Evidence for a Cystic Fibrosis Enteropathy

Fecal calprotectin in pediatric gastrointestinal diseases: Pros and cons

BACKGROUND

Fecal calprotectin is a valuable biomarker for assessing intestinal inflammation in pediatric gastrointestinal diseases. However, its role, pros, and cons in various conditions must be comprehensively elucidated.

AIM

To explore the role of fecal calprotectin in pediatric gastrointestinal diseases, including its advantages and limitations.

METHODS

A comprehensive search was conducted on PubMed, PubMed Central, Google Scholar, and other scientific research engines until February 24, 2024. The review included 88 research articles, 56 review articles, six meta-analyses, two systematic reviews, two consensus papers, and two letters to the editors.

RESULTS

Fecal calprotectin is a non-invasive marker for detecting intestinal inflammation and monitoring disease activity in pediatric conditions such as functional gastrointestinal disorders, inflammatory bowel disease, coeliac disease, coronavirus disease 2019-induced gastrointestinal disorders, gastroenteritis, and cystic fibrosis-associated intestinal pathology. However, its lack of specificity and susceptibility to various confounding factors pose challenges in interpretation. Despite these limitations, fecal calprotectin offers significant advantages in diagnosing, monitoring, and managing pediatric gastrointestinal diseases.

CONCLUSION

Fecal calprotectin holds promise as a valuable tool in pediatric gastroenterology, offering insights into disease activity, treatment response, and prognosis. Standardized protocols and guidelines are needed to optimize its clinical utility and mitigate interpretation challenges. Further research is warranted to address the identified limitations and enhance our understanding of fecal calprotectin in pediatric gastrointestinal diseases.

Cystic fibrosis and fat malabsorption: Pathophysiology of the cystic fibrosis gastrointestinal tract and the impact of highly effective CFTR modulator therapy

Cystic fibrosis (CF) is a progressive, genetic, multi-organ disease affecting the respiratory, digestive, endocrine, and reproductive systems. CF can affect any aspect of the gastrointestinal (GI) tract, including the esophagus, stomach, small intestine, colon, pancreas, liver, and gall bladder. GI pathophysiology associated with CF results from CF membrane conductance regulator (CFTR) dysfunction. The majority of people with CF (pwCF) experience exocrine pancreatic insufficiency resulting in malabsorption of nutrients and malnutrition. Additionally, other factors can cause or worsen fat malabsorption, including the potential for short gut syndrome with a history of meconium ileus, hepatobiliary diseases, and disrupted intraluminal factors, such as inadequate bile salts, abnormal pH, intestinal microbiome changes, and small intestinal bacterial overgrowth. Signs and symptoms associated with fat malabsorption, such as abdominal pain, bloating, malodorous flatus, gastroesophageal reflux, nausea, anorexia, steatorrhea, constipation, and distal intestinal obstruction syndrome, are seen in pwCF despite the use of pancreatic enzyme replacement therapy. Given the association of poor nutrition status with lung function decline and increased mortality, aggressive nutrition support is essential in CF care to optimize growth in children and to achieve and maintain a healthy body mass index in adults. The introduction of highly effective CFTR modulator therapy and other advances in CF care have profoundly changed the course of CF management. However, GI symptoms in some pwCF may persist. The use of current knowledge of the pathophysiology of the CF GI tract as well as appropriate, individualized management of GI symptoms continue to be integral components of care for pwCF.

Quantification of Enteric Dysfunction in Cystic Fibrosis: Inter- and Intraindividual Variability

OBJECTIVES

To test the utility of various biomarkers as indicators of gut dysfunction in cystic fibrosis (CF) and determine whether intraindividual variations in these measures are repeatable over short intervals and whether interindividual variations correlate with clinical outcomes.

STUDY DESIGN

We performed a cross-sectional, limited longitudinal study of children with CF aged 1-21 years who provided blood and stool samples at 2 or 3 visits, 2 weeks and 3 months apart, which were assayed for markers of intestinal inflammation (fecal calprotectin [fCal], lipocalin-2 [fLcn2], neopterin), and permeability (plasma lipopolysaccharide [LPS] antibodies, LPS-binding protein) by enzyme immunoassays. Control specimens were obtained from children without CF who had undergone esophagogastroduodenoscopy and had no evidence of gut inflammation.

RESULTS

Twenty-six of 29 participants with CF completed the study. Sixty-nine stools (57 case/12 control) and 76 plasmas (60 case/16 control) were analyzed. LPS antibody had reliable intraindividual stability. fCal, fLcn2, and neopterin were significantly greater in CF than in control samples. fCal was negatively correlated with 3-month interval change (Δ) in weight-for-age z-score, body mass index/weight-for-length z-score, and forced expiratory volume in 1 second. fLcn2 was negatively correlated with FEV1 but not with anthropometrics. No marker correlated with Δbody mass index/weight-for-length z-score or ΔFEV1.

CONCLUSIONS

fLcn2 is elevated in people with CF and might predict worse interval pulmonary function. Expanded studies are warranted to test if fLcn2 correlates with changes in additional outcomes.

