 Infant participants will be enrolled at or within 5 weeks of birth and followed throughout the weaning period. During the weaning period, participants will be randomly assigned to either receive LGG-containing yogurt or placebo yogurt everyday for 3 months. All participants will have height and weight measurements taken at study entry and at Month 3 study completion. The number of diarrhea episodes experienced by participants during the study will be assessed at study completion to determine participants health. 