There has been a growing interest in evaluating the role of gut and intra-lesional microbiome in the pathogenesis of various benign and malignant conditions of the GI tract, liver and pancreas. In addition, the feasibility of using microbiome signature as non-invasive biomarker for benign and malignant disease conditions of the GI tract has also been studied. While research on the impact of microbiome and genomics has been conducted in some pancreatic disorders such as acute pancreatitis, pre-malignant mucinous pancreatic cystic neoplasms (eg, IPMN) and pancreatic cancer, very little data is available regarding the microbiome signature and genomics associated with FP. As such, it would be clinically important to conduct a pilot study to investigate the microbiome and genomics associated in patients with or without FP defined by MRI-PDFF pancreatic fat fraction measurement.

Fatty pancreas (FP) is a pathological metabolic condition characterized by excessive intra-pancreatic fat deposition (IPFD). FP is an increasingly recognized metabolic condition with a prevalence of 16% to 35% in Asian populations. While ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) have been used for fat quantitation in organs, MRI is best suited for this purpose since its signal is dependent on fat content. Quantitative proton density fat fraction measurement by MRI (MRI-PDFF) is regarded as the current gold standard for fat quantification in organs such as liver and pancreas since the fat fraction measurements by MRI are reproducible, accurate and have been validated against histology. In a meta-analysis of 9 studies using MRI for pancreatic fat quantification, the upper limit of normal of pancreatic fat in healthy subjects was 6.2%.

FP has gained clinical attention since FP has been associated with both benign and malignant diseases of the pancreas. For example, recent retrospective studies have suggested an increased risk of pancreatic cancer, intraductal papillary mucinous neoplasms (IPMN) and neoplastic progression of Branch Duct type IPMN (BD-IPMN) in patients with FP defined by computed tomography (CT) attenuation indexes . In another retrospective study of 62 patients using MRI-PDFF for pancreatic fat quantification, high pancreatic fat fraction was associated with high-risk IPMN in surgical specimen. In a community cohort study of 685 adult Chinese volunteers, our team was the first to report on the prevalence of FP (16.1%) in Hong Kong adults using MRI for pancreatic fat quantification in 2014 . In our recently published 10-year prospective follow-up study of the same cohort, FP was independently associated with subsequent diabetes development.

Inclusion Criteria:

• Age 18 or older
• Patients with FP, defined by MRI-PDFF pancreatic fat fraction > 6.2%
• Patients who are able to provide written informed consent to participate in the study.

Exclusion Criteria:

• Unable to provide written informed consent
• Recent use of antibiotic, prebiotic, probiotic and symbiotic
• Patients with significant alcohol consumption, defined as alcohol intake of over 20 g daily (140 g weekly) for men and 10 g daily (70 g weekly) for women

Patients who underwent MRI-PDFF for pancreatic fat fraction and liver fat fraction measurements between 1/2022 and 11/2024 for evaluation of FP and fatty liver in GI and hepatology clinics of the Prince of Wales Hospital will be screened for eligibility of this study. Each patient with FP will be matched by sex and age (+/- 3 years) with 1 patient without FP (MRI-PDFF pancreatic fat fraction < 6.2%). Patients with significant alcohol consumption, defined as alcohol intake of over 20g daily (140g weekly) for men and 10g daily (70g weekly) for women will be excluded.