Long-term evaluation of faecal calprotectin levels in a European cohort of children with cystic fibrosis

OBJECTIVE

Intestinal inflammation with contradictory data on faecal calprotectin (fCP) levels is documented in patients with cystic fibrosis (CF). The aim of this study was to longitudinally evaluate fCP in a cohort of children with CF and their relationship with clinical variables.

DESIGN

Prospective observational study to assess evolution of fCP levels, primary aimed at improving fat absorption. Along 1.5 years of follow-up (November 2016-May 2018) with four study visits pertaining to a pilot study (two of four) and to a clinical trial (two of four), the study outcomes were measured.

SETTING

Six European CF centres in the context of MyCyFAPP Project.

SUBJECTS

Children with CF and pancreatic insufficiency (2-18 years old).

MAIN OUTCOME MEASUREMENTS

fCP levels, pulmonary function (percentage of forced expiratory volume in 1 s (FEV1%)) and coefficient of fat absorption (CFA). Additionally, in the last two visits, gastrointestinal (GI) symptoms were evaluated through the PedsQL-GI Questionnaire. Linear mixed regression models were applied to assess association between fCP and FEV1, CFA and GI symptoms.

RESULTS

Twenty-nine children with CF and pancreatic insufficiency were included. fCP levels were inversely associated with total modified specific PedsQL-GI score (p=0.04) and positively associated with diarrhoea (p=0.03), but not with CFA. Along the four study visits, fCP significantly increased (from 62 to 256 µg/g) and pulmonary function decreased (from 97% to 87%), with a significant inverse association between the two study outcomes (p<0.001).

CONCLUSIONS

In children with CF, fCP levels are inversely associated with pulmonary function and thus the specificity of fCP as a marker of intestinal inflammation in paediatric patients with CF warrants further investigation.

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.

Short chain fatty acids: key regulators of the local and systemic immune response in inflammatory diseases and infections

The human intestinal microbiome substantially affects human health and resistance to infections in its dynamic composition and varying release of microbial-derived metabolites. Short-chain fatty acids (SCFA) produced by commensal bacteria through fermentation of indigestible fibres are considered key regulators in orchestrating the host immune response to microbial colonization by regulating phagocytosis, chemokine and central signalling pathways of cell growth and apoptosis, thereby shaping the composition and functionality of the intestinal epithelial barrier. Although research of the last decades provided valuable insight into the pleiotropic functions of SCFAs and their capability to maintain human health, mechanistic details on how SCFAs act across different cell types and other organs are not fully understood. In this review, we provide an overview of the various functions of SCFAs in regulating cellular metabolism, emphasizing the orchestration of the immune response along the gut-brain, the gut-lung and the gut-liver axes. We discuss their potential pharmacological use in inflammatory diseases and infections and highlight new options of relevant human three-dimensional organ models to investigate and validate their biological functions in more detail.

Systematic review on fecal calprotectin in cystic fibrosis

OBJECTIVES

Fecal calprotectin is an inflammatory marker used for monitoring intestinal diseases. It has been studied as a marker of intestinal inflammation in cystic fibrosis (CF), a multi-systemic genetic disease caused by alterations to the CFTR gene. Manifestations of the disease favor a systemic inflammation not limited to the respiratory tract, therefore, calprotectin is a non-invasive and effective diagnostic method. The aim of the study was to perform a systematic review of the literature with a qualitative synthesis of studies.

SOURCES

The articles were selected from PubMed, Web of Science, Scielo and Lilacs.

SUMMARY OF THE FINDINGS

Nine studies were selected for that qualitative synthesis, one was a randomized clinical trial, and eight were case-control or cohort designs. Most studies have indicated that calprotectin is a marker of systemic inflammation in CF and not just intestinal inflammation. Calprotectin is an aid in monitoring inflammatory bowel conditions in patients with cystic fibrosis.

CONCLUSION

Further studies should be conducted to investigate the role of this marker in the systemic inflammation of CF.

The association of fecal calprotectin and respiratory exacerbation in cystic fibrosis patients

Background

CF patients experience several episodes of pulmonary exacerbations and reduction in their lung function progressively. Lung function is not the only diagnostic index by physicians to decide if CF patients require antibiotic therapy following pulmonary exacerbations. Non-invasive fecal indicators are increasingly being used to assess intestinal inflammation. Calprotectin is the most extensively utilized fecal biomarker in recent CF researches.

Methods

In this longitudinal study, 30 CF patients (1–18 years) without current infectious gastroenteritis were recruited from Mofid Children's Hospital and Masih Daneshvari Hospital, Tehran, Iran. Then, fecal calprotectin levels were evaluated before treatment, two weeks after systemic antibiotic administration, as well as recurrence of pulmonary exacerbation after first post-hospital discharge.

Results

The initial fecal calprotectin level in CF patients receiving antibiotics was 651.13 ± 671.04, significantly decreasing two weeks after antibiotic therapy and following recurrence (171.81 ± 224.40, 607.93 ± 549.89, respectively; P < 0.01). Following systemic antibiotic treatment, the patient's respiratory and GI symptoms improved (P < 0.01).

