Together, our study supports that gut dysbiosis in AD patients, especially B. fragilis enrichment and it’s PUFA metabolites PGE2 and 12-HHTrE abundance, triggers C/EBPβ/AEP signaling activation, leading to AD-like pathologies in Thy1-C/EBPβ transgenic mice. This evidence concerns the gene CEBPB and Alzheimer disease.