Changes in fecal microbiota with CFTR modulator therapy: A pilot study

Nutritional status in the era of highly effective CFTR modulators

Advances in cystic fibrosis (CF) diagnostics and therapeutics have led to improved health and longevity, including increased body weight and decreased malnutrition in people with CF. Highly effective CFTR modulator therapies (HEMT) are associated with increased weight through a variety of mechanisms, accelerating trends of overweight and obesity in the CF population. Higher body mass index (BMI) is associated with improved pulmonary function in CF, yet the incremental improvement at overweight and obese BMIs is not clear. Improvements in pulmonary health with increasing BMI are largely driven by increases in fat-free mass (FFM), and impact of HEMT on FFM is uncertain. While trends toward higher weight and BMI are generally seen as favorable in CF, the increased prevalence of overweight and obesity has raised concern for potential risk of traditional age- and obesity-related comorbidities. Such comorbidities, including impaired glucose tolerance, hypertension, cardiac disease, hyperlipidemia, fatty liver, colon cancer, and obstructive sleep apnea, may occur on top of pre-existing CF-related comorbidities. CF nutrition recommendations are evolving in the post-modulator era to more individualized approaches, in contrast to prior blanket high-fat, high-calorie prescriptions for all. Ultimately, it will be essential to redefine goals for optimal weight and nutritional status to allow for holistic health and aging in people with CF.

Impact of extended Elexacaftor/Tezacaftor/Ivacaftor therapy on the gut microbiome in cystic fibrosis

BACKGROUND

There is a paucity of knowledge on the longer-term effects of CF transmembrane conductance regulator (CFTR) modulator therapies upon the gut microbiome and associated outcomes. In a pilot study, we investigated longitudinal Elexacaftor/Tezacaftor/Ivacaftor (ETI) therapy on the gut microbiota, metabolomic functioning, and clinical outcomes in people with CF (pwCF).

STUDY DESIGN

Faecal samples from 20 pwCF were acquired before and then following 3, 6, and 17+ months of ETI therapy. Samples were subjected to microbiota sequencing and targeted metabolomics to profile and quantify short-chain fatty acid composition. Ten healthy matched controls were included for comparison. Clinical data, including markers of intestinal function were integrated to investigate relationships.

RESULTS

Extended ETI therapy increased core microbiota diversity and composition, which translated to gradual shifts in whole microbiota composition towards that observed in healthy controls. Despite becoming more similar over time, CF microbiota and functional metabolite compositions remained significantly different to healthy controls. Antibiotic treatment for pulmonary infection significantly explained a relatively large degree of variation within the whole microbiota and rarer satellite taxa. Clinical outcomes were not significantly different following ETI.

CONCLUSIONS

Whilst differences persisted, a positive trajectory towards the microbiota observed in healthy controls was found. We posit that progression was predominately impeded by pulmonary antibiotics administration. We recommend future studies use integrated omics approaches within a combination of long-term longitudinal patient studies and model experimental systems. This will deepen our understanding of the impacts of CFTR modulator therapy and respiratory antibiotic interventions upon the gut microbiome and gastrointestinal pathophysiology in CF.

The gastrointestinal microbiome, small bowel bacterial overgrowth, and microbiome modulators in cystic fibrosis

People with cystic fibrosis (pwCF) have an altered gastrointestinal microbiome. These individuals also demonstrate propensity toward developing small intestinal bacterial overgrowth (SIBO). The dysbiosis present has intestinal and extraintestinal implications, including potential links with the higher rates of gastrointestinal malignancies described in CF. Given these implications, there is growing interest in therapeutic options for microbiome modulation. Alternative therapies, including probiotics and prebiotics, and current CF transmembrane conductance regulator gene modulators are promising interventions for ameliorating gut microbiome dysfunction in pwCF. This article will characterize and discuss the current state of knowledge and expert opinions on gut dysbiosis and SIBO in the context of CF, before reviewing the current evidence supporting gut microbial modulating therapies in CF.

