 The skin and intestinal tracts of humans are covered with microbes, and the gene products of these microbes are collectively known as the human microbiome. Many studies in recent years have linked the microbiome to many aspects of human health and disease. Premature infants are vulnerable to invasive infections, some of which may originate from the microbes that colonize the skin and in the intestinal tract. Therefore, determining the patterns of early life colonization and the sources of colonization in these infants may be critical to determining infectious risks. This prospective study is proposed to identify the sources of microbes that colonize extremely low birth weight ELBW; 1000 g birth weight infants immediately following birth through the first month of life. The study team plans to non-invasively survey the skin and stool of ELBW preterm infants in combination with sampling of their mothers skin and stool and the intensive care nursery ICN environment. As controls, the study team will perform a similar survey of full term mother-infant pairs. Samples will be analyzed using high throughput sequencing techniques to determine microbial content. 