Presence of Gut Microbiota Worsens D‐Galactosamine and Lipopolysaccharide‐Induced Hepatic Injury in Mice

Acute liver failure is a serious, life-threatening disease. Although the gut microbiota has been considered to play a role in liver failure, the extent to which it is involved in the pathogenesis of this disease has not been fully elucidated to date. Therefore, we here analyzed the importance of the presence of intestinal microbiota in the pathogenesis of acute liver injury, using D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-treated mice, which is a widely used experimental model of acute liver injury. First, administration of the antibiotic polymyxin B markedly alleviated liver injury. Liver injury was also reduced in germ-free mice, leading to the conclusion that the presence of intestinal microbiota aggravates D-GalN/LPS-induced liver injury. The amount of bacteria and LPS transferred from the gut to the blood was not increased by D-GalN/LPS, suggesting that the worsening of liver injury was not simply owing to the entry of bacteria into the circulation. In conclusion, acute liver injury in polymyxin B-pretreated or germ-free mice was ameliorated by modulation of the gut microbiota. Modification of the gut microbiota using polymyxin B may hence have the potential to alleviate acute liver injury in human patients.