Scientific evidence confirms that the early period of human life that begins at conception and continue until 24 months of life (also called the first 1000 days of life ) plays a vital role for promoting the development of chronic diseases throughout the entire life span, indicating the important impact of maternal health status on the health of future child. The microbiome is one of the key elements that play a pivotal role during the first 1000 days of life. The emerging evidence suggests that microbial colonization starts prior to birth and is shaped by the maternal microbiota. Therefore, it is likely that the colonization process is initiated in utero. Subsequent to birth, this complex colonization process is then further influenced by host genetics as well as internal factors such as gestational age and external factors such as type of feeding (breast milk versus formula), mode of delivery (caesarean versus vaginal) and antibiotic exposure.