Effects of dietary Clostridium butyricum on growth and intestinal mucosal barrier functions of juvenile channel catfish (Ictalurus punctatus)

Background Channel catfish (Ictalurus punctatus) is an economically important aquaculture species, but it frequently experiences intestinal health problems. Clostridium butyricum is a probiotic that plays an important role in enhancing intestinal mucosal barrier functions, thus promoting intestinal health and growth performance in fish. However, research on the application of C. butyricum in channel catfish remains limited. Therefore, this study conducted an 8-week feeding trial to explore the effects of dietary C. butyricum supplementation on the growth performance and intestinal mucosal barrier of juvenile channel catfish.Methods Experimental Design: Juvenile channel catfish were randomly divided into two groups, the control diet (CD; without C. butyricum) and the experimental diet supplemented with C. butyricum at 1x10^8 CFU/g feed (CB).Diet Preparation: Both diets were nutritionally identical, except for the addition of C. butyricum in the CB diet.Sampling: After the 8-week feeding trial, fish were sampled to measure growth parameters, intestinal enzyme activities, intestinal mucosal barrier-related gene expression, gut microbiota composition, and intestinal metabolites.Analyses: Digestive enzymes and antioxidant enzymes activities were measured using biochemical assays. Gene expression of intestinal barrier-related proteins, immune factors, and chemical barrier markers were analyzed. Gut microbiota was assessed by 16S rRNA high-throughput sequencing. Intestinal metabolites were analyzed by LC-MS untargeted metabolomics.Statistical Analysis: Data were analyzed using standard statistical methods to compare differences between the two groups.