Objective: Gut microbiota provide a diverse "organ" or biocenosis responsible for protection against pathogens and the development of both intestinal and immune systems. Microbiota are also responsible for the synthesis of vitamins and short-chain fatty acids, which in turn affect the host's metabolism. It was hypothesized that gut microbiota are influenced by fetal life followed by intensive development throughout the first years of life.
Materials and methods: We analyzed the available literature (PubMed, Embase, Google Scholar) on prenatal and early childhood development of gut microbiota.
Results: A body of evidence suggests in utero colonization. The main factors determining gut microbiota include the type of delivery and post-natal feeding method. The composition of the intestinal flora is also influenced by fetal age at birth, antibiotic therapy, pre- and probiotic supplementation, and other environmental factors. The multifaceted nature of this process guarantees the uniqueness of its composition for each human being.
Conclusions: Although the composition of intestinal microbiota is subject to continuous and dynamic changes, it seems that the perinatal period is critical for the emergence of its proper pattern, which may guarantee health or otherwise illness in adult life.