IL17A and central nervous system disorder: The fact that IL-17 is predominantly derived from gut-bacteria-driven Th17 cells further supports the impact of gut immunity on central nervous system disorders: dysbiosis of the gut microbiota induces excessive Th17/IL-17 axis activation, which enters the brain via the bloodstream, promoting neuronal hyperexcitability and seizures (Soltani Khaboushan et al., 2022; Sharma et al., 2025; Choi et al., 2021; Margetts et al., 2022; Huppert et al., 2010).