IL1B and colitis: Antibiotic-treated mice receiving melatonin-treated feces showed marked relief of Oxa-induced colitis, including weight loss, colonic shortening, and histological severity (Figures 7B–G), which coincided with a decrease in the level of the inflammatory cytokine TNFα, but not in the level of IL-1β, in the colon (Figures 7H, I).