Direct healthcare costs of Rome IV or Rome III-defined irritable bowel syndrome in the United Kingdom

Predictors of response to low-dose amitriptyline for irritable bowel syndrome and efficacy and tolerability according to subtype: post hoc analyses from the ATLANTIS trial

BACKGROUND

Low-dose amitriptyline, a tricyclic antidepressant (TCA), was superior to placebo for irritable bowel syndrome (IBS) in the AmitripTyline at Low-dose ANd Titrated for Irritable bowel syndrome as Second-line treatment (ATLANTIS) trial.

OBJECTIVE

To perform post hoc analyses of ATLANTIS for predictors of response to, and tolerability of, a TCA.

DESIGN

ATLANTIS randomised 463 adults with IBS to amitriptyline (232) or placebo (231). We examined the effect of baseline demographic and disease-related patient characteristics on response to amitriptyline and the effect of amitriptyline on individual symptoms and side effects by subtype.

RESULTS

There was a quantitative difference in amitriptyline effectiveness in those ≥50 years vs <50 on the IBS severity scoring system (IBS-SSS) (interaction p=0.048, mean difference in ≥50 years subgroup -46.5; 95% CI -74.2 to -18.8, p=0.0010), and subjective global assessment of relief (interaction p=0.068, OR in ≥50 years subgroup 2.59; 95% CI 1.47 to 4.55, p=0.0010), and those in the 70% most deprived areas of England compared with the 30% least deprived for a ≥30% improvement in abdominal pain (interaction p=0.021, OR in 70% most deprived subgroup 2.70; 95% CI 1.52 to 4.77, p=0.0007). Stronger treatment effects were seen in men, with higher Patient Health Questionnaire-12 scores, and with IBS with diarrhoea. Mean differences in individual IBS-SSS components favoured amitriptyline, and side effects were similar, across almost all IBS subtypes.

CONCLUSION

These exploratory analyses demonstrate there are unlikely to be deleterious effects of amitriptyline in any particular IBS subtype and could help identify patients in whom amitriptyline may be more effective.

TRIAL REGISTRATION NUMBER

ISRCTN48075063.

Is there a sex difference in response to FODMAP diet group education for IBS? A clinical practice service evaluation

Background: While the low fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet, low FODMAP diet (LFD) has demonstrated effectiveness in managing irritable bowel syndrome (IBS) symptoms, little is known about sex-specific responses to this dietary intervention. Aim: This study evaluates the role of sex differences in symptom improvement following a dietitian-led, group education session on the LFD for IBS patients. Methods: A total of 305 patients, including 249 with a diagnosis of IBS and 56 classified as having suspected IBS, were enrolled in this study (79.7% female). Patients attended two group education sessions on the LFD. Primary outcomes were measured using the IBS Symptom Severity Score (IBS-SSS) and the Global Symptom Question (GSQ). Secondary outcomes included stool frequency, stool consistency and individual symptoms assessed by the Gastrointestinal Symptom Rating Scale. Statistical analyses were performed to compare baseline and follow-up data within and between sexes. Results: Both male and female patients experienced significant reductions in IBS-SSS scores and improvements in GSQ satisfactory relief, stool frequency, stool consistency and individual gastrointestinal (GI) symptoms following the LFD (p < 0.05). There were no significant between-sex differences in the extent of symptom relief (p > 0.05). Conclusion: The study found no significant sex-based differences in symptom reduction or GI relief following the intervention. These findings suggest that, despite differing symptom profiles and IBS prevalence, both male and female patients achieve similar relief with the LFD group education.

Low-dose amitriptyline for irritable bowel syndrome: a qualitative study of patients' and GPs' views and experiences

BACKGROUND

Irritable bowel syndrome (IBS) can cause troublesome symptoms, which impact patients' quality of life and incur considerable health service resource use. Guidelines suggest low-dose amitriptyline for IBS as second-line treatment, but this is rarely prescribed in primary care.

