Lactobacillus complex fermentation of whey protein to reduce foodborne allergy symptoms in mice

Bovine whey protein, a common ingredient in foods for infants and young children, represents the primary source of nutrition for this demographic. However, bovine whey protein contains β-lactoglobulin (β-LG), which is not found in human whey protein, and some α-lactalbumin (α-LA) with a different amino acid sequence, which has the potential to cause allergic reactions. Eating bovine whey protein can cause allergic reactions in the human immune system. This phenomenon refers to an allergy to bovine whey protein. It is estimated that this condition affects 1.9% to 4.9% of infants globally. <i>Lactobacilli</i> possess a robust protein hydrolysis system capable of disrupting epitopes associated with whey protein allergies while yielding hydrolyzed products and bioactive peptides. This process represents a safe and effective approach to reducing the allergenicity of milk. Consequently, we established a mouse model for whey protein allergy and evaluated the effects of fermented whey protein produced by <i>Lactobacillus</i> on allergic symptoms in mice using ELISA, real-time fluorescence quantitative PCR (RT-qPCR), and HE staining techniques. Furthermore, we analyzed the intestinal flora of allergic mice through 16S rDNA sequencing to elucidate the relationship between <i>Lactobacillus</i>-mediated alterations in gut microbiota and allergic phenotypes within this study. The results showed that compared with the whey protein group, the levels of immunoglobulin E (IgE), histamine and mast cell protease in the serum of mice in the lactic acid bacteria fermented whey protein group were significantly increased, and the secretion of T helper 2 (Th2) type cytokines was inhibited, the production of T helper 1 (Th1) type cytokines was promoted, and the inflammation caused by sensitized mice was significantly alleviated. Furthermore, the fermentation of whey protein by <i>Lactobacillus</i> resulted in an improvement in the intestinal flora of mice, accompanied by promotion of the growth of probiotics such as <i>Lactobacillus</i>, <i>Odoribacter</i> and <i>Bacteroides</i>. This effectively alleviated the allergic reaction in mice. The findings of this experiment provide a theoretical basis for the development of hypoallergenic dairy products and offer a certain degree of guidance for the clinical treatment of allergic diseases.