Bile is a yellow‐green liquid produced in the liver from cholesterol and stored in the gallbladder of vertebrates. Bile improves the efficacy of lipid digestion by acting as an emulsifier and is essential in activating bile salt lipase, an enzyme that has broad substrate specificity. Bile improves the absorption of lipid soluble nutrients while also facilitating the excretion of cholesterol and toxic metabolites, particularly bilirubin. Dietary fishmeal alternatives often disturb bile acid status in fish resulting in either increased excretion/decreased intestinal reabsorption and/or decreased bile acid synthesis. Saponins and high molecular mass proteins are believed to contribute to altered bile acid status, which may reduce fish productivity. This situation can worsen with increased incorporations of plant‐based proteins in aquafeeds, but also may be mitigated by processing of fishmeal alternatives as well as the dietary inclusion of some bile acids/salts. This area of research will likely increase due to the roles dietary bile acids/salts can have on protecting digestive organs and improving nutrient utilization. This, however, depends on the bile type, level and fish species. This review discusses these aspects in regard to fish nutrition to help increase the inclusion of dietary fishmeal alternatives and thus enhance aquaculture sustainability.
This study was aimed to evaluate the effects of dietary supplementation of Bacillus cereus as probiotics on growth, fillet quality, serum biochemical parameters and intestinal histology of Pengze crucian carp (Carassius auratus var. Pengze). Fish were fed basic diet (Control group) and three diets such as CD7, CD9 and CD11 supplemented with B. cereus at dose of 107, 109 and 1011 CFU/kg for 70 days. The results showed that supplementation of 109 CFU/kg B. cereus significantly improved the growth performance compared to that in the Control group. The textures of muscle were improved by dietary supplementation of probiotics, and the hardness, gumminess, chewiness and the resilience of fish fillet increased with increasing dose of B. cereus. Total cholesterol including high‐density lipoprotein and low‐density lipoprotein level in serum decreased correspondingly with increasing level of probiotics whereas, acid phosphatase and catalase activities increased in serum. B. cereus supplementation enhanced the immunity and antioxidant capacity via an increase in acid phosphatase, alkaline phosphatase, glutathione peroxidase, reduce glutathione, and catalase, accompanied by a significant reduction in malondialdehyde. Higher intestinal fold height was observed in CD9 group than other groups. The lowest enterocyte height was exhibited in the Control group, HE values increased with increasing dose of probiotics. Moreover, dietary inclusion of B. cereus significantly affected the digestive enzymes activities in terms of higher lipase and trypase activities. In conclusion, dietary supplementation of B. cereus could promote the growth, elevate the immunity and antioxidant status of carp, and importantly improve the texture of fish fillet.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.