This invention relates to methods of preserving the integrity of peptides inthe gut. In particular it concerns the useof certain compounds as inhibitors of gut proteases. Compounds identified ashaving gut protease inhibitory activity arebiguanides, certain bile acids and pharmaceutically acceptable salts of thesecompounds. This activity makes these compoundsuseful for co-administration with prophylactic or therapeutic peptides. Thisinvention relates to methods of inhibiting gutproteases and peptide formulations comprising these gut protease inhibitor.
