Background: Although clinical trials and animal models have evaluated the alterations of the microbiome in chronic pancreatitis (CP), the gut microbiota composition and diversity in cerulein-induced CP is unknown. This study aimed to evaluate the changes of gut microbiota in a CP mice model, and to determine whether these gut microbiota changes were consistent with those in patients with CP.
Methods: A total of ten male C57BL/6j mice were randomly divided into two groups. The experimental group were injected intraperitoneally with cerulein, while the normal control group received comparable injections of saline, the entire molding process lasted 6 weeks. Histology analysis was used to assess pancreatic morphological changes and fibrosis, meanwhile the gut microbiota composition and diversity were analyzed by high throughput sequencing. Spearman correlation analysis was used to determine whether body weight and weight changes were associated with changes in gut microbial abundance.
Results: The bacterial richness and diversity of CP mice decreased, and the gut microbiota changed, including lower levels of Firmicutes , decreased Firmicutes/Bacteroidetes  ratio and increased abundance of Bacteroidetes, Actinobacteria  and Verrucomicrobia . We found statistically significant differences in body weight and weight changes between the two groups. However, there was no significant correlation between alterations of gut microbiota and in body weight and weight changes.
Conclusion: Our results showed that the gut microbiota in cerulein-induced CP was changed.
Keywords: chronic pancreatitis, cerulein, gut microbiota, body weight, weight changes