1. Universitair Ziekenhuis Brussel (UZ Brussel), Vrije Universiteit Brussel (VUB), Department of Gastro-Enterology, Laarbeeklaan 101, 1090 Brussels, Belgium
2. Universitair Ziekenhuis Brussel (UZ Brussel), Department of Clinical Biology, Laarbeeklaan 101, 1090 Brussels, Belgium