British Society of Gastroenterology guidelines on the management of irritable bowel syndrome

Managing pain in irritable bowel syndrome: current perspectives and best practice

INTRODUCTION

Irritable bowel syndrome (IBS) is characterized by chronic symptoms (>6 months) of abdominal pain in combination with a disturbed bowel habit. There is an association between the intensity of abdominal pain and the need for health care utilization. A bidirectionally disordered gut-brain interaction is central in the pathophysiology of IBS where a number of factors, gastrointestinal and non-gastrointestinal, can contribute to the illness experience. In order to treat abdominal pain in IBS, mapping these factors in a multidimensional clinical profile is helpful.

AREAS COVERED

This review covers basic epidemiology and pathophysiology of abdominal pain in IBS, the diagnostic approach, and a multidimensional treatment model where the management of abdominal pain is in focus.

EXPERT OPINION

A personalized treatment of abdominal pain in IBS is possible in patients who understand the diagnosis, the potential of therapies used, and where a good continuity in the patient-doctor relationship is established.

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.

Irritable bowel syndrome - controversies in diagnosis and management

INTRODUCTION

The irritable bowel syndrome (IBS) is the best-recognized disorder of gut brain interactions (DGBI). However, it is controversial if the Rome IV criteria iteration for IBS diagnosis is fit for purpose.

AREAS COVERED

This review critically evaluates Rome IV criteria for diagnosis of IBS and addresses clinical considerations in IBS treatment and management, including dietary factors, biomarkers, disease mimics, symptom severity, and subtypes. The role of diet in IBS is critically reviewed along with the influence of the microbiota, including small intestinal bacterial overgrowth.

EXPERT OPINION

Emerging data suggest the Rome IV criteria are more suitable for identifying severe IBS and least useful for sub-diagnostic patients who are still likely to benefit from IBS treatment. Despite convincing evidence that IBS symptoms are diet-driven and often postprandial, a relationship to eating is not a Rome IV diagnostic criterion. Few IBS biomarkers have been identified, suggesting the syndrome is too heterogeneous to be measured by a single marker, and combined biomarker, clinical, dietary, and microbial profiling may be needed for objective characterization. With many organic diseases mimicking and overlapping with IBS, it's important clinicians are knowledgable about this to mitigate the risk of missing comorbid organic intestinal disease and to optimally treat IBS symptoms.

Gut Symptoms during FODMAP Restriction and Symptom Response to Food Challenges during FODMAP Reintroduction: A Real-World Evaluation in 21,462 Participants Using a Mobile Application

BACKGROUND

There is limited evidence regarding the use of low FODMAP diet apps. This study aimed to evaluate the effectiveness of an app intended to reduce symptoms in FODMAP restriction and symptoms and tolerance of high FODMAP food challenges during FODMAP reintroduction and personalisation.

METHODS

Data were collected from 21,462 users of a low FODMAP diet app. Self-reported gut symptoms during FODMAP restriction, reintroduction, and personalisation and dietary triggers were identified from symptom response data for FODMAP food challenges.

RESULTS

Compared with baseline, at the end of FODMAP restriction, participants (n = 20,553) reported significantly less overall symptoms (11,689 (57%) versus 9105 (44%)), abdominal pain (8196 (40%) versus 6822 (33%)), bloating (11,265 (55%) versus 9146 (44%)), flatulence (10,318 (50%) 8272 (40%)), and diarrhoea (6284 (31%) versus 4961 (24%)) and significantly more constipation (5448 (27%) versus 5923 (29%)) (p < 0.001 for all). During FODMAP reintroduction, participants (n = 2053) completed 8760 food challenges; the five most frequent challenges and n/N (%) of dietary triggers identified were wheat bread 474/1146 (41%), onion 359/918 (39%), garlic 245/699 (35%), milk 274/687 (40%), and wheat pasta 222/548 (41%). The most frequently reported symptoms during food challenges were overall symptoms, abdominal pain, bloating, and flatulence.

CONCLUSIONS

In a real-world setting, a low FODMAP diet app can help users improve gut symptoms and detect dietary triggers for long-term self-management.

Tenapanor in the Treatment of Irritable Bowel Syndrome with Constipation: Discovery, Efficacy, and Role in Management

Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction (DGBI). IBS significantly impacts the quality of life of patients. Since its pathogenesis is unclear and can be multifactorial, it highlights the need for new and improved pharmaceutical drugs that not only improve bowel symptoms, but also address global IBS symptoms, such as abdominal pain. Tenapanor, a recently Food & Drug Administration (FDA)-approved medication for IBS with constipation (IBS-C), is a small molecule inhibitor of the sodium/hydrogen exchanger isoform 3 (NHE₃) that inhibits the absorption of sodium and phosphate in the gastrointestinal tract, resulting in fluid retention and softer stool. Furthermore, tenapanor reduces intestinal permeability to improve visceral hypersensitivity and abdominal pain. Due to its recent approval, tenapanor was not included in the recent IBS guidelines, however, it may be considered for IBS-C patients failing first-line treatment of soluble fiber. In this review article, we aim to provide in-depth information to the reader regarding the design of tenapanor, its development through Phase I, II and III randomized clinical trials, and its role in the treatment of IBS-C.

Updates in the diagnosis and management of coeliac disease

Coeliac disease is a common autoimmune disorder induced by ingesting gluten, the protein component of wheat, barley, and rye. It is estimated that one-in-hundred people worldwide have coeliac disease, of whom the majority remain undiagnosed. Coeliac disease is characterized by a wide range of gastrointestinal and extraintestinal symptoms but can also present asymptomatically. Diagnosing coeliac disease depends on the concordance of clinical, serological and histopathological data. However, the diagnosis can be challenging and frequently overlooked. Undiagnosed coeliac disease is associated with an increased risk of complications and detrimental effects on quality of life. Early diagnosis and treatment of coeliac disease are necessary to reduce the risk of long-term complications.

The prevalence and burden of Rome IV bowel disorders of gut brain interaction in patients with non-alcoholic fatty liver disease: a cross-sectional study

Rome IV bowel disorders of gut brain interaction (DGBI) and non-alcoholic fatty liver disease (NAFLD) are highly prevalent entities with overlapping pathophysiology and risk factors. We aimed to evaluate the prevalence and burden of Rome IV irritable bowel syndrome (IBS) in patients with NAFLD. Patients diagnosed with NAFLD were recruited from a specialist liver clinic. All participants completed assessments to determine liver fibrosis severity, including liver stiffness measurement (LSM), completed the Rome IV diagnostic questionnaire for bowel disorders of gut brain interaction, the IBS symptom severity score (IBS-SSS), and the EQ-5D-5L to measure of quality-of-life (QoL). 142 patients with NAFLD (71 (50%) female, mean age 53.5 (SD ± 14.9), BMI 35.2 (SD ± 8.1) kg/M²) were recruited. 79 (55.6%) patients met criteria for a Rome IV bowel DGBI, including 50 patients (35.2%) who met the criteria for IBS (mean IBS-SSS 277.2 (SD ± 131.5)). There was no difference in liver fibrosis scores between those with and without Rome IV IBS (FIB-4 scores p = 0.14, LSM p = 0.68). Patients with NAFLD and Rome IV IBS had significantly worse QoL scores (EQ-VAS p = 0.005 and EQ-5D-5L index p = 0.0007), impairment of usual activities of daily living (p = 0.012) and were more likely to report anxiety or depression (p = 0.038). Rome IV bowel DGBI such as IBS are highly prevalent in patients with NAFLD attending liver clinics and are associated with impaired QoL and psychosocial distress.

Microbial inulinase promotes fructan hydrolysis under simulated gastric conditions

Fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) have emerged as key contributors to digestive discomfort and intolerance to certain vegetables, fruits, and plant-based foods. Although strategies exist to minimize FODMAP consumption and exposure, exogenous enzyme supplementation targeting the fructan-type FODMAPs has been underexploited. The objective of this study was to test the hydrolytic efficacy of a food-grade, non-genetically engineered microbial inulinase preparation toward inulin-type fructans in the INFOGEST in vitro static simulation of gastrointestinal (GI) digestion. Purified inulin was shown to undergo acid-mediated hydrolysis at high gastric acidity as well as predominantly inulinase-mediated hydrolysis at lower gastric acidity. Inulinase dose-response simulations of inulin, garlic, and high-fructan meal digestion in the gastric phase suggest that as little as 50 inulinase units (INU) and up to 800 INU per serving promote fructan hydrolysis better than the control simulations without inulinase. Liquid chromatography-mass spectrometry (LC-MS) profiling of fructo-oligosaccharides (FOS) in the gastric digestas following inulinase treatment confirms the fructolytic activity of inulinase under simulated digestive conditions. Altogether, these in vitro digestion data support the use of microbial inulinase as an exogenous enzyme supplement for reducing dietary fructan-type FODMAP exposure.