AIM

To explore patients' and GPs' views and experiences of using low-dose amitriptyline for IBS.

DESIGN AND SETTING

Qualitative interview study with patients and GPs in England, nested within the ATLANTIS trial of low-dose amitriptyline versus placebo (ISRCTN48075063).

METHOD

Semi-structured telephone interviews were conducted with 42 patients at 6 months post-randomisation, with 19 patients again at 12 months post-randomisation, and with 16 GPs between April 2020 and March 2022. Reflexive thematic analysis was used to analyse patient and GP data separately, then together, to identify unique and cross-cutting themes.

RESULTS

We found concerns about amitriptyline being an antidepressant, medicalising IBS, and side effects. Perceived benefits included the low and flexible dose, ease of treatment, and familiarity of amitriptyline and its potential to offer benefits beyond IBS symptom relief. These concerns and perceived benefits were expressed in the context of desire for a novel approach to IBS: GPs were keen to offer more options for IBS and patients sought a cure for their symptoms.

CONCLUSION

Patients and GPs felt that the potential benefits of trying low-dose amitriptyline for IBS outweighed their concerns. When offering low-dose amitriptyline for IBS, GPs could address patient concerns about taking an antidepressant for IBS, highlighting the low and flexible dosage, and other potential benefits of amitriptyline such as improved sleep.

Comparison of Rifaximin Monotherapy and Rifaximin Combined with Probiotics in Patients with Irritable Bowel Syndrome: A Randomized Controlled Trial

Background/Objective: Rifaximin is a nonabsorbable antibiotic used to treat irritable bowel syndrome (IBS). Recent studies on Helicobacter pylori eradication treatment have reported synergistic effects and low adverse effects when antibiotics are used in combination with probiotics; yet, such studies have not been conducted in IBS. Probiotics can enhance gut microbiota modulation, inhibition of pathogen adhesion to the gut epithelia, improvement in gut barrier function, anti-inflammatory effects, and improvement of gut immunity. Therefore, this study aimed to investigate the efficacy and safety of rifaximin in combination with probiotics compared to rifaximin monotherapy in patients with IBS. Methods: Patients with IBS were randomly allocated to receive rifaximin monotherapy or a combination of rifaximin and probiotics. The primary outcome was the response rate of the total IBS severity scoring system (IBS-SSS) score (>50-point decrease). Secondary outcomes were based on the response rate of the IBS quality of life (IBS-QOL) score and the IBS-SSS1 subscore (>10-point decrease in both scores). Results: Among 70 patients, the responder rates for the total IBS-SSS score were 65.7% in the combination therapy group and 31.4% in the monotherapy group at weeks 4 and 8, respectively (p = 0.004). The responder rates for IBS-QOL were 65.7% versus (vs.) 37.1% and 65.7% vs. 34.2% at weeks 4 and 8, respectively (p = 0.017 and p = 0.009, respectively). The IBS-SSS1 subscore responder rates were 65.7% vs. 40.0% at week 4 and 68.6% vs. 37.1% at 8 weeks (p = 0.031 and p = 0.017, respectively). Conclusions: Rifaximin combined with probiotics was superior to rifaximin monotherapy in patients with IBS. This combination therapy is considered an effective and safe treatment option for patients with IBS. However, further studies are needed to investigate the mechanisms of therapy and long-term outcomes.

Anxiety and Depression Disorders in Vietnamese Patients With Irritable Bowel Syndrome: A Cross-Sectional Clinic-Based Study

Background

Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disorder. Growing evidence suggests a significant association between IBS and psychological problems, such as anxiety and depression. This study was conducted to assess the prevalence of anxiety and depression in Vietnamese patients diagnosed with IBS according to Rome IV criteria.

Methods

This cross-sectional study recruited 186 consecutive patients who underwent outpatient clinic visits and colonoscopy for gastrointestinal symptoms. IBS diagnosis was established using the validated Rome IV criteria. Anxiety and depression were assessed using a validated Vietnamese version of the Hospital Anxiety and Depression Scale (HADS).

