['To study the mechanism by which Helicobacter pylori (H pylori) damages human gallbladder epithelial cells (HGBEC).', 'H pylori isolated from gallbladder were cultured in a liquid medium. Different concentration supernatants and sonicated extracts of H pylori cells were then added to HGBEC in a primary culture. The morphological changes in HGBEC as well as changes in the levels of alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and glutamyltransferase (GGT) were measured.', 'According to the culture curve of HGBEC, it was convenient to study the changes in HGBEC by adding H pylori sonicated extracts and H pylori culture supernatants. Both H pylori sonicated extracts and H pylori culture supernatants had a significant influence on HGBEC morphology, i.e. HGBEC grew more slowly, their viability decreased and their detachment increased. Furthermore, HGBEC ruptured and died. The levels of ALP (33.84+/-6.00 vs 27.01+/-4.67, P<0.05), LDH (168.37+/-20.84 vs 55.51+/-17.17, P<0.01) and GGT (42.01+/-6.18 vs 25.34+/-4.33, P<0.01) significantly increased in the HGBEC culture supernatant in a time- and concentration-dependent. The damage to HGBEC in H pylori culture liquid was more significant than that in H pylori sonicated extracts.'] Does helicobacter pylori damage human gallbladder epithelial cells in vitro?