic acid) and significantly lower levels of ω-6 polyunsaturated fatty acids (e.g., arachidonic acid) compared with NYO. In vitro digestion experiments showed that BYO significantly increased the hydrolysis of allergenic proteins and significantly reduced the IgE-binding capacity of their digestive products. In vivo assays showed that BYO intervention (6 g/kg) dose-dependently improved body mass loss, splenic inflammatory infiltration and jejunal barrier damage, and inhibited the increase in spleen index, allergy symptom scores, and serum IgE, IgG, and His levels in β-LG-induced mice. It also upregulated T-bet and Foxp-3 expression, promoted Ifn-γ expression, and downregulated Gata-3 and IL-4 expressions, thereby restoring the Th1/Th2 balance. Conclusion: BYO, rich in ω-3 polyunsaturated fatty acids, alleviates β-LG-induced allergic responses through multiple mechanisms, including promoting protein digestion, regulating Th1/Th2 imbalance, suppressing inflammation, and repairing intestinal barrier function. This finding highlights its potential as a natural anti-allergic functional food.