Microbial variations in the multibody sites of the pancreatic ductal adenocarcinoma patients

Objectives: We aimed to investigate microbial characteristics across multibody sites of pancreatic ductal adenocarcinoma (PDAC) and identify novel microbial markers for PDAC. Method: We conducted 16S ribosomal RNA (rRNA) amplicon sequencing on saliva, duodenal fluid, and pancreatic tissue obtained via endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) from 63 PDAC patients and 22 benign controls. Results: From controls to PDAC patients, the contribution of salivary and duodenal microbes to the assembly of pancreatic microbes increased. In PDAC patients and controls, duodenal microbes contributed more significantly to the pancreatic microbial assembly than salivary microbes. Prevotella dentalis, Peptoanaerobacter stomatis, Slackia exigua , etc. were enriched, whereas Loigolactobacillus coryniformis, Akkermansia muciniphila, Faecalibacterium prausnitzii , etc., were reduced in pancreatic tissue, duodenal fluid, and saliva of PDAC patients ( P < 0.05). We developed microbial classifiers for discriminating PDAC based on the differential species shared among the three sites with the areas under the curves (AUCs) of 0.946, 0.991, and 0.971 in pancreatic tissue, duodenal fluid, and saliva, respectively. Faecalibacterium prausnitzii in duodenal fluid, Prevotella dentalis and Slackia exigua in saliva, and Anaeroglobus geminatus and Propionibacterium acidifaciens across all three sites were “driver” microbes contributing to the variations from controls to PDAC patients. Conclusions: Salivary and duodenal microbes were significant contributors to the pancreatic microbial composition associated with PDAC. Novel microbial markers with high discriminative power were identified, underscoring their potential for PDAC detection.