1 Harvard Medical School and Harvard T H Chan School of Public Health, Boston, MA, USA; Sangath, Goa, India.
2 Biocon Ltd, Bangalore, India.
3 The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India.
4 The Lancet, London, UK.
5 Harvard Business School and Lakshmi Mittal and Family South Asia Institute, Harvard University, Cambridge, MA 02138, USA. Electronic address: tkhanna@hbs.edu.