A Low FODMAP Diet Reduces Symptoms in Treated Celiac Patients With Ongoing Symptoms-A Randomized Controlled Trial

Celiac Disease, Gluten Sensitivity, and Diet Management

PURPOSE OF REVIEW

Celiac disease is a common chronic inflammatory condition of the small bowel triggered by gluten in wheat, rye and barley in the diet. Non-celiac gluten sensitivity presents with symptoms similar to celiac disease with the ingestion of gluten or other components of wheat. In this article, we review challenges presented by a gluten free diet for the treatment of both disorders.

RECENT FINDINGS

Wheat is ubiquitous in the diet and medications/products. A registered dietitian is mandatory for patient education on the gluten free diet. Naturally gluten free foods provide a healthy diet for those with celiac disease. Whole grains labelled gluten free, including oats, are encouraged in the diet as refined grains may be deficient in fiber, protein, and micronutrients, particularly folate. Gluten contamination is the most common cause of persistent symptoms in celiac disease though shared equipment of food preparation may not be as large a problem as suspected. Most with celiac disease on a gluten free diet will fully recover and gain weight that poses a problem for those overweight to start. The gluten free diet may have a negative impact on quality of life for both celiac patients and their families. Those with hypervigilance of the gluten free diet and avoidance of dining out have the lowest quality of life. The gluten free diet is currently the only effective treatment for celiac disease. A registered dietitian is needed to educate patients on the complexity of the gluten free diet with a goal of healthy eating, maintaining a healthy weight, and avoiding disordered eating or diet hypervigilance; key to a good quality of life.

Celiac Disease Affects 1% of Global Population: Who Will Manage All These Patients?

Celiac disease is a common gastrointestinal condition with an estimated global prevalence of up to 1%. Adequate long-term surveillance of patients is imperative to ensure strict adherence to treatment with a gluten-free diet and the ensuing clinical and histologic recovery. Traditionally, this has been accomplished by means of regular on-site attendance at specialist health care facilities, accompanied for most patients by follow-up endoscopic and laboratory tests. However, the rapidly increasing prevalence of celiac disease and the limited health care resources challenge the current centralized and nonindividualized follow-up strategies. The improved noninvasive surveillance tools and online health care services are further changing the landscape of celiac disease management. There is a clear need for more personalized and on-demand follow-up based on early treatment response and patient-related factors associated with long-term prognosis. Additional scientific evidence on the optimal implementation of follow-up for pediatric and adulthood celiac disease is nevertheless called for.

How Future Pharmacologic Therapies for Celiac Disease Will Complement the Gluten-Free Diet

The only proven treatment for celiac disease is adherence to a strict, lifelong, gluten-free diet. However, complete dietary gluten avoidance is challenging and a substantial number of patients do not respond fully, clinically, or histologically, despite their best efforts. As celiac disease is common and its central pathophysiology is well elucidated, it has become attractive for drug development to address the limitations of dietary treatment. Most efforts address nonresponsive celiac disease, defined as continued symptoms and/or signs of disease activity despite a gluten-free diet, and the more severe forms of refractory celiac disease, types I and II. An increasing spectrum of therapeutic approaches target defined mechanisms in celiac disease pathogenesis and some have advanced to current phase 2 and 3 clinical studies. We discuss these approaches in terms of potential efficiency, practicability, safety, and need, as defined by patients, regulatory authorities, health care providers, and payors.

A Look Into the Future: Are We Ready for an Approved Therapy in Celiac Disease?

As it appears that we are currently at the cusp of an era in which drugs that are new, re-purposed, or "supplements" will be introduced to the management of celiac disease, we need to reflect on whether the framework is set for celiac disease to be treated increasingly with pharmaceuticals as well as diet. This refers to reflecting on the rigor of current diagnostic practices; the limitations of the current standard of care, which is a gluten-free diet; and that we lack objective markers of disease severity. Investigating these issues will help us to identify gaps in technology and practices that could be critical for selecting patients with a well-defined need for an improved or alternative treatment. Both aspects, circumscribed limitations of the gluten-free diet and diagnostics helping to define celiac disease target groups, together with the guiding requirements by the responsible regulatory authorities, will contribute to defining the subgroups of patients with confirmed celiac disease eligible for distinct pharmacologic strategies. Because many patients with celiac disease are diagnosed in childhood, these aspects need to be differentially discussed for the pediatric setting. In this perspective, we aimed to describe these contextual issues and then looked ahead to the future. What might be the major challenges in celiac disease clinics in the coming years once drugs are an option alongside diet? And what will be the future objectives for researchers who further decipher the mucosal immunology of celiac disease? Speculating on the answers to these questions is as stimulating as it is fascinating to be part of this turning point.

