IL9 and colitis: Specifically, B. adolescentis administration reduced diarrhea scores and spleen weight, increased colon length, and lowered cumulative histological grades by decreasing proinflammatory cytokines such as TNFα, IL-6, IL-1β, IL-18, IL-22, IL-9 and increasing anti-inflammatory cytokines IL-10 and IL-4 in mice colitis model.