The study aim to delineate the effects of the naturally occurring peptide liver-enriched antimicrobial peptide 2 (LEAP-2) on postprandial glucose metabolism and food intake in healthy volunteers. The overall objective is to investigate the physiological importance of LEAP-2 in healthy subjects.

In a recent study, the molecular phenotype of enteroendocrine cells in the small intestine before and after Roux-en-Y Gastric Bypass (RYGB) surgery in obese individuals was examined. Enteroendocrine cells were identified and isolated from intestinal biopsies and analysed for differentially expressed genes by Illumina High Throughput RNA-sequencing. It was discovered that the gene encoding liver-enriched antimicrobial peptide 2 (LEAP-2), a naturally occurring peptide in humans, was significantly upregulated compared to baseline expression. Interestingly, LEAP-2 was recently shown to antagonize ghrelin function in response to feeding in mice. Moreover, the mature murine LEAP-2 peptide is identical in mice and humans. Thus, LEAP-2 has been identified as an endogenous peptide that may be able to alter feeding behaviour and maintenance of glucose levels during calorie restriction.

The study hypothesis is that LEAP-2 alters postprandial glucose metabolism and decreases appetite as well as food intake in relation to a liquid mixed meal and a standardised ad libitum meal compared with saline (placebo) in healthy subjects.

Inclusion Criteria:

• Caucasian men
• Age between 18 and 25 years
• Body mass index between 20-35 kg/m2
• Informed consent

Exclusion Criteria:

• Anaemia (haemoglobin below normal range)
• Alanine aminotransferase (ALAT) and/or aspartate aminotransferase (ASAT) >2 times normal values) or history of hepatobiliary and/or gastrointestinal disorder(s)
• Nephropathy (serum creatinine above normal range and/or albuminuria)
• Allergy or intolerance to ingredients included in the standardised meals
• First-degree relatives with diabetes and/or glycated haemoglobin (HbA1c) >48 mmol/mol
• Regular tobacco smoking or use of other nicotine-containing products
• Any ongoing medication that the investigator evaluates would interfere with trial participation.
• Any physical or psychological condition that the investigator evaluates would interfere with trial participation including any acute or chronic illnesses

Day A and B will be conducted in a randomised, double-blinded order (blinded for the participant and the investigator) and noted by a third person not participating in the collection or analyses of data. The infusion order will be opened after the primary data analyses.