The effects of brewers' spent grain on high-fat diet-induced fatty liver

Obesity drives nonalcoholic fatty liver disease (NAFLD). This study investigated the effects of dietary brewers' spent grain (BSG) supplementation on obesity-induced NAFLD. Mice fed a high-fat diet supplemented with 30% BSG (HFD30) had reduced body weight and decreased plasma total cholesterol (TC) concentrations compared with HFD-fed mice. Retroperitoneal white adipose tissue (RWAT) and liver weights were reduced. Consistent with reduced hepatic triacylglycerol, TC, and non-esterified fatty acid concentrations, HFD30-fed mice showed reduced hepatic steatosis. 3-hydroxy-3-methylglutaryl-CoA reductase and low-density lipoprotein receptor genes were increased, whereas carnitine palmitoyltransferase 1 alpha, ATP-binding cassette subfamily A member 1 (Abca1), and cholesterol 7 alpha-hydroxylase genes were upregulated in the liver of HFD30-fed mice. Abca1 gene expression was also increased in epididymal WAT and RWAT of HFD30-fed mice. BSG supplementation increased and decreased fecal fat and bile acid concentrations, respectively. Taken together, BSG supplementation reduced HFD-induced hepatic lipid accumulation by increasing fatty acid oxidation and bile acid synthesis in the liver as well as decreasing lipid absorption in the intestine.