Changes in fecal lipidome after treatment with ivacaftor without changes in microbiome or bile acids

BACKGROUND

Alterations in gastrointestinal health are prominent manifestations of cystic fibrosis (CF) and can independently impact pulmonary function. Ivacaftor has been associated with robust improvements in pulmonary function and weight gain, but less is known about the impact of ivacaftor on the fecal microbiome, lipidome, and bile acids.

METHODS

Stool samples from 18 patients with CF and gating mutations (ages 6-61 years, 13 pancreatic insufficient) were analyzed for fecal microbiome and lipidome composition as well as bile acid concentrations at baseline and after 3 months of treatment with ivacaftor. Microbiome composition was also assessed in a healthy reference cohort.

RESULTS

Alpha and beta diversity of the microbiome were different between CF and reference cohort at baseline, but no treatment effect was seen in the CF cohort between baseline and 3 months. Seven lipids increased with treatment. No differences were seen in bile acid concentrations after treatment in CF. At baseline, 403 lipids and unconjugated bile acids were different between pancreatic insufficient (PI-CF) and sufficient (PS-CF) groups and 107 lipids were different between PI-CF and PS-CF after 3 months of treatment.

CONCLUSIONS

The composition and diversity of the fecal microbiome were different in CF as compared to a healthy reference, and did not change after 3 months of ivacaftor. We detected modest differences in the fecal lipidome with treatment. Differences in lipid and bile acid profiles between PS-CF and PI-CF were attenuated after 3 months of treatment.

Gastrointestinal Pathologies in Pediatric Patients With Cystic Fibrosis Undergoing Endoscopy: A Single-Center Retrospective Review Over 15 Years

Introduction Previous studies have demonstrated an increased incidence of gastrointestinal (GI) pathologies, specifically celiac disease (CD) and eosinophilic esophagitis (EoE), in patients with cystic fibrosis (CF). However, there is minimal data available regarding endoscopic findings in pediatric patients with CF and GI mucosal disease.  Methods A retrospective chart review was performed on patients with CF under 18 years of age who underwent esophagogastroduodenoscopy (EGD) or colonoscopy with biopsy over a 15-year period at our institution. Patient characteristics including assigned sex at birth, CF genetic mutations (if identified), and cystic fibrosis transmembrane conductance regulator (CFTR) modulator use were recorded. Data obtained at the time of biopsy included body mass index (BMI), indication for the procedure, exocrine pancreatic status, visual endoscopic findings, and histologic findings. Results A total of 72 patients with CF were included in the study. 24% (n=17) were found to have abnormal endoscopic biopsy results. EoE (13% of all patients, n=9) and CD (6% of all patients, n=4) were the most common GI diagnoses present on endoscopic biopsy. All 3 patients taking CFTR modulator medications at the time of endoscopy had normal biopsy results. Of the 17 patients found to have abnormal pathology results, 14 (82%) were taking proton-pump inhibitor (PPI) medication at the time of endoscopy. Conclusion This study highlights the probable increased frequency of GI disease in the pediatric CF population. These findings underscore the importance of maintaining a broad differential diagnosis while considering utilization of endoscopy with biopsy in pediatric patients with CF who have GI symptoms.

The gut microbiota in adults with cystic fibrosis compared to colorectal cancer

BACKGROUND

Gut dysbiosis is implicated in colorectal cancer (CRC) pathogenesis. Cystic fibrosis (CF) is associated with both gut dysbiosis and increased CRC risk. We therefore compared the faecal microbiota from individuals with CF to CRC and screening samples. We also assessed changes in CRC-associated taxa before and after triple CF transmembrane conductance regulator (CFTR) modulator therapy.

METHODS

Bacterial DNA amplification comprising V4 16S rRNA analysis was conducted on 84 baseline and 53 matched follow-up stool samples from adults with CF. These data were compared to an existing cohort of 430 CRC and 491 control gFOBT samples from the NHS Bowel Cancer Screening Programme. Data were also compared to 26 previously identified CRC-associated taxa from a published meta-analysis.

