Display omitted •The intestinal microbiota follows a common successional pattern in early life.•Particular bacterial taxa are mainly transmitted from the mother to the infant after birth.•Infants receive specific bacterial signals at specific immunological time windows.•C-section and antibiotic use disrupt the colonization and development process explaining later life health impact.•Targeted treatment of age-specific microbial defects may offer novel ways to promote health. Microbes colonising the infant intestine, especially bacteria, are considered important for metabolic and immunological programming in early life, potentially affecting the susceptibility of the host to disease. We combined published data to provide a global view of microbiota development in early life. The results support the concept that the microbiota develops with age in an orchestrated manner, showing common patterns across populations. Furthermore, infants are colonised at birth by specific, selected maternal faecal bacteria and likely their bacteriophages. Therefore, infants are adapted to receiving specific bacterial signals, partly derived from the maternal microbiota, at successive immunological time windows during early development. Birth by caesarean section compromises the initial vertical transmission of microbes whereas antibiotic use shifts the microbiota away from the normal developmental pattern. These disruptions alter the microbial signals that the host receives, potentially affecting child development.