Document Type: Research Articles
Division of Preventive Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Instituto de Gastroenterologia Boliviano-Japones, La Paz, Bolivia.
Sotero del Rio Hospital, Santiago, Chile.
Faculty of Medical Technology, Niigata University of Health and Welfare, Niigata, Japan.
Faculty of Health and Medical Sciences, Hokuriku University, Kanazawa, Ishikawa, Japan.
Faculty of Health Sciences, Niigata University of Health and Welfare, Niigata, Japan.
Salmonella typhi and Helicobacter infections have been shown to increase risk of gallbladder cancer (GBC), but
findings have been inconsistent. Other bacterial infections may also be associated with GBC. However, information on
microbial pathogens in gallbladder bile of GBC patients is scarce. We aimed to investigate the microbial communities in
gallbladder bile of patients with GBC and cholelithiasis (CL). Seven GBC patients and 30 CL patients were enrolled in
this study. Genomic DNA was extracted from bile and the V3-V4 region of 16S rRNA was amplified. The sequencing
results were compared with the 16S database, and the bacteria were identified by homology searches and phylogenetic
analysis. DNA was detected in the bile of three GBC (42.9%; Bolivia, 1; Chile, 2) and four CL patients (13.3%; Bolivia,
1; Chile, 3). Of the 37 patients, 30 (81.1%) were negative and unable to analyze. Salmonella typhi and Helicobacter sp.
were not detected in bile from any GBC patients. As the predominant species, Fusobacterium nucleatum, Escherichia
coli, and Enetrobacter sp. were detected in bile from GBC patients. Those in bile from CL patients were Escherichia
coli, Salmonella sp., and Enerococcus gallinarum. Escherichia coli was detected in bile samples from both GBC and
CL patients. Whether the bacteria detected in bile from GBC patients would associated with the development of GBC
warrant further investigation.