Clinical Presentation and Spectrum of Gluten Symptomatology in Celiac Disease

Views on the clinical presentation and symptomatology of celiac disease have evolved alongside advances in disease detection and understanding of disease pathogenesis. Although historically regarded as a pediatric illness characterized by malabsorption, it is now better viewed as an immune illness of gluten-specific T cells with systemic manifestations affecting all ages. Its broad presentation, including frequent extraintestinal manifestations and asymptomatic disease, contributes to suboptimal disease detection. Adverse symptoms greatly impact patient quality of life and can result from chronic gluten exposure in untreated disease or those poorly responsive to the gluten-free diet. They can also present as acute symptoms after episodic gluten exposure. Functional gastrointestinal disease is a common comorbidity. Biomarkers like interleukin-2 that are highly sensitive and specific for celiac disease highlight a role for gluten-specific T cells in acute gluten symptomatology. A mechanistic understanding of symptoms will inform approaches to better measure and treat them effectively.

Global research trend and hotspot in the low FODMAP diet: a bibliometric analysis

BACKGROUND

According to national guidelines, a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) is a second-line therapy option for irritable bowel syndrome (IBS) and improves functional intestinal symptoms. Numerous noteworthy results have been published in this field over the past fifteen years. This study aims to analyze the global research trend and hotspot of the low FODMAP diet research, and provide a comprehensive perspective and direction for researchers.

METHODS

The Science Citation Index-Expanded of the Web of Science Core Collection (WoSCC) was used to identify low FODMAP diet-related articles and reviews. Three bibliometric programs (CiteSpace, VOSviewer, Scimago Graphic) were utilized to analyze and visualize the annual publications, authors, countries, institutions, journals, citations, and keywords.

RESULTS

In total, 843 documents related to the low FODMAP diet research were published in 227 journals by 3,343 authors in 1,233 institutions from 59 countries. The United States, which was the most engaged nation in international collaboration, had the largest annual production and the fastest growth. The most productive organization was Monash University, and the most fruitful researcher was Gibson PR. Nutrients ranked first in terms of the number of published documents. The article "A diet low in FODMAPs reduces symptoms of irritable bowel syndrome" (Halmos EP, 2014) received the most co-citations. Keywords that appear frequently in the literature mainly involve two main aspects: the clinical efficacy evaluation and mechanism exploration of the low FODMAP diet. The term "gut microbiota" stands out as the most prominent keyword among the burst keywords that have remained prevalent till date.

CONCLUSION

The restriction stage of the low FODMAP diet is superior to other dietary therapies for IBS in terms of symptom response, but it has a negative impact on the abundance of gut Bifidobacteria and diet quality. Identification of biomarkers to predict response to the low FODMAP diet is of great interest and has become the current research hotspot.

Efficacy of a Low-FODMAP Diet for Coeliac Patients with Persistent IBS-like Symptoms despite a Gluten-Free Diet: A Systematic Review

Background: Persistent symptoms in coeliac disease (CD) can be due to not only poor gluten-free diet (GFD) adherence and complications of CD, but also functional gastrointestinal disorders such as irritable bowel syndrome (IBS). Although the role of a low fermentable oligo-, di-, and monosaccharides and polyols (FODMAP) diet is well-established in IBS, little data are available on its role in coeliac patients with persistent IBS-like symptoms despite a GFD. Methods: We systematically reviewed the literature in accordance with the PRISMA guidelines for studies evaluating the role of FODMAPs and/or a low-FODMAP diet in coeliac patients with persistent symptoms. PubMed and Embase were searched from inception to 16 January 2024 for eligible full-text papers. The study protocol was registered on Open Science Framework. Results: A total of 239 records were identified, and six papers were included. Of these, four were interventional studies comparing a low-FODMAP GFD to a regular GFD for persistent symptoms in 115 total coeliac patients (two randomized controlled trials and two open-label studies). A low-FODMAP GFD for a minimum of 4 weeks was significantly more effective than a regular GFD in reducing symptoms (p < 0.05 in 3/4 studies). Dietary FODMAP content of a conventional GFD was significantly lower than that of non-coeliac patients on a gluten-containing diet (both p < 0.05), especially regarding high-FODMAP grain products. However, coeliac patients consumed more servings of fruits/vegetables high in FODMAP. No relationship between FODMAP intake and persistence of symptoms was reported. Conclusions: A low-FODMAP diet may be beneficial for uncomplicated celiac patients with persistent IBS-like symptoms despite strict adherence to a GFD.

