Allergic diseases and chronic inflammatory diseases of the respiratory system, such as asthma or chronic rhinosinusitis, continue to pose a real challenge to modern medicine. The causes of the growing problem generated by these diseases is thought to be in the interaction of genes and the environment. In the light of current knowledge, it seems that the environmentally dependent interaction between the airway microbiota ecosystem and the epithelium is able to shape the functions of the local immune system, producing a number of molecular and clinical consequences. In this paper, an attempt was made to describe the role of microbiota composition disorders (dysbiosis) of the upper respiratory tract and allergies in the development of chronic rhinosinusitis in children. The research results obtained in a Polish cohort of young children diagnosed with chronic rhinosinusitis with or without concomitant asthma are summarised. Some of the children presented with features of secondary dysbiosis, which was associated with sensitisation to house dust mite allergens. It was noted that frequent courses of antibiotic therapy correlated with microbiota dysfunction, reducing biodiversity. It was also observed that patients suffering from asthma had specific dysbiosis in the upper respiratory tract. It is characterised by an altered proportion between the main types of bacteria and is expressed by a reduced Patescibacteria/Actinobacteria ratio, constituting an independent factor of asthma in the study group, similar to atopy and reduced perception of the sweet taste. An attempt was also made to identify possible therapeutic and prophylactic interventions to treat and prevent dysbiosis in children suffering from chronic rhinosinusitis.

children, dysbiosis, house dust mite allergy, chronic rhinosinusitis, allergen immunotherapy