Results

The mean age of IBS patients was 49.5 ± 12.0 years, with females comprising 53.8%. IBS-M was the most prevalent subtype (39.8%), followed by IBS-C (39.2%) and IBS-D (21.0%). Using the HADS cut-off of ≥ 11 points for probable anxiety and depression, the prevalence was 21.0% and 11.8%, respectively. Expanding the criterion to a HADS of ≥ 8, indicating significant symptoms, increased the prevalence to 55.9% for anxiety and 40.8% for depression disorders. Patients with IBS-C, IBS-D, or IBS-M exhibited a significantly higher risk of depressive disorders compared to those without IBS, with odds ratios of 4.261, 7.013, and 6.585, respectively (p < 0.001). Additionally, men were less likely than women to experience depressive disorders.

Conclusion

The findings revealed a high prevalence of depression and anxiety disorders among Vietnamese patients with IBS. Those with the IBS-M or IBS-D subtypes and a greater number of gastrointestinal symptoms were more likely to experience higher levels of depression and anxiety, particularly women.

An evidence-based update on the diagnosis and management of irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction affecting 5% of the population. The cardinal symptoms are abdominal pain and altered stool form or frequency.

AREAS COVERED

Diagnosis and management of IBS. We searched the literature for diagnostic accuracy studies, randomized controlled trials, and meta-analyses. A positive diagnosis of IBS, alongside testing to exclude celiac disease, is recommended. Exhaustive investigation has a low yield. Patients should be offered traditional dietary advice. If response is incomplete, specialist dietetic guidance should be considered. Probiotics may be beneficial, but quality of evidence is poor. First-line treatment of constipation is with laxatives, with secretagogues used where these are ineffective. Anti-diarrheal drugs should be used first-line for diarrhea, with second-line drugs including 5-hydroxytryptamine-3 antagonists, eluxadoline, or rifaximin, where available. First-line treatment of abdominal pain should be with antispasmodics, with gut-brain neuromodulators prescribed second-line. Low-dose tricyclic antidepressants, such as amitriptyline, are preferred. Brain-gut behavioral therapies are effective and have evidence for efficacy in patients refractory to standard therapies.

EXPERT OPINION

Despite substantial advances, there remains scope for improvement in terms of both the diagnosis and management of IBS. Reinforcement of positive diagnostic strategies for the condition and novel treatment paradigms are required.

Efficacy of fermented foods in irritable bowel syndrome: a systematic review and meta-analysis of randomized controlled trials

Objective

Fermented foods (FFs) may theoretically benefit irritable bowel syndrome (IBS) symptoms, but the role of FFs for IBS patients in the real world is inconsistent and has not been systematically assessed. We performed a systematic review and meta-analysis to examine this issue.

Methods

PubMed, MEDLINE, Embase and Cochrane Library databases were searched up to August 2024. Randomized controlled trials (RCTs) investigating the efficacy of FFs in IBS were eligible for the analysis. Two authors independently screened studies and extracted data. Data were pooled using relative risk (RR) of dichotomous data and standardized mean difference (SMD) for continuous data.

Results

A total of 16 RCTs with 1,264 IBS patients were included. There were 12 RCTs involving 975 patients providing primary outcomes which was defined as symptom relief. The proportion of symptom relief was associated with the administration of FFs (RR 1.22, 95% CI 1.04-1.42, p = 0.01, I 2 = 0%). For secondary outcomes, FFs also exerted a beneficial effect on global symptoms scores (SMD = -0.15; 95% CI -0.29 to -0.02, p = 0.02, I 2 = 46%), but no significant improvement on abdominal pain scores and bloating scores. Subgroup analysis showed that fermented milk had a beneficial effect on symptom relief (RR 1.19, 95% CI 1.01 to 1.39, p = 0.04, I 2 = 0%).