Conclusion

Our findings revealed that fecal calprotectin modifications are associated with CF pulmonary exacerbations and antibiotic treatment could reduce calprotectin levels. Therefore, the fecal calprotectin level could be considered as a diagnostic tool and an index to follow the response to treatment in CF pulmonary exacerbations.

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.

Elevated Levels of Toxic Bile Acids in Serum of Cystic Fibrosis Patients with CFTR Mutations Causing Pancreatic Insufficiency

Hepatobiliary involvement is a hallmark in cystic fibrosis (CF), as the causative CF Transmembrane Conductance Regulator (CFTR) defect is expressed in the biliary tree. However, bile acid (BA) compositions in regard to pancreatic insufficiency, which is present at an early stage in about 85% of CF patients, have not been satisfactorily understood. We assess the pattern of serum BAs in people with CF (pwCF) without CFTR modulator therapy in regard to pancreatic insufficiency and the CFTR genotype. In 47 pwCF, 10 free and 12 taurine- and glycine-conjugated BAs in serum were prospectively assessed. Findings were related to genotype, pancreatic insufficiency prevalence (PIP)-score, and hepatic involvement indicated by serum liver enzymes, as well as clinical and ultrasound criteria for CF-related liver disease. Serum concentrations of total primary BAs and free cholic acid (CA) were significantly higher in pwCF with higher PIP-scores (p = 0.025, p = 0.009, respectively). Higher total BAs were seen in pwCF with PIP-scores ≥0.88 (p = 0.033) and with pancreatic insufficiency (p = 0.034). Free CA was higher in patients with CF-related liver involvement without cirrhosis, compared to pwCF without liver disease (2.3-fold, p = 0.036). pwCF with severe CFTR genotypes, as assessed by the PIP-score, reveals more toxic BA compositions in serum. Subsequent studies assessing changes in BA homeostasis during new highly effective CFTR-modulating therapies are of high interest.

Abdominal Symptoms Assessed With the CFAbd-Score are Associated With Intestinal Inflammation in Patients With Cystic Fibrosis

OBJECTIVES

This prospective study evaluated the relationship between fecal markers of intestinal inflammation and cystic fibrosis (CF)-associated abdominal symptoms. These were assessed using the CFAbd-Score, a CF-specific patient-related outcome measure developed and validated, following FDA guidelines.

METHODS

In feces from patients with CF (n = 41) and healthy volunteers (n = 27), concentrations of fecal calprotectin (FC), M2-pyruvate kinase (M2-PK), interleukins IL-1β, IL-6, IL-8, and neutrophilic elastase (NE) were measured. Abdominal symptoms during the 2 preceding weeks were recorded using the CFAbd-Score. This patient-reported outcome measure (PROM) for assessment of the multi-organic abdominal involvement in CF includes 28 items in five domains.

RESULTS

Inflammatory parameters FC, IL-1β, M2-PK, and NE in feces, as well as CFAbd-Scores resulted significantly higher in CF patients than in healthy controls (all P < 0.01). Furthermore, significant differences between both groups were found for pain-symptoms, disorders of bowel movement, impaired quality of life, as well as disorders of eating and appetite. With 83% sensitivity and 74% specificity, FC was the most reliable measure for CF-related intestinal inflammation, which, in the CFAbd-Score, was associated to significantly higher rates of abdominal pain, as well as to general quality of life items such as gastrointestinal-related impaired sleep and frustration.

CONCLUSION

Using the CFAbd-Score as a CF-specific PROM for identification and quantification of abdominal symptoms revealed that abdominal pain and impaired quality of life are associated with intestinal inflammation in CF.

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.

What Do We Know about the Microbiome in Cystic Fibrosis? Is There a Role for Probiotics and Prebiotics?

Cystic fibrosis (CF) is a life-shortening genetic disorder that affects the cystic fibrosis transmembrane conductance regulator (CFTR) protein. In the gastrointestinal (GI) tract, CFTR dysfunction results in low intestinal pH, thick and inspissated mucus, a lack of endogenous pancreatic enzymes, and reduced motility. These mechanisms, combined with antibiotic therapies, drive GI inflammation and significant alteration of the GI microbiota (dysbiosis). Dysbiosis and inflammation are key factors in systemic inflammation and GI complications including malignancy. The following review examines the potential for probiotic and prebiotic therapies to provide clinical benefits through modulation of the microbiome. Evidence from randomised control trials suggest probiotics are likely to improve GI inflammation and reduce the incidence of CF pulmonary exacerbations. However, the highly variable, low-quality data is a barrier to the implementation of probiotics into routine CF care. Epidemiological studies and clinical trials support the potential of dietary fibre and prebiotic supplements to beneficially modulate the microbiome in gastrointestinal conditions. To date, limited evidence is available on their safety and efficacy in CF. Variable responses to probiotics and prebiotics highlight the need for personalised approaches that consider an individual’s underlying microbiota, diet, and existing medications against the backdrop of the complex nutritional needs in CF.

