The role of gut microbiome in cirrhosis

Our gastrointestinal tract houses trillions of micro-organisms and good balance in the ecosystem is essential for maintaining a healthy state. The liver and gut connect via the enterohepatic circulation. Specifically, the connection of these with the brain (i.e., the liver-gut-brain axis) form crosstalk among the organs, making a disease from one organ to a multi-system level.

The liver and gut interact in various ways. Gut dysbiosis is one of the important hallmarks noted in patients with cirrhosis. This includes a change in microbiota composition, overgrowth of intestinal bacteria, alteration in gut permeability and bacterial translocation. Furthermore, the degree of changes in gut microbiome correlates with the severity of liver disease and portal hypertension, and biomarkers are expected from derivation of these associations.

Understanding the mechanisms of changes in gut microbiome in cirrhosis, therapies can be made possible by enriching the favourable factors, modifying the harmful factors and removing the primary triggers. Lactulose and rifaximin are simple examples of indirectly manipulating the gut microbiota in treating cirrhosis-related complications. Several early-phase studies have been conducted to confirm the safety and efficacy of faecal microbiota transplantation in patients with cirrhosis and hepatic encephalopathy. Probiotics are also under the flashlight in modern medicine, but conflicting data are present.

In this lecture, we will deepen our knowledge on this topic, which is ultimately hoped to pave the way to personalised medicine according to gut microbiome from each individual.