Feasibility, and barriers to use escitalopram in functional gastrointestinal disorders

Background and study aims: The feasibility and barriars of escitalopram use in patients with functional gastrointestinal disorders (FGIDs) are still debated. We aimed to evaluate the feasibility, safety and efficacy and barriars of escitalopram use in managing FGIDs in the Saudi population. Patients and Methods: We included 51 patients who received escitalopram for irritable bowel syndrome (n = 26), functional heartburn (n = 10), globus sensation (n = 10) or combined disorders (n = 5). We used an irritable bowel syndrome-severity scoring system IBS-SSS), GerdQ questionnaire and Glasgow Edinburg Throat Scale (GETS) to assess disease severity change before and after treatment. Results: The median age was 33 years (25th- 75th percentiles: 29-47), and 26 (50.98%) were males. Forty-one patients experienced side effects (80.39%), but most side effects were mild. The most common side effects were drowsiness/fatigue/dizziness (54.9%), xerostomia (23.53%), nausea/vomiting (21.57%) and weight gain (17.65%). IBS-SSS was 375 (255-430) and 90 (58-205) before and after treatment, respectively (p < 0.001). GerdQ score was 12 (10-13) before treatment and 7 (6-10) after treatment (p = 0.001). GETS score before treatment was 32.5 (21-46) and after treatment became 22 (13-31) (p = 0.002). Thirty-five patients refused to take the medications, and seven patients discontinued the medication. Possible causes of the poor compliance were fear of the medications and not being convinced of taking psychiatric medications for functional disorders (n = 15). Conclusion: Escitalopram could be a safe and effective treatment for functional gastrointestinal disorders. Targeting and managing factors leading to poor compliance could further improve the treatment outcome.

Fecal microbiota transplantation for irritable bowel syndrome: a systematic review and meta-analysis of randomized controlled trials

Objective

Whether fecal microbiota transplantation (FMT) in patients with irritable bowel syndrome (IBS) is effective in improving outcomes remains controversial. We assessed the safety and efficacy of FMT for patients with IBS.

Methods

In this systematic review and meta-analysis, we searched PubMed, Embase, Web of Science, the Cochrane Library, the clinicaltrials.gov and International Clinical Trials Registry Platform (ICTRP) up to February 25, 2022, updated to March 28, 2023. Randomized controlled trials (RCTs) compared the stool and capsule FMT with placebo in patients with IBS were included. Two authors independently assessed study eligibility, extracted the data, and assessed risk of bias. We did meta-analysis with RevMan, and the Stata software was used for sensitivity analysis and meta-regression. The GRADE system was used to assess the quality of evidences. Mean difference (MD) or standardized Mean difference (SMD) with 95% CI for continuous data, and risk ratios (RR) with 95% CI for dichotomous data were used with random-effects models. The primary outcomes included the clinical response rate and IBS-SSS score. This study is registered with PROSPERO: CRD42022328377.

Results

Nineteen reports from nine RCTs were included finally. Compared with the placebo, a single stool FMT could significantly decrease the IBS-SSS score at 1 month (MD=-65.75, 95%CI [-129.37, -2.13]), 3 months (MD=-102.11, 95% CI [-141.98, -62.24]), 6 months (MD=-84.38, 95%CI [-158.79, -9.97]), 24 months (MD=-110.41, 95%CI [-145.37, -75.46]), and 36 months (MD=-104.71, 95%CI [-137.78, -71.64]). It also could improve the clinical response rate at 3 months (RR=1.91, 95% [1.12, 3.25]), 24 months (RR=2.97, 95% [1.94, 4.54]), and 36 months (RR=2.48, 95% [1.65, 3.72]), and increase the IBS-QoL score at 3 months, 24 months, and 36 months. FMT did not increase the serious adverse event. The risk of bias was low, and the quality of evidence based on GRADE system was moderate in the stool FMT group. However, we did not find positive effect of capsule FMT on patients with IBS based on the current available data.

Conclusion

A single stool FMT is effective and safe for patients with IBS. However, some factors may affect the effectiveness of FMT, and the relationship between the gut microbiome and the effect of FMT for IBS is still unclear.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022328377.

Gut Microbiome-Brain Alliance: A Landscape View into Mental and Gastrointestinal Health and Disorders

Gut microbiota includes a vast collection of microorganisms residing within the gastrointestinal tract. It is broadly recognized that the gut and brain are in constant bidirectional communication, of which gut microbiota and its metabolic production are a major component, and form the so-called gut microbiome-brain axis. Disturbances of microbiota homeostasis caused by imbalance in their functional composition and metabolic activities, known as dysbiosis, cause dysregulation of these pathways and trigger changes in the blood-brain barrier permeability, thereby causing pathological malfunctions, including neurological and functional gastrointestinal disorders. In turn, the brain can affect the structure and function of gut microbiota through the autonomic nervous system by regulating gut motility, intestinal transit and secretion, and gut permeability. Here, we examine data from the CAS Content Collection, the largest collection of published scientific information, and analyze the publication landscape of recent research. We review the advances in knowledge related to the human gut microbiome, its complexity and functionality, its communication with the central nervous system, and the effect of the gut microbiome-brain axis on mental and gut health. We discuss correlations between gut microbiota composition and various diseases, specifically gastrointestinal and mental disorders. We also explore gut microbiota metabolites with regard to their impact on the brain and gut function and associated diseases. Finally, we assess clinical applications of gut-microbiota-related substances and metabolites with their development pipelines. We hope this review can serve as a useful resource in understanding the current knowledge on this emerging field in an effort to further solving of the remaining challenges and fulfilling its potential.

Antibiotics and Probiotics for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a disorder of a gut-brain interaction characterised by abdominal pain and a change in stool form or frequency. Current symptom-based definitions and the classification of IBS promote heterogeneity amongst patients, meaning that there may be several different pathophysiological abnormalities leading to similar symptoms. Although our understanding of IBS is incomplete, there are several indicators that the microbiome may be involved in a subset of patients. Techniques including a faecal sample analysis, colonic biopsies, duodenal aspirates or surrogate markers, such as breath testing, have been used to examine the gut microbiota in individuals with IBS. Because of a lack of a clear definition of what constitutes a healthy gut microbiota, and the fact that alterations in gut microbiota have only been shown to be associated with IBS, a causal relationship is yet to be established. We discuss several hypotheses as to how dysbiosis may be responsible for IBS symptoms, as well as potential treatment strategies. We review the current evidence for the use of antibiotics and probiotics to alter the microbiome in an attempt to improve IBS symptoms. Rifaximin, a non-absorbable antibiotic, is the most studied antibiotic and has now been licensed for use in IBS with diarrhoea in the USA, but the drug remains unavailable in many countries for this indication. Current evidence also suggests that certain probiotics, including Lactobacillus plantarum DSM 9843 and Bifidobacterium bifidum MIMBb75, may be efficacious in some patients with IBS. Finally, we describe the future challenges facing us in our attempt to modulate the microbiome to treat IBS.

Effects of a Low-FODMAP Diet on Irritable Bowel Syndrome in Both Children and Adults-A Narrative Review

Irritable bowel syndrome is a typical gastrointestinal disease that causes bloating, flatulence, abdominal pain, diarrhoea, constipation, or alteration of the last two in adults and children. A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) is one of the potential treatment strategies to reduce abdominal symptoms and increase the quality of life. The present narrative review aims to present a general overview of current studies that have evaluated the efficacy of a low-FODMAP diet against other diets in gastrointestinal symptoms, nutrient intake in adults and children, and lifestyle quality. The research was performed using seven searchable databases, which included the Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews (CDSR), Excerpta Medica Database (EMBASE), Medline, PubMed, Scopus, and Web of Science, up to March 2023. In conclusion, there is significant evidence that the follow-up of a low-FODMAP diet might be a feasible first-line therapeutic strategy to reduce stomach discomfort, pain, bloating, and quality of life for patients with irritable bowel syndrome.

Current evidence for dietary therapies in irritable bowel syndrome

PURPOSE OF REVIEW

Diet appears to trigger symptoms in the majority of individuals with irritable bowel syndrome (IBS) and is associated with a reduced quality of life. There has been a recent focus on the role of dietary therapies to manage individuals with IBS. The aim of this review is to discuss the utility of traditional dietary advice (TDA), low-FODMAP diet (LFD) and gluten-free diet (GFD) in IBS.

RECENT FINDINGS

Several recent randomized controlled trials (RCTs) have been published demonstrating the efficacy of the LFD and GFD in IBS, with the evidence base for TDA being predominantly based on clinical experience, with emerging RCTs evaluating TDA. Only one RCT has been published to date comparing TDA, LFD and GFD head to head, with no difference noted between diets in terms of efficacy. However, TDA has been noted to be more patient-friendly and is commonly implemented as a first-line dietary therapy.

SUMMARY

Dietary therapies have been demonstrated to improve symptoms in patients with IBS. In view of insufficient evidence to recommend one diet over another currently, specialist dietetic input in conjunction with patient preference is required to determine implementation of dietary therapies. Novel methods of dietetic delivery are required in view of the lack of dietetic provision to deliver these therapies.

