Microbial relative abundance correlated with survival prognosis in patients with pancreaticobiliary cancers, including cholangiocarcinoma (CCA) and pancreatic adenocarcinoma, according to findings recently published in BMC Microbiology.

Using 16 S rRNA gene amplicon sequencing, researchers analyzed the DNA of microbiota found in the bile collected from surgically resected gallbladders in 244 patients with pancreaticobiliary lesions treated at Kagoshima University in Japan from May 2009 to August 2018. Lesion distribution totaled 112 pancreatic, 101 bile duct (CCA), 17 gallbladder, and 14 other lesions, some of which were benign (n=15).

Lymph node metastasis correlated with microbiota abundance depending on the type of pancreaticobiliary cancer. Campylobacter, Citrobacter, and Leptotrichia significantly increased in patients with CCA with lymph node metastasis compared to those without (P =.025; P =.001; P =.007, respectively). Enterobacter, Hungatella, Mycolicibacterium, Phyllobacterium, and Sphingomonas significantly increased in patients with pancreatic ductal adenocarcinomas with lymph node metastasis compared to those without (P =.004; P =.007; P =.018; P =.023; P =.058, respectively).

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Gender and age also influenced the abundance of various strains of microbiota. Women had a higher abundance of Escherichia and Streptococcus strains compared with men (P =.007; P =.030, respectively). Patients over 70 demonstrated a higher abundance of Sphingomonas and Fusobacterium strains compared with patients under 70 (P =.011; P =.044, respectively).

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Relative abundance of individual microbiota strains provided prognostic value. Overall, patients with a high relative abundance of Enterococcus, Eggerthella, Klebsiella, Corynebacterium, Moraxella, Hungatella, Paracoccus, Dermacoccus, Citrobacter, Lawsonella, and Pseudoxanthomonas exhibited significantly worse prognoses than those lower abundance. Conversely, patients with a higher relative abundance of Streptococcus, Escherichia, Veillonella, and Dialister had better prognoses compared to those with lower abundance.

Patients with CCA with a higher relative abundance of Enterococcus, Corynebacterium, Lawsonella, Staphylococcus, Moraxella, Haemophilis, Hungatella, and Bacteroides had worse prognoses, while the increased presence of Streptococcus, Fusobacterium, and Veillonella had improved prognoses.

Patients with pancreatic lesions with a greater relative abundance of Klebsiella, Veillonella, Paracoccus, Selenomonas, and Acinetobacter demonstrated poorer prognoses, while a higher abundance of Enterococcus, Staphylococcus, Streptococcus, Raoultella, and Bacteroides improved prognosis. While certain microbes correlated with better prognosis in patients with CCA, many of these same microbes indicated worse prognosis in those with pancreatic adenocarcinomas and in reverse.

Due to the elevated risk of metastasis and poor prognosis in patients with pancreaticobiliary tract cancers, “it is critical to establish new diagnostic, prognostic, and therapeutic biomarkers,” the authors said. “Our findings demonstrate that the alterations in the gallbladder microbiota population could be used to accurately distinguish the overall survival prognosis in pancreaticobiliary tract cancer patients after surgery.”

These microbial biomarkers have implications for “patient counseling, decision making regarding individualized therapy, and follow-up scheduling,” they concluded.


Kirishima M, Yokoyama S, Matsuo K, et al. Gallbladder microbiota composition is associated with pancreaticobiliary and gallbladder cancer prognosis. BMC Microbiol. 2022;22(1):147. doi:10.1186/s12866-022-02557-3