Gut microbiome dysbiosis is not associated with portal vein thrombosis in patients with end-stage liver disease: a cross-sectional study.

BACKGROUND

Portal vein thrombosis (PVT) is a common complication in patients with end-stage liver disease (ESLD). The portal vein in patients with ESLD is proposedly an inflammatory vascular bed due to translocation of endotoxins and cytokines from the gut. We hypothesized that a proinflammatory gut microbiome and elevated trimethylamine N-oxide (TMAO), a driver of thrombosis, may contribute to PVT development.

OBJECTIVES

We investigated whether gut microbiome diversity, bacterial species, metabolic pathways, and TMAO levels are associated with PVT in patients with ESLD.

METHODS

Fecal samples, plasma samples, and data from patients with ESLD and healthy controls were collected through the TransplantLines Biobank and Cohort Study. PVT was defined as a thrombus in the portal vein within a year prior to or after fecal sample collection. Fecal samples were analyzed using Shotgun Metagenomic Sequencing, and TMAO levels were measured in plasma using a Vantera Clinical Analyzer.

RESULTS

One hundred two patients with ESLD, of which 23 with PVT, and 246 healthy controls were included. No significant difference in gut microbiome diversity was found between patients with PVT and without PVT (P = .18). Both ESLD groups had significantly lower alpha diversity than controls. Bacteroides fragilis and 3 Clostridiales species were increased in patients with PVT compared with without PVT. TMAO levels between the 3 groups were not significantly different.

CONCLUSION

We observed profound differences in gut microbiota between patients with ESLD and controls, but minimal differences between patients with ESLD with or without PVT. In our cohort, a gut-derived proinflammatory state was not associated with presence of PVT in patients with ESLD.