Efficacy and safety of probiotics in the treatment of irritable bowel syndrome: A systematic review and meta-analysis of randomised clinical trials using ROME IV criteria

BACKGROUND

Irritable Bowel Syndrome (IBS) is a functional gastrointestinal disorder which affects a great number of patients globally. Clinical trials and meta-analyses have evaluated different therapies for IBS. Some of them have shown that probiotics play a significant role in the management of IBS-patients. Nevertheless, results are controversial, and the efficacy of the administration of probiotics remains to be confirmed, especially in regard to which type of probiotic-strains are beneficial.

AIM

The aim of the present meta-analysis is to assess the efficacy and safety of the administration of probiotics to IBS-patients with a diagnosis based on Rome IV criteria, which is performed for the first time.

METHODS

Electronic databases (Pubmed, Scopus and Cochrane) were searched until 26.01.2023 for randomized controlled trials (RCTs) studying the administration of probiotics in adult IBS-patients, who were categorized according to the Rome IV criteria. The risk of bias was assessed using the Cochrane Risk of Bias tool (ROB) 2.0. Weighted and standardized mean difference with the 95% confidence intervals were used for the synthesis of the results. Primary outcomes were the decrease of IBS-Symptom Severity Score (IBS-SSS) and decrease of abdominal pain. The secondary outcomes were the improvement in quality of life (QoL) and the decrease of bloating. Lastly, the adverse effects of probiotics were evaluated. The protocol of the study has been registered at protocols.io (DOI dx.doi.org/10.17504/protocols.io.14egn218yg5d/v1).

RESULTS

Six double-blind (N = 970) placebo-control RCTs fulfilled the inclusion criteria and overall, nine different strains of probiotics were examined. No significant reduction in IBS-SSS (WMD -43.2, 95% CI -87.5 to 1.0, I2 = 82.9%) was demonstrated, whereas a significant decrease regarding abdominal pain (SMD -0.94, 95% CI -1.53 to -0.35, I2 = 92,2) was shown. Furthermore, no correlation between improvement of QoL and the use of probiotics (SMD -0.64, 95% CI -1.27 to 0.00, I2 = 93,9%) was shown. However, probiotics were associated with a significant reduction in bloating (SMD -0.28, 95% CI -0.47 to -0.09, I2 = 36,0%). A qualitative synthesis was conducted about adverse events and showed that the use of probiotics' is safe without severe adverse events.

CONCLUSIONS

The administration of probiotics to IBS-patients demonstrated a positive effect on pain and bloating, but due to significant heterogeneity and confounding factors, that were not examined in the included studies, a definitive statement cannot be made. Moreover, probiotics did not lead to an improvement in other parameters. There is a need for larger RCTs in IBS-patients diagnosed according to Rome IV (not III) criteria and especially it is essential to be conducted RCTs which examine the administration of specific strains and have similar methodological characteristics.

Dietary interventions for pediatric patients with functional abdominal pain disorders: a systematic review and network meta-analysis

Dietary therapies are recommended for the treatment of pediatrics with functional abdominal pain disorders (FAPDs), but the comparative effectiveness among them is unclear. Therefore, the main aim of this systematic review and meta-analysis was to compare the effectiveness of differential dietary therapies in pediatrics with functional abdominal pain disorders. We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials databases from inception to February 28, 2023. Randomized clinical trials of dietary treatments for pediatric patients with functional abdominal pain disorders were included. The primary outcome was the improvement in abdominal pain. The secondary outcomes were changes in pain intensity and pain frequency. Thirty-one studies after screening 8695 retrieved articles were included, and 29 studies were available for network meta-analysis. Compared with placebo, fiber (RR, 4.86; 95%CI, 1.77 to 13.32; P-score = 0.84), synbiotics (RR, 3.92; 95%CI, 1.65 to 9.28; P-score = 0.75), and probiotics (RR, 2.18; 95%CI, 1.46 to 3.26; P-score = 0.46) had significantly larger effect on the improvement in abdominal pain, the three treatments had larger effect than placebo but statistically insignificant in difference in improving pain frequency and intensity. Similarly, there were no significant differences between the dietary treatments after indirect comparisons of the three outcomes.  Conclusion: Fiber supplements, synbiotics, and probiotics were efficacious in improving abdominal pain of FAPDs in children, suggested by very low or low evidence. The evidence of the efficacy of probiotics is more convincing than fiber and synbiotics when sample size and statistical power were considered. No difference in the efficacy of the three treatments. High-quality trials are needed to further investigate the efficacy of dietary interventions. What is Known: • Multiple dietary treatment options are available for functional abdominal pain disorders in the pediatric population, of which the most beneficial one is currently unknown. What is New: • This NMA found very low to low certainty of the evidence suggesting that fiber, synbiotics, and probiotics might be more efficacious in improving abdominal pain of FAPDs in children than the other dietary treatments. • There were no significant differences between active dietary treatments for changes in abdominal pain intensity.

Inflammatory bowel disease is causally related to irritable bowel syndrome: a bidirectional two-sample Mendelian randomization study

INTRODUCTION

Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are lifelong digestive diseases that severely impact patients' quality of life. The existence of a causal association between IBS and IBD remains unclear. This study aimed to determine the direction of causality between IBD and IBS by quantifying their genome-wide genetic associations and performing bidirectional two-sample Mendelian randomization (MR) analyses.

METHODS

Genome-wide association studies (GWAS) among a predominantly European patient cohort identified independent genetic variants associated with IBS and IBD. Two separate databases (a large GWAS meta-analysis and the FinnGen cohort) for both IBS and IBD were consulted to retrieve statistics on instrument-outcome associations. MR analyses included inverse-variance-weighted, weighted-median, MR-Egger regression, MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) methods, and sensitivity analyses were performed. The MR analyses were carried out for each outcome data, followed by a fixed-effect meta-analysis.

RESULTS

Genetically predicted IBD was associated with an increased risk of IBS. Odds ratios (95% confidence intervals) for samples of 211,551 (17,302 individuals with IBD), 192,789 (7,476 Crohn's disease cases), and 201,143 (10,293 ulcerative colitis cases) individuals were 1.20 (1.00, 1.04), 1.02 (1.01, 1.03), and 1.01 (0.99, 1.03), respectively. After outlier correction using MR-PRESSO, the odds ratio for ulcerative colitis was 1.03 (1.02, 1.05) (p = 0.001). However, an association between genetically influenced IBS and IBD was not identified.

DISCUSSION

This study confirms that IBD is causally related to IBS, which may interfere with the diagnosis and treatment of both diseases.

The national prevalence of disorders of gut brain interaction in the United Kingdom in comparison to their worldwide prevalence: Results from the Rome foundation global epidemiology study

BACKGROUND

There are minimal epidemiological data comparing the burden of disorders of gut brain interaction (DGBI) in the UK with other countries. We compared the prevalence of DGBI in the UK with other countries that participated in the Rome Foundation Global Epidemiology Study (RFGES) online.

METHODS

Participants from 26 countries completed the RFGES survey online including the Rome IV diagnostic questionnaire and an in-depth supplemental questionnaire with questions about dietary habits. UK sociodemographic and prevalence data were compared with the other 25 countries pooled together.

KEY RESULTS

The proportion of participants with at least one DGBI was lower in UK participants compared with in the other 25 countries (37.6% 95% CI 35.5%-39.7% vs. 41.2%; 95% CI 40.8%-41.6%, p = 0.001). The UK prevalence of 14 of 22 Rome IV DGBI, including irritable bowel syndrome (4.3%) and functional dyspepsia (6.8%), was similar to the other countries. Fecal incontinence, opioid-induced constipation, chronic nausea and vomiting, and cannabinoid hyperemesis (p < 0.05) were more prevalent in the UK. Cyclic vomiting, functional constipation, unspecified functional bowel disorder, and proctalgia fugax (p < 0.05) were more prevalent in the other 25 countries. Diet in the UK population consisted of higher consumption of meat and milk (p < 0.001), and lower consumption of rice, fruit, eggs, tofu, pasta, vegetables/legumes, and fish (p < 0.001).

CONCLUSIONS AND INFERENCES

The prevalence and burden of DGBI is consistently high in the UK and in the rest of the world. Opioid prescribing, cultural, dietary, and lifestyle factors may contribute to differences in the prevalence of some DGBI between the UK and other countries.

Smartphone app-delivered gut-directed hypnotherapy improves symptoms of self-reported irritable bowel syndrome: A retrospective evaluation

BACKGROUND

Gut-directed hypnotherapy (GDH) has high rates of durable efficacy for treating irritable bowel syndrome (IBS) but its widespread use is limited due to high costs and poor access. A smartphone app delivering GDH was developed to fill gaps in accessibility but has not been assessed in IBS patients. The current retrospective evaluation aims to assess the efficacy of app-delivered GDH in managing IBS symptoms and to investigate associating factors that predict response.

METHODS

Irritable bowel syndrome patients who downloaded the app between June 2019 and April 2020 were retrospectively evaluated. The first seven sessions were free. Daily GDH, psycho-education, and breathing exercises were included. Overall and individual gastrointestinal symptoms were assessed at baseline and completion using a 100-mm visual analogue scale. Clinical data were extracted.

