Low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet improves symptoms in adults suffering from irritable bowel syndrome (IBS) compared to standard IBS diet: A meta-analysis of clinical studies

The efficacy and real-world effectiveness of a diet low in fermentable oligo-, di-, monosaccharides and polyols in irritable bowel syndrome: A systematic review and meta-analysis

BACKGROUND & AIMS

A diet low in fermentable oligo-, di-, monosaccharides, and polyols (LFD) has been shown to effectively reduce irritable bowel syndrome (IBS) symptoms. Effects resulting from real-world studies may differ from those seen in efficacy studies because of the diversity of patients in real-world settings. This systematic review and meta-analysis aimed to compare the effect of the LFD on reducing IBS symptoms and improving the quality of life (QoL) in efficacy trials and real-world studies.

METHODS

Major databases, trial registries, dissertations, and journals were systematically searched for studies on the LFD in adults with IBS. Meta-analysis was conducted using a random effects model with standardized mean differences (SMD) and 95% confidence intervals (CI). Outcomes of interest were all patient-reported: stool consistency, stool frequency, abdominal pain, overall symptoms, adequate symptom relief, IBS-specific QoL and adherence to the LFD.

RESULTS

Eleven efficacy and 19 real-world studies were reviewed. The meta-analysis results for abdominal pain (SMD 0.35, 95% CI 0.16 to 0.54) and QoL (SMD 0.23, 95% CI -0.05 to 0.50) showed the LFD was beneficial in efficacy studies with no statistically significant results for stool frequency (SMD 0.71, 95% CI 0.34 to 1.07). Real-world studies found improvements in abdominal pain and QoL. Due to heterogeneity, no meta-analysis was done for stool consistency and overall symptoms. In these outcomes, results were mostly supportive of the LFD, but they were not always statistically significant.

CONCLUSIONS

The results of this systematic review and meta-analysis suggest the LFD improves outcomes compared to a control diet (efficacy studies) or baseline data (real-world studies). Because of diverse study designs and heterogeneity of results, a clear superiority of the LFD over control diets could not be concluded. There are no indications of an efficacy-effectiveness gap for the LFD in adults with IBS.

Changes in Fecal Short-Chain Fatty Acids in IBS Patients and Effects of Different Interventions: A Systematic Review and Meta-Analysis

CONTEXT

Short-chain fatty acids (SCFAs) have been reported to be associated with the pathogenesis of irritable bowel syndrome (IBS), but the results are conflicting.

OBJECTIVE

Here, a systematic review of case-control studies detecting fecal SCFAs in IBS patients compared with healthy controls (HCs) and self-controlled studies or randomized controlled trials (RCTs) investigating fecal SCFA alterations after interventions were identified from several databases.

DATA SOURCES

A systematic search of databases (PubMed, Web of Science, and Embase) identified 21 studies published before 24 February 2023. Data extractions: Three independent reviewers completed the relevant data extraction.

DATA ANALYSIS

It was found that the fecal propionate concentration in IBS patients was significantly higher than that in HCs, while the acetate proportion was significantly lower. Low-FODMAP diets significantly reduced the fecal propionate concentration in the IBS patients while fecal microbiota transplantation and probiotic administration did not significantly change the fecal propionate concentration or acetate proportion.

CONCLUSIONS

The results suggested that the fecal propionate concentration and acetate proportion could be used as biomarkers for IBS diagnosis. A low-FODMAP diet intervention could potentially serve as a treatment for IBS while FMT and probiotic administration need more robust trials.

Is the Mediterranean Low Fodmap Diet Effective in Managing Irritable Bowel Syndrome Symptoms and Gut Microbiota? An Innovative Research Protocol

INTRODUCTION

Irritable bowel syndrome (IBS) symptoms can be effectively managed with the low FODMAP diet. However, its efficacy in reducing inflammation is not yet proven. On the contrary, the Mediterranean diet has anti-inflammatory properties with proven efficacy in treating chronic low-grade inflammation-related diseases.

AIM

To publicly share our protocol evaluating the efficacy of the Mediterranean low-FODMAP (MED-LFD) versus NICE recommendations (British National Institute for Health and Care Excellence) diet in managing IBS symptoms and quality of life.

MATERIALS AND METHODS

Participants meeting the Rome IV criteria will be randomly assigned to MED-LFD or NICE recommendations and they will be followed for six months. Efficacy, symptom relief, quality of life and mental health will be assessed using validated questionnaires. In addition, fecal samples will be analyzed to assess gut microbiota, and to measure branched and short-chain fatty acids, and volatile organic compounds (metabolic byproducts from bacteria). Expected results and discussion: By publicly sharing this clinical study protocol, we aim to improve research quality in the field of IBS management by allowing for peer review feedback, preventing data manipulation, reducing redundant research efforts, mitigating publication bias, and empowering patient decision-making. We expect that this protocol will show that MED-LFD can effectively alleviate IBS symptoms and it will provide pathophysiology insights on its efficacy. The new dietary pattern that combines the LFD and the MED approaches allows for the observation of the synergistic action of both diets, with the MED's anti-inflammatory and prebiotic properties enhancing the effects of the LFD while minimizing its limitations. Identifier in Clinical Trials: NCT03997708.

Effects of a low FODMAP diet on the symptom management of patients with irritable bowel syndrome: a systematic umbrella review with the meta-analysis of clinical trials

A low FODMAP diet (LFD) is a common restrictive diet to manage the symptoms of irritable bowel syndrome (IBS). However, there is no consensus on the alleviating effects of this diet. Herein, a systematic umbrella review with meta-analysis was conducted to investigate the effect of an LFD on IBS symptoms and its secondary outcomes in patients, which were not reported in previous meta-analyses. We performed a systematic literature search in PubMed, Scopus, and ISI Web of Science up to December 2023. The methodological quality of systematic reviews and their included trials was evaluated using AMSTAR 2 and the Cochrane risk of bias, respectively. The certainty of the evidence tool was evaluated using the GRADE approach. The data related to IBS symptoms, quality of life (QoL), microbiome diversity, and stool short-chain fatty acids were extracted. A random-effect (if RCTs ≥ 6) or fixed-effect model (if RCTs < 5) was used to recalculate effect sizes and 95% CIs and report them in both qualitative and quantitative terms (pooled risk ratio, Hedges' g, and weighted mean difference). A total of 658 articles were initially identified, with 11 meta-analyses and 24 RCTs reporting 28 outcomes with 1646 participants included. An LFD significantly affected the clinical improvement of total symptoms according to the IBS-SSS questionnaire (RR: 1.42; 95% CI: 1.02, 1.97; P = 0.04) in all the subtypes of IBS and also had favorable effects on stool consistency (WMD: -0.48; 95% CI: -0.902, -0.07) and frequency (WMD: -0.36; 95% CI: -0.61, -0.10) and some other GI symptoms in both less and more than 4 weeks of diet intervention except for stool consistency, which needed more than 4 weeks of LFD implementation. A significant QoL improvement was observed but not in the anxiety and depression state. Furthermore, some studies showed that an LFD may increase fecal pH and dysbiosis and reduce SCFA and the abundance of Bifidobacterium. In conclusion, an LFD can alleviate symptoms and QoL in IBS patients, although dysbiosis may occur. Considering the low certainty of evidence, strong RCTs with more appropriate designs are needed.

Evolution, adaptation, and new applications of the FODMAP diet

The FODMAP diet has been a treatment of irritable bowel syndrome (IBS) for many years. Rigorous scientific evaluation and clinical application of the FODMAP diet have generated deep understanding regarding clinical efficacy, mechanisms of action, and potential adverse effects of this dietary approach. In turn, this knowledge has allowed fine-tuning of the diet to optimize treatment benefits and minimize risks, in the form of the traditional three-phase diet; the FODMAP-gentle approach, which is a less restrictive iteration; and a proposed FODMAP-modified, Mediterranean-style diet which endeavours to optimise both gastrointestinal symptoms and other health parameters. Furthermore, recognition that IBS-like symptoms feature in other conditions has seen the FODMAP diet tested in non-IBS populations, including in older adults with diarrhea and women with endometriosis. These areas represent new frontiers for the FODMAP diet and a space to watch as future research evaluates the validity of these novel clinical applications.

