METHODS: We investigated differences of serum and brain metabolites between the early-onset 5XFAD and late-onset LOAD1 (APOE4.Trem2*R47H) mouse models of AD to C57BL/6J controls at six months of age.<h4>Results</h4>We identified sex differences for several classes of metabolites, such as glycerophospholipids, sphingolipids, and amino acids. Here, TREM2 is linked to Alzheimer disease.