Lack of efficacy of Lactobacillus GG in reducing pulmonary exacerbations and hospital admissions in children with cystic fibrosis: A randomised placebo controlled trial

Background: Intestinal dysbiosis has been described in Cystic Fibrosis (CF) and probiotics have been proposed to restore microbial composition. Aim of the study was to investigate the effects of Lactobacillus rhamnosus GG (LGG) on clinical outcomes in children with cystic fibrosis (CF). Methods: A multicentre, randomised double-blind, clinical trial was conducted in children with CF. After 6 months of baseline assessment, enrolled children (2 to 16 years of age) received Lactobacillus GG (6 × 109 CFU/day) or placebo for 12 months. Primary outcomes were proportion of subjects with at least one pulmonary exacerbation and hospitalisation over 12 months. Secondary endpoints were total number of exacerbations and hospitalisations, pulmonary function, and nutritional status. Results: Ninety-five patients were enrolled (51/95 female; median age of 103 ± 50 months). In a multivariate GEE logistic analysis, the odds of experiencing at least one exacerbation was not significantly different between the two groups, also after adjusting for the presence of different microbial organisms and for the number of pulmonary exacerbations within 6 months before randomisation (OR 0.83; 95% CI 0.38 to 1.82, p = 0.643). Similarly, LGG supplementation did not significantly affect the odds of hospitalisations (OR 1.67; 95% CI 0.75 to 3.72, p = 0.211). No significant difference was found for body mass index and FEV1. Conclusions: LGG supplementation had no effect on respiratory and nutritional outcomes in this large study population of children with CF under stringent randomised clinical trial conditions. Whether earlier interventions, larger doses, or different strains of probiotics may be effective is unknown.