KEY RESULTS

2843 patients with self-reported IBS commenced the free sessions, 1428 (50%) purchased the app and 253 (9%) completed all 42 sessions. Outcome data were available for 190 users who completed all 42 sessions. 64% of patients who completed the GDH and provided outcome data responded (defined as >30% reduction in abdominal pain). Abdominal pain reduced from 60mm (50-73mm) at baseline to 26mm (13-50mm) on study completion (p<0.001 Wilcoxon). Similar results were seen for overall and individual symptoms. On multivariable analysis, symptom response was positively associated with being ≥ 40 years (estimated OR 0.398, p=0.025) and negatively associated with trying probiotics (0.323, p=0.042).

CONCLUSIONS & INFERENCES

Adherence to app-delivered gut-directed hypnotherapy was low but users who completed the program saw notable improvements in their IBS symptoms. Patients ≥40 years, with symptoms for ≥5 years, may respond better. A controlled trial comparing face-to-face to app-delivered GDH is indicated.

Negative Impact of Disorders of Gut-Brain Interaction on Health-Related Quality of Life: Results From the Rome Foundation Global Epidemiology Survey

BACKGROUND & AIMS

This study used the database from the Rome Foundation Global Epidemiology Survey to assess the differences in quality of life overall, and by age and sex, across individual disorders of gut-brain interaction (DGBI), gastrointestinal anatomical region(s), and number of overlapping DGBI.

METHODS

Data were collected via the Internet in 26 countries, using the Rome IV diagnostic questionnaire and a supplemental questionnaire including the Patient-Reported Outcomes Measurement Information Systems Global-10 quality of life measure. Factorial analyses of variance were used to explore physical and mental quality of life, adjusting for multiple comparisons.

RESULTS

Among the 54,127 respondents, quality of life deteriorated significantly with increasing number of overlapping DGBI, with respondents reporting ≥2 DGBI having significantly poorer quality of life than those with only 1 DGBI or those without any DGBI. Men with DGBI reported better quality of life than women, and those aged ≥65 years reported better quality of life than those <65 years. Age, sex, number of overlapping DGBI, somatization, anxiety, depression, and functional experiences (concern, embarrassment, or stress associated with bowel functioning) relating to DGBI, were significant predictors of poorer physical and mental quality of life.

CONCLUSIONS

This study is the most comprehensive assessment of quality of life to date in adults living with a DGBI. It provides a representative picture of DGBI impact on adults in the global adult population and highlights the significant detrimental impact of living with a DGBI on quality of life.

Improving access to gut-directed hypnotherapy for irritable bowel syndrome in the digital therapeutics' era: Are mobile applications a "smart" solution?

Gut-directed hypnotherapy (GDH) is a highly effective brain-gut behavioral therapy which is recommended in international guidelines for the treatment of irritable bowel syndrome (IBS). There is increasing recognition of the value of GDH as part of integrated care alongside medical and dietary approaches. This has led to recent innovations to widen access to GDH to meet the increasing demand. Recent advances include streamlined courses of individualized GDH, group therapy, and remote delivery. In this issue of Neurogastroenterology and Motility, Peters et al. retrospectively report outcomes of smartphone app-delivered GDH in a population with self-reported IBS. While adherence was low, those that completed smart phone-delivered GDH-achieved symptom benefit. This mini-review summarizes the current evidence-base for available modalities of GDH and discusses the current and future utility and development of mobile health applications in the digital therapeutics' era.

Sexual dysfunction worsens both the general and specific quality of life of women with irritable bowel syndrome. A cross-sectional study

BACKGROUND

Irritable bowel syndrome (IBS) and sexual dysfunction (SxD) lowers quality of life (QOL) separately, but the effect of their overlap in unselected populations has not been studied.

OBJECTIVE

To evaluate the QOL of IBS women with and without SxD and compare it with controls.

METHODS

In this cross-sectional assessment, we studied 51 IBS women (Rome IV criteria) and 54 controls. SxD was determined using the female sexual function index questionnaire. QOL was evaluated by the Short Form 36 (SF-36) and IBS-QOL questionnaires.

RESULTS

SxD prevalence was similar between IBS women (39.22%) and controls (38.89%). Compared with other groups, IBS patients with SxD showed lower scores in all domains as well as in the physical, mental summaries of the SF-36 and almost all domains (except for body image, food avoidance, and social reaction compared with IBS patients without SxD) and the total score of IBS-QOL.

CONCLUSIONS

These findings show that SxD worsens both general and specific QOL of women with IBS. The consideration of SxD in patients with IBS will allow us to make a more effective diagnostic and therapeutic approach. Clinical trial registry in Mexico City General Hospital: DI/19/107/03/080.

CLINICAL TRIALS REGISTRATION

NCT04716738.

Prevalence and impact of faecal incontinence among individuals with Rome IV irritable bowel syndrome

BACKGROUND

Little is known about faecal incontinence (FI) in individuals with irritable bowel syndrome (IBS).

AIMS

To compare characteristics of people with IBS reporting FI, compared with people with IBS who do not report FI.

METHODS

We collected demographic, gastrointestinal and psychological symptoms, healthcare usage, direct healthcare costs, impact on work and activities of daily living, and quality of life data from individuals with Rome IV-defined IBS. We asked participants about FI, assigning presence or absence according to Rome-IV criteria.

RESULTS

Of 752 participants with Rome IV IBS, 202 (26.9%) met Rome IV criteria for FI. Individuals with FI were older (p < 0.001), more likely to have IBS-D (47.0% vs. 39.0%, p = 0.008), and less likely to have attained a university or postgraduate level of education (31.2% vs. 45.6%, p < 0.001), or to have an annual income of ≥£30,000 (18.2% vs. 32.9%, p < 0.001). They were more likely to report urgency (44.6% vs. 19.1%, p < 0.001) as their most troublesome symptom and a greater proportion had severe IBS symptom scores, abnormal depression scores, higher somatic symptom-reporting scores or higher gastrointestinal symptom-specific anxiety scores (p < 0.01 for trend for all analyses). Mean health-related quality of life scores were significantly lower among those with, compared with those without, FI (p < 0.001). Finally, FI was associated with higher IBS-related direct healthcare costs (p = 0.002).

CONCLUSIONS

Among individuals with Rome IV IBS, one-in-four repo rted FI according to Rome IV criteria. Physicians should ask patients with IBS about FI routinely.

Irritable bowel syndrome: treatment based on pathophysiology and biomarkers

OBJECTIVE

To appraise the evidence that pathophysiological mechanisms and individualised treatment directed at those mechanisms provide an alternative approach to the treatment of patients with irritable bowel syndrome (IBS).

DESIGN

A PubMED-based literature review of mechanisms and treatment of IBS was conducted independently by the two authors, and any differences of perspective or interpretation of the literature were resolved following discussion.

RESULTS

The availability of several noninvasive clinical tests can appraise the mechanisms responsible for symptom generation in IBS, including rectal evacuation disorders, abnormal transit, visceral hypersensitivity or hypervigilance, bile acid diarrhoea, sugar intolerances, barrier dysfunction, the microbiome, immune activation and chemicals released by the latter mechanism. The basic molecular mechanisms contributing to these pathophysiologies are increasingly recognised, offering opportunities to intervene with medications directed specifically to food components, receptors and potentially the microbiome. Although the evidence supporting interventions for each mechanism is not at the same level of proof, the current state-of-the-art provides the opportunity to advance the practice from treatment based on symptoms to individualisation of treatment guided by pathophysiology and clinically identified biomarkers.

CONCLUSION

These advances augur well for the implementation of evidence-based individualised treatment for patients with IBS based on actionable biomarkers or psychological disturbances.

Probiotics in irritable bowel syndrome and inflammatory bowel disease: review of mechanisms and effectiveness

PURPOSE OF REVIEW

The gastrointestinal (GI) microbiome has been implicated in the pathogenesis of inflammatory bowel disease (IBD) and has been linked with irritable bowel syndrome (IBS). The aim of this article is to critically review the emerging evidence for the mechanisms and effectiveness of probiotics in the management of these conditions.

RECENT FINDINGS

The GI microbiome is strongly influenced by ageing, diet and disease. Probiotics may confer health effects to the host by modulating the metabolic activities of the microbiome to propagate anti-inflammatory effects and reinforce the intestinal barrier, and are considered to be safe to use. Many short-term studies have demonstrated the effectiveness of probiotics overall in IBS, with meta-analyses demonstrating efficacy across specific strains albeit with relatively small effect sizes. Within IBD, some probiotics appear to offer clinical benefit in ulcerative colitis but strain-specific effects are unclear. Evidence for the use of probiotics in Crohn's disease remains limited.

SUMMARY

Probiotics offer considerable potential for the management of IBS and possibly in IBD, however, any benefits conferred appear to be strain-specific. High quality trials of specific probiotics in IBS and IBD, as well as laboratory investigations of their mechanism of action, are required in order to fully understand their potential therapeutic value.

Procedures in Fecal Microbiota Transplantation for Treating Irritable Bowel Syndrome: Systematic Review and Meta-Analysis

BACKGROUND

Irritable bowel syndrome (IBS) is a prevalent gastrointestinal disease with no effective treatment. Altered microbiota composition seems implicated in disease etiology and therefore fecal microbial transplantation (FMT) has emerged as a possible treatment therapy. To clarify the clinical parameters impacting FMT efficacy, we conducted a systematic review with subgroup analysis.

