Metagenomic Analysis of Biliary Microbial Flora in Patients with Gallbladder Cancer or Gallstones-Associated Chronic Cholecystitis

Abstract

Biliary dysbiosis is associated with gallbladder cancer (GBC). We aimed to look for biliary bacteria specifically detected in GBC patients. We used 16S rRNA-based metagenomic analysis to elucidate biliary microbiota in 30 GBC and 30 gallstones-associated chronic cholecystitis patients. Relative abundance of five genera, Streptococcus, Enterococcus, Halomonas, Escherichia and Caulobacter was significantly associated with GBC. Of 15-species, 7 were detected significantly higher in GBC, Streptococcus anginosus, Streptococcus constellatus, Streptococcus intermedius, Actinomyces bowdenii, Actinomyces israelii, Actinomyces gerencseriae, and Escherichia fergusonii were biosafety level-2 infectious bacteria; other 8 species were biosafety level-1 bacteria. These bacterial species may be involved in pathogenesis of GBC.

Keywords:

• Metagenomics
• bile
• gallbladder cancer
• chronic cholecystitis
• gallstones
• environmental risk factor

Acknowledgment

We are indebted to Dr. Roli Budhwar of Bionivid Technology Pvt. Ltd. for performing metagenomic analysis.

Declaration of Interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.

Additional information

Funding

This work was supported by JSPS KAKENHI (grant number 17K09103).