Oral Administration of Saccharomyces boulardii Ameliorates Carbon Tetrachloride-Induced Liver Fibrosis in Rats via Reducing Intestinal Permeability and Modulating Gut Microbial Composition

To investigate the effects of orally administrated Saccharomyces boulardii (S. boulardii) on the progress of carbon tetrachloride (CCl₄)-induced liver fibrosis, 34 male Wistar rats were randomly divided into four experimental groups including the control group (n = 8), the cirrhotic group (n = 10), the preventive group (n = 8), and the treatment group (n = 8). Results showed that the liver expression levels of collagen, type I, alpha 1 (Col1A1), alpha smooth muscle actin (αSMA), transforming growth factor beta (TGF-β) and the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and malondialdehyde (MDA) increased significantly in cirrhotic rats compared with control and decreased by S. boulardii administration. Treatment of S. boulardii also attenuated the increased endotoxin levels and pro-inflammatory cytokines in CCl₄-treated rats. And, these were associated with the changes of intestinal permeability and fecal microbial composition. Our study suggested that oral administration of S. boulardii can promote the liver function of CCl₄-treated rats, and the preventive treatment of this probiotic yeast may decelerate the progress of liver fibrosis.