Administration of these bioactive compounds into Thy1-C/EBPβ transgenic mice essentially recapitulated what we observed with AD-FMT or Bacteroides fragilis alone, underscoring that AD gut microbiota or Bacteroides fragilis-elicited AD-like pathologies and cognitive dysfunctions might be exerted via PGE2 or 12-HHTrE, which stimulated microglia activation and extensive neuroinflammation (Figs. 6 and 7). The gene discussed is CEBPB; the disease is Alzheimer disease.