*Purpose: Liver transplant (LT) recipients have abnormal microbiota before and after transplantation. (1,2) The association between fecal microbiota, metabolites, and clinical outcomes in liver transplantation are not well established. We correlated the microbiota composition and metabolite production in fecal samples with early post-operative outcomes, including infection.

*Methods: In a prospective observational study, we collected fecal samples and determined microbiota composition by 16S ribosomal RNA sequencing in LT recipients. Fecal short chain fatty acid (SCFA), primary, and secondary bile acid concentrations were determined by targeted metabolomic analyses. Inverse Simpson index was used to compare diversity between enrolled subjects and healthy controls. These data were compared to length of stay following transplantation, MELD-Na score at the time of transplant, and post-operative infection. The organisms causing clinical infection were compared to the microbiota of the subjects.

*Results: 13 LT patients were enrolled, and 40 stool samples were collected in the peri-transplant period. In addition to LT, 3 patients received a kidney transplant, 1 patient received a heart transplant, 1 patient is listed for a heart, liver, and kidney transplant. Compared to healthy controls, the microbiota of LT recipients had reduced diversity (p<0.001). [Fig1] The health promoting taxa Bacteroidetes, Ruminococcaceae, and Lachnospiraceae, and microbiota derived SCFAs were markedly diminished.

*Conclusions: The microbiota and metabolome of LT recipients are markedly abnormal and appear to be associated with clinically relevant and microbiologically predictable post-operative infection. Patient recruitment, sample collection, analysis, correlation with outcomes and potential interventional studies are ongoing.

« Back to 2021 American Transplant Congress