Значение на кожния и лигавичен микробиом за имунитета в детската възраст

Skin mediates information from the outer world and provides the first line of defense against pathogens, toxins and hostile environmental conditions. This barrier-function-role is both physical and immunological and it is supported by microbial communities inhabiting the skin. Microorganisms living on the skin and mucous membranes of the oropharynx, upper respiratory tract, conjunctiva, colon and the lower sections of the urogenital tract are called “normal flora“ (physiological, natural, autochthonous, microbiome, microbiota). The skin microbiota contribute to the barrier function by competing with pathogens and, importantly, communicating with immune cells in the skin, to modulate the local and systemic immune responses. The skin microbiota and immune mediators, such as the complement system have a two-way interaction, indicating that commensal microbes should be considered as an essential part of healthy skin. Furthermore, accumulating evidence suggests that the composition of microbiota, especially in the gut but also on the skin, can have major influence on individual health. Age is a major determinant of skin microbial composition. The diversity of microbiota increases during the first years of life, which is associated with a dominance of Lactobaciles (especially genus Streptococcus) on the skin. In puberty there is greater inter-individual variation in diversity than in the younger age groups. At this age the relative abundance of Lactobacilles decreases and is replaced by other groups, namely Actinobacteria and Proteobacteria at the age of 14, the diversity in skin microbiota resembles cloasely that observed for adults. [ABSTRACT FROM AUTHOR]