Abstract

Objective: The aim of this study was to develop and evaluate non-antibiotic strategies againstHelicobacter pyloriby establishing a bovine immune milk platform and designing a synergistic multi-antigen immunogen to enhance humoral immune responses. Methods: InactivatedHelicobacter pylori(H. pylori)was used to immunize dairy cows, and the resulting immune milk was characterized for antibody specificity, acid stability, and target antigens via ELISA, Western blot, agglutination assays, and mass spectrometry. Key identified antigens (UreA, UreB, UreE, UreG, HypA, FlaA, and FlaB) were produced as recombinant proteins. Their immunogenicity was evaluated in a murine model, comparing single antigens with various protein combinations. Immune responses were assessed by antigen-specific IgG ELISA, bacterial agglutination titers, flow cytometry for T-cell activation, and histopathology for safety. Results: Immune milk contained high-titer, acid-stable IgG antibodies targeting multipleH. pylorivirulence factors. In mice, while single proteins induced specific IgG, a multi-antigen cocktail (FlaA + FlaB + HypA + UreA + UreB + UreE + UreG) elicited significantly higher serum agglutination titers (~7 × 103) than single antigens or inactivated whole-cell vaccine, alongside robust CD4+T-cell activation. No formulations showed any hepatorenal or splenic toxicity. Conclusion: Bovine immune milk is a viable platform for acid-stable antibody delivery. A rationally designed multi-antigen cocktail synergistically enhances functional humoral immunity in vivo, providing a promising foundation for developing antibody-based or subunit vaccine strategies againstH. pylori.