Healthy gut microflora and allergy: factors influencing development of themicrobiota

In humans, microbial colonization of the intestine begins just after bit th . However, development of the normal. flora is a gradual process, which is initially determined by factors such as competition of the maternal gut mic roflora, environment and possibly also by genetic aspects. A number of vari ables, such as the degree of hygiene, mode of delivery, use of antibiotics or other medication and a need for nursing in incubators, can all have a su bstantial effect on microbial colonization and development. Current knowled ge on the significance and impact of such alterations on the health of the infant is poor. However, the essential role of the gut microflora in the de velopment of the gut immune system indicates that a close-relationship betw een allergic sensitization and the development of the intestinal microflora may occur in infancy. Intestinal micro-organisms could down-regulate the a llergic inflammation by counterbalancing type 2 T-helper cell responses and by enhancing antigen exclusion through an immunoglobulin (Ig)A response. T he efficacy of probiotics (microbial food additions) in the management of f ood allergy has been demonstrated, and these data suggest that also prebiot ics, food components that target certain indigenous gut bacteria, can possi bly be used for this purpose. Pn conclusion, the developmental pattern off the normal gut microbiota in allergic infants poses an important research a venue, as the role of the gut microflora in the mechanisms of allergy, and thereby the possible targets for efficient bacteriotherapy, are currently u ndetermined.