human metagenome

AbstractBackground: Malignant biliary obstruction (MBO) refers to compression or blockage of the biliary tract by hepato-pancreaticobiliary malignancies. Biliary drainage (BD) is commonly performed in MBO patients. However, the biliary microbiota in MBO and its changes are poorly understood due to the limitations of traditional culture-dependent detection method. Herein, the present study aimed to investigate the biliary microbiota in malignant biliary obstruction and its changes after biliary drainage by next-generation sequencing technology.Methods: Malignant biliary obstruction patients was divided into MBO group (n = 29) and BD group (n = 27) based on whether they had undergone prior biliary drainage. Microbiological features of bile samples from these patients were measured by microbiomics. Conventional bile cultures were also recorded. Bile from liver donors without hepatobiliary pathology were collected as a control group (n = 8) for metagenomic sequencing.Results: Human bile samples from the gallbladder or common bile duct were obtained from liver donors,without any record of hepatobilibary disorder, during liver transplantation surgery. Our analysis revealed that a stable and similar microbiota composition were present in the bile samples of patients with no pathology and those MBO patients who never received biliary procedure. Nevertheless, BD procedures altered the composition of bile microbiota, causing decrease in the diversity and increase in the number of pathogenic bacteria and drug resistance genes.Conclusion: Our findings suggest that the presence of relatively stable microbial communities in biliary tracts (including gallbladders and bile ducts) with no biliary pathology and malignant biliary obstruction. BD alters the composition of the bile microbiota, making it more aggressive and resistant to antibiotics. This provides new insights into biliary tract infections associated with BD.