A dietitian-led low-FODMAP diet webinar: a pre-post study evaluating its impact on symptoms of irritable bowel syndrome

BACKGROUND

Evidence suggests that the low fermentable oligo-, di-, mono-saccharides, and polyols (FODMAP) diet improves irritable bowel syndrome (IBS) symptoms when delivered by a dietitian. However, demand for dietetic appointments exceeds supply. Prerecorded webinars are acceptable and cost-effective for delivering first-line IBS dietary advice.

METHODOLOGY

This study, using a pre-post design, aimed to evaluate the effectiveness of a low-FODMAP diet restriction phase webinar at improving IBS symptoms. Participants with self-reported IBS symptoms were asked to report their IBS symptoms, stool frequency, stool consistency and IBS medication use, before and 8 weeks postwebinar via an online questionnaire. The presence and severity of participants' symptoms and bowel habits were captured using validated tools and a global symptom question.

RESULTS

In total 228 participants responded to both pre- and postsurveys. A statistically significant improvement in all symptoms was observed 8 weeks postwebinar (p < 0.05). The proportion of participants rating their overall symptoms as moderate-to-severe reduced from 85.5% at baseline to 34.6% postwebinar (50.9% reduction [p < 0.001]). The proportion of participants reporting normal stool consistency and frequency significantly increased postwebinar (23.2%-39.9% [p < 0.001] and 76.3%-89% [p < 0.001], respectively). Satisfactory relief of symptoms increased from 16.7% to 53.1%, (p < 0.001) 8 weeks postwebinar.

CONCLUSIONS

These results are comparable with literature on the efficacy of face-to-face delivery of low-FODMAP diet education. Dietitians should consider directing triaged patients with IBS, who have tried first-line dietary advice, to this webinar as an alternative or alongside current practice.

Nonallergic Diseases Associated With Foods

Clinicians are faced with evaluating real and alleged reactions to foods that may be allergic or nonallergic. Pathogenesis, diagnosis, and treatment of various non-IgE-mediated diseases are discussed in this review. These food-related conditions range from mild to severe. Referral for an allergy workup may be pursued despite the lack of IgE-mediated symptoms. Diagnostic testing is available for defined non-IgE-mediated food diseases that are either immunologic or nonimmunologic. These include celiac disease and related disorders, carbohydrate maldigestion, pancreatic insufficiency, and histamine intolerance. In contrast, there is a paucity of definitive studies to prove food intolerance diseases. There are no definitive diagnostic criteria or testing for nonceliac gluten sensitivity. Functional gastrointestinal disorders, such as irritable bowel syndrome, are better stratified diagnostically but still lack reliable testing. Both nonceliac gluten sensitivity and irritable bowel syndrome are linked to dietary triggers including fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. Therefore, dietary alteration alone may be diagnostic and therapeutic when all other conditions are ruled out. These conditions are important considerations when evaluating a patient with history of a food reaction. There is little evidence that foods are causative in other ailments such as acne, migraines, and nasal congestion and hypersecretion.

Gluten and Wheat in Women's Health: Beyond the Gut

Since the rise of awareness of gluten/wheat-related disorders in the academic and clinical field in the last few decades, misinformation regarding the gluten-free diet (GFD) and its impact on health has been spreading among the general population. Despite the established link between gluten and celiac disease (CD), where a GFD is mandatory to reach clinical and histological remission, things are more complicated when it comes to non-celiac gluten/wheat sensitivity (NCGWS) and other autoimmune/dysimmune disorders. In the last conditions, a beneficial effect of gluten withdrawal has not been properly assessed, but still is often suggested without strong supporting evidence. In this context, women have always been exposed, more than men, to higher social pressure related to nutritional behaviors and greater engagement in controlling body weight. With this narrative review, we aim to summarize current evidence on the adherence to a GFD, with particular attention to the impact on women's health.

[Food Intolerance]

The term food intolerance has been used non-specifically to define a wide range of disorders related to food intake. Recently, the use of the term "non-immunological adverse reactions to foods" (RANIAs) was recommended as a more correct clinical definition. The pathophysiological mechanisms can be diverse, sometimes unknown, and there are no validated diagnostic tests, making it difficult to obtain accurate data. The clinical manifestations of non-immunological adverse reactions to foods affect more than one organ or system; and gastrointestinal symptoms (pain, abdominal distension, flatulence, and diarrhea) are the most common. Non-immunological adverse reactions to foods are divided into independent and dependent on host factors. Foods may contain chemicals with pharmacological activity and be present naturally, such as vasoactive amines (histamine) and salicylates, or added for preservation, to improve appearance or flavor (monosodium glutamate, tartrazine, sulfites, and benzoates). In some cases, these types of reactions may be like to hypersensitivity reactions. Concomitant alcohol consumption may worsen symptoms by inhibiting histamine breakdown and increasing intestinal permeability. In patients diagnosed with non-immunological adverse reactions to foods, it is important to rule out some psychological problems: aversions or eating disorders.

[Differential diagnosis in food allergy]

It is important to establish the differential diagnosis of food allergy with other disorders, for example: toxic reactions that occur in any person exposed to a sufficient amount of some allergen, and non-toxic reactions that depend on individual susceptibility (food allergy or intolerance). The differential diagnosis is decisive to establish the appropriate treatment. Food intolerance involves adverse reactions to foods without any immunological response involved, and commonly manifests with gastrointestinal symptoms (malaise, abdominal pain or diarrhea). Food allergy is an exaggerated reaction of the immune system, often mediated by IgE, that can trigger serious symptoms (hives, inflammation, respiratory distress, even anaphylaxis). The complex thing is because the symptoms sometimes overlap. To establish an accurate diagnosis, exhaustive clinical evaluation, laboratory tests and, in some cases, controlled provocation tests are required. It is important to understand these distinctions, because treatment and management vary significantly. Food intolerance involves the elimination or reduction of the food that triggers the allergic reaction and requires rigorous measures (complete avoidance of the allergen and availability of epinephrine in cases of severe reactions).

Self-reported food intolerances in an Indian population: Need for individualization rather than a universal low-FODMAP diet

Background and Aim

Low-fermentable oligo-, di-, and monosaccharides and polyol (FODMAP) diets have been recommended for individuals with food intolerance and irritable bowel syndrome (IBS). Individual food intolerances may, however, not correspond to the FODMAP content alone.

Methods

We conducted a survey on self-reported intolerance to articles of food commonly identified as high FODMAP in 400 healthy Indian subjects (median age 40 years; 69% men) and 204 consecutive consenting patients with IBS (median age 36 years; 58% men).

Results

One-hundred seventy-nine (44.8%) healthy subjects and 147 (72.1%) patients with IBS reported some food intolerance (P < 0.00001); the latter reported intolerance to all items (except nuts) more frequently than healthy subjects. The prevalence, however, varied from 2.5 to 32%. Milk intolerance was reported equally commonly by healthy subjects and patients (23% vs 29.9%). Twenty-three (11.3%) patients and no healthy subjects reported wheat sensitivity. The IBS diarrhea subgroup reported intolerance to milk, pulses, capsicum, cauliflower, leafy vegetables, and dry fruits more frequently than the constipation subgroup.

Conclusion

From among a list of high-FODMAP items, individuals' intolerance varied widely, suggesting that individuals should be the final judge in deciding their elimination diets rather than devise them based on the FODMAP content alone. As in the West, food intolerance was reported more commonly by patients with IBS, especially those with diarrhea, than by healthy individuals. Also noteworthy is the low prevalence of milk intolerance in a subcontinent labeled as high in lactose intolerance. Unlike in the West, wheat intolerance was not reported by any healthy individual.