RESULTS

Faecal CF samples had a lower alpha diversity and clustered distinctly from both CRC and control samples, with no clear clinical variables explaining the variation. Compared to controls, CF samples had an increased relative abundance in 6 of the 20 enriched CRC-associated taxa and depletion of 2 of the 6 taxa which have been reported as reduced in CRC. Commencing triple modulator therapy had subtle influence on the relative abundance of CRC-associated microbiota (n = 23 paired CF samples).

CONCLUSIONS

CF stool samples were clearly dysbiotic, clustering distinctly from both CRC and control samples. Several bacterial shifts in CF samples resembled those observed in CRC. Studies assessing the impact of dietary or other interventions and the longer-term use of CFTR modulators on reducing this potentially pro-oncogenic milieu are needed.

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.

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.

The gut-lung axis in the CFTR modulator era

The advent of CFTR modulators represents a turning point in the history of cystic fibrosis (CF) management, changing profoundly the disease's clinical course by improving mucosal hydration. Assessing changes in airway and digestive tract microbiomes is of great interest to better understand the mechanisms and to predict disease evolution. Bacterial and fungal dysbiosis have been well documented in patients with CF; yet the impact of CFTR modulators on microbial communities has only been partially deciphered to date. In this review, we aim to summarize the current state of knowledge regarding the impact of CFTR modulators on both pulmonary and digestive microbiomes. Our analysis also covers the inter-organ connections between lung and gut communities, in order to highlight the gut-lung axis involvement in CF pathophysiology and its evolution in the era of novel modulators therapies.

Tezacaftor/Ivacaftor therapy has negligible effects on the cystic fibrosis gut microbiome

People with cystic fibrosis (pwCF) experience a range of persistent gastrointestinal symptoms throughout life. There is evidence indicating interaction between the microbiota and gut pathophysiology in CF. However, there is a paucity of knowledge on the potential effects of CF transmembrane conductance regulator (CFTR) modulator therapies on the gut microbiome. In a pilot study, we investigated the impact of Tezacaftor/Ivacaftor dual combination CFTR modulator therapy on the gut microbiota and metabolomic functioning in pwCF. Fecal samples from 12 pwCF taken at baseline and following placebo or Tezacaftor/Ivacaftor administration were subjected to microbiota sequencing and to targeted metabolomics to assess the short-chain fatty acid (SCFA) composition. Ten healthy matched controls were included as a comparison. Inflammatory calprotectin levels and patient symptoms were also investigated. No significant differences were observed in overall gut microbiota characteristics between any of the study stages, extended also across intestinal inflammation, gut symptoms, and SCFA-targeted metabolomics. However, microbiota and SCFA metabolomic compositions, in pwCF, were significantly different from controls in all study treatment stages. CFTR modulator therapy with Tezacaftor/Ivacaftor had negligible effects on both the gut microbiota and SCFA composition across the course of the study and did not alter toward compositions observed in healthy controls. Future longitudinal CFTR modulator studies will investigate more effective CFTR modulators and should use prolonged sampling periods, to determine whether longer-term changes occur in the CF gut microbiome. IMPORTANCE People with cystic fibrosis (pwCF) experience persistent gastrointestinal (GI) symptoms throughout life. The research question "how can we relieve gastrointestinal symptoms, such as stomach pain, bloating, and nausea?" remains a top priority for clinical research in CF. While CF transmembrane conductance regulator (CFTR) modulator therapies are understood to correct underlying issues of CF disease and increasing the numbers of pwCF are now receiving some form of CFTR modulator treatment. It is not known how these therapies affect the gut microbiome or GI system. In this pilot study, we investigated, for the first time, effects of the dual combination CFTR modulator medicine, Tezacaftor/Ivacaftor. We found it had negligible effects on patient GI symptoms, intestinal inflammation, or gut microbiome composition and functioning. Our findings are important as they fill important knowledge gaps on the relative effectiveness of these widely used treatments. We are now investigating triple combination CFTR modulators with prolonged sampling periods.

