Changes in intestinal microbiota in pediatric cystic fibrosis patients after 6 months of elexacaftor-tezacaftor-ivacaftor therapy.

Objectives: Cystic fibrosis (CF) is frequently associated with gastrointestinal problems, including intestinal microbiota dysbiosis. Cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapies, such as elexacaftor-tezacaftor-ivacaftor (ELX/TEZ/IVA), have demonstrated improvements in lung function, abdominal symptoms, and quality of life in patients with CF. However, the impact of these modulators on the intestinal microbiota in the pediatric population remains incompletely understood. The objective of this study was to characterize the changes in the intestinal microbiota of pediatric patients with CF after 6 months of treatment with ELX/TEZ/IVA.

Methods: Thirty-one patients with CF, aged 6-18 years, were recruited. Stool samples were collected before the initiation of treatment and approximately 6 months thereafter. Microbiota analysis was performed using 16S rRNA gene amplicon sequencing. Statistical analyses were employed to evaluate changes in alpha and beta diversity and variations in the relative abundance of different bacterial taxa. Clinical variables such as concomitant use of azithromycin and probiotics were considered.

Results: After 6 months of treatment, no significant changes in the alpha diversity were observed. However, alterations in bacterial composition were detected. A decrease in the abundance of potentially pathogenic bacteria, such as Enterobacteriaceae members (Escherichia/Shigella) was observed. The abundance of genus Blautia increased. Differential analysis according to antibiotic and probiotic consumption revealed specific changes in microbiota composition.

Conclusions: ELX/TEZ/IVA therapy for 6 months induces changes in the intestinal microbiota composition of pediatric patients with CF, characterized by a reduction in potentially harmful bacteria and an increase in potentially beneficial bacteria. These findings suggest a modulation towards a healthier intestinal microbiota profile.