Exploring the Nutrition Strategies Employed by Ultra-Endurance Athletes to Alleviate Exercise-Induced Gastrointestinal Symptoms-A Systematic Review

(1) Background: Participation in ultra-endurance sports, particularly ultra-running, has increased over the previous three decades. These are accompanied by high energetic demands, which may be further exacerbated by extreme environmental conditions. Preparation is long-term, comprising of sufficient exercise management, supportive dietary habits, and nutritional intakes for optimal adaptations. Gastrointestinal symptoms are often cited as causing underperformance and incompletion of events. Though the majority do not pose serious long-term health risks, they may still arise. It has been suggested that the nutritional interventions employed by such athletes prior to, during, and after exercise have the potential to alter symptom incidence, severity, and duration. A summary of such interventions does not yet exist, making it difficult for relevant personnel to develop recommendations that simultaneously improve athletic performance by attenuating gastrointestinal symptoms. The aim of this research is to systematically review the literature investigating the effects of a nutrition intervention on ultra-endurance athletes exercise-induced gastrointestinal symptom incidence, severity, or duration. (2) Methods: A systematic review of the literature was conducted (PubMed, CINAHL, Web of Science, and Sports Discus) in January 2023 to investigate the effects of various nutrition interventions on ultra-endurance athletes' (regardless of irritable bowel syndrome diagnosis) exercise-induced gastrointestinal symptoms. Variations of key words such as "ultra-endurance", "gastrointestinal", and "nutrition" were searched. The risk of bias in each paper was assessed using the ADA quality criteria checklist. (3) Results: Of the seven eligible studies, one was a single field-based case study, while the majority employed a crossover intervention design. A total of n = 105 participants (n = 50 male; n = 55 female) were included in this review. Practicing a diet low in short-chain, poorly absorbed carbohydrates, known as fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs), as well as employing repetitive gut challenges of carbohydrates, remain the most promising of strategies for exercise-induced gastrointestinal symptom management. (4) Conclusion: Avoiding high-FODMAP foods and practicing repetitive gut challenges are promising methods to manage gastrointestinal symptoms. However, sample sizes are often small and lack supportive power calculations.

A personalized management approach in disorders of the irritable bowel syndrome spectrum

Symptoms of the disorders across the irritable bowel syndrome (IBS) spectrum include several different, usually postprandial, abdominal complaints. Up to date, dietary treatments of the IBS have neither been personalized nor diagnosed with sufficient scientific evidence. They have mostly been treated using 'one-size-fits-all' approaches. Such include exclusion diets, a low fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet, and gluten-free diets, lactose-free diets, a diet recommended by the UK National Institute for Health and Care Excellence, and a wheat-free diet. The exact pathophysiology of IBS disorders across the spectrum is still unclear. However, the symptom profile of IBS spectrum disorders seems similar to that of food intolerance/malabsorption syndromes. Celiac disease, fructose malabsorption, histamine intolerance and lactose intolerance represent food intolerance/malabsorption disorders based on the indigestion of sugars and/or proteins. Helicobacter pylori infection may potentially promote the development of IBS and, when facing a case of IBS-like symptoms, a search for intolerance/malabsorption and H. pylori should be added to find the correct treatment for the respective patient. This review will discuss why the 'one-size-fits-all' dietary approach in the treatment of complaints across the IBS spectrum cannot be successful. Hence, it will provide an overview of the most common overall dietary approaches currently used, and why those should be discouraged. Alternatively, a noninvasive diagnostic workup of the pathophysiologic factors of food intolerance/malabsorption in each patient with symptoms of the IBS spectrum is suggested. Additionally, if H. pylori is found, eradication therapy is mandatory, and if food intolerance/malabsorption is detected, an individual and personalized dietary intervention by a registered dietician is recommended.

The Effects of Agave Fructans in a Functional Food Consumed by Patients with Irritable Bowel Syndrome with Constipation: A Randomized, Double-Blind, Placebo-Controlled Trial

Irritable bowel syndrome displays three different subtypes: constipation (IBS-C), diarrhea (IBS-D), and mixed (IBS-M). Treatment with dietary fiber is used, with consideration given both to the chemical composition of the fiber and to the different subtypes of IBS. The IBS-D subtype is usually treated with a low-FODMAPs diet, whereas the IBS-C subtype suggests prebiotics and probiotics to promote microbiota restoration. The aim of this study was to assess the effects of employing agave fructans as the soluble fiber of a jelly (Gelyfun®gastro) containing 8 g per serving in the IBS-C group (n = 50), using a randomized, double-blind, time-limited trial for four weeks. We evaluated changes in the frequency and types of bowel movements through the Bristol scale, and the improvement of the condition was evaluated using quality of life (IBS-QOL) and anxiety-depression (HADS) scales. The main results were that the number of bowel movements increased by more than 80%, with at least one stool per day from fifteen days onwards, without a laxative effect for the group treated. Finally, the quality of life with the prebiotic jelly was significantly improved compared to the placebo in all specific domains, in addition to significantly reducing anxiety and depression.

Diet-microbiota interaction in irritable bowel syndrome: looking beyond the low-FODMAP approach

BACKGROUND

Diet is one of the main modulators of the gut microbiota, and dietary patterns are decisive for gut-microbiota-related diseases, including irritable bowel syndrome (IBS). The low-FODMAP diet (LFD) is commonly used to treat IBS, but its long-term effects on microbiota, symptoms and quality of life (QoL) are unclear. Alternative dietary strategies promoting beneficial gut microbiota, combined with reduced symptoms and improved QoL, are therefore of interest.

AIMS

To review current evidence on the diet-microbiota-interaction as a modulator of IBS pathophysiology, and dietary management of IBS, with particular emphasis on strategies targeting the gut microbiota, beyond the LFD.

METHODS

Literature was identified through PubMed-searches with relevant keywords.

RESULTS

Dietary patterns with a low intake of processed foods and a high intake of plants, such as the Mediterranean diet, promote gut microbiota associated with beneficial health outcomes. In contrast, Western diets with a high intake of ultra-processed foods promote a microbiota associated with disease, including IBS. Increasing evidence points towards dietary strategies consistent with the Mediterranean diet being equal to the LFD in alleviating IBS-symptoms and having a less negative impact on QoL. Timing of food intake is suggested as a gut microbiota modulator, but little is known about its effects on IBS.

CONCLUSIONS

Dietary recommendations in IBS should aim to target the gut microbiota by focusing on improved dietary quality, considering the impact on both IBS-symptoms and QoL. Increased intake of whole foods combined with a regular meal pattern and limitation of ultra-processed foods can be beneficial strategies beyond the LFD.

The Efficacy of a Diet Low in Fermentable Oligo-, Di-, Monosaccharides, and Polyols in Irritable Bowel Syndrome Compared to Its "Real-world" Effectiveness: Protocol for a Systematic Review

BACKGROUND

Irritable bowel syndrome (IBS) is associated with various gastrointestinal and nongastrointestinal symptoms and reduced quality of life. A diet low in fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs) is one therapeutic option for IBS. Although the efficacy of the low FODMAP diet has been reported in several systematic reviews, the efficacy-effectiveness gap of the low FODMAP diet has not yet been assessed.

OBJECTIVE

This systematic review aims to compare the efficacy of the low FODMAP diet from efficacy randomized controlled trials (RCTs) with the effectiveness of studies conducted in "real-world" settings.

METHODS

RCTs, prospective and retrospective cohort studies, and retrospective audits assessing the low FODMAP diet in adults with IBS will be searched in 4 databases: Embase, MEDLINE, CENTRAL, and CINAHL. Two independent reviewers will perform study selection, data extraction, and risk of bias assessment and assess selected quality aspects from the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) protocol. Outcomes assessed are stool frequency, stool consistency, abdominal pain, overall symptom scores, adequate symptom relief, IBS-specific quality of life, and diet adherence. Data will be summarized with forest plots without summary statistics, tables, and narrative descriptions.

RESULTS

The search, title and abstract screening, and full-text screening were completed in March 2021, and an updated search was done in May 2022. As of May 2023, data analysis is almost finished, and manuscript writing is in progress. Submission of the manuscript is expected by July 2023.