Thinking outside the box: a review of gastrointestinal symptoms and complications in cystic fibrosis

INTRODUCTION

Gastrointestinal (GI)-related symptoms, complications, and comorbidities in cystic fibrosis (CF) are common and research to reduce their burden is a priority for the CF community. To enable future research, this review aimed to summarize the range of GI symptoms, complications and comorbidities seen in CF, the underlying pathophysiology, and treatments.

AREAS COVERED

This was a rapid systematic review undertaken using the recommendations from the Cochrane Rapid Reviews Methods Group. We searched databases including PubMed, Embase, Medline and the Cochrane database and identified those studies reporting GI-related symptoms, complications, or comorbidities in CF or their treatment. Our searches identified 2,930 studies and a total 119 studies met our inclusion criteria. Where a prevalence could be determined, GI symptoms were reported in 33.7% of study participants. The range of symptoms reported was broad and the highest median prevalence included flatulence (43.5%), bloating and abdominal distension (36%), and fatty stool (36%). Meconium ileus was reported in 12% and distal intestinal obstruction syndrome in 8.5.

EXPERT OPINION

GI-related symptoms, complications, and comorbidities in CF are common. More consistent characterization and recording of these symptoms in clinical studies may help achieve the priority of reducing the burden of GI disease in CF.

Nutritional and metabolic management for cystic fibrosis in a post-cystic fibrosis transmembrane conductance modulator era

PURPOSE OF REVIEW

The introduction of highly effective cystic fibrosis transmembrane conductance regulator modulators has resulted in a paradigm shift towards treating underlying cause of cystic fibrosis (CF) rather than the ensuing complications. In this review, we will describe the impact of these small molecules on growth, nutrition, and metabolic status in people with CF (pwCF).

RECENT FINDING

Results of clinical trials and real world data demonstrate that these small molecules are having a significant impact of on augmenting body weight, improving nutritional status and reducing gastrointestinal symptom burden. Early treatment can also positively impact on pancreatic endocrine and exocrine function.

SUMMARY

Nutritional and metabolic management of pwCF needs to change in order to maximize long term health and avoid future complications relating to obesity and increased cardiovascular risk. Longitudinal registry studies will be key to improve our understanding of the longer-term outcome of these new therapies.

Genome Capture Sequencing Selectively Enriches Bacterial DNA and Enables Genome-Wide Measurement of Intrastrain Genetic Diversity in Human Infections

Within-host evolution produces genetic diversity in bacterial strains that cause chronic human infections. However, the lack of facile methods to measure bacterial allelic variation in clinical samples has limited understanding of intrastrain diversity's effects on disease. Here, we report a new method termed genome capture sequencing (GenCap-Seq) in which users inexpensively make hybridization probes from genomic DNA or PCR amplicons to selectively enrich and sequence targeted bacterial DNA from clinical samples containing abundant human or nontarget bacterial DNA. GenCap-Seq enables accurate measurement of allele frequencies over targeted regions and is scalable from specific genes to entire genomes, including the strain-specific accessory genome. The method is effective with samples in which target DNA is rare and inhibitory and DNA-degrading substances are abundant, including human sputum and feces. In proof-of-principle experiments, we used GenCap-Seq to investigate the responses of diversified Pseudomonas aeruginosa populations chronically infecting the lungs of people with cystic fibrosis to in vivo antibiotic exposure, and we found that treatment consistently reduced intrastrain genomic diversity. In addition, analysis of gene-level allele frequency changes suggested that some genes without conventional resistance functions may be important for bacterial fitness during in vivo antibiotic exposure. GenCap-Seq's ability to scalably enrich targeted bacterial DNA from complex samples will enable studies on the effects of intrastrain and intraspecies diversity in human infectious disease. IMPORTANCE Genetic diversity evolves in bacterial strains during human infections and could affect disease manifestations and treatment resistance. However, the extent of diversity present in vivo and its changes over time are difficult to measure by conventional methods. We developed a novel approach, GenCap-Seq, to enrich microbial DNA from complex human samples like sputum and feces for genome-wide measurements of bacterial allelic diversity. The approach is inexpensive, scalable to encompass entire targeted genomes, and works in the presence of abundant untargeted nucleic acids and inhibiting substances. We used GenCap-Seq to investigate in vivo responses of diversified bacterial strains to antibiotic treatment. This method will enable new ideas about the effects of intrastrain diversity on human infections to be tested.