Fecal Calprotectin and Phenotype Severity in Patients with Cystic Fibrosis: A Systematic Review and Meta-Analysis

Inflammation plays an important role in the outcome of patients with cystic fibrosis (CF). It may develop due to cystic fibrosis transmembrane conductance regulator protein dysfunction, pancreatic insufficiency, or prolonged pulmonary infection. Fecal calprotectin (FC) has been used as a noninvasive method to detect inflammation. Therefore, the aim of the current meta-analysis was to investigate the relationship between FC and phenotype severity in patients with CF. In this study, searches were conducted in PubMed, Science Direct, Scopus, and Embase databases up to August 2021 using terms such as "cystic fibrosis," "intestine," "calprotectin," and "inflammation." Only articles published in English and human studies were selected. The primary outcome was the level of FC in patients with CF. The secondary outcome was the relationship between FC and clinical severity. Statistical analysis was performed using Comprehensive Meta-Analysis software. Of the initial 303 references, only six articles met the inclusion criteria. The mean (95% confidence interval [CI]) level of FC was 256.5 mg/dL (114.1-398.9). FC levels were significantly associated with pancreatic insufficiency (mean, 243.02; 95% CI, 74.3 to 411.6; p=0.005; I²=0), pulmonary function (r=-0.39; 95% CI, -0.58 to -0.15; p=0.002; I²=60%), body mass index (r=-0.514; 95% CI, 0.26 to 0.69; p<0.001; I²=0%), and Pseudomonas colonization (mean, 174.77; 95% CI, 12.5 to 337.02; p=0.035; I²=71%). While FC is a reliable noninvasive marker for detecting gastrointestinal inflammation, it is also correlated with the severity of the disease in patients with CF.

The Intestinal Microbiome and Cystic Fibrosis Transmembrane Conductance Regulator Modulators: Emerging Themes in the Management of Gastrointestinal Manifestations of Cystic Fibrosis

PURPOSE OF REVIEW

While commonly associated with pulmonary manifestations, cystic fibrosis (CF) is a systemic disease with wide-ranging effects on the gastrointestinal (GI) tract. This article reviews major recent updates in gastroenterological CF care and research.

RECENT FINDINGS

The high burden of GI symptoms in CF has led to recent studies assessing GI-specific symptom questionnaires and scoring systems. Intestinal dysbiosis potentially contributes to gastrointestinal symptoms in patients with CF and an increased risk of gastrointestinal cancers in CF. An increased incidence of colorectal cancer (CRC) has led to CF-specific CRC screening and surveillance recommendations. Pharmacologic therapies targeting specific cystic fibrosis transmembrane conductance regulator (CFTR) mutations have shown promise in treating GI manifestations of CF. New research has highlighted the importance of intestinal dysbiosis in CF. Future studies should assess whether CFTR modulators affect the gut microbiome and whether altering the gut microbiome will impact GI symptoms and GI cancer risk.

The Use of Fecal Calprotectin Testing in Paediatric Disorders: A Position Paper of the European Society for Paediatric Gastroenterology and Nutrition Gastroenterology Committee

OBJECTIVES

The aim of the study was to review the evidence regarding the clinical use and value of fecal calprotectin (FC) measurements in different gastrointestinal disorders in children.

METHODS

A literature search was conducted in the PubMed, MEDLINE, EMBASE, and Cochrane databases until October 31, 2019. Subtopics were identified and each assigned to individual authors.

RESULTS

A total of 28 recommendations were voted on using the nominal voting technique. Recommendations are given related to sampling, measurement methods, and results interpretation. The 14 authors anonymously voted on each recommendation using a 9-point scale (1 strongly disagree to 9 fully agree). Consensus was considered achieved if at least 75% of the authors voted 6, 7, 8, or 9.

CONCLUSIONS

Consensus was reached for all recommendations. Limitations for the use of FC in clinical practice include variability in extraction methodology, performance of test kits as well as the need to establish local reference ranges because of the influence of individual factors, such as age, diet, microbiota, and drugs. The main utility of FC measurement at present is in the diagnosis and monitoring of inflammatory bowel disease (IBD) as well as to differentiate it from functional gastrointestinal disorders (FAPDs). FC, however, has neither utility in the diagnosis of infantile colic nor to differentiate between functional and organic constipation. A rise in FC concentration, may alert to the risk of developing necrotizing enterocolitis and help identifying gastrointestinal involvement in children with Henoch-Schönlein purpura. FC measurement is of little value in Cow's Milk Protein Allergy, coeliac disease (CD), and cystic fibrosis. FC does neither help to distinguish bacterial from viral acute gastroenteritis (AGE), nor to diagnose Helicobacter Pylori infection, small intestinal bacterial overgrowth (SIBO), acute appendicitis (AA), or intestinal polyps.

