Disordered Control of Intestinal Sweet Taste Receptor Expression and Glucose Absorption in Type 2 Diabetes

We previously established that the intestinal sweet taste recep-tors (STRs), T1R2 and T1R3, were expressed in distinct epithelial cells in the human proximal intestine and that their transcript levels varied with glycemic status in patients with type 2 diabetes. Here we determined whether STR expression was 1) acutely regulated by changes in luminal and systemic glucose levels, 2) disordered in type 2 diabetes, and 3) linked to glucose absorp-tion. Fourteen healthy subjects and 13 patients with type 2 di-abetes were studied twice, at euglycemia (5.2 6 0.2 mmol/L) or hyperglycemia (12.3 6 0.2 mmol/L). Endoscopic biopsy speci-mens were collected from the duodenum at baseline and after a 30-min intraduodenal glucose infusion of 30 g/150 mL water plus 3 g 3-O-methylglucose (3-OMG). STR transcripts were quan-tified by RT-PCR, and plasma was assayed for 3-OMG concentra-tion. Intestinal STR transcript levels at baseline were unaffecte