Testing the Potential Metabolic Effect of the Human Gut Bacterial Peptide, RUCILP, in Healthy Men

The goal of this randomized, double-blinded and placebo-controlled clinical cross-over trial is in healthy men to explore the potential metabolic effects of the naturally occurring gut bacterial polypeptide, RUCILP. This bacterial peptide is produced by commensal strains of Ruminococcus torques in the human gut microbiota. In preclinical studies of rodents, RUCILP lowers blood glucose and stimulates release of plasma insulin, glucagon-like peptide-1(GLP-1) and Peptide YY (PYY) but induces a decline of glucose-dependent insulinotropic polypeptide (GIP). In the present trial, the investigators want to explore potential effects of intraduodenally delivered RUCILP on release of plasma concentrations of GLP-1, GIP and PYY. In addition, the investigators will test for potential effects of intestinal RUCILP infusion on plasma concentrations of glucose, insulin and metabolome. Participants will have a duodenal tube placed into which RUCILP or placebo will be infused over 3 hours after an initial standardized liquid meal infusion into the duodenal tube. Participants will on different days and in a randomized order receive either placebo or RUCILP infusion into the tube. Safety is acutely monitored under the intervention and postintervention safety is monitored by clinical biochemistry measures of hematology, and liver and kidney functions. The study participants will further keep a diary of any experienced adverse effects during the week after the intervention. Primary OUTCOMES: a composite of changes in plasma concentrations of GLP-1, GIP and PYY. Secondary OUTCOMES: changes in plasma glucose, plasma insulin and plasma metabolome profile.