Increased Fecal Calprotectin Is Associated with Worse Gastrointestinal Symptoms and Quality of Life Scores in Children with Cystic Fibrosis

In cystic fibrosis (CF), cystic fibrosis transmembrane regulator (CFTR) dysfunction leads to digestive disorders that promote intestinal inflammation and dysbiosis enhancing gastrointestinal symptoms. In pancreatic insufficiency CF patients, both intestinal inflammation and dysbiosis, are associated with an increase in the fecal calprotectin (FC) level. However, associations between the FC level, gastrointestinal symptoms, and quality of life (QoL) remain poorly studied. We aimed to assess such associations in pancreatic insufficiency CF children. The FC level was measured in pancreatic insufficiency CF children’s stool samples. Children and their parents completed two questionnaires: The Gastrointestinal Symptoms Scales 3.0-PedsQL^TM and the Quality of Life Pediatric Inventory 4.0-PedsQL^TM. Lower scores indicated worse symptomatology or QoL. Thirty-seven CF children were included. A FC level above 250 µg/g was associated with worse gastrointestinal symptoms and QoL scores. The FC level was inversely correlated with several gastrointestinal scores assessed by children (i.e., Total, “Heart Burn Reflux”, “Nausea and Vomiting”, and “Gas and Bloating”). Several QoL scores were correlated with gastrointestinal scores. The FC level was weakly associated with clinical parameters. Some gastrointestinal and QoL scores were related to disease severity associated parameters. In CF, the FC level, biomarker previously related to intestinal inflammation and dysbiosis, was associated with worse digestive symptoms and QoL scores.

Motor dysfunction of the gut in cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) is a multisystem disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Cystic fibrosis transmembrane conductance regulator is extensively expressed in the intestine and has an important role in the regulation of the viscosity and pH of gut secretions. Several studies have reported a delay in small bowel and colonic transit times in patients with CF which have been attributed to the secretory dysfunction. Our aim was to determine whether intestinal contractility is affected in these patients.

METHODS

Consecutive patients with CF referred to our institution between 2014 and 2017 (n = 16) were prospectively investigated using automated non-invasive techniques for morpho-functional evaluation of the gut developed in our laboratory. On separate days, intraluminal images of the gut were obtained by capsule endoscopy and external images by abdominal MRI. Analysis of images (endoluminal and external) was performed with original, previously validated programs based on computer vision and machine learning techniques and compared with age- and sex-matched controls.

KEY RESULTS

Patients with CF exhibited important reduction in contractile activity and increased retention of static turbid luminal content in the small bowel by endoluminal image analysis. Morpho-volumetric analysis of MRI images found increased ileo-colonic volumes in CF. Significant correlations between abnormalities detected by intraluminal and external imaging techniques were found. The presence and severity of digestive symptoms were not related to abnormal gut function.

CONCLUSION AND INFERENCES

Impaired transit and pooling of gut contents in patients with CF is associated with impaired intestinal motility.

Fecal calprotectin in the pediatric population: a 2020 update

Calprotectin is a calcium and zinc-binding protein, formed by a hetero complex of S100A8 and S100A9 proteins, which belong to the S-100 protein family consisting in more than 20 different proteins with a tissue-specific expression pattern. This protein is secreted extracellularly from stimulated neutrophils or released by cell disruption or death. The presence of calprotectin in feces quantitatively relates to neutrophil migration toward the gastrointestinal (GI) tract; thus, it represents a useful marker of intestinal inflammation. Fecal calprotectin (FC) has been proven largely useful for determining the inflammatory origin of GI symptoms differentiating between organic and non-organic diseases. Indeed, increased FC levels are also seen in gastroenteritis, microscopic colitis, polyps, malignancies and cystic fibrosis. To date, there are many evidences regarding usefulness in the detection of fecal calprotectin for the management of gastrointestinal disorders, both in children and adults but, especially in the pediatric population, still clear indications for its use are lacking. Its incorporation in primary care reduces the risk of missing an organic disease and facilitates the indication for expensive and invasive investigations as colonoscopy. We herein review and discuss the last evidence on the usefulness of FC in children, with its current indications and future prospective.

The Role of Gastrointestinal-Related Fatty Acid-Binding Proteins as Biomarkers in Gastrointestinal Diseases

The fatty acid-binding proteins play a major role in intracellular transportation of long-chain fatty acids. Nine fatty acid-binding proteins have been identified, with each having individual tissue-specific functions in addition to regulation of fatty acids. This review focuses on the three fatty acid-binding proteins found in the gastrointestinal tract and discusses their role as diagnostic or disease monitoring markers in neonatal necrotizing enterocolitis, acute mesenteric ischemia, celiac disease, and inflammatory bowel disease. Of these three fatty acid-binding proteins, intestinal fatty acid-binding protein is of the most interest due to its exclusive expression in the gastrointestinal tract. The elevation of intestinal fatty acid-binding protein in blood and urine reflects enterocyte damage, regardless of the underlying cause. The short half-life of intestinal fatty acid-binding protein also means it is a relatively sensitive marker. In contrast, there is currently less evidence to support liver fatty acid-binding protein and ileal bile acid-binding protein as sensitive biomarkers in these conditions. More extensive studies with specific endpoints are required to validate the roles of these fatty acid-binding proteins in gastrointestinal diseases.