METHODS

A literature search was performed identifying randomized controlled trials (RCTs) comparing FMT with placebo in IBS adult patients (8-week follow-up) with a reported improvement in global IBS symptoms.

RESULTS

Seven RCTs (489 participants) met the eligibility requirements. Although FMT seems not to be effective in global improvement of IBS symptoms, subgroup analysis shows that FMT through gastroscopy or nasojejunal tube are effective IBS treatments (RR 3.03; 95% CI 1.94-4.73; I² = 10%, p < 0.00001). When considering non-oral ingestion routes, IBS patients with constipation symptoms are more likely to benefit from FMT administration (p = 0.003 for the difference between IBS subtypes regarding constipation). Fresh fecal transplant and bowel preparation seem also to have impact on FMT efficacy (p = 0.03 and p = 0.01, respectively).

CONCLUSION

Our meta-analysis revealed a set of critical steps that could affect the efficacy of FMT as clinical procedure to treat IBS, nevertheless more RCTs are needed.

Volatile organic compounds as potential biomarkers of irritable bowel syndrome: A systematic review

BACKGROUND

Irritable bowel syndrome (IBS) is a prevalent gastrointestinal disease characterized by intermittent abdominal pain with altered bowel habits. Due to the condition's chronicity, patients suffer from poor quality of life, while the healthcare burden continues to grow. There is currently no reliable biomarker for the diagnosis of IBS, and the current approach depends on ruling-out organic diseases such as inflammatory bowel disease (IBD) and colorectal cancer by markers of inflammation like fecal calprotectin and C-reactive protein, or invasive procedures like a colonoscopy. Volatile organic compounds (VOCs) are growing in popularity as a biomarker due to its accuracy and ease of use.

PURPOSE

This systematic review of Medline and Cochrane's databases aimed to identify VOCs in the diagnosis of IBS. 57% of the studies proved that VOCs could identify IBS patients from healthy controls with AUC ranging from 0.83 to 0.99. Studies that distinguished IBS from IBD patients had slightly higher AUC of 0.87-0.98. Combining VOC into panels allowed the creation of discriminative algorithms. Though current research is limited by areas of heterogeneity in VOC sampling and small sample sizes, our review shows that VOC analysis has the potential to be a noninvasive point-of-care test that differentiates IBS from other organic gastrointestinal diseases.

Factors associated with lower disease-specific and generic health-related quality of life in Rome IV irritable bowel syndrome

BACKGROUND

Little is known about associations with reduced quality of life in irritable bowel syndrome (IBS) or impact of IBS on quality of life compared with other chronic conditions.

METHODS

We collected demographic, gastrointestinal and psychological symptoms, healthcare usage, direct healthcare costs, impact on work and activities of daily living data from 752 individuals with Rome IV-defined IBS. We used the irritable bowel syndrome quality of life (IBS-QOL) and the EQ-5D-5L questionnaires to examine characteristics associated with lower quality of life.

RESULTS

The mean IBS-QOL among all 752 individuals with Rome IV IBS was 48.4 (SD 22.3) and the mean EQ-5D score was 0.570 (SD 0.283), the latter being comparable to people with stroke, leg ulcers or chronic obstructive pulmonary disease. Lower levels of both disease-specific and generic quality of life were associated with severe IBS symptom scores, abnormal anxiety or depression scores, and higher somatoform symptom-reporting and gastrointestinal symptom-specific anxiety scores (p < 0.001 for all analyses). Those with lower quality of life had significantly higher healthcare usage and direct healthcare costs and more impairment in work and activities of daily living (p < 0.01 for all analyses). Avoidance of alcohol, lower educational level, abnormal anxiety, depression or somatoform symptom-reporting scores, and impairment in social leisure activities, home management or maintaining close relationships were all independently associated with lower quality of life.

CONCLUSION

IBS has a substantial impact on the quality of life of those affected, and worse than observed in some severe chronic organic conditions.

Italian guidelines for the management of irritable bowel syndrome: Joint Consensus from the Italian Societies of: Gastroenterology and Endoscopy (SIGE), Neurogastroenterology and Motility (SINGEM), Hospital Gastroenterologists and Endoscopists (AIGO), Digestive Endoscopy (SIED), General Medicine (SIMG), Gastroenterology, Hepatology and Pediatric Nutrition (SIGENP) and Pediatrics (SIP)

The irritable bowel syndrome (IBS) is a chronic disorder of gut-brain interaction. IBS is still associated with areas of uncertainties, especially regarding the optimal diagnostic work-up and the more appropriate management. Experts from 7 Italian Societies conducted a Delphi consensus with literature summary and voting process on 27 statements. Recommendations and quality of evidence were evaluated using the grading of recommendations, assessment, development, and evaluation (GRADE) criteria. Consensus was defined as >80% agreement and reached for all statements. In terms of diagnosis, the consensus supports a positive diagnostic strategy with a symptom-based approach, including the psychological comorbidities assessment and the exclusion of alarm symptoms, together with the digital rectal examination, full blood count, C-reactive protein, serology for coeliac disease, and fecal calprotectin assessment. Colonoscopy should be recommended in patients with alarm features. Regarding treatment, the consensus strongly supports a dietary approach for patients with IBS, the use of soluble fiber, secretagogues, tricyclic antidepressants, psychologically directed therapies and, only in specific IBS subtypes, rifaximin. A conditional recommendation was achieved for probiotics, polyethylene glycol, antispasmodics, selective serotonin reuptake inhibitors and, only in specific IBS subtypes, 5-HT3 antagonists, 5-HT4 agonists, bile acid sequestrants.

Willingness to pay for medications among patients with Rome IV Irritable Bowel Syndrome

BACKGROUND

Little is known about willingness to pay for medications among individuals with irritable bowel syndrome (IBS).

METHODS

We collected demographic, gastrointestinal symptom, psychological health, quality of life, and healthcare usage data from 752 adults with Rome IV-defined IBS. We examined willingness to pay for a hypothetical medication in return for improvement in IBS symptoms using a contingent valuation method, according to these variables.

RESULTS

The median amount of money individuals was willing to pay was £1-£50 (IQR £0-£100) per month for a medication with a 100% chance of improving IBS symptoms. Women, compared with men, (92.7% willing to pay "£0," 89.8% "£1-£50," 87.3% "£51-£100," 78.9% "£101-£200," and 78.5% "more than £200," p = 0.008) were less likely to be willing to pay for a pill with a 100% chance of improving IBS symptoms whilst those with an annual income of £30,000 or more (12.2% willing to pay "£0," 25.2% "£1-£50," 33.5% "£51-£100," 40.2% "£101-£200," and 35.1% "more than £200," p = 0.002) were more likely. We observed a higher willingness to pay among those with lower IBS-related quality of life (p = 0.002 for trend). Of all 752 individuals, 92.7%, 74.5%, and 58.0% would be willing to pay for a medication that would give them a 100%, 50%, or 30% chance of improving IBS symptoms, respectively.

CONCLUSION

Patients with IBS are willing to pay for medications which improve IBS symptoms. Future studies should investigate the relative importance of medication pricing, efficacy, and side effect profile among individuals with IBS.

British Dietetic Association consensus guidelines on the nutritional assessment and dietary management of patients with inflammatory bowel disease

BACKGROUND

Despite increased awareness of diet and nutrition being integral to the management of patients with inflammatory bowel disease (IBD), there are gaps in the knowledge of IBD healthcare providers regarding nutrition. Furthermore, high quality evidence on nutritional assessment and dietary management of IBD is limited. A Delphi consensus from a panel of experts allows for best-practice guidelines to be developed, especially where high quality evidence is limited. The aim was to develop guidelines for the nutritional assessment and dietary management of IBD using an eDelphi online consensus agreement platform.

METHODS

Seventeen research topics related to IBD and nutrition were systematically reviewed. Searches in Cochrane, Embase®, Medline® and Scopus® electronic databases were performed. GRADE was used to develop recommendations. Experts from the IBD community (healthcare professionals and patients with IBD) were invited to vote anonymously on the recommendations in a custom-built online platform. Three rounds of voting were carried out with updated iterations of the recommendations and evaluative text based on feedback from the previous round.

RESULTS

From 23,824 non-duplicated papers, 167 were critically appraised. Fifty-five participants completed three rounds of voting and 14 GRADE statements and 42 practice statements achieved 80% consensus. Comprehensive guidance related to nutrition assessment, nutrition screening and dietary management is provided.

CONCLUSIONS

Guidelines on the nutritional assessment and dietary management of IBD have been developed using evidence-based consensus to improve equality of care. The statements and practice statements developed demonstrate the level of agreement and the quality and strength of the guidelines.

Diagnostic yield of colonoscopy for organic disease in irritable bowel syndrome and its risk factors: A meta-analysis

BACKGROUND

Colonoscopy is commonly performed in patients with irritable bowel syndrome (IBS) to rule out organic disease. We performed a meta-analysis to assess the prevalence of organic disease detected at colonoscopy in IBS and its potential risk factors.

