Healthy volunteers will ingest a 13C-octaoate containing test meal and 13C in expiratory air will be followed. Normal values will be calculated data of these tests.

This is a clinical study for establishing reference values in a 13C-octanoate breath test and a 13C-sodium acetate breath test. Healthy volunteers (n=75) will eat a solid test meal of scrambled eggs and toast containing 13C-octanoate. 13C-content of exhaled air will be measured at baseline and followed for the next 4 hours. One week later, the healthy volunteers (n=75) will drink a standardized nutritional shake (Ensure Plus Vanille, Abbott) containing 13C-sodium acetate. 13C-content of exhaled air will be measured at baseline and for the next 4 hours. Estimated gastric emptying time will be calculated using established algorithms.

Inclusion Criteria:

• Subjects free of relevant abdominal complaints
• Written informed consent

Exclusion Criteria:

• Age under 18
• Previous history of gastrointestinal disease or surgery (excludes appendectomy, hernia repair and anorectal disorders)
• Known diabetes mellitus, scleroderma, neurological impairment or other major current disease
• Subjects unable to stop medication that alters gut function for 1 week prior to the study, including anticholinergics, calcium canal inhibitors, beta blocker, prokinetics, proton-pump inhibitors, DDV-IV-Inhibitors, Inkretin-mimetica, non-steroidal anti-inflammatory drugs, macrolid antibiotics
• Pregnancy beyond week 12 (no pregnancy test will be performed)
• Involvement in any other clinical trial during the course of this trial, nor within a period of 14 days prior to its beginning or 14 days after its completion
• Known allergy or intolerance against hen egg protein or gluten