Decreased Fecal Calprotectin Levels in Cystic Fibrosis Patients After Antibiotic Treatment for Respiratory Exacerbation

OBJECTIVES

In all patients with cystic fibrosis (CF), gastrointestinal (GI) tract CF transmembrane conductance regulator dysfunction occurs early in life. The identical pathophysiological triad of obstruction, infection, and inflammation causes disease of the airways and in the intestinal tract (CF enteropathy). Mucus accumulation within GI tract is a niche for abnormal microbial colonization, leading to dysbiosis. Fecal calprotectin (FC) is a neutrophil cytosolic protein released during apoptosis and necrosis and reflects inflammatory status. Systemic antibiotic treatment for pulmonary exacerbations has been shown to improve systemic inflammatory markers and serum and sputum calprotectin. Antibiotic treatment aimed at pulmonary complaints may improve GI tract inflammatory status. We hypothesized that high levels of FC present during pulmonary exacerbation are due, in part, to multiorgan dysbiosis and thus should diminish with systemic antibiotic treatment.

METHODS

This prospective pilot study enrolled 14 patients with CF, with no current GI symptoms. FC levels and lung function were measured at the beginning and end of systemic antibiotic treatment.

RESULTS

Compared to preantibiotic treatment baseline values, end of treatment FC levels declined significantly after antibiotic treatment, P = 0.004 and similarly, there was significant improvement in forced expiratory volume in 1 second, P = 0.002.

CONCLUSIONS

High levels of FC during respiratory exacerbation may reflect a systemic exacerbation rather than solely pulmonary. Antibiotic treatment lowered the FC levels possibly by its impact on the intestinal microbiome.

Gut microbiota signatures in cystic fibrosis: Loss of host CFTR function drives the microbiota enterophenotype

Background

Cystic fibrosis (CF) is a disorder affecting the respiratory, digestive, reproductive systems and sweat glands. This lethal hereditary disease has known or suspected links to the dysbiosis gut microbiota. High-throughput meta-omics-based approaches may assist in unveiling this complex network of symbiosis modifications.

Objectives

The aim of this study was to provide a predictive and functional model of the gut microbiota enterophenotype of pediatric patients affected by CF under clinical stability.

Methods

Thirty-one fecal samples were collected from CF patients and healthy children (HC) (age range, 1–6 years) and analysed using targeted-metagenomics and metabolomics to characterize the ecology and metabolism of CF-linked gut microbiota. The multidimensional data were low fused and processed by chemometric classification analysis.

Results

The fused metagenomics and metabolomics based gut microbiota profile was characterized by a high abundance of Propionibacterium, Staphylococcus and Clostridiaceae, including Clostridium difficile, and a low abundance of Eggerthella, Eubacterium, Ruminococcus, Dorea, Faecalibacterium prausnitzii, and Lachnospiraceae, associated with overexpression of 4-aminobutyrate (GABA), choline, ethanol, propylbutyrate, and pyridine and low levels of sarcosine, 4-methylphenol, uracil, glucose, acetate, phenol, benzaldehyde, and methylacetate. The CF gut microbiota pattern revealed an enterophenotype intrinsically linked to disease, regardless of age, and with dysbiosis uninduced by reduced pancreatic function and only partially related to oral antibiotic administration or lung colonization/infection.

Conclusions

All together, the results obtained suggest that the gut microbiota enterophenotypes of CF, together with endogenous and bacterial CF biomarkers, are direct expression of functional alterations at the intestinal level. Hence, it’s possible to infer that CFTR impairment causes the gut ecosystem imbalance.This new understanding of CF host-gut microbiota interactions may be helpful to rationalize novel clinical interventions to improve the affected children’s nutritional status and intestinal function.

Energy Balance and Mechanisms of Weight Gain with Ivacaftor Treatment of Cystic Fibrosis Gating Mutations

OBJECTIVE

To determine if ivacaftor treatment results in weight gain and improved pulmonary function in people with cystic fibrosis transmembrane conductance regulator gating mutations.

STUDY DESIGN

Children and adults with cystic fibrosis and at least 1 cystic fibrosis transmembrane conductance regulator gating mutation were evaluated in this observational study before and after 3 months of ivacaftor treatment. Body size and composition, total energy expenditure, resting energy expenditure (REE%) as percent predicted, coefficient of fat absorption (CFA%), fecal calprotectin, fecal elastase, and quality of life were assessed. Some outcomes were explored by pancreatic status.

RESULTS

There were 23 patients (5-61 years of age) who completed the study; 70% had pancreatic insufficiency (PI). Patients gained 2.5 ± 2.2 kg (P < .001) with increased (P < .05) fat-free mass (0.9 ± 1.9 kg) and fat mass (1.6 ± 1.5 kg). REE% decreased by 5.5 ± 12.0% (P < .05), fecal calprotectin decreased by 30 ± 40 µg/g stool (P < .01), and total energy expenditure was unchanged. Improvements were greater for PI than patients who were pancreatic-sufficient. CFA% increased significantly only with PI. The change (Δ) in weight was positively correlated with the percent change in forced expiratory volume at 1 second (r = 0.46; P = .028) and ΔCFA% (r = 0.47; P = .032) and negatively with ΔREE% (r = -0.50; P = .017). Together, ΔREE%, ΔCFA%, and the percent change in forced expiratory volume at 1 second explained 58% of the variance in weight gain (adjusted R² = 0.579; P = .0007). Growth status and muscle strength improved, as did quality of life in several domains. Fecal elastase increased in most patients with pancreatic sufficiency, with no change in those with PI.