METHODS

Medline, Embase, and Web of Science were searched through January 2022. Observational studies that reported diagnostic yield of colonoscopy for organic disease including colorectal cancer (CRC), inflammatory bowel disease (IBD), or microscopic colitis (MC) in adult IBS patients were eligible. Pooled prevalence and risk difference (RD) with 95% confidence intervals (CIs) were calculated.

RESULTS

Of 2490 citations identified, 12 studies were eligible containing 28,630 patients with IBS undergoing colonoscopy. Pooled prevalence of CRC, IBD, and MC in IBS was 0.78%, 4.48%, and 2.35%, respectively. No difference in the yield for CRC, IBD, and MC was seen between IBS and non-IBS patients. CRC was rare in IBS patients without alarm symptoms or younger than 40 years (<0.1%). Pooled Prevalence of CRC (2.47% vs. 0.11%; RD 2.57%, 95% CI 0.37%-4.78%) and IBD (8.86% vs. 4.25%; RD 10.75%, 95% CI 4.81%-16.68%) was significantly higher in IBS patients with alarm symptoms compared with those without. IBD and MC were more likely to be detected at colonoscopy in IBS-D compared with IBS-C. The prevalence of CRC and MC was higher in IBS patients with older age than younger age.

CONCLUSION

We provide the first pooled estimate of yield of colonoscopy in IBS and its risk factors, which may be used to inform clinical decision and support guidelines.

Randomised clinical trial: efficacy and safety of the live biotherapeutic product MRx1234 in patients with irritable bowel syndrome

BACKGROUND

MRx1234 is a live biotherapeutic product that contains a strain of Blautia hydrogenotrophica. It is in development for the treatment of irritable bowel syndrome (IBS).

AIMS

To assess the efficacy and safety of MRx1234 in patients with IBS with predominant constipation (IBS-C) or diarrhoea (IBS-D) METHODS: We conducted a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial. Patients aged 18-70 years in two parallel cohorts (IBS-C; IBS-D) were randomised (1:1) to MRx1234 or placebo for 8 weeks. The primary efficacy endpoint was overall responder rate-a composite of improved bowel habit (IBS-C: stool frequency; IBS-D: stool consistency) and abdominal pain intensity-for ≥50% of the treatment period in each cohort. Statistical testing was at a one-sided 0.10 significance level.

RESULTS

Of 366 randomised patients (164 IBS-C; 202 IBS-D), 365 received any study medication (177 MRx1234, 188 placebo). Numerically, although not statistically significantly different, more patients who received MRx1234 than placebo were overall responders in the IBS-C (25.0% vs. 17.1%) and IBS-D (23.4% vs. 17.8%) cohorts. Similar results were observed in the additional combined cohort analysis (24.1% vs. 17.5%; p = 0.063). For the components of the primary endpoint, significantly more patients on MRx1234 than placebo reported improvement in bowel habit in the IBS-C, IBS-D and combined cohorts, while improvements in abdominal pain were observed in each cohort. The safety profile of MRx1234 was similar to placebo.

CONCLUSIONS

MRx1234 has the potential to become a novel, safe treatment option for patients with IBS-C or IBS-D, and for those who have mixed symptoms or transition between subtypes.

CLINICALTRIALS

gov #NCT03721107.

Functional Implications and Clinical Potential of MicroRNAs in Irritable Bowel Syndrome: A Concise Review

MicroRNAs (miRNAs) are tiny (20-24 nucleotides long), non-coding, highly conserved RNA molecules that play a crucial role within the post-transcriptional regulation of gene expression via sequence-specific mechanisms. Since the miRNA transcriptome is involved in multiple molecular processes needed for cellular homeostasis, its altered expression can trigger the development and progression of several human pathologies. In this context, over the last few years, several relevant studies have demonstrated that dysregulated miRNAs affect a wide range of molecular mechanisms associated with irritable bowel syndrome (IBS), a common gastrointestinal disorder. For instance, abnormal miRNA expression in IBS patients is related to the alteration of intestinal permeability, visceral hyperalgesia, inflammatory pathways, and pain sensitivity. Besides, specific miRNAs are differentially expressed in the different subtypes of IBS, and therefore, they might be used as biomarkers for precise diagnosis of these pathological conditions. Accordingly, miRNAs have noteworthy potential as theragnostic targets for IBS. Hence, in this current review, we present an overview of the recent discoveries regarding the clinical relevance of miRNAs in IBS, which might be useful in the future for the development of miRNA-based drugs against this disorder.

A postbiotic fermented oat gruel may have a beneficial effect on the colonic mucosal barrier in patients with irritable bowel syndrome

BACKGROUND

Impaired intestinal permeability and microbial dysbiosis are important pathophysiological mechanisms underlying irritable bowel syndrome (IBS). ReFerm®, also called Profermin®, is a postbiotic product of oat gruel fermented with Lactobacillus plantarum 299v. In this study, we investigated whether ReFerm® has a beneficial effect on the intestinal epithelial barrier function in patients with IBS.

MATERIALS AND METHODS

Thirty patients with moderate to severe IBS-diarrhoea (IBS-D) or IBS-mixed (IBS-M) were treated with enema containing ReFerm® or placebo. The patients underwent sigmoidoscopy with biopsies obtained from the distal colon at baseline and after 14 days of treatment with ReFerm® or placebo twice daily. The biopsies were mounted in Ussing chambers, and paracellular and transcellular permeabilities were measured for 120 min. In addition, the effects of ReFerm® or placebo on the epithelial barrier were investigated in vitro using Caco-2 cells.

RESULTS

ReFerm® reduced paracellular permeability (p < 0.05) and increased transepithelial resistance (TER) over time (p < 0.01), whereas the placebo had no significant effect in patients. In ReFerm®-treated Caco-2 cells, paracellular and transcellular permeabilities were decreased compared to the control (p < 0.05) and placebo (p < 0.01). TER was increased in Caco-2 ReFerm®-treated cells, and normalised TER was increased in ReFerm®-treated Caco-2 cells compared to control (p < 0.05) and placebo-treated (p < 0.05) cells.

CONCLUSION

ReFerm® significantly reduced paracellular permeability and improved TER in colonic biopsies collected from patients with IBS and in a Caco-2 cell model. Our results offer new insights into the potential benefits of ReFerm® in IBS management. Further studies are needed to identify the molecular mechanisms underlying the barrier-protective properties of ReFerm®.

CLINICAL TRIAL REGISTRATION

[https://clinicaltrials.gov/], identifier [NCT05475314].

The Gut Microbiome and Its Implication in the Mucosal Digestive Disorders

The gastrointestinal (GI) tract is one of the most studied compartments of the human body as it hosts the largest microbial community including trillions of germs. The relationship between the human and its associated flora is complex, as the microbiome plays an important role in nutrition, metabolism and immune function. With a dynamic composition, influenced by many intrinsic and extrinsic factors, there is an equilibrium maintained in the composition of GI microbiota, translated as "eubiosis". Any disruption of the microbiota leads to the development of different local and systemic diseases. This article reviews the human GI microbiome's composition and function in healthy individuals as well as its involvement in the pathogenesis of different digestive disorders. It also highlights the possibility to consider flora manipulation a therapeutic option when treating GI diseases.

Double-blinded randomised placebo controlled trial of enterosgel (polymethylsiloxane polyhydrate) for the treatment of IBS with diarrhoea (IBS-D)

OBJECTIVE

Irritable bowel syndrome with diarrhoea (IBS-D) is a common and challenging condition that significantly reduces quality of life. Enterosgel (polymethylsiloxane polyhydrate) is an intestinal adsorbent which sequesters harmful molecules and is safe and effective in acute infective diarrhoea. This randomised controlled multicentre trial aimed to investigate its safety and efficacy in patients with IBS-D.

DESIGN

After a 2-week screening phase, participants were randomised into an 8-week double-blind phase, followed by an 8-week open-label and follow-up phase. Participants recorded stool consistency, pain and global symptoms in e-diaries and questionnaires. The primary outcome was the percentage of responders on a composite abdominal pain (≥30% decrease in the weekly score) and stool consistency (50% reduction in days per week with at least one stool of BSFS type 6 or 7) score during at least 4 weeks of the treatment period.

RESULTS

440 patients with IBS-D were randomised to the double-blind phase with 393 continuing to the open-label phase. The Primary outcome responder rate by intention-to-treat for enterosgel versus placebo was 37.4% vs 24.3% (OR 1.95, NNT 8, p=0.002). Enterosgel also improved stool consistency (48.5% vs 32.5%, p<0.0001) abdominal pain (53.3% vs 40.2%, p=0.003), stool frequency (treatment effect -0.32 (-0.62 to -0.02)) and urgency (treatment effect -0.59 (-0.85 to -0.33)). 60% of patients reported adequate relief of symptoms after open-label treatment. Adverse event frequency was similar in both groups, with no serious events attributable to enterosgel.

CONCLUSION

Enterosgel is safe and effective in IBS-D, providing an alternative to the limited current treatment options.

TRIAL REGISTRATION NUMBER

ISRCTN17149988.

