1. Department of Chemical Engineering and David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
2. Division of Gastroenterology Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA.
3. Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
4. Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.