DPP4 and diabetes mellitus: In time, a comparison with other diabetes drugs, such as metformin, DPP-4 inhibitors, and insulin, as well as a direct examination of the gastrointestinal tract’s physiological functions, including contractility and slow-wave frequency, may provide further information regarding the blood glucose lowering effects of SGLT inhibition and the direct effect of SGLT inhibition on myenteric neurons.