CONCLUSIONS

Mechanisms identified for ivacaftor-associated weight gain were decreased REE, gut inflammation, and fat malabsorption (CFA).

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02141464.

The intestinal microbiome and paediatric liver disease

The intestinal microbiome has been the intense focus of recent study, but how the microbiota affects connected organs, such as the liver, has not been fully elucidated. The microbiome regulates intestinal permeability and helps to metabolise the human diet into small molecules, thus directly affecting liver health. Several studies have linked intestinal dysbiosis to the severity and progression of liver diseases, such as non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, primary sclerosing cholangitis, total parenteral nutrition-associated liver disease, and cystic fibrosis-associated liver disease. However, there is limited information and interpretation with regard to how the microbiome could contribute to liver disease in the paediatric population. Notably, the gut microbiota is distinct at birth and does not establish an adult profile until the third year of life. Clinical research suggests that paediatric liver disease differs in both severity and rate of progression compared with adult forms, suggesting independent mechanisms of pathogenesis. We discuss data linking the intestinal microbiome to liver disease development and therapeutic efforts to modify the microbiome in children.

Probiotics in cystic fibrosis patients: A double blind crossover placebo controlled study: Pilot study from the ESPGHAN Working Group on Pancreas/CF

BACKGROUND

A potential positive effect of probiotics in cystic fibrosis (CF) on fecal calprotectin (FCP), pulmonary exacerbations and weight has been described in small controlled trials.

METHODS

A double-blind multicenter cross-over study (2 × 4 m) was performed looking at abdominal pain, nutritional status, pulmonary function, pulmonary exacerbation, FCP and lactulose/mannitol gut permeability test. Patients kept a diary with daily scoring of abdominal pain, stool frequency and consistency as well as treatment changes.

RESULTS

31 CF patients entered the study of which 25 finished it. At start patients aged 9.3yrs (6.9-12.2), had a median BMI z-score of -0.5 (-1.5-0.08), height z-score of -0.4 (-1.1-0.05) and FEV1% of 100% (87.2-106.6). Median FCP at start was 61 μg/g (17-108) and gut permeability 0.079 (0.051-0.122). No significant changes were observed in the clinical parameters (BMI, FEV1%, abdominal pain, exacerbations). Despite being frequently abnormal (17/28 (61%) >50 mg/kg), FCP did not change significantly with probiotics. The proportion of patients with normal permeability was 8% during placebo and 32% during probiotic treatment (p = 0.031). FCP correlated to BMI z-score (p = 0.043) and gut permeability to abdominal pain (p = 0.015). The microbiome revealed a high predominance of Actinobacteria and Proteobacteriae. Probiotic supplementation did not result in a shift at the phylum nor at phylogenetic level.

CONCLUSION

Normalization of gut permeability was observed in 13% of patients during probiotic treatment. However, none of the previously described effects could be confirmed.

Approach to chronic abdominal pain in Cystic Fibrosis

Abdominal pain in individuals with CF is challenging for the patient as well as the physician, as the differential diagnosis can be complex. Most gastrointestinal manifestations of CF present with regional abdominal pain. Pain localization, which requires knowledge of gut development and innervation, is crucial to understanding the pathophysiology of abdominal pain in CF. The location of the pain, together with the clinical presentation, shapes the differential diagnosis and thus guides the evaluation and management.

Bacterial overgrowth, dysbiosis, inflammation, and dysmotility in the Cystic Fibrosis intestine

Gastrointestinal disease in Cystic Fibrosis (CF) is caused by defective chloride and bicarbonate transport in intestinal cells leading to reduced intraluminal fluidity, increased mucous viscosity and consequently development of intestinal inflammation, dysbiosis and often times dysmotility. This triad is also referred to as the "CF gut". A diagnosis is mainly based on clinical observation and treatment is often times decided empirically. This review of the literature should provide CF caregivers with some tools to identify intestinal inflammation, dysbiosis and dysmotility as possible cause for their patient's gastrointestinal complaints and provide an overview of our current approach to its management.

Risk factors for lung disease progression in children with cystic fibrosis

To identify potential risk factors for lung disease progression in children with cystic fibrosis (CF), we studied the longitudinal data of all children with CF (aged ≥5 years) registered in the Dutch CF Registry (2009-2014).Lung disease progression was expressed as a decline in lung function (forced expiratory volume in 1 s (FEV₁) % pred) and pulmonary exacerbation rate. Potential risk factors at baseline included sex, age, best FEV₁ % pred, best forced vital capacity % pred, genotype, body mass index z-score, pancreatic insufficiency, medication use (proton pump inhibitors (PPIs), prophylactic antibiotics and inhaled corticosteroids), CF-related diabetes, allergic bronchopulmonary aspergillosis and colonisation with Pseudomonas aeruginosaThe data of 545 children were analysed. PPI use was associated with both annual decline of FEV₁ % pred (p=0.017) and future pulmonary exacerbation rate (p=0.006). Moreover, lower FEV₁ % pred at baseline (p=0.007), prophylactic inhaled antibiotic use (p=0.006) and pulmonary exacerbations in the baseline year (p=0.002) were related to pulmonary exacerbations in subsequent years.In a cohort of Dutch children with CF followed for 5 years, we were able to identify several risk factors for future exacerbations. In particular, the association between PPI use and lung disease progression definitely requires further investigation.

