As a result, a double-transgenic APPswe/PS1ΔE9 (Swedish mutant of Amyloid Precursor Protein, and deletion mutant of human presenilin 1), mouse AD model (TG) and their wild-type (WT) littermates were used here to determine how the GM is modified by changes in the levels of sex hormones, comparing male, castrated male, and female mice. The gene discussed is PSEN1; the disease is Alzheimer disease.