Strikingly, some human clinical trials (phase I and II) have been conducted with L. lactis producing either IL-10 or trefoil factor (TTF) to treat, respectively IBD (Braat et al., 2006) and oral mucositis (Limaye et al., 2013), confirming both the feasibility and the potential in the use of recombinant probiotics for human health. Here, IL10 is linked to irritable bowel syndrome.