Stool Gluten Peptide Detection Is Superior to Urinary Analysis, Coeliac Serology, Dietary Adherence Scores and Symptoms in the Detection of Intermittent Gluten Exposure in Coeliac Disease: A Randomised, Placebo-Controlled, Low-Dose Gluten Challenge Study

Monitoring adherence to a gluten-free diet is an important goal of coeliac disease management. Urine and stool gluten immunogenic peptide (GIP) assays provide an objective readout of gluten ingestion, with the former favoured due to its convenience and acceptability. This study assessed stool GIP excretion after low-dose gluten challenge designed to mimic accidental gluten exposure. A total of 52 coeliac participants undertook a randomised, double-blind gluten (50-1000 mg) or placebo challenge. Stool and urinary GIP, serology, dietary adherence and symptoms were assessed. Stool GIP was 100% sensitive for gluten intake ≥250 mg and 71% for 50 mg. Peak GIP detection was 12-36 h after gluten exposure. The mean stool GIP after 1000 mg gluten ingestion remained above the limit of quantification for 5 days. Urine GIP assessment had poor sensitivity for GIP excretion compared to stool. Serology, dietary adherence score and symptoms did not correlate with gluten excretion during lead-in. We conclude that stool GIP detection is highly sensitive, with levels related to gluten dose and time from ingestion. Weekly or bi-weekly testing will detect low-level exposure more effectively than urine GIP assessments or traditional methods. In this seronegative, apparently well-treated cohort, a high frequency of baseline-positive GIP suggests ongoing gluten exposure, but the assessment of patient behaviour and assay specificity is needed.

Effects of a low FODMAP diet on gut microbiota in individuals with treated coeliac disease having persistent gastrointestinal symptoms - a randomised controlled trial

Individuals with coeliac disease (CeD) often experience gastrointestinal symptoms despite adherence to a gluten-free diet (GFD). While we recently showed that a diet low in fermentable oligo-, di-, monosaccharides and polyols (FODMAP) successfully provided symptom relief in GFD-treated CeD patients, there have been concerns that the low FODMAP diet (LFD) could adversely affect the gut microbiota. Our main objective was therefore to investigate whether the LFD affects the faecal microbiota and related variables of gut health. In a randomised controlled trial GFD-treated CeD adults, having persistent gastrointestinal symptoms, were randomised to either consume a combined LFD and GFD (n 39) for 4 weeks or continue with GFD (controls, n 36). Compared with the control group, the LFD group displayed greater changes in the overall faecal microbiota profile (16S rRNA gene sequencing) from baseline to follow-up (within-subject β-diversity, P < 0·001), characterised by lower and higher follow-up abundances (%) of genus Anaerostipes (Pgroup < 0·001) and class Erysipelotrichia (Pgroup = 0·02), respectively. Compared with the control group, the LFD led to lower follow-up concentrations of faecal propionic and valeric acid (GC-FID) in participants with high concentrations at baseline (Pinteraction ≤ 0·009). No differences were found in faecal bacterial α-diversity (Pgroup ≥ 0·20) or in faecal neutrophil gelatinase-associated lipocalin (ELISA), a biomarker of gut integrity and inflammation (Pgroup = 0·74), between the groups at follow-up. The modest effects of the LFD on the gut microbiota and related variables in the CeD patients of the present study are encouraging given the beneficial effects of the LFD strategy to treat functional GI symptoms (Registered at clinicaltrials.gov as NCT03678935).

