In this study, the microbial community of cholesterol gallstones and bile were examined by polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE). The DGGE results showed that there are 13 genera in cholesterol gallstones. Pseudomonas was the dominant bacterium; moreover, Klebsiella and Bacillus had greater abundance than other genera. There were 6 genera disclosed in both of cholesterol gallstones and bile. In 4 patients, the bacteria community of cholesterol gallstones had higher similarity than from bile. The bacterial species that can cause the formation of cholesterol gallstones may be similar between different patients. The highest similarity coefficient between cholesterol gallstones and bile was only 38%, indicating the bacterial community of cholesterol gallstone was different from bile.
