Abstract
Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis that may be difficult to distinguish from pancreatic ductal adenocarcinoma (PDAC). Emerging evidence suggests the substantial involvement of gut microbiome dysbiosis in various disorders, including pancreatic diseases. This study investigates the differences in pancreatic tissue-specific microbiomes between AIP and PDAC. Pancreatic tissues were obtained from patients with type 1 AIP (n = 17) or PDAC (n = 24) via ultrasound-guided tissue acquisition and subjected to 16S rRNA sequencing. The sequences were used to determine the bacterial alpha diversity and characterize the microbiome structures related to different sample groups. The pancreatic microbiome in PDAC exhibited increased bacterial alpha diversity compared to that in AIP. The abundances of 16 bacteria were significantly different between the AIP and PDAC groups, and most of them (15/16) were increased in PDAC relative to that in AIP. The bacterial index calculated using these bacteria had a favorable discriminative ability for these different groups, with an area under the curve value of 0.91. Functional analysis demonstrated that the pentose phosphate pathway, gondoate biosynthesis, and several pathways related to adenosine biosynthesis were positively associated with the bacterial index. The findings from this preliminary study indicate that pancreatic microbiome, as a new diagnostic alternative, may potentially help with the differential diagnosis of AIP and PDAC.
Data availability
Raw data generated by this study was deposited at the DNA Data Bank of Japan (DDBJ): BioProject accession number: PRJDB39974; BioSample accession number: SSUB045271 (https://ddbj.nig.ac.jp/search). Sequence law data was also available at the DRA accession number: DRA026007). Annotation of the sample IDs in DDBJ for clinical information is also available in Table S1 in the supporting information.
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Acknowledgements
We would like to thank Editage (www.editage.com) for English language editing.
Funding
This work was supported by a JSPS KAKENHI Grant-in-Aid for Young Scientists (B), Grant Number 22K16032, and research grant D1 from Kansai Medical University.
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T.T and K.N prepared original drafts of the manuscript. K.N, T.I, J.Y, T.S, T.T, T.S, A.O, M.M and S.N conducted the experiments and curated the data. T.I and M.N reviewed and revised the manuscript. T.I and M.N supervised the study. All the authors contributed to the manuscript and approved the submitted version.
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This study was approved by the Medical Ethics Committee of the Fujita Health University (ID: HM18-094).
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Nakamaru, K., Ito, T., Shimogama, T. et al. Distinct difference of pancreatic tissue-specific microbiome in autoimmune pancreatitis and pancreatic ductal adenocarcinoma. Sci Rep (2026). https://doi.org/10.1038/s41598-026-44821-w
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DOI: https://doi.org/10.1038/s41598-026-44821-w
