The present invention relates to the general field of therapy of Inflammatory Bowel Disease (IBD) and/or Irritable Bowel Syndrome (IBS). Thus, the invention relates to a molecule selected from the trappin-2 protein or an active fraction thereof, a member of the WAP family proteins or an active fraction thereof or a member of the Serpin family proteins or an active fraction thereof for the treatment of Irritable Bowel Syndrome (IBS). The invention also relates to a recombinant food-grade bacterium comprising a gene selected from a gene coding for the trappin-2 protein or an active fraction thereof, a gene coding for a member of the WAP family proteins or an active fraction thereof, or a gene coding for a member of the Serpin family proteins or an active fraction thereof.