Gut Microbiota-Mediated Modulation of Neurodevelopmental Behavior in CLCN4- Deficient Mice

Neurodevelopmental disorders (NDDs) are associated with gut–brain axis dysfunction, and chloride ion channel 4 (CLCN4) has been implicated in their pathology. We investigated whether CLCN4 knockout (KO) alters gut microbiota and contributes to NDD-like phenotypes in mice. CLCN4-KO mice displayed behavioral abnormalities, microbial dysbiosis, and increased serum p-cresol levels, along with altered hippocampal signaling proteins (PSD95, AKT, ERK). Treatment with haloperidol (Halo) modified gut microbiota, reduced p-cresol, and improved behavior, effects accompanied by increased hippocampal protein activation in homozygous KO mice but abolished by antibiotic-induced dysbiosis. Prevotellaceae_UCG-001 abundance correlated positively with hippocampal protein activation and negatively with hyperactivity, and Halo treatment significantly increased this population. Fecal microbiota transplantation (FMT) from wild-type mice restored gut microbial balance, memory, and protein phosphorylation in KO mice. These findings indicate that CLCN4 deficiency contributes to NDD-like behaviors via microbiota-mediated mechanisms and highlight Halo and FMT as promising microbiota-targeted strategies.