The rationale in using recombinant L. lactis for a local delivery of IL-10 in IBD is due to the large number of scientific studies proving that the topical treatment with this cytokine has clinic benefits[100] although systemic IL-10 administration in Crohn’s disease patients has been associated with considerable side effects which are partly due to the fact that systemic IL-10 induces the pro-inflammatory cytokine IFN-γ[101-103]. The gene discussed is IL10; the disease is inflammatory bowel disease.