BRD2 and Azoospermia: <h4>Objective</h4>To establish a non-invasive predictive model for microdissection testicular sperm extraction (micro-TESE) outcomes in FSH-normal non-obstructive azoospermia (NOA) patients by integrating gut microbiota profiling with serum biomarkers.<h4>Methods</h4>We conducted a retrospective clinical analysis of 58 men and established a busulfan-induced FSH-normal NOA mouse model.