Postcholecystectomy Gut Microbiome Changes and the Clinical Impact: A Systematic Review With Narrative Synthesis.

Background: Cholecystectomy (CCE) can affect the enterohepatic circulation of bile acids and result in gut microbiome changes. This systematic review aimed to clarify the effect of CCE on gut microbiome composition and its clinical impact.

Method: A systematic search was conducted in PubMed, Web of Science, and Scopus, combining keywords such as "cholecystectomy" or "post-cholecystectomy" with "gut microbiome," "stool microbiome," or "gut dysbiosis." Data were extracted and synthesized using narrative review. Study quality was assessed using the Newcastle-Ottawa scale.

Results: A total of 1373 articles were screened and 14 studies were selected. Significant but inconsistent microbiome changes were reported. Changes were observed in alpha and beta diversity. At phylum level, an increase in Bacteroides and Ascomycota, decrease in Firmicutes, Actinomycetes, and Basidiomycota, and both increase and decrease in Fusobacteria were reported. At genus level, an increase in Prevotella and a decrease in Faecalibacterium were reported. In post-CCE diarrhea, decreased beta diversity, a decreased F/B ratio, an increase in Prevotella, an increase in Phocaeicola vulgatus, and a decrease in Prevotella copri were noted. For post-CCE syndrome, a higher abundance of Proteobacteria and decreased Firmicutes/Bacteroides (F/B) ratio were reported. A decreased relative abundance of Bifidobacterium longum subsp. longum from controls to CCE without colonic neoplasia to CCE with colonic neoplasia, and an increased abundance of Candida glabrata from controls, to CCE without colonic neoplasia and CCE with colonic neoplasia, were reported.

Conclusion: Patients who underwent CCE had significant gut dysbiosis. However, current studies could not clarify the detailed gut microbial structural and functional changes associated with CCE.