The intestinal epithelium contains columnar epithelial cells (ECs) and M cells, and fucosylation of the apical surface of ECs and M cells is involved in distinguishing the two populations and in their response to commensal flora and environmental stress. Here, we show that fucosylated ECs (F-ECs) were induced in the mouse small intestine by the pro-inflammatory agents dextran sodium sulfate and indomethacin, in addition to an enteropathogen derived cholera toxin. Although F-ECs showed specificity for the M cell-markers, lectin Ulex europaeus agglutinin-1 and our monoclonal antibody NKM 16-2-4, these cells also retained EC-phenotypes including an affinity for the EC-marker lectin wheat germ agglutinin. Interestingly, fucosylation of Peyer's patch M cells and F-ECs was distinctly regulated by alpha(1,2)fucosyltransferase Fut1 and Fut2, respectively. These results indicate that Fut2-mediated F-ECs share M cell-related fucosylated molecules but maintain distinctive EC characteristics, Fut1 is, therefore, a reliable marker for M cells. (C) 2010 Elsevier Inc. All rights reserved.