CONCLUSIONS

The findings of this systematic review will compare the efficacy of the low FODMAP diet for IBS found in RCTs to the diet's real-world effectiveness.

TRIAL REGISTRATION

PROSPERO CRD42021278952; https://tinyurl.com/32jk43ev.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/41399.

The effect of starch- and sucrose-reduced diet accompanied by nutritional and culinary recommendations on the symptoms of irritable bowel syndrome patients with diarrhoea

Background

Irritable bowel syndrome (IBS) is a common gastrointestinal condition which entails a high burden in the quality of life (QoL) of patients. Nutritional interventions have been proposed to alleviate symptoms, since still no effective treatments exist for IBS.

Objectives

Our aim is to analyse the feasibility of the use of starch- and sucrose-reduced diet (SSRD).

Design

In this study, we used a SSRD accompanied by nutritional and culinary recommendations to measure the effects in IBS patients with diarrhoea.

Methods

In all, 34 participants completed a 4-week nutritional intervention based on SSRD. Symptoms, QoL and dietary habits were assessed by several questionnaires that were completed at the beginning, daily, after 2 weeks, at the end, and after 2 months.

Results

85.29% of the participants reached the primary endpoint [reduction of 50 points or more in IBS-symptom severity scale (SSS)], and 58.82% the secondary endpoint (reduction of 50% or more in IBS-SSS). The relief of symptoms and improvement of the QoL were significant after 2 weeks of intervention, at the end and after 2 months. Dietary habits were consistent with the diet and high adherence was achieved.

Conclusions

SSRD and individualized nutritional and culinary guidance improved symptoms and QoL of IBS patients with diarrhoea, with a high adherence.

Irritable Bowel Syndrome and the Gut Microbiome: A Comprehensive Review

Irritable Bowel Syndrome (IBS) is a functional disorder of the gastrointestinal tract characterized by abdominal pain and altered bowel habits. It has a prevalence of 10 to 25% in the United States and has a high disease burden, as evidenced by reduced quality of life, decreased work productivity and increased healthcare utilization and costs. IBS has been associated with several intra-intestinal and extra-intestinal conditions, including psychiatric comorbidities. Although the pathophysiology of IBS has not been fully elucidated, it involves dysregulation of communication between the brain and gut (brain–gut axis) which is associated with alterations in intestinal motility, gut permeability, visceral hypersensitivity and gut microbiota composition. The purpose of this article is to review the role the gut microbiota plays in the pathophysiology of IBS, understand factors that affect the gut microbiome and explore the microbiome as a target of treatment.

FODMAP dietary restrictions in the management of children with functional abdominal pain disorders: A systematic review

BACKGROUND

Evidence for the management of pediatric functional abdominal pain disorders (FAPD) is lacking. The aim of this systematic review was to update evidence on the efficacy and safety of implementing low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) dietary restrictions for the management of children with FAPD.

METHODS

The Cochrane Library, EMBASE, and MEDLINE databases were searched up to October 2021 for randomized controlled trials (RCTs) that compared the use of a low-FODMAP diet with any comparator in children aged 3-18 years with FAPD. The primary outcome was abdominal pain intensity.

KEY RESULTS

Five RCTs assessing the effects of a low-FODMAP diet were included. An effect of a low-FODMAP diet on abdominal pain intensity was only found in two trials. In one trial, there was a decrease in abdominal pain intensity on a 0-10 point Visual Analogue Scale (VAS) between low-FODMAP and gastrointestinal protective diet groups after 2 months (mean difference, MD 1.77, 95% confidence interval, CI, 1.23 to 2.31, n = 60). In another trial, there was a difference in abdominal pain intensity during the 3-day intervention between the low-FODMAP and typical Singaporean diet groups (MD -1.36 cm, 95% CI -2.38 to -0.34, n = 10) measured using a 0-10 cm VAS.

CONCLUSIONS & INTERFERENCES

There is insufficient evidence for or against the efficacy and safety of using a low-FODMAP diet for the management of children with FAPD.

Diet for Functional Gastrointestinal Disorders/Disorders of Gut-Brain Interaction

Dietary interventions may alleviate symptoms related to functional gastrointestinal disorders, now termed disorders of gut-brain interaction. We reviewed which interventions have high-quality data to support their use in gastroesophageal reflux disease (GERD), functional dyspepsia (FD), irritable bowel syndrome, and chronic idiopathic constipation.

Review article: exclude or expose? The paradox of conceptually opposite treatments for irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a heterogeneous disorder of gut-brain interaction (DGBI) maintained by interacting biological, psychological, and social processes. Interestingly, there are two contrasting yet evidence-based treatment approaches for reducing IBS symptoms: exclusion diets such as those low in fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) and exposure-based cognitive-behavioural therapy (CBT). Exclusion diets recommend patients avoid foods thought to be symptom-inducing, whereas exposure-based CBT encourages patients to expose themselves to foods.

AIMS

To address the paradox of conceptually opposite exclusion diets and exposure-based CBT for IBS.

METHODS

In this conceptual review, we describe the rationale, practical implementation, evidence base and strengths and weaknesses of each treatment. We conducted up-to-date literature search concerning the low FODMAP diet and CBT, and performed a secondary analysis of a previously conducted trial to illustrate a key point in our review.

RESULTS

The low FODMAP diet has demonstrated efficacy, but problems with adherence, nutritional compromise, and heightened gastrointestinal-specific anxiety raise caution. Exposure-based CBT has demonstrated efficacy with substantial evidence for gastrointestinal-specific anxiety as a key mechanism of action. Mediation analysis also showed that increased FODMAP intake mediated decreased symptom severity in exposure-based CBT. However, there is minimal evidence supporting which treatment "works best for whom" and how these approaches could be best integrated.

CONCLUSIONS

Even though exclusion diets and exposure-based CBT are conceptually opposite, they each have proven efficacy. Clinicians should familiarise themselves with both treatments. Further research is needed on predictors, mechanisms and moderators of treatment outcomes.

Diet and Pediatric Functional Gastrointestinal Disorders in Mediterranean Countries

Background: The increased intake of FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyol) rich foods has been suggested as a possible trigger of functional gastrointestinal disorders (FGIDs). Despite the high FODMAP content, the Mediterranean diet (MD) appears to have beneficial effects on health. Our aim was to evaluate whether the prevalence of FGIDs in different Mediterranean countries may be influenced by FODMAP consumption and adherence to the MD. Methods: A school-based, cross-sectional, multicenter study was performed in six countries in the Mediterranean area: Croatia, Greece, Israel, Italy, Macedonia, and Serbia. Subjects 4-18 years were examined in relation to their eating habits and the presence of FGIDs, using Rome IV criteria, 3-day food diaries and Mediterranean Diet Quality Index in Children and Adolescents (KIDMED) questionnaires. Results: We enrolled 1972 subjects between 4 and 9 years old (Group A), and 2450 subjects between 10 and 18 years old (Group B). The overall prevalence of FGIDs was 16% in Group A and 26% in Group B. FODMAP intake was significantly different among countries for both age groups. In both groups, no significant association was found between FGIDs and FODMAPs. Adherence to the MD in all countries was intermediate, except for Serbia, where it was low. In both groups, we found a statistically significant association between FGIDs and the KIDMED score (Group A: OR = 0.83, p < 0.001; Group B: OR = 0.93, p = 0.005). Moreover, a significant association was found between the KIDMED score and functional constipation (Group A: OR = 0.89, p = 0.008; Group B: OR = 0.93, p = 0.010) and postprandial distress syndrome (Group A: OR = 0.86, p = 0.027; Group B: OR = 0.88, p = 0.004). Conclusions: Our data suggest that the prevalence of FGIDs in the Mediterranean area is not related to FODMAP consumption, whereas adherence to the MD seems to have a protective effect.

