Dynamic Upper and Lower Airway Microbiotas in Paediatric Bronchiectasis Exacerbations: A Pilot Study

Abstract

IntroductionNon-cystic fibrosis bronchiectasis is a respiratory health condition with many possible aetiologies, some of which are potentially reversible in childhood with early diagnosis and appropriate treatment. It is important to understand factors which contribute to progression or potential resolution of bronchiectasis. It is evident that respiratory exacerbations are a key feature of bronchiectasis disease progression. In this pilot study we document how the microbiota of the upper and lower airways presents during the course of an exacerbation and treatment.MethodsWe recruited children (aged 1-15) undergoing antibiotic treatment for bronchiectasis exacerbations at Starship Children’s Hospital and outpatient clinics. Sputum and nasal swabs were taken before and after antibiotic treatment. Sample DNA was extracted, then bacterial 16S rRNA genes amplified and sequenced via Illumina MiSeq.ResultsThirty patients were recruited into this study with 81 samples contributing to the final dataset, including 8 patients with complete sets of upper and lower airway samples at both (before and after antibiotics) timepoints. Changes in alpha-diversity over the course of an exacerbation and treatment were non-significant. However, sample composition did alter over the course of an exacerbation, with most notably a reduction in the relative abundance of amplicon sequence variants assigned to Haemophilus.DiscussionHaemophilus has been associated with more severe symptoms in respiratory infections and a reduction in its relative abundance may represent a positive shift in a patient’s microbiota. Current treatments for bronchiectasis may preserve bacterial diversity while altering microbiota composition.

The Respiratory Microbiome in Paediatric Chronic Wet Cough: What Is Known and Future Directions

“…Despite this variability, a small number of genera are consistently observed to be among the most abundant taxa in the airway bacteriome of children with PBB or bronchiectasis, specifically: Haemophilus , Moraxella , Streptococci , and Neisseria [ 28 , 29 , 30 , 31 , 32 , 33 ]. Anaerobic taxa (e.g., Prevotella , Fusobacterium , and Veillonella ) are also common, but with higher variability in relative abundance across studies [ 28 , 29 , 31 ].…”

“…To date, only one study has assessed the lower airway bacteriome among children with bronchiectasis longitudinally. Broderick and colleagues [ 33 ] examined the sputum bacteriome among 30 children with bronchiectasis (median age 6 years; range 1–15 years) before and after antibiotic treatment for an acute exacerbation. Despite heterogeneity in the types of antibiotics used, no significant differences in alpha or beta diversity were observed, suggesting stability of the sputum bacteriome during treatment.…”

Human nasal microbiota shifts in healthy and chronic respiratory disease conditions

“…In chronic respiratory tract diseases, such as bronchiectasis (BE), the microbial factor and dysfunctional immunity contribute to the pathophysiology, while the underlying cause of the disease is still unclear in a large part of cases [16]. While the lower respiratory tract microbiota of BE patients has been explored to some extent [17][18][19][20][21], the content and role of nasal microbiota in BE patients is still sparse [22]. However, in similar morbidities, like chronic obstructive pulmonary disease, lung microbiota closely reflected the oral, and nasal microbiota [23].…”

Immune response plays a role in Mycoplasma pneumoniae pneumonia

“…Numerous studies have shown that disturbance of the microbiome is closely related to the exacerbation of many respiratory diseases, such as bronchiectasis, asthma, COVID-19, and ventilator-associated pneumonia (4)(5)(6)(7). The pulmonary microbiome is correlated with some outcomes of MPP, such as bronchial mucus plugs and refractory MPP (8,9).…”