Taken together, the present results signalize that Nile tilapia fed the OLG diet (1.5 to 2 g/kg) showed better growth rates and feed efficacy, activated immune mechanisms, and modulated serum metabolites, which led to the progress of resistance against S. iniae. The addition of these molecules enhanced the production of growth-related hormones (GH and IGF-1), which suggested they contributed to improving the growth features in O. niloti cus. Additionally, the mixture (OLG) offers a promising approach to improve fish health, growth, and immune function in Nile tilapia farms, and can potentially be used as probiotic candidates in O. niloticus production in the future.