Gut liver brain axis in diseases: the implications for therapeutic interventions

Gut-liver-brain axis is a three-way highway of information interaction system among the gastrointestinal tract, liver, and nervous systems. In the past few decades, breakthrough progress has been made in the gut liver brain axis, mainly through understanding its formation mechanism and increasing treatment strategies. In this review, we discuss various complex networks including barrier permeability, gut hormones, gut microbial metabolites, vagus nerve, neurotransmitters, immunity, brain toxic metabolites, β-amyloid (Aβ) metabolism, and epigenetic regulation in the gut-liver-brain axis. Some therapies containing antibiotics, probiotics, prebiotics, synbiotics, fecal microbiota transplantation (FMT), polyphenols, low FODMAP diet and nanotechnology application regulate the gut liver brain axis. Besides, some special treatments targeting gut-liver axis include farnesoid X receptor (FXR) agonists, takeda G protein-coupled receptor 5 (TGR5) agonists, glucagon-like peptide-1 (GLP-1) receptor antagonists and fibroblast growth factor 19 (FGF19) analogs. Targeting gut-brain axis embraces cognitive behavioral therapy (CBT), antidepressants and tryptophan metabolism-related therapies. Targeting liver-brain axis contains epigenetic regulation and Aβ metabolism-related therapies. In the future, a better understanding of gut-liver-brain axis interactions will promote the development of novel preventative strategies and the discovery of precise therapeutic targets in multiple diseases.

Celiac Disease: An Academy of Nutrition and Dietetics Evidence-Based Nutrition Practice Guideline

Celiac disease is an autoimmune disorder in which the immune system of genetically susceptible individuals elicits a reaction to gluten causing small intestine damage. If left undiagnosed and untreated, the resulting nutrition malabsorption can lead to anemia, bone disease, growth faltering, or other consequences. The condition is lifelong and lacks a cure; the only treatment is lifelong adherence to a gluten-free diet (GFD). This diet is challenging to follow and adversely influences quality of life; however, it is essential to ensure intestinal recovery and prevent future negative health consequences. The Academy of Nutrition and Dietetics convened an expert panel complemented by a celiac disease patient advocate to evaluate evidence for six topics, including medical nutrition therapy; the GFD; oat consumption; micronutrients; pro-/prebiotics; and the low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet. This publication outlines the Academy of Nutrition and Dietetics Evidence Analysis Library methods used to complete the systematic review and guideline development, and summarizes the recommendations and supporting evidence. The guidelines affirm that all individuals with celiac disease should follow a GFD (1C, Imperative) that may include gluten-free oats in adults (2D, Conditional). Children should follow a nutritionally adequate GFD that supports healthy growth and development (Consensus, Imperative) and does not unnecessarily restrict gluten-free oats (Consensus, Conditional). The guidelines indicate nutritional care should include routine nutritional assessment (Consensus, Imperative) and medical nutrition therapy (Consensus, Imperative). At this time, the guidelines do not support a recommendation for the addition of the low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet (2C, Conditional); prebiotic or probiotic supplementation (2D, Conditional); or micronutrient supplementation (in the absence of nutritional deficiency) (Consensus, Conditional). The 2021 Celiac Disease Evidence-Based Nutrition Guideline will assist registered dietitian nutritionists in providing appropriate evidence-based medical nutrition therapy to support people with celiac disease in achieving and maintaining nutritional health and avoiding adverse celiac disease consequences throughout their lives.

The Occurrence of Gluten-Related Antibodies, Sensitization to Selected Food Allergens, and Antibodies against Intrinsic Factor in Adult Patients with Diarrhea-Predominant Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder. Due to the possible overlap of IBS clinical symptoms with gluten-related diseases, food allergies, and autoimmune gastritis (AIG), the aim of this study was to present the frequency of anti-tissue transglutaminase 2 (TTG2) autoantibodies, anti-deamidated gluten peptide (DGP) antibodies, specific immunoglobulin E antibodies (sIgE) to selected food allergens, and anti-intrinsic factor (IF) autoantibodies in adult patients with diarrhea-predominant IBS (IBS-D). The study involved 244 patients (170 women) aged 18-75 years. The antibodies were measured with the use of multiparametric immunoassays. Elevated antibody concentrations, irrespective of the class of tested antibody, occurred in 44 patients (17.6%), including 11 patients (4.5%) with positive DGP antibodies, four patients (1.6%) with TTG2 autoantibodies, six patients (2.5%) with IF autoantibodies, and 31 patients (12.7%) with sIgE to food allergens. Sensitization to gluten, proteins from cow's milk, and bovine serum albumin was found in 2.1%, 5.3%, and 9.0% of patients, respectively. Our study showed a high percentage of positive results for the tested antibodies in the IBD-D patients, which indicates the need to perform serological tests for CD, food allergies, and AIG in this group of patients.

