.gov/pubmed/10723647> If we proceed with a cohort study, we can think further on how we would structure that. Thanks, Karen On 4/17/13 12:13 PM, "Nathan Wolfe' wrote: >http://www.ncbi.nlm.nih.gov/pubmed?LinkName=pubmed_pubmed&from_uid=1970 >527 >3 >Dr. Nathan Wolfe I Founder and CEO I Metabiota >Email