GAMIN is a longitudinal trial that will randomize 450 children aged 28 days to 59 months to a single dose of azithromycin or placebo. We hypothesize that a single dose of azithromycin will result in a significant difference in the intestinal microbiome and increase child growth over a 6-month period compared those receiving placebo. Our long-term goal is to answer questions surrounding how antibiotic administration can influence the intestinal microflora as well as to evaluate mechanisms behind azithromycin’s effect on all-cause mortality.