Dysbiosis of the Fecal Microbiota in Patients with Cholangiocarcinoma: A Pilot Study

Background: Cholangiocarcinoma (CCA)-associated gut microbiota dysbiosis remains undefined. Our research assessed associations between changes in the gut microbiota and CCA. Methods: The composition and diversity of the fecal microbiota of 40 patients with CCA and 95 healthy controls were determined with 16S rRNA sequencing. Findings: The abundance and diversity of the gut microbiota were markedly reduced in the CCA group compared with the healthy control group, although most of the gut microorganisms were the same. Firmicutes and Bacteroidetes were the most dominant phyla in both groups. Proteobacteria (12.87% vs. 3.38%) was the third dominant phylum in the CCA group and was significantly more prevalent than in the healthy control group. In the CCA group, 21 genera were dominant, accounting for 83.89% of all genera. In the healthy control group, 19 genera were dominant, accounting for 84.72%. Fifteen genera were shared between groups. Among the dominant genera, Bacteroides, Roseburia, Blautia, Lachnospiracea_incertae_sedis, and Ruminococcus were significantly less abundant (p<0.05), and Escherichia, Streptococcus, Klebsiella and Veillonella were significantly more abundant in the CCA (p<0.05). The most significant metabolic pathways related to the gut microbiota were Neurodegenerative Diseases, Metabolism of Other Amino Acids, Infectious Diseases, Metabolism, and Amino Acid Metabolism. Lastly, diagnostic models constructed from nine genera distinguished the CCA and healthy control groups (area under the curve of 0.8424 for the training set and 0.8185 for the validation set). Interpretation: Gut microbiota dysbiosis may plan an important role in CCA pathogenesis. Funding Statement: This work is supported by the Zhejiang Provincial Natural Science Foundation of China (Grant No. LY17H160010). Declaration of Interests: All authors confirm that there are no conflicts of interest concerned about this research. Ethics Approval Statement: The institutional ethics committee of the First Affiliated Hospital, College of Medicine, Zhejiang University, approved the study protocol. All participants signed written informed consent prior to enrollment.