Efficacy and Acceptability of Dietary Therapies in Non-Constipated Irritable Bowel Syndrome: A Randomized Trial of Traditional Dietary Advice, the Low FODMAP Diet, and the Gluten-Free Diet

BACKGROUND & AIMS

Various diets are proposed as first-line therapies for non-constipated irritable bowel syndrome (IBS) despite insufficient or low-quality evidence. We performed a randomized trial comparing traditional dietary advice (TDA) against the low FODMAP diet (LFD) and gluten-free diet (GFD).

METHODS

Patients with Rome IV-defined non-constipated IBS were randomized to TDA, LFD, or GFD (the latter allowing for minute gluten cross-contamination). The primary end point was clinical response after 4 weeks of dietary intervention, as defined by ≥50-point reduction in IBS symptom severity score (IBS-SSS). Secondary end points included (1) changes in individual IBS-SSS items within clinical responders, (2) acceptability and food-related quality of life with dietary therapy, (3) changes in nutritional intake, (4) alterations in stool dysbiosis index, and (5) baseline factors associated with clinical response.

RESULTS

The primary end point of ≥50-point reduction in IBS-SSS was met by 42% (n = 14/33) undertaking TDA, 55% (n = 18/33) for LFD, and 58% (n = 19/33) for GFD (P = .43). Responders had similar improvements in IBS-SSS items regardless of their allocated diet. Individuals found TDA cheaper (P < .01), less time-consuming to shop (P < .01), and easier to follow when eating out (P = .03) than the GFD and LFD. TDA was also easier to incorporate into daily life than the LFD (P = .02). Overall reductions in micronutrient and macronutrient intake did not significantly differ across the diets. However, the LFD group had the greatest reduction in total FODMAP content (27.7 g/day before intervention to 7.6 g/day at week 4) compared with the GFD (27.4 g/day to 22.4 g/day) and TDA (24.9 g/day to 15.2 g/day) (P < .01). Alterations in stool dysbiosis index were similar across the diets, with 22%-29% showing reduced dysbiosis, 35%-39% no change, and 35%-40% increased dysbiosis (P = .99). Baseline clinical characteristics and stool dysbiosis index did not predict response to dietary therapy.

CONCLUSIONS

TDA, LFD, and GFD are effective approaches in non-constipated IBS, but TDA is the most patient-friendly in terms of cost and convenience. We recommend TDA as the first-choice dietary therapy in non-constipated IBS, with LFD and GFD reserved according to specific patient preferences and specialist dietetic input.

CLINICALTRIALS

gov: NCT04072991.

The Potential Role of Human Milk Oligosaccharides in Irritable Bowel Syndrome

Irritable Bowel Syndrome (IBS) is the most common gastrointestinal (GI) disorder in Western populations and therefore a major public health/economic concern. However, despite extensive research, psychological and physiological factors that contribute to the aetiology of IBS remain poorly understood. Consequently, clinical management of IBS is reduced to symptom management through various suboptimal options. Recent evidence has suggested human milk oligosaccharides (HMOs) as a potential therapeutic option for IBS. Here, we review literature concerning the role of HMOs in IBS, including data from intervention and in vitro trials. HMO supplementation shows promising results in altering the gut microbiota and improving IBS symptoms, for instance by stimulating bifidobacteria. Further research in adults is required into HMO mechanisms, to confirm the preliminary results available to date and recommendations of HMO use in IBS.

Linaclotide Reduced Response Time for Irritable Bowel Syndrome With Constipation Symptoms: Analysis of 4 Randomized Controlled Trials

INTRODUCTION

These post hoc analyses provide clinically relevant data concerning time to response for individual irritable bowel syndrome with constipation (IBS-C) symptoms after linaclotide use.

METHODS

Time-to-response data were pooled from 4 randomized controlled trials. Response time for abdominal symptoms (pain, discomfort, and bloating) and complete spontaneous bowel movements (CSBMs) were analyzed using the Kaplan-Meier method; patients were categorized as early responders (≤4 weeks), late responders (>4-12 weeks), or nonresponders.

RESULTS

Among 2,350 patients (1,172 placebo and 1,178 linaclotide 290 μg), >50% of patients with IBS-C who initiated linaclotide treatment experienced a decrease of ≥30% in abdominal pain, discomfort, or bloating within 3-4 weeks (median). The median time to achieving ≥3 CSBMs was 4 weeks. Although not all linaclotide-treated patients responded within 12 weeks, a late response occurred between 4 and 12 weeks in 1 in 6 patients for abdominal pain and in approximately 1 in 10 patients for CSBM frequency. Comparisons of early responders, late responders, and nonresponders for both response definitions indicated that women, Whites, and patients with less severe baseline abdominal symptoms were more likely to respond early.

DISCUSSION

Although treatment responses with linaclotide occurred in >50% of patients with IBS-C within 4 weeks of treatment initiation, benefits for individual abdominal symptoms and/or CSBM frequency can still occur between 4 and 12 weeks. A lack of improvement in one symptom does not negate the possibility of response for others, highlighting the importance of discussing all symptoms with patients and not assuming treatment futility at 4 weeks.

Patient satisfaction after remotely delivered gut-directed hypnotherapy for irritable bowel syndrome during the COVID-19 era: implications for future practice

Objective

Gut-directed hypnotherapy (GDH) is an evidence-based treatment for irritable bowel syndrome (IBS). Adoption of remote GDH has been accelerated by the COVID-19 pandemic. We aimed to evaluate patient experience and satisfaction following remote GDH.

Design

On completing 12 sessions of remote GDH via Skype using the Manchester protocol, patients with refractory IBS completed a feedback form on their experience. The proportion reporting positive outcomes (≥30% improvement in global IBS symptoms or abdominal pain, satisfaction, recommendation to family/friends) were compared by patient factors (age, gender, proximity, preferences).

Results

Of 52 patients completing the feedback form, 27 (52%) indicated that they would have opted for remote over face-to-face GDH, regardless of the pandemic situation. On a five-point scale (5=easy), patients rated the platform easy-to-use (mean 4.5±0.8) without impairment of communication (mean rating 4.6±0.8). Following remote GDH, 30/52 (58%) reported ≥30% global IBS symptom improvement, and 24/52 (46%) reported ≥30% pain reduction. 90% would recommend remote GDH to others. Only 39% felt they would have benefitted more from face to face. Those who would have chosen remote GDH regardless of the pandemic were more likely to be satisfied (p=0.01). Age, gender and proximity did not influence outcomes, satisfaction and likelihood of recommending remote GDH to others. Difficulties during remote sessions were infrequent in both those that were satisfied, and those that would have preferred face to face.

Conclusion

These data support the need to continue developing remote GDH in the post-COVID era but suggest that there is still a role for face-to-face GDH, with patient choice being an important factor.

Functional Abdominal Cramping Pain: Expert Practical Guidance

Functional abdominal cramping pain (FACP) is a common complaint, which may present either on its own or in association with a functional gastrointestinal disorder. It is likely caused by a variety of, probably partly unknown, etiologies. Effective management of FACP can be challenging owing to the lack of usable diagnostic tools and the availability of a diverse range of treatment approaches. Practical guidance for their selection and use is limited. The objective of this article is to present a working definition of FACP based on expert consensus, and to propose practical strategies for the diagnosis and management of this condition for physicians, pharmacists, and patients. A panel of experts on functional gastrointestinal disorders was convened to participate in workshop activities aimed at defining FACP and agreeing upon a recommended sequence of diagnostic criteria and management recommendations. The key principles forming the foundation of the definition of FACP and suggested management algorithms include the primacy of cramping pain as the distinguishing symptom; the importance of recognizing and acting upon alarm signals of potential structural disease; the recognition of known causes that might be addressed through lifestyle adjustment; and the central role of antispasmodics in the treatment of FACP. The proposed algorithm is intended to assist physicians in reaching a meaningful diagnostic endpoint based on patient-reported symptoms of FACP. We also discuss how this algorithm may be adapted for use by pharmacists and patients.

Potential of natural products in the treatment of irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a kind of functional bowel disease that is characterized by bellyache, abdominal distension, and diarrhea. Although not life-threatening, IBS has a long course and recurrent attacks and seriously affects the life quality of patients. Current drugs for treating IBS possess remarkable limitations, such as limited efficacy and severe adverse reactions. Therefore, developing novel medications to treat IBS is quite essential, and natural products may be a substantial source.

PURPOSE

This is the first systematic review elaborating the recent advancement of natural products as potential drugs for the therapy of IBS.

METHODS

A comprehensive retrieval of studies was carried out in scientific databases including PubMed, Web of Science, Elsevier, and CNKI. By using ("irritable bowel syndrome" OR "IBS") AND ("natural product" OR "natural compound" OR "phytochemical") as keywords, the eligible studies were screened, and the relevant information about therapeutic action and mechanism of natural products treating IBS was extracted.

RESULTS

Natural products against IBS consisted of four categories, namely, terpenoids, flavonoids, alkaloids, and phenols. Furthermore, the underlying mechanisms for natural products treating IBS were tightly associated with increased TJs and mucus protein expression, regulation of the brain-gut axis and gut microbiota structure, and inhibition of inflammatory response and intestinal mucosal damage.

