Common presence of Helicobacter DNA in the gallbladder of patients with gallstone diseases and controls

Abstract

Background: Several species of Helicobacter colonise the biliary tract of animals and cause hepatobiliary diseases. Helicobacter species have also been identified in the gallbladder of a high proportion of Chilean patients with gallbladder cancer.

Aim: To determine the presence of Helicobacter species, particularly Helicobacter pylori and Helicobacter bilis, in the gallbladder of patients with non-malignant gallbladder diseases and control patients.

Patients and methods: DNA was extracted from gallbladder samples from 122 consecutive patients undergoing cholecystectomy. The presence of Helicobacter genus-specific or Helicobacter pylori and Helicobacter bilis species-specific DNA was determined by polymerase chain reaction and sequence analysis. The presence of Helicobacter pylori-specific immunoglobulin G in the serum (n=84) and bile (n=104) samples was determined by enzyme linked immunosorbent assay.

Results: Helicobacter DNA was detected in 61 (50.0%) gallbladder samples: 29 of 60 (48.3%) patients with symptomatic gallstone, six of 10 (60.0%) patients with asymptomatic gallstones, 11 of 15 (73.3%) patients with other biliary diseases, and 15 of 37 (40.5%) control patients, respectively. Among them, 39 samples were positive for Helicobacter pylori but none were positive for Helicobacter bilis. Sequence analysis of Helicobacter genus-positive samples showed that 56 samples were Helicobacter pylori and five were Helicobacter species 'Liver 3' strain. Overall, there was no significant difference in the detection rate of Helicobacter DNA or the levels of serum and bile Helicobacter pylori-specific immunoglobulin G in the various biliary disease groups compared with control patients. Neither was there any significant difference in the blood biochemistry and liver function tests between patients with positive and negative Helicobacter DNA detection.

Conclusion: Helicobacter species' DNA are commonly present in the gallbladder of patients with gallstone diseases and in controls, implying that Helicobacter infection alone may not play a significant role in the formation of gallstones. However, our results do not exclude the possibility of Helicobacter infection as a cofactor in the development of gallstones.