Dietary pectin caused greatly changes in bile acid profiles of Pelteobagrus fulvidraco

Abstract To reveal the impact of dietary fiber (DF) on the bile acid (BA) profiles of fish, yellow catfish (Pelteobagrus fulvidraco) were fed diet containing 300 g kg-1 dextrin (CON diet, control) or pectin (a type of soluble DF, PEC diet) for 7 days, and then the BA profiles were analyzed by UHPLC-MS/MS. A total of 26 individuals of BAs were detected in the fish body, with 8, 10, 14, and 22 individuals of BAs were detected in the liver, serum, bile and hindgut digesta, respectively. The conjugated BAs (CBAs) of fish were dominated by taurine-CBAs (TCBAs). The concentrations of free BAs (FBAs) and the values of FBAs/CBAs in the bile of fish fed the PEC diet were nearly 5 and 7 times higher, respectively, than those in fish fed the CON diet. The values of glycine-CBAs/TCBAs in the liver, serum and bile of fish fed the PEC diet were significantly lower, and in the hindgut digesta was higher than that of fish fed the CON diet (P < 0.05). These results suggested that dietary pectin greatly changed the BA profiles of Pelteobagrus fulvidraco, attributed to inhibition of reabsorption of BAs. Therefore, attention should be paid to the impact to BA homeostasis when replacing fishmeal with DF-rich plant ingredients in the fish diet.