This study has identified polymorphisms in the DEFB1 gene to influence the development of periodontitis and periodontitis with T2DM and therefore could be considered a potential marker for identifying susceptible individuals. The peptides can be synthesized and used therapeutically in topical applications, mouthwash, or toothpaste, and this, in turn, can reduce the severity of the disease. This evidence concerns the gene DEFB1 and type 2 diabetes mellitus.