Future studies with longer durations, larger and more diverse cohorts, and comprehensive gut microbiota assessments are warranted to further elucidate the long-term metabolic effects, potential mechanisms of action—particularly involving GLP-1 and DPP-4 pathways—and the broader applicability of citrus flavonoid-based nutraceutical in populations at higher risk for type 2 diabetes and cardiometabolic disorders. This evidence concerns the gene DPP4 and type 2 diabetes mellitus.