RESUMEN
The microbiota of the human gastrointestinal tract inhabits a complex ecosystem.Intestinal normal flora is obtained by newborn after birth,and suffers influences on the type of delivery,the type of feeding and contamination from the environment.There is emerging evidence indicating that quantitative and qualitative changes on gut microbiota contribute to alterations in the mucosal activation of immune system leading to intra-or extra-intestinal diseases.A balance between pathogenic and beneficial microbiota throughout childhood is important to gastrointestinal health,including protection against pathogens,inhibition of pathogens,nutrient processing,and regulation of host fat storage.Probiotics can promote an intentional modulation of intestinal microbiota favoring the health of the host.This paper is a review about modulation of intestinal microbiota on prevention and adjuvant treatment of intra-and extra intestinal pediatric diseases.