Biomolecules from Plant Wastes Potentially Relevant in the Management of Irritable Bowel Syndrome and Co-Occurring Symptomatology

During and following the processing of a plant’s raw material, considerable amounts are wasted, composted, or redistributed in non-alimentary sectors for further use (for example, some forms of plant waste contribute to biofuel, bioethanol, or biomass production). However, many of these forms of waste still consist of critical bioactive compounds used in the food industry or medicine. Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders. The primary treatment is based on symptomatology alleviation and controlled dietary management. Thus, this review aimed to describe the possible relevance of molecules residing in plant waste that can be used to manage IBS and co-occurring symptoms. Significant evidence was found that many forms of fruit, vegetable, and medicinal plant waste could be the source of some molecules that could be used to treat or prevent stool consistency and frequency impairments and abdominal pain, these being the main IBS symptoms. While many of these molecules could be recovered from plant waste during or following primary processing, the studies suggested that enriched food could offer efficient valorization and prevent further changes in properties or stability. In this way, root, stem, straw, leaf, fruit, and vegetable pomaces were found to consist of biomolecules that could modulate intestinal permeability, pain perception, and overall gastrointestinal digestive processes.

Psychological and Nutritional Factors in Pelvic Floor Disorders

This article discusses the role of psychological and nutritional factors in gastrointestinal pelvic floor disorders such as dyssynergic defection and explores the use of multidisciplinary strategies to enhance treatment.

Food intolerances and the small intestine

The article presents an analysis of the literature on food intolerance (FS) associated with the presence in the diet of fermentable oligodimosaccharides and polyols FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols), histamine and food additives. The relationship between FS and insufficient activity of enzymes of the small intestine mucosa, in particular, in patients with irritable bowel syndrome, is discussed. FS often noted in them forces them to strictly adhere to the elimination diet and significantly impair the quality of life due to dissatisfaction with the results of treatment. Analysis of the literature has confirmed in many patients with irritable bowel syndrome an etiotropic relationship with poor food tolerance and dictates the need for randomized studies to further study the pathogenetic mechanisms of increasing food tolerance under the influence of cytoprotective therapy.

Gut bless you: The microbiota-gut-brain axis in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common clinical label for medically unexplained gastrointestinal symptoms, recently described as a disturbance of the microbiota-gut-brain axis. Despite decades of research, the pathophysiology of this highly heterogeneous disorder remains elusive. However, a dramatic change in the understanding of the underlying pathophysiological mechanisms surfaced when the importance of gut microbiota protruded the scientific picture. Are we getting any closer to understanding IBS' etiology, or are we drowning in unspecific, conflicting data because we possess limited tools to unravel the cluster of secrets our gut microbiota is concealing? In this comprehensive review we are discussing some of the major important features of IBS and their interaction with gut microbiota, clinical microbiota-altering treatment such as the low FODMAP diet and fecal microbiota transplantation, neuroimaging and methods in microbiota analyses, and current and future challenges with big data analysis in IBS.

Narrative review: Risk of eating disorders and nutritional deficiencies with dietary therapies for irritable bowel syndrome

BACKGROUND AND AIMS

Dietary treatments are growing in popularity as interventions for chronic digestive conditions. Patients with irritable bowel syndrome (IBS) often change their eating behaviors to mitigate symptoms. This can occur under the direction of their physician, a dietitian, or be self-directed. Poorly implemented and monitored diet treatments occur frequently with considerable risks for negative consequences. We aim to review the literature related to dietary treatments and risks associated with nutritional deficiencies and disordered eating.

METHODS

Searches were conducted from June to December 2020 on PubMed, MEDLINE, EMBASE, DARE and the Cochrane Database of Systematic Reviews using relevant keywords based on the Patient, Intervention, Comparator and Outcome (PICO) format. Studies included both adult and pediatric populations. Results are synthesized into a narrative review.

RESULTS

While dietary approaches are efficacious in many research studies, their translation to clinical practice has been less clear. Patients with IBS are at risk for nutritional deficiencies, disordered eating, increased anxiety, and decreases in quality of life in both adult and pediatric groups.

CONCLUSIONS

Physicians prescribing dietary treatment for IBS should be aware of nutritional and psychological risks and implement mitigation measures. These include using a combination of brief, validated questionnaires and clinical history, and collaboration with registered dietitians and/or psychologists. Recommendations for clinical decisions are provided.

Study of efficacy and mechanism of low FODMAPs diet on diarrhea-type irritable bowel syndrome based on a gut microbiota-dependent metabolite

BACKGROUND

The changes in gut microbiota-dependent metabolites can cause irritable bowel syndrome (IBS). It is important to investigate whether a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) plays a therapeutic role in IBS treatment by affecting the production of phenylalanine (PHE), a gut microbiota-dependent metabolite.

AIM

To investigate the efficacy of a low FODMAPs diet in diarrhea-type irritable bowel syndrome (IBS-D) and its molecular mechanism for regulating GLP-1 secretion by affecting PHE, a gut microbiota-dependent metabolite.

METHODS

Thirty patients who met the Rome IV diagnostic criteria for IBS-D were enrolled and treated with a low FODMAPs diet for 4 wk. Thirty healthy volunteers served as baseline controls. The changes of clinical symptom scores, and serum PHE, GLP-1, and TNF-α, as well as IFN-γ before and after treatment were recorded. In in vitro experiment, different doses of PHE were added into NCI-H716 cells to observe the regulatory effect of PHE on GLP-1.

RESULTS

The clinical symptom scores after treatment in the IBS group were significantly lower than those before treatment (P < 0.0001 & P < 0.001). After treatment, the levels of PHE and GLP-1 increased (P < 0.05), but those of TNF-α and IFN-γ decreased significantly (P < 0.0001 & P < 0.001). No adverse reactions occurred in the IBS group. In in vitro experiment, GLP-1 expression levels were found to rise with increasing PHE concentrations, and 1 mmol/L PHE could significantly increase GLP-1 secretion.

CONCLUSION

Low FODMAPs diet improves the symptoms in IBS-D patients via mechanisms that may be related to the regulation of GLP-1 by affecting PHE and thereby inhibiting the secretion of pro-inflammatory cytokines.

The Emerging Role of Gut Microbiota in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Current Evidence and Potential Therapeutic Applications

The well-known symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) are chronic pain, cognitive dysfunction, post-exertional malaise and severe fatigue. Another class of symptoms commonly reported in the context of ME/CFS are gastrointestinal (GI) problems. These may occur due to comorbidities such as Crohn's disease or irritable bowel syndrome (IBS), or as a symptom of ME/CFS itself due to an interruption of the complex interplay between the gut microbiota (GM) and the host GI tract. An altered composition and overall decrease in diversity of GM has been observed in ME/CFS cases compared to controls. In this review, we reflect on genetics, infections, and other influences that may factor into the alterations seen in the GM of ME/CFS individuals, we discuss consequences arising from these changes, and we contemplate the therapeutic potential of treating the gut to alleviate ME/CFS symptoms holistically.

Why use nutraceutical strategies for the Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a chronic functional bowel disorder, often stress-related, identified by many abdominal symptoms, the most important of which is the chronic visceral abdominal pain. Therefore, IBS commonly impairs the quality of life of patients, moreover it is frequently linked to depressive and anxiety symptoms. The treatment of IBS primarily focuses on symptoms relief. Unfortunately, up to now, no efficacious therapies have been found. Therefore, it would be important to develop new anti-IBS interventions. The aim of this brief review is to summarize the current evidence of nutraceutical supplementation in IBS treatment, with probiotics, prebiotics, synbiotics, butyrate, palmitoylethanolamide and colostrum. Since nutraceutics are over the counter products, the review has the purpose to better inform the medicinal chemist and the practitioner about the possible benefit mechanisms and the many advantages that these therapies offer. All of these compounds present multiple mechanisms of action, such as restoring the physiological microbiota, potentiating gastrointestinal barrier's function, immunomodulatory, anti-inflammatory and antinociceptive activities. From the literature data it results that these compounds are not only capable to improve IBS symptomatology, but mainly display an optimal safety and tolerability profile. Although extensive studies must be carried out to reinforce the evidences from the so far limited clinical trials, the supplementation with these compounds may be useful considering the warnings of prescription medicines for special populations of patients, such as elders, youngsters, or patients who need a combination therapy. Finally, the nutraceutical approach may improve adherence to treatment, given its better acceptance by the patients compared to pharmacological therapy.