Conclusion

Fermented foods, especially fermented milk with probiotics properties, appear to be efficacious in irritable bowel syndrome. However, given the limitations of current evidence, this conclusion should be interpreted with caution.

Systematic Review Registration

This study was registered on the International Prospective Register of Systematic Reviews (PROSPERO) as CRD42024576608.

The Role of Gut Microbiome in Irritable Bowel Syndrome: Implications for Clinical Therapeutics

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder (FGID) characterized by chronic or recurrent gastrointestinal symptoms without organic changes, and it is also a common disorder of gut-brain interaction (DGBIs).. The symptoms of IBS not only affect the quality of life for individual patients but also place a significant burden on global healthcare systems. The lack of established and universally applicable biomarkers for IBS, along with the substantial variability in symptoms and progression, presents challenges in developing effective clinical treatments. In recent years, preclinical and clinical studies have linked the pathogenesis of IBS to alterations in the composition and function of the intestinal microbiota. Within the complex microbial community of the gut, intricate metabolic and spatial interactions occur among its members and between microbes and their hosts. Amid the multifaceted pathophysiology of IBS, the role of intestinal microenvironment factors in symptom development has become more apparent. This review aims to delve into the changes in the composition and structure of the gut microbiome in individuals with IBS. It explores how diet-mediated alterations in intestinal microbes and their byproducts play a role in regulating the pathogenesis of IBS by influencing the "brain-gut" axis, intestinal barrier function, immune responses, and more. By doing so, this review seeks to lay a theoretical foundation for advancing the development of clinical therapeutics for IBS.

Toll-like receptor 4 plays a vital role in irritable bowel syndrome: a scoping review

Background

Irritable bowel syndrome (IBS) is a common gastrointestinal disease. Recently, an increasing number of studies have shown that Toll-like receptor 4 (TLR4), widely distributed on the surface of a variety of epithelial cells (ECs) and immune sentinel cells in the gut, plays a vital role in developing IBS.

Objectives

We sought to synthesize the existing literature on TLR4 in IBS and inform further study.

Methods

We conducted a systematic search of the PubMed, Embase (Ovid), Scopus, Web of Science, MEDLINE, and Cochrane Library databases on June 8, 2024, and screened relevant literature. Critical information was extracted, including clinical significance, relevant molecular mechanisms, and therapeutic approaches targeting TLR4 and its pathways.

Results

Clinical data showed that aberrant TLR4 expression is associated with clinical manifestations such as pain and diarrhea in IBS. Aberrant expression of TLR4 is involved in pathological processes such as intestinal inflammation, barrier damage, visceral sensitization, and dysbiosis, which may be related to TLR4, NF-κB, pro-inflammatory effects, and CRF. Several studies have shown that many promising therapeutic options (i.e., acupuncture, herbs, probiotics, hormones, etc.) have been able to improve intestinal inflammation, visceral sensitization, intestinal barrier function, intestinal flora, defecation abnormalities, and depression by inhibiting TLR4 expression and related pathways.

Conclusion

TLR4 plays a crucial role in the development of IBS. Many promising therapeutic approaches alleviate IBS through TLR4 and its pathways. Strategies for targeting TLR4 in the future may provide new ideas for treating IBS.

The Impact and Interactions of Race and Gender on Healthcare Use and Spending in Irritable Bowel Syndrome

BACKGROUND & AIMS

Studies examining the effects of social determinants of health on healthcare use in irritable bowel syndrome (IBS) are scarce. We aimed to assess healthcare spending among different racial/ethnic groups and genders in adults with IBS.

METHODS

We performed a retrospective cohort analysis of adults diagnosed with IBS between 2016 and 2021 using Optum's de-identified Clinformatics Data Mart database. We analyzed total annual and IBS-specific costs, utilization and costs of individual services, and prescriptions. We compared outcomes across racial/ethnic groups and by gender after adjusting for covariates and examined race-gender interactions.