Role of Nutrition in Gastroesophageal Reflux, Irritable Bowel Syndrome, Celiac Disease, and Inflammatory Bowel Disease

There remains a paucity of data on the efficacy of nutritional interventions in luminal gastrointestinal disorders. This review appraises the evidence supporting dietary modification in gastroesophageal reflux disease (GERD), irritable bowel syndrome, Celiac disease, and inflammatory bowel disease. Alhough the use of elimination diets; high fat/low carb; low fermentable oligosaccharides, disaccharides, monosaccharides and polyols; and lactose-free diets in GERD have been studied, the evidence supporting their efficacy remains weak and mixed. Patients with GERD should avoid eating within 3 hours of lying recumbent. Studied dietary interventions for disorders of gut-brain interaction include low fermentable oligosaccharides, disaccharides, monosaccharides and polyols and gluten-restricted and lactose-free diets. While all can be effective in carefully, individually selected patients, the evidence for each intervention remains low. In patients with inflammatory bowel disease, enteral nutrition is established in pediatric populations as useful in reducing inflammation and partial enteral nutrition has a growing evidence base for use in adults and children. Specific carbohydrate diets and the Crohn's disease exclusion diet show promising evidence but require further study to validate their efficacy prior to recommendation. Overall, the evidence supporting nutritional therapy across luminal gastrointestinal disorders is mixed and often weak, with few well-designed randomized controlled trials (RCTs) demonstrating consistent efficacy of interventions. RCTs, particularly cross-over RCTs, show potential to compare dietary interventions.

The role of gluten challenge in the diagnosis of celiac disease: a review

INTRODUCTION

Duodenal biopsy is the gold standard in the diagnosis of celiac disease, with increasing utilization of serology. A gluten challenge may be required, for example, when dietary gluten reduction precedes appropriate diagnostic evaluations. Evidence on the best challenge protocol is currently sparse. Pharmaceutical trials in recent years may have provided new insights into the challenge and advanced the development of novel sensitive histological and immunological methods.

AREAS COVERED

This review outlines the current perspectives on the use of gluten challenge in the diagnosis of celiac disease and explores future directions in this area.

EXPERT OPINION

Comprehensive elimination of celiac disease before dietary gluten restriction is essential to avoid diagnostic uncertainties. Gluten challenge continues to have an important role in certain clinical scenarios, although it is important to understand its limitations in the diagnostic evaluation. The evidence so far permits no unequivocal recommendation considering the timing, duration, and amount of gluten used in the challenge. Thus, these decisions should be made on a case-by-case basis. Further studies with more standardized protocols and outcome measures are called for. In the future novel immunological methods may help to shorten or even avoid gluten challenge.

Nutritional assessment of women with celiac disease compared to the general population

BACKGROUND & AIMS

The nutritional quality of a gluten-free diet is debated because of the elimination of grains that are important sources of nutrients. The aim of this cross-sectional study was to perform a nutritional assessment in treated women with celiac disease and ongoing symptoms, and compare dietary intake with a healthy reference group (Norkost 3).

METHODS

Celiac disease patients with biopsy confirmed mucosal healing, but persistent gastrointestinal symptoms, were included from an ongoing clinical trial. Nutritional assessment included anthropometrics, blood samples and dietary intake obtained by two 24 h recalls. Dietary intake in celiac women was compared with dietary intake in healthy women (Norkost 3). Two sample t-test was used for comparison of CeD and Norkost 3 women. Adjustment for age, BMI, education and smoking, by use of multiple linear regression analysis, did not change the results.

