作者单位:Christian Med Coll & Hosp, Wellcome Trust Res Lab, Div Gastrointestinal Sci, Vellore, Tamil Nadu[1]Harvard Med Sch, Boston, MA 02115 USA[2]Biocon Ltd, Bangalore, Karnataka, India[3]Harvard Univ, Harvard Business Sch, Cambridge, MA 02138 USA[4]The Lancet, London, England[5]