Introduction

Growing evidence suggests an increased morbidity and mortality following an episode of acute pancreatitis (AP)¹. To date, there are no robust biomarkers predicting recurrent acute pancreatitis (RAP), occurrence of post discharge mortality, and the development of diabetes mellitus and pancreatic exocrine insufficiency (PEI). In a European-wide multicenter study the orointestinal microbiome could be used to predict severity of AP². Here, we now aim to assess the early-phase microbiome to predict post-discharge mortality and morbidity.

Aims & Methods

Between 2019 and 2022, buccal and rectal swabs were prospectively collected from 424 patients with acute pancreatitis within 72h after hospital admission in 15 European centers (P-MAPS-study)². Follow-up data regarding the outcome after discharge of the index AP were collected using a RedCAP database until December 2024 via telephone interviews and/or from patient medical records. Endpoints included the association of the buccal and rectal microbiome with post discharge mortality, development of RAP, PEI, diabetes, development of chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDA). Existing 16S rRNA (buccal) and metagenomic (rectal) Nanopore sequencing data were reclassified with an updated library. For α- and β-diversity statistics, multiple regression models or distance-based redundancy analysis (db-RDA) were used controlling for potential confounders, such as age, body mass index, medication and concomitant diseases.

Results

Post discharge data were available for 294 participants with a median time of follow-up of 2.7 years. During this period 66 patients (22.4%) developed RAP, 16 (5.4%) CP, 23 (7.8%) PEI, 25 (8.5%) diabetes, 4 (1.4%) PDA, and 20 (6.8%) died after hospital discharge. Sequencing data from 267 buccal and 265 rectal samples were deemed suitable for subsequent analysis. Notably, preliminary analysis revealed significant associations between the buccal and rectal microbiome and post discharge development of diabetes (db-RDA p-value 0.021* and 0.016*) buccal samples and post discharge mortality (db-RDA p-value 0.049*) and rectal samples and RAP (db-RDA p-value 0.011*). No significant differences were found regarding CP, PEI and PDA.

Conclusion

Microbial sequencing collected at the initial phase of acute pancreatitis in the emergency room show significant association with long-term complications after AP and post-discharge mortality emphasizing the role of the orointestinal microbiota in acute pancreatitis.

References

1. Czapári D., Váradi A. & Farkas N. Detailed Characteristics of Post-discharge Mortality in Acute Pancreatitis. Gastroenterology 2023 Sep;165(3):682-695
2. Ammer-Herrmenau C., Antweiler K. & Asendorf T. Gut microbiota predicts severity and reveals novel metabolic signatures in acute pancreatitis. Gut. 2024 Feb 23;73(3):485-495

Introduction

Acute pancreatitis (AP) is a common clinical emergency, with 20%–30% of cases progressing to severe acute pancreatitis (SAP), which has a mortality rate of up to 40%. Gut microbiota dysbiosis is closely associated with AP severity, yet its underlying mechanisms remain unclear.

Aims & Methods

This study aimed to elucidate how microbiota dysbiosis exacerbates AP.AP was induced in Specific Pathogen-Free (SPF) and Germ-Free (GF) C57BL/6 male mice to investigate the effects of microbiota dysbiosis on neutrophil recruitment, neutrophil extracellular trap (NET) formation, pancreatic injury, and systemic inflammation. Single-cell sequencing of neutrophils from SPF and GF AP mice was conducted to assess microbiota-driven changes in neutrophil distribution, gene expression, and signaling pathways. Serum cfDNA levels were measured in 50 AP patients and 30 healthy controls. Key findings were validated in vivo and in vitro.

Results

Serum cfDNA (NETs) levels were significantly elevated in AP patients compared to healthy controls and decreased during recovery. GF-treated mice exhibited reduced pancreatic edema, inflammatory infiltration, and acinar cell necrosis, with lower pathology scores. Immunohistochemistry confirmed decreased MPO and F4/80-positive cells in pancreatic tissues, while ELISA showed reduced levels of amylase, lipase, IL-6, and TNF-α in GF-treated mice. Single-cell sequencing revealed a lower proportion of pancreatic neutrophils and an increase in acinar cells in GF-treated mice, whereas the NET formation pathway was activated in SPF-treated mice. The TLR2/MYD88/NLRP3/Caspase-1 signaling cascade, which promotes NET formation, was also activated in SPF mice. Consistent with pathway analysis, CXCL1, CCL9, and CXCR2 expression was upregulated, while Reg3β expression was downregulated in SPF_AP mice. Dual immunofluorescence demonstrated reduced MPO/CitH3 (NETs) formation in GF-treated mice. Neutrophils from GF-treated mice released significantly less cfDNA upon PMA stimulation. Serum cfDNA levels were elevated in both AP-induced mice and AP patients.