RESULTS

Among 95,319 adults with IBS, healthcare spending varied significantly by race and gender. Total all-cause and IBS-specific costs were lower in men than in women and in Asian and Hispanic patients than in White patients. Compared with White patients, Black patients had higher total IBS-specific costs, all-cause prescription costs, IBS-related radiology and laboratory costs, and emergency department (ED) care, while Asian and Hispanic patients incurred lower costs for ED care, hospitalizations, and all-cause prescriptions. Endoscopy costs were lower in racial minority groups. Women had higher spending for most services compared with men, but gender differences in most IBS-related services were small. All-cause hospitalization and endoscopy costs were higher in men, but IBS-specific hospitalization and endoscopy costs were higher in women. Gender disparities in all-cause individual services also varied by race.

CONCLUSIONS

Overall and IBS-related spending is higher in women, but gender differences in IBS-related care are small. Racial/ethnic comparisons show reduced spending in Asian and Hispanic patients, increased ED care in Black patients, and variations in spending patterns. Gender disparities differ by race.

Personalisation of therapy in irritable bowel syndrome: a hypothesis

Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction characterised by symptoms of abdominal pain, occurring at least 1 day per week, and a change in stool frequency or form. Individuals with IBS are usually subtyped according to their predominant bowel habit, which is used to direct symptom-based treatment. However, this approach is probably an oversimplification of a complex and multidimensional condition, and other factors, such as psychological health, are known to influence symptom severity and prognosis. We have previously used latent class analysis, a method of mathematical modelling, to show that people with IBS can be classified into seven unique clusters based on a combination of gastrointestinal symptoms, abdominal pain, extraintestinal symptoms, and psychological comorbidity. The clusters can be used to predict the prognosis of IBS (eg, symptom severity), health-care use (eg, consultation behaviour, prescribing, and costs), and impact (eg, quality of life, work and productivity, activities of daily living, and income). These clusters could also be used to increase the personalisation of IBS treatment that better recognises the heterogenous nature of the condition. We present new data providing additional validation of our seven-cluster model and conduct a comprehensive evidence-based review of IBS management. Based on this evidence, we propose a framework of first-line and second-line treatments according to IBS cluster. Finally, we discuss what further research is needed to implement this approach in clinical practice, including the need for randomised trials comparing cluster-based treatment with conventional treatment according to stool subtype.

Low-dose titrated amitriptyline as second-line treatment for adults with irritable bowel syndrome in primary care: the ATLANTIS RCT

Background

Irritable bowel syndrome, characterised by abdominal pain and a change in stool form or frequency, is most often managed in primary care. When first-line therapies are ineffective, National Institute for Health and Care Excellence guidelines suggest considering low-dose tricyclic antidepressants as second-line treatment, but their effectiveness in primary care is unknown and they are infrequently prescribed by general practitioners.

Objective

To evaluate the clinical and cost-effectiveness of low-dose titrated amitriptyline as a second-line treatment for irritable bowel syndrome in primary care.

Design

A pragmatic, randomised, multicentre, two-arm, double-blind, placebo-controlled trial. A nested, qualitative study explored participant and general practitioner experiences of treatments and trial participation, and implications for wider use of amitriptyline for irritable bowel syndrome in primary care. Participants, clinicians, investigators and analysts were masked to allocation.

Setting

Fifty-five general practices in three regions in England (Wessex, West of England, West Yorkshire).

Participants

Patients aged ≥ 18 years meeting Rome IV criteria for irritable bowel syndrome with ongoing symptoms after trying first-line treatments and no contraindications to TCAs.

Intervention

Amitriptyline 10 mg once-daily, self-titrated by participants to a maximum of 30 mg once-daily or matched placebo for 6 months. Participants randomised 1 : 1 with most having the option to continue blinded treatment for a further 6 months.

