Department of Healthcare;
The First Affiliated Hospital;
Sun Yat-sen University;
Guangzhou;
China;
Outpatient Clinic of Internal Medicine Department;
The First Affiliated Hospital;
Sun Yat-sen University;
Guangzhou;
China;
Department of Endocrinology;
The First Affiliated Hospital;
Sun Yat-sen University;
Guangzhou;
China;
Berberine; Metformin; Type 2 Diabetes Mellitus; Efficacy; Safety; Meta-Analysis;