Phase II is a hospital based intervention (n = 297 infants) measuring the colonizing ability, safety, and tolerance of a probiotic supplement, Lactobacillus plantarum in the neonatal gut. Newborn infants ≥ 35 weeks of gestation will be randomized to receive either L. plantarum preparations (containing 109 organisms) or placebo preparations orally once a day for the first 7 days of life. The final stage of the project will be a community-based randomized double-blind placebo-controlled trial of L. plantarum enrolling over 8,000 newborns to examine the efficacy of probiotic supplementation in reducing neonatal infection in Indian neonates.