Main outcome measures

The primary participant-reported outcome was the effect of amitriptyline on global irritable bowel syndrome symptoms at 6 months, measured using the irritable bowel syndrome Severity Scoring System, with a 35-point between-group difference defined as the minimum clinically important difference. The key secondary outcome was the proportion of participants reporting subjective global assessment of relief at 6 months, defined as somewhat, considerable, or complete relief of symptoms. Other secondary outcomes included: effect on global symptoms, via the irritable bowel syndrome Severity Scoring System, and subjective global assessment of relief of irritable bowel syndrome symptoms at 3 and 12 months; effect on somatic symptom-reporting at 6 months; anxiety an-d depression scores; ability to work and participate in other activities at 3, 6 and 12 months; acceptability, tolerability and adherence to trial medication.

Results

Four hundred and sixty-three participants were randomised to amitriptyline (232) or placebo (231). An intention-to-treat analysis of the primary outcome showed a significant difference in favour of amitriptyline for irritable bowel syndrome Severity Scoring System score between arms at 6 months [-27.0, 95% confidence interval (CI) -46.9 to -7.10; p = 0.008]. For the key secondary outcome of subjective global assessment of relief of irritable bowel syndrome symptoms, amitriptyline was superior to placebo at 6 months (odds ratio 1.78, 95% CI 1.19 to 2.66; p = 0.005). Amitriptyline was superior to placebo across a range of other irritable bowel syndrome symptom measures but had no impact on somatoform symptom-reporting, anxiety, depression, or work and social adjustment scores. Adverse event trial withdrawals were more common with amitriptyline (12.9% vs. 8.7% for placebo) but most adverse events were mild. The qualitative study thematically analysed 77 semistructured interviews with 42 participants and 16 GPs. Most participants found the self-titration process acceptable and empowering.

Conclusions

General practitioners should offer low-dose amitriptyline to patients with irritable bowel syndrome whose symptoms do not improve with first-line therapies. Guidance and resources should support GP-patient communication to distinguish amitriptyline for irritable bowel syndrome from use as an antidepressant and to support patients managing their own dose titration.

Study registration

This trial is registered as ISRCTN48075063.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 16/162/01) and is published in full in Health Technology Assessment Vol. 28, No. 66. See the NIHR Funding and Awards website for further award information.

Microbiome-driven IBS metabotypes influence response to the low FODMAP diet: insights from the faecal volatome

BACKGROUND

Irritable bowel syndrome (IBS) is a common and debilitating disorder manifesting with abdominal pain and bowel dysfunction. A mainstay of treatment is dietary modification, including restriction of FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols). A greater response to a low FODMAP diet has been reported in those with a distinct IBS microbiome termed IBS-P. We investigated whether this is linked to specific changes in the metabolome in IBS-P.

METHODS

Solid phase microextraction gas chromatography-mass spectrometry was used to examine the faecal headspace of 56 IBS cases (each paired with a non-IBS household control) at baseline, and after four-weeks of a low FODMAP diet (39 pairs). 50% cases had the IBS-P microbial subtype, while the others had a microbiome that more resembled healthy controls (termed IBS-H). Clinical response to restriction of FODMAPs was measured with the IBS-symptom severity scale, from which a pain sub score was calculated.

FINDINGS

Two distinct metabotypes were identified and mapped onto the microbial subtypes. IBS-P was characterised by a fermentative metabolic profile rich in short chain fatty acids (SCFAs). After FODMAP restriction significant reductions in SCFAs were observed in IBS-P. SCFA levels did not change significantly in the IBS-H group. The magnitude of pain and overall symptom improvement were significantly greater in IBS-P compared to IBS-H (p = 0.016 and p = 0.026, respectively). Using just five metabolites, a biomarker model could predict microbial subtype with accuracy (AUROC 0.797, sensitivity 78.6% (95% CI: 0.78-0.94), specificity 71.4% (95% CI: 0.55-0.88).

INTERPRETATION

A metabotype high in SCFAs can be manipulated by restricting fermentable carbohydrate, and is associated with an enhanced clinical response to this dietary restriction. This implies that SCFAs harbour pro-nociceptive potential when produced in a specific IBS niche. By ascertaining metabotype, microbial subtype can be predicted with accuracy. This could allow targeted FODMAP restriction in those seemingly primed to respond best.

