The results of our randomized, double-blind, double-dummy study over a 12-month period in UC patients showed that the herbal preparation of myrrh, chamomile extract, and coffee charcoal is well tolerated and exhibits a good safety profile. In addition, we found first evidence that the efficacy of this treatment is non-inferior to that of the gold standard therapy mesalazine as maintenance therapy for UC patients. However, the therapeutic effect of the two treatment methods may be introduced via different modes of action. They are crucial in maintaining immune homeostasis and establishing tolerance to foreign, nonpathogenic antigens, including those found in commensal bacteria and food. Because of their potent, antigen-specific suppressive capability, CD4 + CD25high regulatory T cells have special relevance for the course of disease in IBD and may be promising candidates for immune therapy in a variety of chronic inflammatory diseases, including IBD. In fact, in multiple animal models regulatory T cells have been shown to be effective in both the cure and the prevention of experimental colitis. For example, the transfer of regulatory T cells into mice with colitis leads to resolution of the lamina propria infiltrates and reappearance of normal intestinal architecture. Although further investigation is warranted, it has been proposed that active IBD is particularly associated with a quantitative shift rather than a functional defect of regulatory T cells. Therefore, it has been proposed that the relative or absolute number of regulatory T cells plays a crucial role in the prevention and therapy of UC. Current treatment strategies for IBD rely on the use of nonspecific Fingolimod immunosuppressive or anti-inflammatory agents. Because evidence to date suggests that regulatory T cells are indeed functional in IBD patients, expansion of autologous cells might be a feasible therapeutic approach in the future. Well in line with this, we showed that regulatory T cells from healthy donors and UC patients exert similar suppressive activity. Antigen-specific regulatory T cells may offer an effective therapy through specific and potent targeting of the response to disease-driving antigens at the site of inflammation. It is, however, likely that current immunosuppressive or anti-inflammatory approaches influence the course of regulatory T cells, and it may even be possible that they achieve their therapeutic success at least in part via interaction with regulatory T cells. Maul et al. reported a decrease in the frequency of regulatory T cells in the peripheral blood and an increased frequency in mucosal lymphoid tissues in IBD patients with active disease. Regrettably, no information about current medication use was given in this study. Currently, it remains speculative whether the pattern of the Tcell population in the herbal treatment group is a more natural course of regulatory T cells. It is likely, but not yet confirmed, that herbal therapy with myrrh, chamomile extract, and coffee charcoal achieves treatment success not via relevant plasma levels but via direct effects at the mucosa. In contrast, published studies describe a broader spectrum including more systemic effects for mesalazine.