The lungs are the main organs of the respiratory system, experiencing continuous and direct exposure to environmental particles and several microbial antigens - both innocuous and pathogenic - through inhalation and oropharyngeal aspiration. The interstitial lung microbiota in healthy lungs not only play a crucial role in the growth and development of the lungs but are also an important protective mechanism against external affection, which has been demonstrated by a variety of genomic and bioinformatics analysis, revealing diverse communities of microbiota in the lung. In addition, they participate in the homeostasis of airway immunity and several common lung diseases, such as asthma, lung fibrosis, and chronic obstructive pulmonary disease (COPD), which have emerged as a leading cause of morbidity and mortality worldwide and contribute to over 5 million global deaths annually. Recently, accumulating evidence has suggested that progression of dysbiosis can be associated with worsening of lung disease.

However, unlike intestinal microbiota, studies of pulmonary microbiota and related dysbiosis are still in their infancy. Despite appropriate treatment and improved prognosis, patients still experience recurrent respiratory tract infections, leading to bronchiectasis and continuing decline in lung function, severely impacting their quality of life. Moreover, non-infectious inflammatory and interstitial lung complications contribute substantially to overall morbidity. These conditions develop much more often than appreciated and represent a major therapeutic challenge. Therefore, an understanding of the ongoing situation and the development of new strategies to contain pulmonary dysbiosis in lung diseases are urgently needed.

This Special Issue aims to collect original research and review articles regarding research into new targets or potential drugs for the prevention of lung diseases associated with pulmonary dysbiosis and the lung microbiota. We welcome both original research and review articles.

Potential topics include but are not limited to the following:

• New noninvasive microbiota-related biomarkers for the diagnosis of asthma, COPD, and lung fibrosis
• New targets in dysbiosis for the prevention of airway diseases
• Novel drug delivery approaches through regulating microbiota homeostasis for the treatment of asthma and lung fibrosis
• Host-pathogen interactions in lung dysbiosis by single-cell RNA sequencing
• The impact of lung microbiota homeostasis on shaping lung inflammation and infection
• Therapeutic properties and mechanisms of antibiotic and microbiota modulators for the prevention of asthma, COPD, and lung fibrosis
• Novel combinations between microbiota modulators and chemicals for the prevention of allergic asthma
• Prospects and paradigms of immunotherapy on the microbiota homeostasis of airway diseases
• Molecular pathological reviews on the dysbiosis of airway diseases