IL1B and colitis: Moreover, treatment with L. johnsonii also alleviated IS-induced colitis; it suppressed colon shortening [F(1,14) = 15.561, p = 0.001], myeloperoxidase activity [F(1,14) = 82.048, p < 0.001], NF-κB activaton, and IL-6, TNF-α, IL-1β, iNOS, and COX-2 expression (Figs 6o–w and S4a–c).