Clinical and stool microbiome correlates of simple post-ERCP hyperamylasemia in children undergoing therapeutic ERCP for pancreatobiliary obstructive disorders: an exploratory pilot study.

BACKGROUND

Simple post-ERCP hyperamylasemia is a common biochemical finding after therapeutic endoscopic retrograde cholangiopancreatography (ERCP), but pediatric data integrating procedural characteristics with stool microbiome features remain limited.

METHODS

We performed an exploratory single-center observational pilot study of 24 successful therapeutic ERCP procedures in children younger than 18 years with pancreatobiliary obstructive disorders between January 2024 and December 2025. The primary endpoint was simple post-ERCP hyperamylasemia, defined as serum amylase >3 times the upper limit of normal within 24 h after ERCP without new or worsening abdominal pain. Baseline clinical variables, predefined stool microbiome features derived from pre-ERCP metagenomic data (Shannon diversity, Enterococcus abundance, and Bifidobacterium abundance), and intraprocedural variables were compared between groups. Exploratory signal prioritization was used only to identify candidate associations for future validation.

RESULTS

Hyperamylasemia occurred in 8/24 procedures (33.3%). Compared with non- hyperamylasemia group, the affected children had higher baseline gamma-glutamyl transferase and C-reactive protein, longer procedure time, more difficult cannulation, more inadvertent pancreatic duct cannulation, more pancreatic contrast injection, and more rescue precut access. Stool microbiome features in the hyperamylasemia group included lower Shannon diversity, higher Enterococcus abundance, and lower Bifidobacterium abundance. Procedure time and Shannon diversity emerged as the most interpretable combined signals, but all model estimates should be viewed cautiously because of the small event count.

CONCLUSION

In this pilot dataset, simple post-ERCP hyperamylasemia clustered with technically demanding procedures and a low-diversity, Enterococcus-enriched stool microbiome profile. These findings are hypothesis-generating and require prospective multicenter validation before they can inform pediatric ERCP surveillance or risk-stratification research.