Effect of probiotic Lysinibacillus macroides on the innate immune system of the common carp, Cyprinus carpio, utilizing a machine learning approach

The present study aimed to examine the effects of the probiotic Lysinibacillus macroides (LM) on the innate immune parameters of common carp (Cyprinus carpio) using a machine learning (ML) approach. C. carpio were fed diets supplemented with 0% LM (control), 2% LM, 4% LM, 6% LM, and 8% LM for 60 days. As indicators of innate immunity, neutrophil adherence, serum lysozyme activity, and nitroblue tetrazolium activity were measured. Using parameter optimization and evaluation techniques based on a regression tree approach, the best predictive models for the innate immunity of C. carpio under different feeding regimes were determined through an ML methodology. Nitroblue Tetrazolium (NBT) activity, neutrophil adherence, and serum lysozyme were significantly enhanced by the supplemented diet. Lysinibacillus macroides was administered in a concentration-dependent manner. Gradient Boosting models predicted immunological changes with R2 values exceeding 0.85. We conclude that L. macroides could be a promising probiotic agent to enhance the innate immunity of common carp, and that ML technologies offer constructive explanations for the mechanisms underlying probiotic-mediated immunomodulation.