Factors influencing the development of intestinal microbiota of infants

The gut microbiota is a complex biodiversity of microorganisms, including many different species, that colonize the human intestinal tract. The development and establishment of the gut microbiota in infants is subject to change over time as a result of multiple factors. As previously believed, the colonization of the infant’s intestine with microorganisms begins immediately after birth, however, a growing body of evidence suggests that the intrauterine environment is not sterile, and the transfer of microbiota from mother to fetus occurs during pregnancy. Many prenatal factors can modulate the composition and development of the infant’s intestinal microbiota, such as the characteristics of the mother’s diet, obesity, smoking, and the use of antibacterial drugs during gestation. The method of delivery and the type of feeding are fundamental factors for the subsequent development and establishment of the infant’s microbiota at birth and the postpartum period, respectively. The objective of this review is to identify and analyze the most significant modifiable factors (maternal nutrition, mode of delivery, feeding type) that determine the development of the infant’s intestinal microbiota based on a summary of literature data. This review is necessary to create a theoretical basis that can be used by physicians (neonatologists, pediatricians) to develop practical measures to optimize and correct the microbiocenosis, and prevent diseases in children associated with its disruption (allergy, obesity, diabetes mellitus, necrosing ulcerative colitis).