Department of Biological Engineering, MIT, Cambridge, Massachusetts, United States of America. Center for Microbiome Informatics and Therapeutics, MIT, Cambridge, Massachusetts, United States of America. Aerodigestive Center, Division of Gastroenterology, Hepatology and Nutrition, Boston Children's Hospital, Boston, Massachusetts, United States of America. Division of Gastroenterology, Hepatology and Nutrition, Boston Children's Hospital, Boston, Massachusetts, United States of America. Division of Pulmonary Medicine, Boston Children's Hospital, Boston, Massachusetts, United States of America.