FUNDING

This research was co-funded by Addenbrooke's Charitable Trust, Cambridge University Hospitals and the Wellcome Sanger Institute, and supported by the NIHR Cambridge Biomedical Research Centre (BRC-1215-20014).

Intestinal barrier function in the naked mole-rat: an emergent model for gastrointestinal insights

The intestinal barrier plays a crucial role in homeostasis by both facilitating the absorption of nutrients and fluids and providing a tight shield to prevent the invasion by either pathogen or commensal microorganisms. Intestinal barrier malfunction is associated with systemic inflammation, oxidative stress, and decreased insulin sensitivity, which may lead to the dysregulation of other tissues. Therefore, a deeper understanding of physiological aspects related to an enhanced barrier function is of significant scientific and clinical relevance. The naked mole-rat has many unusual biological features, including attenuated colonic neuron sensitivity to acid and bradykinin and resistance to chemical-induced intestinal damage. However, insight into their intestinal barrier physiology is scarce. Here, we observed notable macroscopic and microscopic differences in intestinal tissue structure between naked mole-rats and mice. Moreover, naked mole-rats showed increased number of larger goblet cells and elevated mucus content. In measuring gut permeability, naked mole-rats showed reduced permeability compared with mice, measured as transepithelial electrical resistance, especially in ileum. Furthermore, intestinal ion secretion induced by serotonin, bradykinin, histamine, and capsaicin was significantly reduced in naked mole-rats compared with mice, despite the expression of receptors for all these agonists. In addition, naked mole-rats exhibited reduced prosecretory responses to the nonselective adenylate cyclase activator forskolin. Collectively, these findings indicate that naked mole-rats possess a robust and hard-to-penetrate gastrointestinal barrier that is resistant to environmental and endogenous irritants. Naked mole-rats may therefore provide valuable insights into the physiology of the intestinal barrier and set the stage for the development of innovative and effective therapies.NEW & NOTEWORTHY This is the first study to characterize the intestinal function of naked mole-rats. We found that these animals show a robust gut tissue structure, displaying thicker intestinal layers, longer villi, and larger crypts. Naked mole-rats showed more and larger goblet cells, with increased mucus content. Intestinal permeability, especially in the ileum, was substantially lower than that of mice. Finally, naked mole-rats showed reduced intestinal anion secretion in response to serotonin, bradykinin, histamine, capsaicin, and forskolin.

Healthcare Costs of Irritable Bowel Syndrome and Irritable Bowel Syndrome Subtypes in the United States

INTRODUCTION

Contemporaneous data on healthcare costs of irritable bowel syndrome (IBS) in the United States are lacking. We aimed to estimate all-cause and IBS-specific costs in patients with and without IBS and to compare costs across IBS subtypes.

METHODS

Using Optum's deidentified Clinformatics Data Mart Database, we performed a retrospective cohort analysis of patients with and without IBS using data spanning 2016-2021. Patients with IBS were identified by ICD-10 codes. Controls were randomly selected from Clinformatics Data Mart Database participants. Primary outcomes were total all-cause and IBS-specific healthcare costs. Secondary outcomes were costs of individual services associated with any claim. Costs were compared between IBS and control groups and across IBS subtypes using propensity score weighting. Comorbidities were measured with the Elixhauser Comorbidity Index.

RESULTS

Comparison of 102,887 patients with IBS (77.9% female; mean ± SD age 60.3 ± 18.4 years; 75.8% white) and 102,887 controls demonstrated higher median (interquartile range) total costs per year ( P < 0.001) for patients with IBS ($13,288 [5,307-37,071]) than controls ($5,999 [1,800-19,426]). IBS was associated with increased healthcare utilization and higher median annual costs per patient for all services. Median (interquartile range) annual IBS-specific spending was $1,127 (370-5,544) per patient. Propensity score-weighted analysis across IBS subtypes revealed differences in total all-cause and IBS-specific costs and in costs of individual services. Highest spending was observed in IBS with constipation (all-cause $16,005 [6,384-43,972]; IBS-specific $2,222 [511-7,887]).

