In the present study, oral administration of S. cerevisiae I4 increased the serum level of IL–10 and decreased the serum level of pro-inflammatory cytokines IL–6, TNF–α and IL–1β of the Balb/c mice induced by DSS, indicating that the strain could inhibit the abnormal pathogenic immune response in the mice with colitis. The gene discussed is IL1B; the disease is colitis.