A Low-FODMAP Diet Improves the Global Symptoms and Bowel Habits of Adult IBS Patients: A Systematic Review and Meta-Analysis

Background: A low-fermentable oligo-, di-, monosaccharides, and polyols (FODMAP) diet has been reported to be associated with improving the symptoms of irritable bowel syndrome (IBS); however, its efficacy as evaluated by different studies remains controversial. Objective: A systematic review and meta-analysis of randomized controlled trials (RCTs) were conducted to explore the efficacy of a low-FODMAP diet (LFD) in alleviating the symptoms of IBS. Methods: A search of the literature for RCTs that assessed the efficacy of an LFD in treating IBS patients was conducted using the electronic databases PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science. The searches in each database were conducted from the inception of the database to February 2021. Two independent reviewers screened citations and a third reviewer resolved disagreements. Two independent reviewers also performed eligibility assessments and data extraction. The RCTs that evaluated LFDs vs. a normal IBS or usual diet and assessed changes of IBS symptoms were included in the search. Data were synthesized as the relative risk of global symptoms improvement, mean difference of IBS Severity Scoring System (IBS-SSS) score, sub-items of IBS-SSS irritable bowel syndrome-related quality of life (IBS-QOL), hospital anxiety and depression scale (HADS), stool consistency/frequency, and body mass index (BMI) using a random effects model. The risk of bias was assessed using Risk of Bias Tool 2 (RoB 2). The bias of publication was assessed based on Egger's regression analysis. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Results: A total of 2,768 citations were identified. After full-text screening, a total of 10 studies were eligible for the systematic review and were subsequently used to compare an LFD with various control interventions in 511 participants. An LFD was associated with the improvement of global symptoms [n = 420; Risk Ratio (RR) = 1.54; 95% Confidence Interval (CI) 1.18 to 2; I ² = 38%], improvement of stool consistency [n = 434; Mean difference (MD) = -0.25; 95% CI -0.44 to -0.06; I ²= 19%), and a reduction trend of stool frequency (n = 434; MD = -0.28; 95% CI -0.57 to 0.01; I ² = 68%) compared with control interventions. There was no statistically significant change in IBS-QOL (n = 484; MD = 2.77; 95% CI -2 to 7.55; I ² = 62%), anxiety score (n = 150; MD = -0.45; 95% CI -3.38 to 2.49; I ² = 86%), depression score (n = 150; MD = -0.05; 95% CI -2.5 to 2.4; I ² = 88%), and BMI (n = 110; MD = -0.22; 95% CI -1.89 to 1.45; I ² = 14%). The overall quality of the data was "moderate" for "global improvement of IBS symptom," "stool consistency," "stool consistency for IBS with diarrhea (IBS-D)," and "stool frequency for IBS-D," and "low" or "very low" for other outcomes according to GRADE criteria. Conclusion: An LFD is effective in reducing the global symptoms and improving the bowel habits of adult IBS patients. The efficacy for IBS-D patients can also be more pronounced. Systematic Review Registration: CRD42021235843.

The role of visceral hypersensitivity in the pathogenesis of irritable bowel syndrome

This research includes visceral sensitivity and its mechanisms involved in the development of irritable bowel syndrome. Visceral hypersensitivity occupies the key place. The research has the description of etiological factors that form visceral hypersensitivity and also visceral sensitivity instrumental research methods, based on the use of the balloon dilation. The research also has the schemes of drug therapy for irritable bowel syndrome meanwhile the special attention is paid to the possible use of the sorbed probiotics and psychopharmacological drugs.

Dietary modulation of gut microbiota for the relief of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a frequently diagnosed gastrointestinal (GI) disorder characterized by recurrent abdominal pain, bloating, and changes in the stool form or frequency without any structural changes and overt inflammation. It is not a life-threatening condition but causes a considerable level of discomfort and distress. Among the many pathophysiologic factors, such as altered GI motility, visceral hypersensitivity, and low-grade mucosal inflammation, as well as other immunologic, psychologic, and genetic factors, gut microbiota imbalance (dysbiosis), which is frequently found in IBS, has been highlighted as an etiology of IBS. Dysbiosis may affect gut mucosal homeostasis, immune function, metabolic regulation, and even visceral motor function. As diet is shown to play a fundamental role in the gut microbiota profile, this review discusses the influence of diet on IBS occurring through the modulation of gut microbiota. Based on previous studies, it appears that dietary modulation of the gut microbiota may be effective for the alleviation of IBS symptoms and, also an effective IBS management strategy based on the underlying mechanism; especially because, IBS currently has no specific treatment owing to its uncertain etiology.

Low fermentable oligosaccharide, disaccharide, monosaccharide, and polyol diet in patients with diarrhea-predominant irritable bowel syndrome: A prospective, randomized trial

BACKGROUND AND AIM

Low fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) diet improves irritable bowel syndrome (IBS) symptoms. Data on long-term "modified" FODMAP diet are emerging. We aimed to assess efficacy and acceptability of short-term "strict" low FODMAP diet (LFD) and long-term "modified" FODMAP diet in patients with diarrhea-predominant IBS (IBS-D).

METHODS

This prospective randomized trial included patients with IBS-D (Rome IV) and IBS severity scoring system (IBS-SSS) ≥ 175. In phase I (4 weeks), patients were randomized to strict LFD and traditional dietary advice (TDA) groups. From 4 to 16 weeks, LFD group was advised systematic reintroduction of FODMAPs ("modified" FODMAP diet). Response was defined as > 50-point reduction in IBS-SSS.

RESULTS

Of the total 166 patients with IBS-D screened, 101 (mean age 41.9 ± 17.1 years, 58% male) were randomized to LFD (n = 52) and TDA (n = 49) groups. Both at 4 and 16 weeks, total IBS-SSS and IBS quality of life score reduced significantly in both groups, but there was significantly greater reduction in LFD group. By intention-to-treat analysis, responders in LFD group were significantly higher than TDA group (4 weeks-62.7% [32/51] vs 40.8% [20/49], respectively, P = 0.0448; 16 weeks-52.9% [27/51] vs 30.6% [15/49], respectively; P = 0.0274). Compliance to LFD was 93% at 4 weeks and 64% at 16 weeks. Energy, carbohydrate, fat, and fiber intake showed reduction in LFD group at 4 weeks, which improved till 16 weeks.

CONCLUSIONS

Strict LFD for short-term and "modified" LFD for long term in IBS-D patients is acceptable and leads to significant improvement in symptoms and quality of life.

Irritable bowel syndrome in midlife women: a narrative review

Midlife women between the ages of 40 and 65 years have reported multiple challenges due to menopausal, developmental, and situational transitions from younger to older adulthood. During the midlife period, many women seek health care for gastrointestinal symptoms and irritable bowel syndrome (IBS). Multiple factors including stress, poor sleep, diet, and physical inactivity may contribute to IBS or gastrointestinal symptoms in midlife women. As such, a comprehensive assessment and treatment approach is needed for midlife women suffering gastrointestinal symptoms. This article reviews the main aspects of the menopausal transition, sex hormonal changes, abdominal and pelvic surgery, psychosocial distress, behavioral factors, and gut microbiome, as well as their relevance on IBS and gastrointestinal symptoms in midlife women. Also, management strategies for IBS in midlife women are discussed. To date, gastrointestinal symptoms during midlife years remain a critical area of women’s health. Additional research is needed to better understand the contributors to gastrointestinal symptoms in this group. Such efforts may provide a new window to refine or develop treatments of gastrointestinal symptoms for midlife women.

A Low-FODMAP Diet in the Management of Children With Functional Abdominal Pain Disorders: A Protocol of a Systematic Review

The available interventions for the management of children with functional abdominal pain disorders (FAPD) are limited. A diet low in fermentable oligosaccharides, disaccharides monosaccharides, and polyols (FODMAPs) is widely used in adults and children with FAPD, despite limited available evidence. We aim to systematically review evidence on the efficacy and safety of using a low-FODMAP diet for the management of children with FAPD.

