1 Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
2 Department of Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
3 Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
4 University of Groningen, University Medical Center Groningen, Genomics Coordination Center, Groningen, the Netherlands.
5 Department of Medical Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
6 Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands. sasha.zhernakova@gmail.com.
7 Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands. serena.sanna@irgb.cnr.it.
8 Institute for Genetic and Biomedical Research (IRGB), National Research Council (CNR), Cagliari, Italy. serena.sanna@irgb.cnr.it.