Cystic fibrosis transmembrane conductance regulator modulators and the exocrine pancreas: A scoping review

BACKGROUND

Cystic fibrosis transmembrane conductance regulator (CFTR) modulators improve pulmonary outcomes in subjects with cystic fibrosis (CF); however, the effects on pancreatic manifestations are not well characterized. We hypothesized that CFTR modulators would improve measures of exocrine pancreatic function and outcomes.

METHODS

We performed a systematic search to identify studies reporting measures of the exocrine pancreas in humans treated with CFTR modulators. Only studies reporting baseline and on-treatment assessments were included.

RESULTS

Of 630 identified studies, 41 met inclusion criteria. CFTR modulators reduced acute pancreatitis events by 85% overall (rate ratio 0.15, 95% confidence interval (CI) 0.04, 0.52), with a greater effect seen in the subgroup with pancreas sufficient CF (PS-CF) (rate ratio 0.13 (95% CI 0.03, 0.53). Among 293 subjects with baseline and on-treatment evaluation of pancreas sufficiency, 253 were pancreas insufficient at baseline and 54 (21.3%) converted to pancreas sufficiency. Of 32 subjects with baseline FE-1 values <200 mcg/g, 16 (50%) increased to ≥200 mcg/g. Serum trypsin decreased by a mean of 565.9 ng/mL (standard deviation (SD) 311.8), amylase decreased by 38.2 U/L (SD 57.6), and lipase decreased by 232.3 U/L (SD 247.7).

CONCLUSIONS

CFTR modulator use reduces acute pancreatitis frequency and improves indirect measures of exocrine pancreas function. Future interventional studies that evaluate the mechanism and impact of CFTR modulators on acute pancreatitis and pancreas sufficiency in patients with CFTR dysfunction are warranted.

Modulation, microbiota and inflammation in the adult CF gut: A prospective study

BACKGROUND

Cystic Fibrosis (CF) has prominent gastrointestinal and pancreatic manifestations. The aim of this study was to determine the effect of Cystic fibrosis transmembrane conductance regulator (CFTR) modulation on, gastrointestinal inflammation, pancreatic function and gut microbiota composition in people with cystic fibrosis (CF) and the G551D-CFTR mutation.

METHODS

Fourteen adult patients with the G551D-CFTR mutation were assessed clinically at baseline and for up to 1 year after treatment with ivacaftor. The change in gut inflammatory markers (calprotectin and lactoferrin), exocrine pancreatic status and gut microbiota composition and structure were assessed in stool samples.

RESULTS

There was no significant change in faecal calprotectin nor lactoferrin in patients with treatment while all patients remained severely pancreatic insufficient. There was no significant change in gut microbiota diversity and richness following treatment.

CONCLUSION

There was no significant change in gut inflammation after partial restoration of CFTR function with ivacaftor, suggesting that excess gut inflammation in CF is multi-factorial in aetiology. In this adult cohort, exocrine pancreatic function was irreversibly lost. Longer term follow-up may reveal more dynamic changes in the gut microbiota and possible restoration of CFTR function.

