Cystic fibrosis is a rare genetic disease that manifests through serious respiratory and digestive problems. There appears to be a connection between these symptoms and the gastrointestinal microbiota.
More than 70,000 people around the world suffer from cystic fibrosis. France was the first country to introduce systematic testing at birth.
Alteration in the CFTR protein involved
Cystic fibrosis is caused by a change in the CFTR protein (Cystic fibrosis transmembrane conductance regulator), resulting from a mutation in its gene. The normal CFTR protein regulates exchanges of water and mineral salts across cell membranes. When it is defective, it leads to an increase in the viscosity of the mucus, causing it to accumulate in the respiratory and digestive tracts. This accumulation provides a foundation for bacterial infections in the respiratory tract and can eventually lead to respiratory failure. On the digestive side, cystic fibrosis leads to pancreatic insufficiency that affects digestion, the absorption of nutrients, growth, and presents with alternating diarrhea and constipation.
Imbalance in the microbiota
An imbalance in the intestinal microbiota may be associated with respiratory symptoms of cystic fibrosis. This dysbiosis, observed before the onset of the first signs, may be aggravated by the disease and accompanying antibiotic treatments. It contributes to undernutrition, growth delays, and, more generally, to digestive and respiratory complications in these patients.
Treatment for these patients is given in specialist centers; its specific goal is to clear out the bronchi using bronchial decongestants and bronchodilators, combined with sessions of respiratory rehabilitation. Every three to four months, preventative antibiotic treatment is prescribed. Digestive problems are treated with a hypercaloric diet, supplemented with pancreatic extracts and vitamins.
In the future, new therapeutic strategies that aim to have an impact on the microbiota during the first weeks of life through nursing or the use of probiotics could delay the onset of respiratory damage, reinforce these patients’ immune systems, and, as a result, reduce the morbidity and mortality associated with cystic fibrosis.
Cystic Fibrosis Foundation https://www.cff.org/What-is-CF/About-Cystic-Fibrosis/
Le dépistage néonatal systématique de la mucoviscidose en France : état des lieyx et perspectives après 5 ans de fonctionnement. Haute Autorité de Santé, janvier 2009. https://www.has-sante.fr/portail/upload/docs/application/pdf/2009-04/rapport_depistage_neonatal_systematique_de_la_mucoviscidose_en_france.pdf
Hoen GA, Li J, Moulton LA, et al. Associations between gut microbial colonization in early life and respiratory outcomes in cystic fibrosis. J Pediatr 2015 ; 167 : 138-47.
Madan JC. Neonatal Gastrointestinal and Respiratory Microbiome in Cystic Fibrosis: Potential Interactions and Implications for Systemic Health. Clin Ther. 2016 April ; 38(4): 740–746.