The March 2013 issue of Immunology and Cell Biology contains a special feature that focuses on the role of the intestinal epithelial barrier and innate immune cells, examines their crosstalk with the commensal flora, and assesses their contribution to intestinal immunity in health and disease. There is a complexity of interaction among these distinct components and the Reviews of this special feature examine, unravel and investigate the action and reaction in the intestinal homeostasis‐perturbation cycle. Further background information on this important topic is available through the accompanying web focus which links to related articles from across Nature Publishing Group.