CFTR and Gastrointestinal Cancers: An Update

Cystic Fibrosis (CF) is a disease caused by mutations in the CFTR gene that severely affects the lungs as well as extra-pulmonary tissues, including the gastrointestinal (GI) tract. CFTR dysfunction resulting from either mutations or the downregulation of its expression has been shown to promote carcinogenesis. An example is the enhanced risk for several types of cancer in patients with CF, especially cancers of the GI tract. CFTR also acts as a tumor suppressor in diverse sporadic epithelial cancers in many tissues, primarily due to the silencing of CFTR expression via multiple mechanisms, but especially due to epigenetic regulation. This review provides an update on the latest research linking CFTR-deficiency to GI cancers, in both CF patients and in sporadic GI cancers, with a particular focus on cancer of the intestinal tract. It will discuss changes in the tissue landscape linked to CFTR-deficiency that may promote cancer development such as breakdowns in physical barriers, microbial dysbiosis and inflammation. It will also discuss molecular pathways and mechanisms that act upstream to modulate CFTR expression, such as by epigenetic silencing, as well as molecular pathways that act downstream of CFTR-deficiency, such as the dysregulation of the Wnt/β-catenin and NF-κB signaling pathways. Finally, it will discuss the emerging CFTR modulator drugs that have shown promising results in improving CFTR function in CF patients. The potential impact of these modulator drugs on the treatment and prevention of GI cancers can provide a new example of personalized cancer medicine.

Intestinal Inflammation and Alterations in the Gut Microbiota in Cystic Fibrosis: A Review of the Current Evidence, Pathophysiology and Future Directions

Cystic fibrosis (CF) is a life-limiting autosomal recessive multisystem disease. While its burden of morbidity and mortality is classically associated with pulmonary disease, CF also profoundly affects the gastrointestinal (GI) tract. Chronic low-grade inflammation and alterations to the gut microbiota are hallmarks of the CF intestine. The etiology of these manifestations is likely multifactorial, resulting from cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction, a high-fat CF diet, and the use of antibiotics. There may also be a bidirectional pathophysiological link between intestinal inflammation and changes to the gut microbiome. Additionally, a growing body of evidence suggests that these GI manifestations may have significant clinical associations with growth and nutrition, quality of life, and respiratory function in CF. As such, the potential utility of GI therapies and long-term GI outcomes are areas of interest in CF. Further research involving microbial modulation and multi-omics techniques may reveal novel insights. This article provides an overview of the current evidence, pathophysiology, and future research and therapeutic considerations pertaining to intestinal inflammation and alterations in the gut microbiota in CF.

The Gut-Lung Axis in Cystic Fibrosis

Cystic fibrosis (CF) is a heritable, multiorgan disease that impacts all tissues that normally express cystic fibrosis transmembrane conductance regulator (CFTR) protein. While the importance of the airway microbiota has long been recognized, the intestinal microbiota has only recently been recognized as an important player in both intestinal and lung health outcomes for persons with CF (pwCF). Here, we summarize current literature related to the gut-lung axis in CF, with a particular focus on three key ideas: (i) mechanisms through which microbes influence the gut-lung axis, (ii) drivers of microbiota alterations, and (iii) the potential for intestinal microbiota remediation.

PROMISE: Working with the CF community to understand emerging clinical and research needs for those treated with highly effective CFTR modulator therapy

Highly effective CFTR modulator drug therapy is increasingly available to those with cystic fibrosis. Multiple observational research studies are now being conducted to better understand the impacts of this important therapeutic milestone on long-term outcomes, patient care needs, and future research priorities. PROMISE is a large, multi-disciplinary academic study focused on the broad impacts of starting elexacaftor/tezacaftor/ivacaftor in the US population age 6 years and older. The many areas of investigation and rationale for each are discussed by organ systems, along with recognition of remaining important questions that will not be addressed by this study alone. Knowledge gained through this and multiple complementary studies around the world will help to understand important health outcomes, clinical care priorities, and research needs for a large majority of people treated with these or similarly effective medications targeting the primary cellular impairment in cystic fibrosis.