Study of microbiome in liver transplantation

Jiang, Tianxiao (2026): Study of microbiome in liver transplantation. Dissertation, LMU München: Faculty of Medicine

Abstract

Introduction: Biliary complications are major contributors to morbidity after liver transplantation (LT). Recent evidence suggests that the biliary tract harbors a resident microbiome, yet its clinical relevance in LT remains unclear. This study aimed to investigate the biliary microbiome at the time of transplantation and explore its relationship to post-transplant outcomes. Methods: In this prospective observational study, 31 LT cases were enrolled. Paired donor bile fluid and biliary mucosa samples were collected intraoperatively. Active bacterial communities were profiled using RNA-based 16S rRNA sequencing. Microbiome composition, diversity, and associations with clinical parameters were statistically analyzed. Results: The biliary tract exhibited a distinct, non-sterile microbiome. Microbiome composition remained largely stable intraoperatively. Lower microbial richness in donor bile was linked to ITBL, while higher diversity was observed in cholangitis. Opportunistic and biofilm-forming genera were enriched in cases with biliary leaks or strictures. Donor antibiotic exposure reduced microbial diversity, whereas corticosteroid treatment was associated with increased richness. Discussion: This study represents the first RNA-based analysis to characterize the biliary microbiome in LT. The findings reveal that microbial profiles present at transplantation are associated with subsequent biliary complications, suggesting their potential as early biomarkers. Donor treatment regimens influence microbiome structure, highlighting opportunities for targeted interventions. These insights expand current understanding of microbiota-host interactions in transplantation and may inform future strategies to mitigate post-LT complications.

• Item Type: Theses (Dissertation, LMU Munich)
• Subjects: 600 Technology, Medicine; 600 Technology, Medicine > 610 Medical sciences and medicine
• Faculties: Faculty of Medicine
• Language: English
• Date of oral examination: 27. January 2026
• 1. Referee: Andrassy, Joachim
• Signature of the printed copy: 0700/UMD 22656