Plain language summary
The lungs are under constant exposure to microorganisms contained in inhaled air and the upper respiratory tract. In healthy subjects, the lower airways are colonized by bacteria. Changes in the microbiome are found in several lung diseases associated with chronic airway inflammation including chronic obstructive pulmonary disease, asthma and cystic fibrosis. The aim of the study was to find out whether the throat microbiota of children with asthma and cystic fibrosis differ from healthy children. Another aim was to find out whether the throat microbiota of children with asthma differ from those with cystic fibrosis. The study compared the throat microbiota of healthy school-aged children with that of age-matched children with asthma and cystic fibrosis. Results indicate that the microbiota of cystic fibrosis, asthmatic, and healthy children show high levels of similarities with a strong core microbiota. The cystic fibrosis group show a decrease in both diversity and total bacterial load in the throat in comparison to asthmatic and control children. The cystic fibrosis group also showed a significant increase in typical pathogens in the throat. Based on the results, the authors conclude that the three patient groups had a core microbiome and a host regulation that favours the growth of commensals.
Abstract
A genuine microbiota resides in the lungs which emanates from the colonization by the oropharyngeal microbiota. Changes in the oropharyngeal microbiota might be the source of dysbiosis observed in the lower airways in patients suffering from asthma or cystic fibrosis (CF). To examine this hypothesis, we compared the throat microbiota from healthy children (n = 62) and that from children with asthma (n = 27) and CF (n = 57) aged 6 to 12 years using 16S rRNA amplicon sequencing. Our results show high levels of similarities between healthy controls and children with asthma and CF revealing the existence of a core microbiome represented by Prevotella, Streptococcus, Neisseria, Veillonella, and Haemophilus. However, in CF, the global diversity, the bacterial load, and abundances of 53 OTUs were significantly reduced, whereas abundances of 6 OTUs representing opportunistic pathogens such as Pseudomonas, Staphylococcus, and Streptococcus were increased compared to those in healthy controls controls and asthmatics. Our data reveal a core microbiome in the throat of healthy children that persists in asthma and CF indicating shared host regulation favoring growth of commensals. Furthermore, we provide evidence for dysbiosis with a decrease in diversity and biomass associated with the presence of known pathogens consistent with impaired host defense in children with CF.
Methodological quality
Allocation concealment
:
Not applicable
