Dietary probiotic prototypes and their effects on growth performance, immune function, and gut microbiota of rainbow trout (Oncorhynchus mykiss).

This study focused on developing novel probiotic formulations for rainbow trout aquaculture by testing two formulations containing bacterial strains isolated from the gut of rainbow trout. The effects on growth, immune response, liver enzyme activity, immunity-related gene expression, and gut microbiota composition were evaluated. A completely randomized design was used, involving 450 rainbow trout distributed into 70-l fiberglass tanks with six dietary treatments and three replicates per treatment (total of 18 tanks).