CONCLUSION

Natural products could be extremely prospective candidate drugs used to treat IBS, and further preclinical and clinical researches are needed to guarantee their efficacy and safety.

In Vitro Efficacy of Targeted Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols Enzymatic Digestion in a High-Fidelity Simulated Gastrointestinal Environment

Background and Aims

Irritable bowel syndrome (IBS) is characterized by abdominal pain and changes in bowel habits. Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) are poorly absorbed short-chain carbohydrates that may drive commensal microbial gas production, promoting abdominal pain in IBS. Low-FODMAP diet can result in symptomatic improvement in 50%-80% of IBS patients. However, this diet is not meant to be sustained long term, with concern for downstream nutrition and microbial issues. In this study, we evaluate the function of a targeted FODMAP enzymatic digestion food supplement FODMAP enzymatic digestion (FODZYME) containing a fructan-hydrolase enzyme (with significant inulinase activity) in a simulated gastrointestinal environment.

Methods

Using SHIME (Simulator of the Human Intestinal Microbial Ecosystem), a multi-compartment simulator of the human gut, FODZYME dose finding assay in modeled gastrointestinal conditions assessed enzymatic ability to hydrolyze 3 g of inulin. Full intestinal modeling assessing digestion of inulin, absorption of fructose, gas production, and other measures of commensal microbial behavior was completed using 1.125 g of FODZYME.

Results

After 30 minutes, 90% of the inulin was converted to fructose by 1.125 g of FODZYME. Doubling dosage showed no significant improvement in conversion, whereas a half dose decreased performance to 77.2%. Seventy percent of released fructose was absorbed during simulated small intestinal transit, with a corresponding decrease in microbial gas production, and a small decrease in butyrate and short-chain fatty acid production.

Conclusion

FODZYME specifically breaks down inulin in representative gastrointestinal conditions, resulting in decreased gas production while substantially preserving short-chain fatty acid and butyrate production in the model colon. Our results suggest dietary supplementation with FODZYME would decrease intestinal FODMAP burden and gas production.

Progress in traditional Chinese medicine study of constipation predominant irritable bowel syndrome

The etiology and pathogenesis of constipation predominant irritable bowel syndrome (IBS-C) have not been fully elucidated. The lack of satisfactory treatment and the rising incidence of IBS-C often affect the lives of patients in different degrees. This paper summarizes the understanding of the etiology, pathogenesis, and common effective treatment methods for IBS-C in recent years from the perspective of traditional Chinese medicine (TCM), with an aim to provide a reference for further study of the role of TCM in IBS-C treatment.

Geraniol Treatment for Irritable Bowel Syndrome: A Double-Blind Randomized Clinical Trial

Geraniol is an acyclic monoterpene alcohol with well-known anti-inflammatory and antimicrobial properties which has shown eubiotic activity towards gut microbiota (GM) in patients with irritable bowel syndrome (IBS).

METHODS

Fifty-six IBS patients diagnosed according to Rome III criteria were enrolled in an interventional, prospective, multicentric, randomized, double-blinded, placebo-controlled trial. In the treatment arm, patients received a low-absorbable geraniol food supplement (LAGS) once daily for four weeks.

RESULTS

Patients treated with LAGS showed a significant reduction in their IBS symptoms severity score (IBS-SSS) compared to the placebo (195 vs. 265, p = 0.001). The rate of responders according to IBS-SSS (reduction ≥ 50 points) was significantly higher in the geraniol vs placebo group (52.0% vs. 16.7%, p = 0.009) mainly due to the IBS mixed subtype. There were notable differences in the microbiota composition after geraniol administration, particularly a significant decrease in a genus of Ruminococcaceae, Oscillospira (p = 0.01), a decreasing trend for the Erysipelotrichaceae and Clostridiaceae families (p = 0.1), and an increasing trend for other Ruminococcaceae taxa, specifically Faecalibacterium (p = 0.09). The main circulating proinflammatory cytokines showed no differences between placebo and geraniol arms.

CONCLUSION

LAGS was effective in treating overall IBS symptoms, together with an improvement in the gut microbiota profile, especially for the IBS mixed subtype.

Diagnostic management of patients reporting symptoms after wheat ingestion

Many patients report symptoms after wheat ingestion experiencing a wide spectrum of clinical manifestations. Three possible diagnoses have been recognized: celiac disease (CD), wheat allergy (WA), and non-celiac (gluten) wheat sensitivity (NCGS/NCWS). CD is a chronic immune-mediated disease of the small bowel caused by exposure to dietary gluten in genetically predisposed individuals, with a prevalence of approximately 1%. It is characterized by mucosal inflammation and atrophy following exposure to gluten and improvement after gluten withdrawal. Food allergies are immunological responses to a food antigen. WA is the expression of an immunologically mediated process that can be immunoglobulin E (IgE) or non-IgE mediated; its many symptoms include urticaria/angioedema, asthma, rhinitis, and anaphylaxis. NCGS/NCWS is characterized by gastrointestinal and/or extra-intestinal symptoms after ingestion of gluten-containing food in subjects not affected by CD or WA. The aim of this review is to help physicians and nutritionists diagnose the cause of symptoms reported after wheat ingestion, thus avoiding patient frustration, inappropriate testing, and incorrect or missed diagnoses. An algorithm for the diagnostic approach in these patients is provided, to help to diagnose CD, WA, NCGS/NCWS or to identify possible functional disorders as the wheat-sensitive irritable bowel syndrome. A personalized approach, regular follow-up, and the help of a skilled healthcare professional are mandatory for patients with symptoms following wheat ingestion is provided. A gluten-free-diet is often recommended for patients with self-reported gluten/wheat-dependent symptoms; for patients with symptoms similar to those of functional diseases while there is evidence that a low-FODMAP diet could be the first option.

Efficacy of probiotics for the treatment of irritable bowel syndrome

A review of current literature data was made, substantiating the high prevalence and social significance of irritable bowel syndrome (IBS). In different regions of the world, the prevalence of IBS ranges from 10% to 15%. The pathogenesis of IBS is a multifactorial process, including dysmotility, sluggish immune inflammation, changes in intestinal permeability, dysbiosis, exposure to infectious agents, malnutrition, neurohumoral dysregulation, changes in the central nervous system (psychological stress, cognitive dysfunction) in combination with genetic factors. The complexity of the pathogenesis determines the heterogeneity of the clinical manifestations of IBS, among which there may be forms with a predominance of pain, constipation, diarrhea, flatulence, which in turn complicates approaches to the treatment of this disease. The decisive importance of fecal dysbiosis for the pathogenesis of functional bowel pathology is now recognized. A 2019 systematic review showed a clear decrease in the genera Bifidobacterium and Faecalibacterium, an increase in the families Lactobacillaceae, Enterobacteriaceae and the genus Bacteroides in patients with IBS compared with healthy individuals. The Rome IV criteria, the recommendations of the British Society of Gastroenterology, the United European Gastroenterology and the European Society for Neurogastroenterology and Motility, the Russian Gastroenterological Association substantiate the use of probiotics for the treatment of IBS. Placebo-controlled clinical studies confirm the action of Bifidobacterium longum 35624 to normalize the frequency and form of stools, relieve general symptoms, abdominal pain, bloating, and improve the quality of life in patients with IBS. The expert council, held on March 18, 2022 in Moscow, chaired by the chief gastroenterologist of the Ministry of Health of the Russian Federation, Academician of the RAS V.T. Ivashkin, confirmed the effectiveness of probiotics for the treatment of IBS.

Diet and irritable bowel syndrome: an update from a UK consensus meeting

There has been a renewed interest in the role of dietary therapies to manage irritable bowel syndrome (IBS), with diet high on the agenda for patients. Currently, interest has focussed on the use of traditional dietary advice (TDA), a gluten-free diet (GFD) and the low FODMAP diet (LFD). A consensus meeting was held to assess the role of these dietary therapies in IBS, in Sheffield, United Kingdom.Evidence for TDA is from case control studies and clinical experience. Randomised controlled trials (RCT) have demonstrated the benefit of soluble fibre in IBS. No studies have assessed TDA in comparison to a habitual or sham diet. There have been a number of RCTs demonstrating the efficacy of a GFD at short-term follow-up, with a lack of long-term outcomes. Whilst gluten may lead to symptom generation in IBS, other components of wheat may also play an important role, with recent interest in the role of fructans, wheat germ agglutinins, as well as alpha amylase trypsin inhibitors. There is good evidence for the use of a LFD at short-term follow-up, with emerging evidence demonstrating its efficacy at long-term follow-up. There is overlap between the LFD and GFD with IBS patients self-initiating gluten or wheat reduction as part of their LFD. Currently, there is a lack of evidence to suggest superiority of one diet over another, although TDA is more acceptable to patients.In view of this evidence, our consensus group recommends that dietary therapies for IBS should be offered by dietitians who first assess dietary triggers and then tailor the intervention according to patient choice. Given the lack of dietetic services, novel approaches such as employing group clinics and online webinars may maximise capacity and accessibility for patients. Further research is also required to assess the comparative efficacy of dietary therapies to other management strategies available to manage IBS.