Effects of Jinhua instant dark tea in patients with type 2 diabetes mellitus: study protocol for a multicenter, open-label, randomized controlled trial. - Chen, Ningsu; Zhao, Kai; Xu, Ye; Qi, Yana; Cheng, Daomei; Zhao, Mengnan; Meng, Dejiao; Shi, Lei; Yu, Jiajie (Trials, 2025)