The Effect of Traditional Chinese Medicine Combined with Metformin Therapy on Gut Microbiota Abundances in Middle-aged and Elderly Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

Review question / Objective: No prior scientific study has demonstrated how metformin and traditional Chinese medicine (TCM) can be combined to regulate the abundances of gut microbiota in middle-aged and older individuals with type 2 diabetes mellitus (T2DM).In this research, we conducted a meta-analysis to analyse the changes in abundance of various gut microbiota species after combined therapy with TCM and metformin compared to metformin alone in middle-aged and older adults to provide a rationale for gut microbiota as a therapeutic target in T2DM.Background: Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease characterised by elevated blood glucose levels as the main clinical manifestation; it is caused by genetic or environmental factors and leads to absolute or relative insufficiency of insulin secretion or dysfunction of insulin action in the body .If the symptoms of T2DM are not effectively controlled, the disease continues to develop, which causes complications such as cardiovascular and cerebrovascular diseases, retinopathy, and diabetic nephropathy.INPLASY registration number: This protocol was registered with the International Platform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY) on 23 March 2023 and was last updated on 23 March 2023 (registration number INPLASY202330087).