The present invention concerns antibodies recognizing Mycobacterium avium paratuberculosis epitopes able to cross-reacting with the beta-cell antigen ZnT8 to be used as early biomarkers of type 1 diabetes, epitopes for in vitro prognostic and diagnostic methods suitable to reveal a risk to develop type 1 diabetes, therapies for the prevention of T1D by avoiding, controlling or monitoring Mycobacterium paratuberculosis infection.