Contribution of gut bacteria to liver pathobiology

Abstract

Emerging evidence suggests a strong interaction between the gut microbiota and health and disease. The interactions of the gut microbiota and the liver have only recently been investigated in detail. Receiving approximately 70% of its blood supply from the intestinal venous outflow, the liver represents the first line of defense against gut-derived antigens and is equipped with a broad array of immune cells (i.e., macrophages, lymphocytes, natural killer cells, and dendritic cells) to accomplish this function. In the setting of tissue injury, whereby the liver is otherwise damaged (e.g., viral infection, toxin exposure, ischemic tissue damage, etc.), these same immune cell populations and their interactions with the infiltrating gut bacteria likely contribute to and promote these pathologies. The following paper will highlight recent studies investigating the relationship between the gut microbiota, liver biology, and pathobiology. Defining these connections will likely provide new targets for therapy or prevention of a wide variety of acute and chronic liver pathologies.

Figure 1

Diagramatic representation of the liver sinusoid. HA; hepatic artery. BD; bile duct. PV; portal vein. DC; dendritic cell. KC; Kupffer cell. NKT; natural killer T cell. T; T cell. NK; natural killer cell.

Figure 2

Diagram of the points of future study/intervention to treat or prevent various liver diseases. Discussed in summary section of the text.