Notably, the pathways of the immune system (IL-17 and NOD-like receptor signaling pathway) and digestive system (protein and carbohydrate digestion and absorption) markedly decreased (P < 0.05) at the pediveliger and later stages compared to those at the D-stage, while the pathways showed an opposite trend during infections (Staphylococcus aureus and pathogenic Escherichia coli infection) (Figure 6). This evidence concerns the gene IL17A and escherichia coli infection.