Bile acids promote lipopolysaccharide clearance via the hepato-biliary pathway in broiler chickens

Lipopolysaccharide (LPS) acts as a trigger that disrupts metabolic functions and the immune system. While bile acids (BA) have detoxification and anti-inflammatory effects, their role in promoting LPS excretion in broiler chickens remains unclear. This study aimed to investigate the potential of exogenous BA to enhance hepatic clearance of LPS and thereby potentially alleviate LPS-induced liver injury in broiler chickens. Forty-five 21-day-old male broiler chickens were randomly assigned to three groups: the control group, which received daily intraperitoneal injections of a solvent for LPS treatment and a gavage solvent for BA treatment; the LPS group, which received daily intraperitoneal injections of 0.5 mg/kg body weight LPS and a gavage solvent for BA treatment; the LPS + BA group, which received daily intraperitoneal injections of 0.5 mg/kg body weight LPS and 60 mg/kg body weight BA by gavage. BA administered by gavage protected the broiler chickens from increases in liver and spleen indices, systemic inflammatory response, and hepatic damage induced by LPS. Hepatic clearance of LPS was enhanced, as evidenced by decreased serum LPS levels and accelerated excretion into the gallbladder. Additionally, the LPS-induced downregulation of detoxification genes, including those for the lipoprotein receptor and bile acids export pump, was reversed by BA administered by gavage. Furthermore, nuclear transcription factors such as the Farnesoid X receptor (FXR) and Liver X receptor α (LXRα) were enhanced in BA-treated broiler chickens. These findings suggest that BA administration via gavage enhances hepatic LPS clearance through the upregulation of hepatic uptake and efflux proteins, likely mediated by the activation of nuclear transcription factors FXR and LXRα.