1Laboratory of Functional and Metabolic Imaging, Center for Biomedical Imaging, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Vaud, Switzerland, Lausanne, Switzerland, 2Service of Biomedicine, University Hospital of Lausanne, Lausanne, Vaud, Switzerland, Lausanne, Switzerland, 3Center for Biomedical Imaging, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Vaud, Switzerland, Lausanne, Switzerland, 4Laboratory of behavioral genetics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Vaud, Switzerland, Lausanne, Switzerland, 5Sapienza University of Rome, Department of Public Health and Infectious diseases, Section of Microbiology, Rome, Italy, Rome, Italy, 6Swiss Center for Liver Disease in Children, Department of Pediatrics, University Hospitals Geneva, Geneva, Switzerland, Geneva, Switzerland