RESULTS

In total, 59 women with celiac disease and 925 women that participated in Norkost 3 were included, with a mean age of 45 years in both groups. Women with celiac disease had a higher proportion of energy (E%) from fat (39 vs 34%, P < 0.001) and saturated fat (15 vs 13%, P = 0.01), a lower E% from protein (16 vs 18%, P = 0.01) and a lower intake of dietary fiber (19 vs 22 g, P = 0.002) compared to Norkost 3 women. Women with celiac disease had a lower intake of bread, fruit and milk, and a higher intake of cereals and cheese compared to Norkost 3 women. The average requirement was not met for several micronutrients, but blood analysis revealed few nutritional deficiencies: two women with insufficient vitamin D status and one with insufficient folic acid status.

CONCLUSION

The women with celiac disease had an unbalanced diet with a higher intake of total- and saturated fatty acids and a lower intake of fiber compared to the general population. These findings emphasizes the need for nutritional follow-up of celiac patients and development of nutrient dense gluten-free products.

AGA Clinical Practice Update on Management of Refractory Celiac Disease: Expert Review

DESCRIPTION

The purpose of this expert review is to summarize the diagnosis and management of refractory celiac disease. It will review evaluation of patients with celiac disease who have persistent or recurrent symptoms, differential diagnosis, nutritional support, potential therapeutic options, and surveillance for complications of this condition.

METHODS

This expert review was commissioned and approved by the American Gastroenterological Association (AGA) Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the CPUC and external peer review through standard procedures of Gastroenterology. These Best Practice Advice (BPA) statements were drawn from a review of the published literature and from expert opinion. Since systematic reviews were not performed, these BPA statements do not carry formal ratings of the quality of evidence or strength of the presented considerations. Best Practice Advice Statements BEST PRACTICE ADVICE 1: In patients believed to have celiac disease who have persistent or recurrent symptoms or signs, the initial diagnosis of celiac disease should be confirmed by review of prior diagnostic testing, including serologies, endoscopies, and histologic findings. BEST PRACTICE ADVICE 2: In patients with confirmed celiac disease with persistent or recurrent symptoms or signs (nonresponsive celiac disease), ongoing gluten ingestion should be excluded as a cause of these symptoms with serologic testing, dietitian review, and detection of immunogenic peptides in stool or urine. Esophagogastroduodenoscopy with small bowel biopsies should be performed to look for villous atrophy. If villous atrophy persists or the initial diagnosis of celiac disease was not confirmed, consider other causes of villous atrophy, including common variable immunodeficiency, autoimmune enteropathy, tropical sprue, and medication-induced enteropathy. BEST PRACTICE ADVICE 3: For patients with nonresponsive celiac disease, after exclusion of gluten ingestion, perform a systematic evaluation for other potential causes of symptoms, including functional bowel disorders, microscopic colitis, pancreatic insufficiency, inflammatory bowel disease, lactose or fructose intolerance, and small intestinal bacterial overgrowth. BEST PRACTICE ADVICE 4: Use flow cytometry, immunohistochemistry, and T-cell receptor rearrangement studies to distinguish between subtypes of refractory celiac disease and to exclude enteropathy-associated T-cell lymphoma. Type 1 refractory celiac disease is characterized by a normal intraepithelial lymphocyte population and type 2 is defined by the presence of an aberrant, clonal intraepithelial lymphocyte population. Consultation with an expert hematopathologist is necessary to interpret these studies. BEST PRACTICE ADVICE 5: Perform small bowel imaging with capsule endoscopy and computed tomography or magnetic resonance enterography to exclude enteropathy-associated T-cell lymphoma and ulcerative jejunoileitis at initial diagnosis of type 2 refractory celiac disease. BEST PRACTICE ADVICE 6: Complete a detailed nutritional assessment with investigation of micronutrient and macronutrient deficiencies in patients diagnosed with refractory celiac disease. Check albumin as an independent prognostic factor. BEST PRACTICE ADVICE 7: Correct deficiencies in macro- and micronutrients using oral supplements and/or enteral support. Consider parenteral nutrition for patients with severe malnutrition due to malabsorption. BEST PRACTICE ADVICE 8: Corticosteroids, most commonly open-capsule budesonide or, if unavailable, prednisone, are the medication of choice and should be used as first-line therapy in either type 1 or type 2 refractory celiac disease. BEST PRACTICE ADVICE 9: Patients with refractory celiac disease require regular follow-up by a multidisciplinary team, including gastroenterologists and dietitians, to assess clinical and histologic response to therapy. Identify local experts with expertise in celiac disease to assist with management. BEST PRACTICE ADVICE 10: Patients with refractory celiac disease without response to steroids may benefit from referral to a center with expertise for management or evaluation for inclusion in clinical trials.

