The present invention relates to the field of peptide delivery for the treatment of non-Helicobacter associated disease, wherein the peptide is delivered at the mucosa in vivo. In particular, the present invention relates to a method for delivering peptides to the mucosal of an animal in need thereof comprising the steps of: i) inserting a gene encoding a peptide into the gene encoding the urease enzyme of Helicobacter pylori to produce an in-frame gene so that the urease enzyme function is not impaired when the in-frame gene is expressed； and ii) infecting said animal such that the Helicobacter pylori colonises the mucosa.
