Objective: Enterotoxigenic B. fragilis, which produces a ${sim}20;kDa$ heat-labile toxin (BFT), has been associated with diarrheal diseases and submucosal inflammation. To determine if epithelial cells can contribute to BFT-induced inflammation, we assessed the expression of chemokines by BFT-stimulated human intestinal epithelial cells. Methods: The human intestinal epithelial cell lines, HT-29 and Caco-2, were incubated with purified BFT. Chemokine production was measured by ELISA and mRNA levels were assessed by quantitative RT-PCR. Results: BFT stimulation increased expression of the neutrophil chemoattractant and activators ENA-78, GRO-${alpha}$, and IL-8 in human intestinal epithelial cell lines. Up-regulated chemokine mRNA expression was paralleled by increased protein levels. Moreover, BFT stimulation activated NF-${kappa}B$ in HT-29 epithelial cells assessed by electrophoretic mobility shift assay. The IL-8 secretion was significantly suppressed when NF-${kappa}B$ activity was inhibited. Chemokines were predominantly secreted from the basolateral surface of BFT-treated epithelial cells, whereas lactate dehydrogenase, which was used to monitor cell lysis, was released predominantly from the apical surface. Conclusions: The basolateral secretion of chemokines from BFT-stimulated colon epithelial cells suggests that these chemokines can contribute to the inflammatory cell infiltrate in the underlying intestinal mucosa.