The tumoral microbiome of pancreatic intraductal papillary mucinous neoplasm: A single-center retrospective cohort study

Background and AimPancreatic intraductal papillary mucinous neoplasm (IPMN) is one of the most common precancerous lesions of pancreatic carcinoma. Studies have found that the tumoral microbiome has an important influence on pancreatic carcinoma. However, the tumoral microbiome of IPMNs has rarely been explored.MethodsTumoral microbiome gene sequencing was carried out using 16 specimens of IPMN and 45 specimens of IPMN with associated invasive carcinoma (IPMN-IC) by 2bRAD sequencing for microbiome. The profile of the tumoral microbiome was summarized. Associations of the tumoral microbiome with disease grade, histological subtype, and prognosis were analyzed.ResultsA total of 598 species of microbes were identified, comprising 228 genera, 109 families, 60 orders, 29 classes, 14 phyla, and 2 kingdoms. The genus Pseudomonas was detected more frequently and had higher relative abundance in IPMN-ICs; Alcaligenes faecalis was detected with higher relative abundance in IPMNs. Bifidobacterium pseudolongum had a higher relative abundance in the IPMN-IC group, regardless of histological subtype. Moreover, among patients with IPMN-ICs, those with a high relative abundance of B. pseudolongum had better overall survival than those with a low relative abundance. Patients who were positive for Staphylococcus aureus or Mycolicibacillus koreensis had shorter survival. The presence of S. aureus was an independent risk factor for poor prognosis.ConclusionsThere are enriching tumoral microbes in IPMN. The tumoral microbiome of IPMN is different from that of IPMN-IC.