Moreover, earlier researchers have reported that glucose ingestion during oral glucose tolerance tests (OGTT) stimulated more GLP-1 production than during intravenous glucose tolerance test (IVGTT) in patients with type 2 diabetes, thus intragastrically administered glucose may be more efficient in stimulating insulin release from pancreatic beta cells for lowering blood sugar level30. Here, INS is linked to type 2 diabetes mellitus.