The long-held concept of fetus being nurtured in a sterile environment has been challenged by many recent studies that have identified bacterial communities in meconium, amniotic fluid and the placenta concluding that the microbial colonization of fetal gut begins in utero and continues during the first 2 years of life. This microbial colonization of newborn's gut during prenatal, intrapartum, and postnatal period depends on multiple factors, e.g. maternal diet, stress, antibiotic exposure, mode of delivery, type of feeding (human milk versus formula), etc., and imparts a critical role in the development of gastrointestinal, immunological, and neural systems in newborns. This article briefly reviews the current state of knowledge of microbiome in the maternal fetal unit and its impact on subsequent neonatal health and diseases.
Keywords: Microbiome; neonatal; review.