In the current study, participants’ levels of plasma butyrate were measured, and the responses of peripheral blood mononuclear cells (PBMCs) to sodium butyrate were compared between poorly controlled T2DM patients and normoglycemic participants in the presence of lipopolysaccharide; this comparison was made by measuring cytokine production from innate immunity (TNF-α and IL-6) and Th1/Th2 cytokine balance (IFN-γ, IL-13, and IL-10). This evidence concerns the gene IL13 and type 2 diabetes mellitus.