['Bariatric procedures excluding the proximal small intestine improve glycemic control in type 2 diabetes within days. To gain insight into the mediators involved, we investigated factors regulating glucose homeostasis in patients with type 2 diabetes treated with the novel endoscopic duodenal-jejunal bypass liner (DJBL).', 'Seventeen obese patients (BMI 30-50\xa0kg/m(2)) with type 2 diabetes received the DJBL for 24\xa0weeks. Body weight and type 2 diabetes parameters, including HbA1c and plasma levels of glucose, insulin, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon, were analyzed after a standard meal before, during, and 1\xa0week after DJBL treatment.', 'At 24\xa0weeks after implantation, patients had lost 12.7\u2009±\u20091.3\xa0kg (p\u2009<\u20090.01), while HbA1c had improved from 8.4\u2009±\u20090.2 to 7.0\u2009±\u20090.2\xa0% (p\u2009<\u20090.01). Both fasting glucose levels and the postprandial glucose response were decreased at 1\xa0week after implantation and remained decreased at 24\xa0weeks (baseline vs. week 1 vs. week 24: 11.6\u2009±\u20090.5 vs. 9.0\u2009±\u20090.5 vs. 8.6\u2009±\u20090.5\xa0mmol/L and 1,999\u2009±\u200985 vs. 1,536\u2009±\u200951 vs. 1,538\u2009±\u200972\xa0mmol/L/min, both p\u2009<\u20090.01). In parallel, the glucagon response decreased (23,762\u2009±\u20094,732 vs. 15,989\u2009±\u20093,193 vs. 13,1207\u2009±\u20091,946\xa0pg/mL/min, p\u2009<\u20090.05) and the GLP-1 response increased (4,440\u2009±\u2009249 vs. 6,407\u2009±\u2009480 vs. 6,008\u2009±\u2009429 pmol/L/min, p\u2009<\u20090.01). The GIP response was decreased at week 24 (baseline-115,272\u2009±\u200910,971 vs. week 24-88,499\u2009±\u200910,971\xa0pg/mL/min, p\u2009<\u20090.05). Insulin levels did not change significantly. Glycemic control was still improved 1\xa0week after explantation.'] Does endoscopic duodenal-jejunal bypass liner rapidly improve type 2 diabetes?