1. School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore
2. Division
of Gastroenterology and Hepatology, Department of Medicine, Stanford University School of Medicine, Alway Building, Room M211, 300 Pasteur
Drive, Stanford, California 94305, United States
3. Department
of Microbiology and Immunology, Stanford University School of Medicine, Fairchild Building, D300, 299 Campus Drive, Stanford, California 94305, United States
4. School
of Chemical and Biomolecular Engineering, Nanyang Technological University, 62 Nanyang Avenue 637459, Singapore