Methods

The Cochrane Library, EMBASE, and MEDLINE databases will be searched for randomized controlled trials (RCTs) that compare the use a low-FODMAP diet (preferably a 3-step low-FODMAP diet but also only a strict low-FODMAP diet or restriction of individual FODMAPs) with any comparator (i.e., standardized [i.e., average national] or other diet or no intervention) in children with FAPD (regardless of the definition). Each FAPD and each low-FODMAP diet or individual FODMAP restriction will be assessed separately. The Cochrane Collaboration's tool for assessing the risk of bias will be used. The primary outcome will be the abdominal pain intensity. The secondary outcomes will be abdominal pain frequency, stool consistency, other gastrointestinal symptoms, school performance, and psychological functioning associated with FAPD, parent's work absenteeism associated with FAPD of a child, health-related quality of life, compliance, growth, and adverse events. The findings will be published in a peer-reviewed journal and submitted to relevant conferences.

Conclusion

This systematic review of rigorous methodological design will update current evidence on the efficacy and safety of using a low-FODMAP diet. However, it may be limited by the quality of the included studies.

What Are the Pearls and Pitfalls of the Dietary Management for Chronic Diarrhoea?

Chronic diarrhoea affects up to 14% of adults, it impacts on quality of life and its cause can be variable. Patients with chronic diarrhoea are presented with a plethora of dietary recommendations, often sought from the internet or provided by those who are untrained or inexperienced. In this review, we summarise the possible causes of chronic diarrhoea that can be managed by diet, the symptom improvement and quality of life benefits but also the potential risks of such dietary treatments. Clinicians need to consider both the benefits and risks of dietary treatments before making dietary recommendations to manage chronic diarrhoea. The pivotal role that dietitians have in ensuring optimal symptom improvement without jeopardising nutritional and overall health is discussed.

Dietary interventions and irritable bowel syndrome - what really works?

PURPOSE OF REVIEW

The review examines the latest research on the use of dietary interventions in the management of irritable bowel syndrome (IBS) in order to understand what is the evidence supporting the efficacy of a dietary approach in this disorder.

RECENT FINDINGS

A general dietary advice should be offered to all IBS patients. Psyllium supplementation is recommended in IBS with both constipation and diarrhea predominance. There is increasing evidence showing the beneficial effects of a low fermentable oligo-, di-, monosaccharides, and polyols (FODMAP) diet (LFD) on IBS symptoms. FODMAPs that are well tolerated should be reintroduced in daily diet, to increase acceptability of the diet, and limit potentially harmful effects. The benefits observed with the gluten-free diet seem determined by the reduction of FODMAPs rather than gluten. Modulation of gut microbiota using probiotics shows promising results, but there are unanswered questions regarding the optimal strains, dose and duration of treatment. Additional evidence is also needed for the role of prebiotics and synbiotics in IBS.

SUMMARY

Food is both trigger of IBS symptoms and therapeutic tool. Recent studies demonstrated the beneficial effects of LFD on symptom control, as well as the role of probiotics, which seem to contribute to gut health and function.

Impact of diet and the bacterial microbiome on the mucous barrier and immune disorders

The prevalence of chronic immune and metabolic disorders is increasing rapidly. In particular, inflammatory bowel diseases, obesity, diabetes, asthma and chronic obstructive pulmonary disease have become major healthcare and economic burdens worldwide. Recent advances in microbiome research have led to significant discoveries of associative links between alterations in the microbiome and health, as well as these chronic supposedly noncommunicable, immune/metabolic disorders. Importantly, the interplay between diet, microbiome and the mucous barrier in these diseases has gained significant attention. Diet modulates the mucous barrier via alterations in gut microbiota, resulting in either disease onset/exacerbation due to a "poor" diet or protection against disease with a "healthy" diet. In addition, many mucosa-associated disorders possess a specific gut microbiome fingerprint associated with the composition of the mucous barrier, which is further influenced by host-microbiome and inter-microbial interactions, dietary choices, microbe immigration and antimicrobials. Our review focuses on the interactions of diet (macronutrients and micronutrients), gut microbiota and mucous barriers (gastrointestinal and respiratory tract) and their importance in the onset and/or progression of major immune/metabolic disorders. We also highlight the key mechanisms that could be targeted therapeutically to prevent and/or treat these disorders.

Efficacy of a low-FODMAP diet in adult irritable bowel syndrome: a systematic review and meta-analysis

Purpose

This review provides an updated overview of observational and intervention studies investigating the effect of a low-FODMAP (fermentable oligo-, di- and monosaccharides, and polyols) diet (LFD) on gastrointestinal (GI) symptoms, quality of life (QoL), nutritional adequacy, and gut microbiome in irritable bowel syndrome (IBS) patients.

Methods

We systematically searched available literature until October 2020 for studies that investigated the effect of LFDs on GI symptoms, QoL, nutritional adequacy, and the gut microbiome in IBS patients. The data were represented as standardized mean differences (SMD) for IBS severity, and as mean differences (MD) for IBS-QoL. Meta-analyses were performed for the quantitative analyses using random effects models with inverse variance weighing.

Results

Twelve papers (nine parallel trials, three crossover studies) were included for the meta-analysis. The LFD reduced IBS severity by a moderate-to-large extent as compared to a control diet (SMD − 0.66, 95% CI − 0.88, − 0.44, I² = 54%). When analyzing only studies that used the validated IBS-SSS questionnaire, a mean reduction of 45 points (95% CI − 77, − 14; I² = 89%) was observed. Subgroup analyses on adherence, age, intervention duration, IBS subtype, outcome measure, and risk of bias revealed no significantly different results. The LFD also increased IBS-QoL scores, when compared with a control diet (MD 4.93; 95% CI 1.77, 8.08; I² = 42%).

Conclusions

The low-FODMAP diet reduces GI symptoms and improves quality of life in IBS subjects as compared to control diets. Future work is required to obtain definitive answers regarding potential long-term effects of such diets on nutritional adequacy and the gut microbiome.

PROSPERO registration number

CRD42020175157.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-020-02473-0.

FODMAP intake in children with coeliac disease influences diet quality and health-related quality of life and has no impact on gastrointestinal symptoms

Children with coeliac disease (CD) following the gluten-free diet may experience ongoing gastrointestinal symptoms despite strict adherence. The study objective was to evaluate the association between foods high in fermentable oligo/di/monosaccharides, and polyols (FODMAP) and gastrointestinal symptoms, and the potential implications to diet quality and health-related quality of life in CD children. Dietary intake was studied in age-sex matched children 5-18 years (CD, n = 46; non-coeliac mild chronic gastrointestinal complaints [GIC], n = 46; healthy controls [HC], n = 46). CD children consumed fewer foods high in FODMAPs compared to GIC and HC (p < .0001). FODMAP intake was not related to gastrointestinal symptoms in CD children (p > 0.05) but was positively associated with child health-related quality of life (p < 0.05). FODMAP intake from fruits and vegetables was positively associated with diet adequacy and total diet quality in CD children (p < 0.05). FODMAP intake may influence diet quality and health-related quality of life but has no impact on gastrointestinal symptoms in CD children.

Dietary Patterns in Runners with Gastrointestinal Disorders

Individuals with inflammatory bowel disease (IBD), irritable bowel syndrome (IBS) and reflux frequently experience gastrointestinal symptoms (GIS), potentially enhanced by high-intensity running. Food avoidances, food choices, and GIS in runners with IBS/IBD (n = 53) and reflux (n = 37) were evaluated using a reliability and validity tested questionnaire. Comparisons to a control group of runners (n = 375) were made using a Fisher’s Exact test. Runners with IBS/IBD experienced the greatest amount of exercise-induced GIS followed by those with reflux. Commonly reported GIS were stomach pain/cramps (77%; 53%), bloating (52%; 50%), intestinal pain/cramps (58%; 33%), and diarrhea (58%; 39%) in IBS/IBD and reflux groups respectively. In the pre-race meal, those with IBS/IBD frequently avoided milk products (53%), legumes (37%), and meat (31%); whereas, runners with reflux avoided milk (38%), meat (36%), and high-fibre foods (33%). When considering food choices pre-race, runners with IBS/IBD chose grains containing gluten (40%), high fermentable oligo-, di-, mono-saccharides and polyols (FODMAP) fruits (38%), and water (38%). Runners with reflux chose water (51%), grains containing gluten (37%), and eggs (31%). In conclusion, while many runners with IBS/IBD and reflux are avoiding trigger foods in their pre-race meals, they are also consuming potentially aggravating foods, suggesting nutrition advice may be warranted.

