Immunosuppressive Effects via Human Intestinal Dendritic Cells of Probiotic Bacteria and Steroids in the Treatment of Acute Ulcerative Colitis

Abstract

BACKGROUND: In ulcerative colitis (UC) gut bacteria drive inflammation. Bacterial recognition and T-cell responses are shaped by intestinal dendritic cells (DCs); therapeutic effects of probiotic bacteria may relate to modulation of intestinal DC. The probiotic mixture, VSL#3, increases interleukin (IL)-10 and downregulates IL-12p40 production by DC in vitro. We evaluated in vivo effects of oral VSL#3 and steroids on colonic DC in patients with acute UC. METHODS: Rectal biopsies were obtained from patients with active UC before and after treatment with VSL#3, corticosteroids, or placebo, and from healthy controls. Myeloid colonic DC were studied from freshly isolated lamina propria cells usi..