Effects of chronic dexamethasone exposure on bile acid metabolism and cecal epithelia function in goats

Abstract Bile acids (BAs) are synthesized in the liver via the oxidation of cholesterol and further metabolized by microbiota in the gut, where they simultaneously impact gut function. In the present study, 10 goats were randomly divided into 2 groups; 1 group was injected with dexamethasone (Dex; 0.2 mg/kg), and the other group was injected with saline as the control (Con) for 21 d. Expression levels of key genes and proteins in the liver and gut mucosa were analyzed and compared to investigate the impact of chronic stress on BA metabolism and related functions in ruminants. The results revealed that Dex decreased plasma total BAs (TBAs) concentration ( P P P > 0.05). The expression of several genes in the cecal mucosa encoding epithelial tight junction proteins, including occludin ( P tight junction protein 1 ( P claudin 1 ( P defensin beta 1 , which can strengthen the innate immune system, was also upregulated ( P Solute Carrier family 9 member A 2 ( P