[Probiotics, immunity and pediatric health].

Early bacterial stimulation of gut associated immune cells is essential for the development and maturation of the infant's immune response. This "microbial experience" has been affected due to a decrease in vaginal births (which are the first source of bacterial exposure for an infant), the substitution of breast feeding, in favor of almost sterile formulas, an increase use of antibiotics, and an increasingly "cleaner" environment. Increased hygienic measures and pasteurization perpetuate this decreased microbe-host interaction. These changes in environmental and gut microbiota are associated with an altered and inadequate development of immune response, with related health implications. The inadequate host response to infectious diseases, as well as the epidemic of immune related chronic conditions (such as allergy) can be explained in great measure by these changes. The consumption of certain probiotics (specific dietary bacteria that provide a benefit to the host) has positive effects on gut barrier function and immune response. Thus, probiotics are a means of improving host-microbe interactions for health maintenance, and for the management of a number of illnesses. This paper summarizes important aspects of these interactions as well as the role that probiotic bacteria can play in pediatric health.