An Overview on the Upper and Lower Airway Microbiome in Cystic Fibrosis Patients

Background: In cystic fibrosis patients, the mucus is an excellent place for opportunistic bacteria and pathogens to cover. Chronic infections of upper and lower airways play a critical role in the mortality of cystic fibrosis. This study aimed to introduce the microbiota profiles in patients with cystic fibrosis. Materials and Methods: In this study, a comprehensive literature search was done for studies on upper and lower airway microbiota in cystic fibrosis patients. International and national databases were searched for the following MeSH words: microbiota, microbiome, upper airway, lower airway, cystic fibrosis, cystic fibrosis, upper airway microbiome, lower airway microbiome, microbiome pattern in cystic fibrosis, microbiome pattern in cystic fibrosis, upper airway microbiota, lower airway microbiota, and microbiota pattern. Results: Streptococcus spp. are in significantly higher relative abundance in infants and children with cystic fibrosis; however, Pseudomonas spp. are in higher relative abundance in adults with cystic fibrosis. Molecular diagnostic techniques can be remarkably accurate in detecting microbial strains. Conclusion: For the detection and isolation of most bacterial species, independent-culture methods in addition to the standard culture method are recommended, and sampling should include both upper and lower airways.