Cystic Fibrosis (CF) is a fatal, recessive genetic disorder characterized by progressive inflammation and lung damage. It is unclear whether current treatment strategies, which focus on detection and eradication of pathogenic microorganisms in the lung, are the best way to prevent the initiation of early inflammation and lung damage. This study asks how early acquisition of microbial flora occurs in infants with CF and healthy baby controls, and whether this process initiates or influences early inflammation and clinical disease progression in CF.