Conclusion

Gut microbiota dysbiosis exacerbates AP severity by promoting neutrophil recruitment, activating the TLR2/NLRP3/MYD88/Caspase-1 signaling cascade, and enhancing NET formation, leading to aggravated pancreatic injury and systemic inflammation. These findings highlight microbiota modulation as a potential therapeutic strategy to prevent AP progression.

Disclosure

The authors declare that they have no conflict of interests.

Introduction

Exocrine pancreatic insufficiency (EPI) following acute pancreatitis (AP) has been reported heterogeneously with unclear recovery timeline.

Aims & Methods

Aim: To determine the prevalence of EPI after AP and the prevalence and predictors of persistent EPI after AP for at least 6 months.
Methods: Prospective longitudinal study of consecutive adult patients diagnosed with first episode of AP. Excluded patients with previous EPI, follow-up after AP <12months and after EPI <6months. EPI was assessed by elastase fecal-1 and endocrine pancreatic insufficiency (EnPI) by fasting serum glucose, HbA1c and oral glucose tolerance test. Patients with AP who developed EPI were randomized to receive pancreatic enzyme replacement therapy (PERT, 4000IU with each meal and 20000IU with snacks; clinicaltrials.gov NCT05480241) vs. placebo. Clinical, inflammatory, nutritional and immunological factors were evaluated. Evaluated predictors for persistent EPI (≥6months) and compared with transient EPI (<6months) and AP with no EPI groups.

Results

A total of 105 patients (65.7%(n=69) males; mean age:63.8±17.1yo) were enrolled and followed-up, 65.7% with alcoholic/biliary etiology. AP was moderately-severe in 32.4% and severe in 16.2%. EPI (mean elastase fecal-1 176.9±175.8 (vs. 425.1±105.0; p<0.001) was observed in 50 (47.6%) patients, being severe in 60% and 38% of patients with mild AP: 64% at the time, 14% at 1 month, 16% at 3 months and 6% at 6 months of AP diagnosis. EnPI was diagnosed in 17.1%(n=18) and 19.0%(n=20) has previous diabetes mellitus. EPI was persistent (≥6 months after EPI diagnosis) in 58%(n=29; mean elastase fecal-1 83.8±58.5 (vs. 373.6±118.4; p<0.001)), being 31%(n=9) with mild AP. 6-month post-randomization, 44%(n=11/25) under PERT and 40%(n=10/25) under placebo resolved EPI (p=0.598), with statically significance for severe EPI (resolved EPI: PERT-20%; placebo-12%; p=0.04).
After univariate/multivariate analysis, factors significantly associated with persistent EPI were previous diabetes (OR 15.382; p=0.001), EnPI (OR 9.906; p=0.042), recurrent AP (OR 7.182; p=0.028), non-biliary etiology (OR 5.744; p=0.037), increasing AP severity (OR 21.386; p<0.001), mMarshal score ≥2 (OR 23.026; p=0.001), intermediate/intensive care unit admission (OR 19.583; p=0.003), pancreatic necrosis (OR 21.05; p=0.007) and low magnesium (OR 45.690; p=0.045).

Conclusion

EPI following AP is a non-negligible condition, present in almost half of patients during first 6months after AP diagnosis, being severe in about 2/3 of patients and persists for at least 6 months in more than half of patients, Previous diabetes, EnPI, recurrent AP, non-biliary etiology, severe AP and low magnesium were strongly and independent associated with persistent PEI. Since can occur and be persistent even in mild AP, is crucial understand injury mechanisms, stratify patient’s risk, tailoring screening and start PERT early.

References

1. Phillips AE, Beijani J, Culp S, Chennat J, Lee PJ, Machicado JD, et al. Prevalence of exocrine pancreatic insufficiency at 12 months after acute pancreatitis: a prospective, multicentre, longitudinal cohort study. E Clinical Medicine 2024;75:102774.
2. Huang W, de la Iglesia-García D, Baston-Rey I, Calviño-Suarez C, Lariño-Noia J, Iglesias-Garcia J, et al. Exocrine pancreatic insufficiency following acute pancreatitis: Systematic review and meta-analysis. Dig Dis Sci 2019;64(7):1985-2005.
3. Jawaid S, Forsmark CE. Exocrine pancreatic insufficiency following acute pancreatitis: true association or EPIphenomenon?. Dig Dis Sci 2019;67(7):1731-1733.