Impaired distal colonic pH in adults with cystic fibrosis

Longitudinal profiling of the intestinal microbiome in children with cystic fibrosis treated with elexacaftor-tezacaftor-ivacaftor

The intestinal microbiome influences growth and disease progression in children with cystic fibrosis (CF). Elexacaftor-tezacaftor-ivacaftor (ELX/TEZ/IVA), the newest pharmaceutical modulator for CF, restores the function of the pathogenic mutated CF transmembrane conductance regulator (CFTR) channel. We performed a single-center longitudinal analysis of the effect of ELX/TEZ/IVA on the intestinal microbiome, intestinal inflammation, and clinical parameters in children with CF. Following ELX/TEZ/IVA, children with CF had significant improvements in body mass index and percent predicted forced expiratory volume in one second, and required fewer antibiotics for respiratory infections. Intestinal microbiome diversity increased following ELX/TEZ/IVA coupled with a decrease in the intestinal carriage of Staphylococcus aureus, the predominant respiratory pathogen in children with CF. There was a reduced abundance of microbiome-encoded antibiotic resistance genes. Microbial pathways for aerobic respiration were reduced after ELX/TEZ/IVA. The abundance of microbial acid tolerance genes was reduced, indicating microbial adaptation to increased CFTR function. In all, this study represents the first comprehensive analysis of the intestinal microbiome in children with CF receiving ELX/TEZ/IVA.IMPORTANCECystic fibrosis (CF) is an autosomal recessive disease with significant gastrointestinal symptoms in addition to pulmonary complications. Recently approved treatments for CF, CF transmembrane conductance regulator (CFTR) modulators, are anticipated to substantially improve the care of people with CF and extend their lifespans. Prior work has shown that the intestinal microbiome correlates with health outcomes in CF, particularly in children. Here, we study the intestinal microbiome of children with CF before and after the CFTR modulator, ELX/TEZ/IVA. We identify promising improvements in microbiome diversity, reduced measures of intestinal inflammation, and reduced antibiotic resistance genes. We present specific bacterial taxa and protein groups which change following ELX/TEZ/IVA. These results will inform future mechanistic studies to understand the microbial improvements associated with CFTR modulator treatment. This study demonstrates how the microbiome can change in response to a targeted medication that corrects a genetic disease.

Neurogastroenterology and Motility Disorders of the Gastrointestinal Tract in Cystic Fibrosis

PURPOSE OF REVIEW

To discuss all the various motility disorders impacting people with Cystic Fibrosis (PwCF) and provide diagnostic and management approaches from a group of pediatric and adult CF and motility experts and physiologists with experience in the management of this disease.

RECENT FINDINGS

Gastrointestinal (GI) symptoms coexist with pulmonary symptoms in PwCF regardless of age and sex. The GI manifestations include gastroesophageal reflux disease, esophageal dysmotility gastroparesis, small bowel dysmotility, small intestinal bacterial overgrowth syndrome, distal idiopathic obstruction syndrome, constipation, and pelvic floor disorders. They are quite debilitating, limiting the patients' quality of life and affecting their nutrition and ability to socialize. This genetic disorder affects many organ systems and is chronic, potentially impacting fertility and future family planning, requiring a multidisciplinary approach. Our review discusses the treatments of motility disorders in CF, their prevalence and pathophysiology. We have provided a framework for clinicians who care for these patients that can help to guide their clinical management.

Preservation of β-cell Function in Pancreatic Insufficient Cystic Fibrosis With Highly Effective CFTR Modulator Therapy

CONTEXT

Elexacaftor/tezacaftor/ivacaftor (ETI; Trikafta) enhances aberrant cystic fibrosis transmembrane conductance regulator function and may improve the insulin secretory defects associated with a deterioration in clinical outcomes in pancreatic insufficient cystic fibrosis (PI-CF).

OBJECTIVE

This longitudinal case-control study assessed changes in β-cell function and secretory capacity measures over 2 visits in individuals with PI-CF who were initiated on ETI after the baseline visit (2012-2018) and (1) restudied between 2019 and 2021 (ETI group) vs (2) those restudied between 2015 and 2018 and not yet treated with cystic fibrosis transmembrane conductance regulator modulator therapy (controls).

METHODS

Nine ETI participants (mean ± SD age, 25 ± 5 years) and 8 matched controls were followed up after a median (interquartile range) 5 (4-7) and 3 (2-3) years, respectively (P < .01), with ETI initiation a median of 1 year before follow-up. Clinical outcomes, glucose-potentiated arginine, and mixed-meal tolerance test measures were assessed with comparisons of within- and between-group change by nonparametric testing.

RESULTS

Glucose-potentiated insulin and C-peptide responses to glucose-potentiated arginine deteriorated in controls but not in the ETI group, with C-peptide changes different between groups (P < .05). Deterioration in basal proinsulin secretory ratio was observed in controls but improved, as did the maximal arginine-induced proinsulin secretory ratio, in the ETI group (P < .05 for all comparisons). During mixed-meal tolerance testing, early insulin secretion improved as evidenced by more rapid insulin secretory rate kinetics.

CONCLUSION

ETI preserves β-cell function in CF through effects on glucose-dependent insulin secretion, proinsulin processing, and meal-related insulin secretion. Further work should determine whether early intervention with ETI can prevent deterioration of glucose tolerance in PI-CF.

Longitudinal Profiling of the Intestinal Microbiome in Children with Cystic Fibrosis Treated with Elexacaftor-Tezacaftor-Ivacaftor

The intestinal microbiome influences growth and disease progression in children with cystic fibrosis (CF). Elexacaftor-tezacaftor-ivacaftor (ELX/TEZ/IVA), the newest pharmaceutical modulator for CF, restores function of the pathogenic mutated CFTR channel. We performed a single-center longitudinal analysis of the effect of ELX/TEZ/IVA on the intestinal microbiome, intestinal inflammation, and clinical parameters in children with CF. Following ELX/TEZ/IVA, children with CF had significant improvements in BMI, ppFEV1 and required fewer antibiotics for respiratory infections. Intestinal microbiome diversity increased following ELX/TEZ/IVA coupled with a decrease in the intestinal carriage of Staphylococcus aureus, the predominant respiratory pathogen in children with CF. There was a reduced abundance of microbiome-encoded antibiotic-resistance genes. Microbial pathways for aerobic respiration were reduced after ELX/TEZ/IVA. The abundance of microbial acid tolerance genes was reduced, indicating microbial adaptation to increased CFTR function. In all, this study represents the first comprehensive analysis of the intestinal microbiome in children with CF receiving ELX/TEZ/IVA.