Rifaximin and lubiprostone mitigate liver fibrosis development by repairing gut barrier function in diet–induced rat steatohepatitis

Abstract

Background: Although gut-derived lipopolysaccharide (LPS) affects the progression of non-alcoholic steatohepatitis (NASH) pathogenesis, few studies have focused on this relationship to develop treatments for NASH. Aims: To explore the effects of combination with rifaximin and lubiprostone on NASH liver fibrosis through the modulation of gut barrier function. Methods: To induce steatohepatitis, F344 rats were fed a choline-deficient l -amino acid-defined (CDAA) diet for 12 weeks and received oral administration of rifaximin and/or lubiprostone. Histological, molec- ular, and fecal microbial analyses were performed. Barrier function in Caco-2 cells were assessed by in vitro assays. Results: Combination rifaximin/lubiprostone treatment significantly suppressed macrophage expansion, proinflammatory responses, and liver fibrosis in CDAA-fed rats by blocking hepatic translocation of LPS and activation of toll-like receptor 4 signaling. Rifaximin and lubiprostone improved intestinal perme- ability via restoring tight junction proteins (TJPs) with the intestinal activation of pregnane X receptor and chloride channel-2, respectively. Moreover, this combination increased the abundance of Bacteroides, Lactobacillus, and Faecalibacterium as well as decreased that of Veillonella resulting in an increase of fecal short-chain fatty acids and a decrease of intestinal sialidase activity. Both agents also directly suppressed the LPS-induced barrier dysfunction and depletion of TJPs in Caco-2 cells. Conclusion: The combination of rifaximin and lubiprostone may provide a novel strategy for treating NASH-related fibrosis.