Does the use of two probiotic bacteria (Latiplantibacillus plantarum and Bacillus toyonensis) as water additives enhance growth performance, the immune responses, antioxidative maintenance, water quality and intestinal bacterial counts of Nile tilapi

The goal of the current study was to determine how probiotic bacteria ( Latiplantibacillus plantarum and Bacillus toyonensis ) as water additives affected growth performance, immune response, antioxidant indices, water quality and intestinal bacterial counts of Nile tilapia. A total of 120 monosex fingerlings of Nile tilapia (mean weight of 17.4 ± 0.1 g) after two weeks of acclimatization were divided into four groups, each with 30 fish (3 replicates). The first group served as a control (T 1 ), whereas the second, third and fourth groups were exposed to B. toyonensis (T 2 ), L. plantarum (T 3 ) and L . plantarum and B. toyonensis (T 4 ) at doses of 1.0 ml/L water. L. plantarum and B. toyonensis cultures significantly affected the growth performance, immune responses, antioxidative status, and intestinal bacterial counts of Nile tilapia. Latiplantibacillus plantarum- exposed fish showed the best values of feed intake (FI) and feed conversion ratio during the overall experiment. Total coliform , Escherichia coli and Salmonella spp. (TC) were decreased (P<0.001) by probiotic-treated water. Latiplantibacillus and/or Bacillus enhanced growth performance and diminished microorganisms' proliferation in the water and fish intestine. Supplementing the water with probiotic reduced triglyceride, low density lipoprotein (LDL), and very low density lipoprotein (VLDL), and improved immune indices (IgG, IgM, IgA, and lysozyme). Finally, adding the probiotics to water may improve the performance, antioxidant indices, immunity, and intestinal pathogen mitigation . • Feed intake (FI) and feed conversion ratio were improved with Latiplantibacillus plantarum during the overall experiment. • Total coliform, Escherichia coli and Salmonella spp. (TC) were decreased (P<0.001) by probiotic-treated water. • Using of Latiplantibacillus and/or Bacillus enhanced growth performance and diminished microorganisms' proliferation. • Supplementing the water with probiotic reduced triglyceride, LDL, and VLDL as well as immune indices improved.