The role of probiotics in modulating the microbiota of the nose and paranasal sinuses and reducing chronic inflammation of the paranasal sinuses

Introduction: The microbiota of the nose and paranasal sinuses plays a crucial role in maintaining the proper function of the mucous membrane of the upper respiratory tract. It consists of diverse bacteria, viruses, fungi, and other microorganisms. Dysbiosis, i.e. imbalance in the microbiota, can lead to diseases such as chronic rhinosinusitis (CRS). Modern techniques of genetic analysis allow a better understanding of the microbiota's impact on the human immune system. Aim: This review aims to analyze current research on the role of microbiota and dysbiosis and their impact on CRS, as well as present therapeutic possibilities related to microbiotal modulation, such as probiotics. Materials and methods: A literature review was conducted using PubMed and Google Scholar databases, focusing on articles published between 2016 and 2024. Both experimental and clinical studies analyzing the composition of nasal and paranasal sinus microbiota and its changes in CRS patients were included. Discussion: The nasal and paranasal sinus microbiota is characterized by high diversity. In healthy individuals, predominant microorganisms include the bacteria of genera Staphylococcus, Corynebacterium, and Propionibacterium. In CRS, decreased microbiotal diversity and increased numbers of pathogens such as S. aureus and P. aeruginosa are observed. Dysbiosis can lead to chronic inflammation, including through the disruption of the mucosal barrier and the suppression of the immune system. Probiotics can restore the microbiotal balance, reduce inflammation, strengthen the epithelial barrier, and alleviate symptoms of CRS. Conclusions: The microbiota plays a crucial role in otolaryngological health, its disturbances possibly leading to CRS. Understanding the mechanisms by which the microbiota influences human health opens new therapeutic avenues, including the use of probiotics.