GSTM1 and ulcerative colitis: UC: ulcerative colitis; CD: Crohn's disease; CFU: colony-forming unit; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; Hb: hemoglobin; IBD: inflammatory bowel disease; QOL: quality of life; FCAL: fecal calprotectin; UCDAI: Ulcerative Colitis Disease Activity Index; EcN: Escherichia coli Nissle; CDAI: Crohn's Disease Activity Index; DC: dendritic cell; TLR: Toll-like receptor; IL: interleukin; ITT: intention to treat; DAI: disease activity index; EI: endoscopic index; CFU: colony-forming unit