Clinical effects of probiotics in cystic fibrosis patients: A systematic review

Cystic fibrosis (CF) is characterised by a build-up of thick, intransient mucus linings of the digestive and respiratory mucosa, which disrupts digestive system functioning and microbiota composition. In view of the potential for probiotics to enhance microbiota composition in other contexts, this study investigated the current evidence for probiotics as an adjunct to usual therapy for CF. Electronic clinical databases were interrogated for human randomised, controlled, intervention trials (1985-2015) testing the effects of probiotics on clinical endpoints in CF were reviewed. From 191 articles identified in initial searches, six studies met the critical inclusion criteria, and were reviewed in detail. These studies varied in size (n = 22 to 61) but were generally small and showed substantial diversity in protocol, specific probiotic species used and range of clinical outcomes measured. Probiotic administration showed beneficial effects on fecal calprotectin levels, pulmonary exacerbation risk, and quality of life indicators. In one study, such changes were associated with variations in gut microbiota composition. Despite encouraging preliminary results, the limited number of small and highly varied studies to date do not justify the addition of probiotics as an adjunct to current CF treatment protocols. Importantly, very minimal adverse effects of probiotics have been reported.

Host-microbiome interactions in acute and chronic respiratory infections

Respiratory infection is a leading cause of global morbidity and mortality. Understanding the factors that influence risk and outcome of these infections is essential to improving care. We increasingly understand that interactions between the microbial residents of our mucosal surfaces and host regulatory systems is fundamental to shaping local and systemic immunity. These mechanisms are most well defined in the gastrointestinal tract, however analogous systems also occur in the airways. Moreover, we now appreciate that the host-microbiota interactions at a given mucosal surface influence systemic host processes, in turn, affecting the course of infection at other anatomical sites. This review discusses the mechanisms by which the respiratory microbiome influences acute and chronic airway disease and examines the contribution of cross-talk between the gastrointestinal and respiratory compartments to microbe-mucosa interactions.

Severe disease in Cystic Fibrosis and fecal calprotectin levels

Fecal calprotectin (FC) is used to asses the presence of intestinal inflammation also in patients with Cystic Fibrosis (CF) and recent studies showed a correlation between bowel and lung disease in these patients. The aim of this study was to analyze the levels of FC in CF and correlate them with different phenotypes of disease. We enrolled a cohort of 54 CF patients and 50 healthy controls. In these patients, calprotectin has been assayed on a stools sample using an ELISA kit. In all patients we analyzed, FC levels were elevated above the cut-off value and significantly higher than in healthy controls. Among CF patients, FC was significantly higher in patients older than 18 years, with pancreatic insufficiency, underweight status, Pseudomonas Aeruginosa airways colonization, CF-related diabetes mellitus, reduced lung function, or high number of pulmonary exacerbations. These results suggest that in patients with CF, FC levels are not only influenced by the CF enteropathy but also by the severity of the genetic disease. Since we found higher FC levels in patients with a severe phenotype (P. Aeruginosa airways colonization, FEV1<50% of predicted, pancreatic insufficiency, underweight status,) we suggest that this marker could be useful to monitor longitudinally a clinical worsening.

Key mechanisms governing resolution of lung inflammation

Innate immunity normally provides excellent defence against invading microorganisms. Acute inflammation is a form of innate immune defence and represents one of the primary responses to injury, infection and irritation, largely mediated by granulocyte effector cells such as neutrophils and eosinophils. Failure to remove an inflammatory stimulus (often resulting in failed resolution of inflammation) can lead to chronic inflammation resulting in tissue injury caused by high numbers of infiltrating activated granulocytes. Successful resolution of inflammation is dependent upon the removal of these cells. Under normal physiological conditions, apoptosis (programmed cell death) precedes phagocytic recognition and clearance of these cells by, for example, macrophages, dendritic and epithelial cells (a process known as efferocytosis). Inflammation contributes to immune defence within the respiratory mucosa (responsible for gas exchange) because lung epithelia are continuously exposed to a multiplicity of airborne pathogens, allergens and foreign particles. Failure to resolve inflammation within the respiratory mucosa is a major contributor of numerous lung diseases. This review will summarise the major mechanisms regulating lung inflammation, including key cellular interplays such as apoptotic cell clearance by alveolar macrophages and macrophage/neutrophil/epithelial cell interactions. The different acute and chronic inflammatory disease states caused by dysregulated/impaired resolution of lung inflammation will be discussed. Furthermore, the resolution of lung inflammation during neutrophil/eosinophil-dominant lung injury or enhanced resolution driven via pharmacological manipulation will also be considered.