Low FODMAP diet in irritable bowel syndrome: a review of recent clinical trials and meta-analyses

PURPOSE OF REVIEW

The low fermentable oligosaccharides, disaccharides, monosaccharides and polyol (FODMAP) diet is widely used in the dietary management of irritable bowel syndrome (IBS). The aim of this review is to summarize recent evidence regarding the use of the low FODMAP diet in IBS and other gastrointestinal disorders from recent clinical trials and meta-analyses.

RECENT FINDINGS

Several recent systematic reviews and meta-analyses support the use of low FODMAP restriction for global symptoms in IBS in the short term. Uncontrolled follow-up studies show that at least 50% of individuals experience symptom relief following restriction, reintroduction and personalization in the long term. Although evidence from comparative trials in IBS suggests potential benefit of less burdensome approaches (e.g. standard IBS diet and low lactose diet) many studies are insufficiently powered. One established mechanism is colonic gas production that may induce pain signalling measurable in the brain, however altered gastrointestinal epithelial integrity and shifts in microbiome composition and function may also be involved.

SUMMARY

Quality trials of the low FODMAP diet are emerging and have been transformational in supporting the widespread application to IBS management in some areas (e.g. short-term effectiveness), whereas other areas still require considerable improvements in research evidence (e.g. long-term effectiveness, mechanisms and educational delivery).

Review article: Follow-up of coeliac disease

Coeliac disease is a lifelong immune-mediated enteropathy with systemic features associated with increased morbidity and modestly increased mortality. Treatment with a strict gluten-free diet improves symptoms and mucosal damage but is not curative and low-level gluten intake is common despite strict attempts at adherence. Regular follow-up after diagnosis is considered best-practice however this is executed poorly in the community with the problem compounded by the paucity of data informing optimal approaches. The aim of dietary treatment is to resolve symptoms, reduce complication risk and improve quality of life. It follows that the goals of monitoring are to assess dietary adherence, monitor disease activity, assess symptoms and screen for complications. Mucosal disease remission is regarded a key measure of treatment success as healing is associated with positive health outcomes. However, persistent villous atrophy is common, even after many years of a gluten-free diet. As the clinical significance of asymptomatic enteropathy is uncertain the role for routine follow-up biopsies remains contentious. Symptomatic non-responsive coeliac disease is common and with systematic follow-up a cause is usually found. Effective models of care involving the gastroenterologist, dietitian and primary care doctor will improve the consistency of long-term management and likely translate into better patient outcomes. Identifying suitable treatment targets linked to long-term health is an important goal.

Gastrointestinal effects of diets low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols

PURPOSE OF REVIEW

Food ingestion is an exacerbator of gastrointestinal symptoms, regardless of origin. Sufferers mistakenly assume that they have suffered an allergic reaction to a given food. Although classical IgE-mediated allergic reactions are rarely culpable, evidence for a role for intolerance to certain carbohydrates in irritable bowel syndrome (IBS) and related conditions increases. This review assesses the status of a commonly implicated group of poorly absorbed carbohydrates (fermentable oligosaccharides, disaccharides, monosaccharides and polyols - FODMAPs) in gastrointestinal pathophysiology.

RECENT FINDINGS

Although evidence of efficacy for low FODMAP diets in IBS accumulates, the magnitude of this effect has declined in recent studies. Comparisons to other dietary approaches have revealed conflicting results; some suggest superiority, others find parity. Concerns had been raised regarding long-term nutritional, psychological and microbiological impacts of FODMAP restriction; providing that the diet is administered in the recommended manner, these do not appear to be clinically important. The mechanisms whereby FODMAPs cause gastrointestinal symptoms continue to be explored.

SUMMARY

FODMAPS induce gastrointestinal symptoms in susceptible individuals and their restriction provides clinical benefits. The magnitude of these benefits, the superiority of FODMAP restriction over other dietary approaches and the mechanisms of its effects continue to be defined.