Effect of a low-FODMAP diet for the management of functional abdominal pain disorders in children: a study protocol for a randomized controlled trial

Background

Evidence from studies in adults documents that fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) may be triggers of symptoms in individuals with functional abdominal pain disorders (FAPDs). However, in children, the evidence is very limited. We aim to assess the effects of a low-FODMAP diet compared with a regular diet for the management of children with FAPDs.

Methods

We will perform a randomized, quadruple-blinded, controlled trial. Seventy-four children aged 8 to 18 years with a FAPD (Irritable Bowel Syndrome or Functional Abdominal Pain-Not Otherwise Specified), diagnosed according to the Rome IV criteria, will be randomly allocated to receive either a low-FODMAP diet or a regular diet for 4 weeks. The primary outcome will be the percentage of the responders, defined as the participants who have at least 30% improvement in abdominal pain intensity on a Visual Analogue Scale (VAS) during the last week of the trial compared with baseline, that is at least equal to the Reliable Change Index (≥ 25 mm change on VAS). Other outcomes will include changes in stool consistency, abdominal pain frequency, total scores on the Gastrointestinal Symptom Rating Scale, KIDSCREEN-10 Index and World Health Organization Five Well-Being Index, child’s school attendance and parents’ work absenteeism, and BMI-for-age z-score. Compliance, tolerability of the low-FODMAP diet, and adverse events also will be evaluated. Each FAPD subtype will be assessed separately.

Discussion

There is a need for high-quality evidence regarding the dietary management of children with FAPDs. This randomized controlled trial (RCT) of rigorous methodological design will help to establish the effectiveness, if any, of a low-FODMAP diet for the management of FAPDs in the pediatric population. The findings of this RCT will assist with the development of guidelines and influence the direction of further research.

Trial registration

NCT04528914

Data and protocol version identifier: 24/08/2020

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-020-00656-3.

Behavioral and Diet Therapies in Integrated Care for Patients With Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common, symptom-based condition that has negative effects on quality of life and costs health care systems billions of dollars each year. Until recently, management of IBS has focused on over-the-counter and prescription medications that reduce symptoms in fewer than one-half of patients. Patients have increasingly sought natural solutions for their IBS symptoms. However, behavioral techniques and dietary modifications can be effective in treatment of IBS. Behavioral interventions include gastrointestinal-focused cognitive behavioral therapy and gut-directed hypnotherapy to modify interactions between the gut and the brain. In this pathway, benign sensations from the gut induce maladaptive cognitive or affective processes that amplify symptom perception. Symptoms occur in response to cognitive and affective factors that trigger fear of symptoms or lack of acceptance of disease, or from stressors in the external environment. Among the many dietary interventions used to treat patients with IBS, a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols is the most commonly recommended by health care providers and has the most evidence for efficacy. Patient with IBS who choose to follow a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols should be aware of its 3 phases: restriction, reintroduction, and personalization. Management of IBS should include an integrated care model in which behavioral interventions, dietary modification, and medications are considered as equal partners. This approach offers the greatest likelihood for success in management of patients with IBS.

A systematic review of the association between fibromyalgia and functional gastrointestinal disorders

BACKGROUND

Fibromyalgia and functional gastrointestinal disorders (FGID) including irritable bowel syndrome (IBS) are common conditions presenting in clinical settings and are more prevalent in women. While the relationship between IBS and fibromyalgia has been demonstrated, a review of the prevalence of the broader group of FGID in adults with fibromyalgia has not been undertaken. The aim of this review was to systematically review the published literature, identifying the comorbidity of FGID in people with fibromyalgia, and to discuss the clinical implications, limitations of current research and areas of interest for future research.

METHODS

Medline, Embase, CINAHL and Web of Science were searched during June 2019. Results were screened for original research articles meeting established criteria for identification of FGID in adults diagnosed with fibromyalgia.

RESULTS

A total of 14 studies involving 1340 adults with fibromyalgia, 363 healthy controls and 441 adults with other pathologies were included in this review. Only 1 of the 14 studies included surveyed the full range of FGID . Functional gut disorders were matched to Rome II criteria for reporting and comparison. In addition to increased abdominal pain and functional bloating or gas, IBS of mixed-pattern and constipation-types appear to be more prevalent than diarrhoea-predominant IBS in adults with fibromyalgia.

CONCLUSION

This review confirms previous reports that IBS is common in people living with fibromyalgia and suggests that IBS-mixed and constipation types predominate. An association with a range of FGID other than IBS is suggested, but data are limited. Research exploring the association between fibromyalgia and functional gastrointestinal dysfunction beyond IBS are warranted.

Nutritional Composition of Gluten-Free Labelled Foods in the Slovenian Food Supply

The market of gluten-free (GF) foods has been expanding in recent years. GF foods are consumed not only by those with medical predispositions for avoiding gluten, but also by a specific segment of consumers, searching for “healthier” food choices. For these, such practices can present a serious limitation in the variability of food choices. Considering that GF foods are commonly perceived as healthier alternatives, there is a lack of knowledge on the nutritional profile and content of specific nutrients of GF-labelled foods compared to general food supply. A comparison of nutritional composition of GF/non-GF packed foods in the Slovenian food supply was conducted. The nutrient profiling scoring criterion (NPSC) and content of specific nutrients/energy was compared between GF-labelled and regular foods. The highest proportion of GF-labelled products were found in food categories, which typically do not contain gluten (Cheese imitates, Milk imitates, Yoghurt imitates, Canned fish and seafood and Processed meat). Significant differences in the nutrient profile between GF-labelled and regular products were found in Cakes, muffins and pastry, Crisps and snacks, Desserts and Milk imitates. GF-labelled foods often had lower protein and sugar content. Energy value was comparable in most categories and no significant differences in salt content were found, compared to non-GF products. In conclusion, GF-labelled foods will unlikely bring health benefits to those who are not medically required to follow GF diet. Public health initiatives should aim towards promotion of consuming non-processed foods and provision of reliable information about who is required to consume GF foods.

Parental Opinion about the Low FODMAP Diet in Dietary Treatment of Children with Functional Abdominal Pain

The aim of this study was primarily to evaluate differences between parental opinion about the diet and overall changes in children’s symptoms of functional abdominal pain (FAP) during the low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet and National Institute for Health and Care Excellence (NICE) diet. Secondly, this paper examined the agreement between parental perception of children’s symptoms and children’s self-assessment of symptoms during the diet in both treatment groups. Twenty-seven children with diagnosed functional abdominal pain (FAP) were randomized to one of two group, receiving the low FODMAP diet or the diet based on NICE guidelines. Children reported gastrointestinal symptoms at baseline and during the diet. At the end of the intervention, parents assessed their children’s diet and symptoms changes, using Likert scales. The agreement between parental and children assessments of gastrointestinal symptoms was defined as the percentage of compatible answers. In the low FODMAP group a significantly lower percentage of parents (38%) declared that it was easy to follow the diet, compared to the NICE group (57%), (p = 0.017). A high percentage of parents in both groups reported improvement in all symptoms of children during dietary intervention. A high level of agreement was also observed between parental and children’s self-assessment of abdominal pain intensity and frequency. Our research suggests that in parental opinion the low FODMAP diet is as effective as the diet based on NICE guidelines in children with FAP. However, the low FODMAP diet may seem more difficult to follow, and this may have had an impact on the effectiveness and acceptability of the FODMAP diet by children.