GCG and type 2 diabetes mellitus: This leads us to speculate that the reduction of Acinetobacter baumannii may be an indicator of improved cardiovascular risk in elderly T2DM patients, and that the improvement of GLP-1 as an indicator of vascular endothelial function in middle-aged and elderly T2DM patients may depend on the reduction of Acinetobacter baumannii in the intestinal tract of patients.