The «microbiome» of post-liver transplant complications

This paper reviews modern literature and presents a brief analysis of our own data on one of the most pressing issues in modern transplantology and, in particular, transplant hepatology – the role and place of gut-liver axis (GLA) in the early post-transplant period. Objective: to compare the correlation between gut microbiome palette and incidence of certain early postoperative complications in liver transplantation. Materials and methods. The study design is presented as a pilot, prospective, observational, double-blind study based on investigation of the composition of the microbiome residing in the large intestinal in patients that underwent orthotopic liver transplantation (OLTx). The primary cohort of patients consisted of 12 patients who underwent OLTx from a postmortem donor. To assess the gut microbiome palette, biomaterial was collected from all patients in the preand post-transplant period followed by next-generation sequencing. The study was conducted as primary study results registered under number NCT04281797. Results. In the preoperative period, differences close to statistically reliable in relation to Actinobacteria were observed in patients included in the liver transplant waiting list for cirrhosis (LC) and hepatocellular carcinoma (HCC) in cirrhosis. However, due to the pilot nature of the study, this study cohort was limited to an extremely small sample. In turn, in the post-transplant period, there was a statistically significant difference in the taxonomic range of Actinobacteria (p < 0.05) between the above groups, indicating a possible effect of liver transplantation on the gut microbiome. In addition, in the early post-transplant period, there was a marked difference in the microbiome palette between patients with and without acute cellular rejection. Conclusion. GLA and the gut microbiome play a critical role in many liver diseases, and may also have a significant impact on the post-transplant period. In this regard, further research in this direction will not only characterize the predictors and risk factors of bacterial infection and rejection episodes, but will also allow us to form a completely new approach to the treatment tactics for certain complications, including through formation of a microbiota-oriented pharmacotherapy.