A study recently published in the journal SpringerPlus revealed new insights into the pulmonary microbiota in patients with cystic fibrosis and the impact of Pseudomonas aeruginosa infection. The study is entitled “Insights into the respiratory tract microbiota of patients with cystic fibrosis during early Pseudomonas aeruginosa colonization,” and was led by researchers at Laboratoire Universitaire de Biodiversité et Ecologie Microbienne (LUBEM), University of Brest in France.

CF is a rare, life-threatening genetic disease in which a defective gene (CFTR) induces a salt imbalance, causing the body to form unusually thick, sticky mucus that can obstruct the airways and promote dangerous lung infections, resulting in serious respiratory and also gastrointestinal manifestations. CF can affect the cells that produce mucus, sweat and digestive juices. Currently there is no cure for the disease.

Microbial infections are the major cause of morbidity and mortality in CF patients. Bacteria such as P. aeruginosa can induce chronic pulmonary infections and a serious inflammatory response, leading to respiratory failure and early death in CF patients. It is therefore important to better understand P. aeruginosa infection.

In the study, researchers characterized the structure and dynamics of the pulmonary microbial communities in CF patients during the early steps of P. aeruginosa colonization.

Researchers found a high diversity in terms of respiratory microbiota between CF patients, which was related to the young age of the cohort analyzed (mean age of 10 years). A microbiota core of 13 main genera (5 phyla) was found in all patients, being the majority of them obligate anaerobes (organisms that do not require oxygen to grow). This anaerobic core microbiota was found independently of whether the patient was infected with P. aeruginosa suggesting a previously underestimated key role for anaerobes in lung infections in CF patients. The team found that a few genera were more prevalent in patients who had never been infected with P. aeruginosa, indicating that this pathogen can influence the composition of the CF lung microbiota.

The research team concluded that P. aeruginosa status in CF patients has an impact on their lung microbiota composition. Furthermore, a core microbiota including anaerobic bacteria was found to be characteristic of CF patients. The authors believe that it is important to assess the microbiota linked to the pulmonary clinical profiles in CF patients, and suggest that some of the genera found could be potential biomarkers of the pulmonary infection state.