This was an observational, single-site, follow-up study of healthy children who as infants who had completed study 9052A1-3000. An attempt was made to contact all subjects who had completed study 9052A1-3000 by telephone to ask them to participate in study 9052A1-3001. Approximately 66 and 60 subjects were planned to participate in the stool microbiota and stool composition substudies, respectively.