Research into probiotics & Cystic Fibrosis

Kathy Wheddon Nutritional Therapist DipION

Cystic Fibrosis is a disorder that affects the transport of sodium and chloride across cell membranes, leading to excessive amounts of thick, viscous secretions in both the lungs and digestive tract.

Within this article:

assortment of antibiotics
Cystic Fibrosis sufferers often require frequent courses of antibiotic medication

How Cystic Fibrosis Impacts the Gut Microbiome

Cystic Fibrosis sufferers often require frequent courses of antibiotic medication for chest infections that are exacerbated by the sticky mucous clogging their lungs and causing inflammation.

Each course of antibiotics depletes levels of beneficial bacteria in the intestines, which has many implications for our general health and wellbeing. A lack of ‘good’ bacteria can reduce our ability to digest food and absorb vital nutrients. It can also lead to lowered immune function, and increased susceptibility to infections.

Cystic Fibrosis sufferers often have reduced digestive function, due to thickened digestive secretions. Both pancreatic secretions and bile can become more viscous than they should be, and this disrupts their flow through both the pancreatic duct and the bile duct. Pancreatic inflammation and scarring to the liver can occur as a result, but also the patients ability to digest food is severely restricted.

Probiotics for Cystic Fibrosis

A 2022 study1 suggests that Bifidobacteria-dominated microbiota are associated with improved clinical outcomes in children with diagnosed CF and that daily supplementation with Lactobacillus rhamnosus GG® (LGG) is associated with Bifidobacteria-dominated fecal microbiota in some, but not all, CF children.

The trial involved 23 children aged 2 to 16 years, all with a confirmed diagnosis of Cystic Fibrosis. The participants were randomised into two groups, either given supplementation of Lactobacillus rhamnosus GG® or a placebo, and followed for 12 months. No significant difference in microbiome characteristics was identified at the start of the trial between the two groups, but the researchers noted that a majority of the children were dominated by Bifidobacteria (32%) or Bacteroides (16%).

Findings of the study were that the LGG-treated children exhibited a trend towards a distinct gut microbiome, most frequently dominated by Bifidobacteria, at the end of the 12 months study, unlike the children in the placebo group. In terms of Cystic Fibrosis symptoms and outcomes, the children with Bifidobacterium-dominated microbiota were found to have a lower rate of pulmonary exacerbations and intestinal inflammation markers compared with children dominated with Bacteroides. The Bifidobacterium-dominated microbiota children also had fewer days of prescribed antibiotics over the 12 months and better lung function when compared with other groups.

Healthcare professinals can visit the Probiotics Database to read more about the research behind Lactobacillus rhamnosus GG®

Additionally, a 2013 study2 in the Iranian Journal of Paediatrics, revealed that taking probiotic supplements can improve the quality of life of patients with cystic fibrosis (CS). During the trial, 37 cystic fibrosis sufferers between the ages of 2 and 12 years were given either probiotic supplements or a placebo for a period of one month. Their quality of life was then assessed at various intervals using the PedsQL 4.0 questionnaire.

Analysis of the questionnaire findings showed that overall quality of life for those participants taking the probiotics was improved at 3 months, (two months after cessation of supplementation) however these benefits had receded by six months. One of the measurements used to gauge quality of life was the rate of pulmonary exacerbation, (a temporary worsening of lung function due to infection or inflammation). This rate was reduced significantly in the group that were taking the probiotics. Species of bacteria that were contained in the probiotic supplement used this trial included: Lactobacillus casei, Lactobacillus rhamnosus, Streptococcus thermophilus, Bifido-bacterium breve, Lactobacillus acidophilus, Bifidobacterium infantis, and Lactobacillus bulgaricus.

Key Takeaways

  • Cystic Fibrosis affects digestive function and levels of ‘good’ bacteria in the gut which can impact inflammation and immune health
  • Probiotic bacteria secrete digestive enzymes and have immune boosting properties, which could be advantageous in the ongoing support of cystic fibrosis sufferers
  • A dominance of Bifidobacteria in the gut microbiota of Cystic Fibrosis sufferers may be associated with reduced intestinal inflammation and better lung function
  • Strains of bacteria that may be useful in the management of Cystic Fibrosis include Lactobacillus rhamnosus GG®


  1. Ray, Kathryn J et al., (2022) Gut Bifidobacteria enrichment following oral Lactobacillus-supplementation is associated with clinical improvements in children with cystic fibrosis. BMC Pulmonary Medicine, 22(1):287.
  2. Jafari, S. A., Mehdizadeh-Hakkak, A., Kianifar, H. R., Hebrani, P., Ahanchian, H., & Abbasnejad, E. (2013). Effects of probiotics on quality of life in children with cystic fibrosis; a randomized controlled trial. Iranian journal of pediatrics, 23(6): 669–674.