The Role of GLP-1 Receptor Signalling in the Glucose-lowering Effect of Metformin in Patients With T2D

Inclusion Criteria: * Type 2 diabetes for at least three months (diagnosed according to the criteria of the World Health Organization (WHO)), with a HbA1c \<58 mmol/mol. * Caucasian ethnicity * Lifestyle intervention and/or metformin monotherapy * Normal haemoglobin * Age \>18 years * BMI \>23 kg/m2 and \<35 kg/m2 * Informed and written consent Exclusion Criteria: * Liver disease * Gastrointestinal disease, previous intestinal resection, cholecystectomy or any major intra-abdominal surgery * Hypo- or hyperphosphataemia * Reduced kidney function or nephropathy * Treatment with medicine that cannot be paused for 12 hours * Intake of antibiotics two months prior to study * Hypo- or hypercalcaemia * Hypo- and hyperthyroidism * Treatment with oral anticoagulants * Active or recent malignant disease * Any treatment or condition requiring acute or sub-acute medical or surgical intervention * Lack of effective birth control in premenopausal women * Positive pregnancy test on study days in premenopausal women * Pregnancy * Women who are breastfeeding * Any condition considered incompatible with participation by the investigators * If the subjects receive any antibiotic treatment while included in the study they will be excluded