DISCUSSION

Individuals with IBS exhibit higher healthcare utilization and incur substantially higher all-cause costs than those without. Care costs differ by IBS subtype.

Sishen Wan enhances intestinal barrier function via regulating endoplasmic reticulum stress to improve mice with diarrheal irritable bowel syndrome

BACKGROUND

Diarrheal irritable bowel syndrome (IBS-D), characterized primarily by the presence of diarrhea and abdominal pain, is a clinical manifestation resulting from a multitude of causative factors. Furthermore, Sishen Wan (SSW) has demonstrated efficacy in treating IBS-D. Nevertheless, its mechanism of action remains unclear.

METHODS

A model of IBS-D was induced by a diet containing 45 % lactose and chronic unpredictable mild stress. Additionally, the impact of SSW was assessed by measuring body weight, visceral sensitivity, defecation parameters, intestinal transport velocity, intestinal neurotransmitter levels, immunohistochemistry, and transmission electron microscopy analysis. Immunofluorescent staining was used to detect the expression of Mucin 2 (MUC2) and Occludin in the colon. Western blotting was used to detect changes in proteins related to tight junction (TJ), autophagy, and endoplasmic reticulum (ER) stress in the colon. Finally, 16S rRNA amplicon sequencing was used to monitor the alteration of gut microbiota after SSW treatment.

RESULTS

Our study revealed that SSW administration resulted in reduced visceral sensitivity, improved defecation parameters, decreased intestinal transport velocity, and reduced intestinal permeability in IBS-D mice. Furthermore, SSW promotes the secretion of colonic mucus by enhancing autophagy and inhibiting ER stress. SSW treatment caused remodeling of the gut microbiome by increasing the abundance of Blautia, Muribaculum and Ruminococcus torques group.

CONCLUSION

SSW can improve intestinal barrier function by promoting autophagy and inhibiting ER stress, thus exerting a therapeutic effect on IBS-D.

Novel Irritable Bowel Syndrome Subgroups are Reproducible in the Global Adult Population

BACKGROUND & AIMS

Current classification systems for irritable bowel syndrome (IBS) based on bowel habit do not consider psychological impact. We validated a classification model in a UK population with confirmed IBS, using latent class analysis, incorporating psychological factors. We applied this model in the Rome Foundation Global Epidemiological Survey (RFGES), assessing impact of IBS on the individual and the health care system, and examining reproducibility.

METHODS

We applied our model to 2195 individuals in the RFGES with Rome IV-defined IBS. As described previously, we identified 7 clusters, based on gastrointestinal symptom severity and psychological burden. We assessed demographics, health care-seeking, symptom severity, and quality of life in each. We also used the RFGES to derive a new model, examining whether the broader concepts of our original model were replicated, in terms of breakdown and characteristics of identified clusters.

RESULTS

All 7 clusters were identified. Those in clusters with highest psychological burden, and particularly cluster 6 with high overall gastrointestinal symptom severity, were more often female, exhibited higher levels of health care-seeking, were more likely to have undergone previous abdominal surgeries, and had higher symptom severity and lower quality of life (P < .001 for trend for all). When deriving a new model, the best solution consisted of 10 clusters, although at least 2 seemed to be duplicates, and almost all mapped on to the previous clusters.

CONCLUSIONS

Even in the community, our original clusters derived from patients with physician-confirmed IBS identified groups of individuals with significantly higher rates of health care-seeking and abdominal surgery, more severe symptoms, and impairments in quality of life.

Postprandial symptoms in disorders of gut-brain interaction and their potential as a treatment target

Postprandial, or meal-related, symptoms, such as abdominal pain, early satiation, fullness or bloating, are often reported by patients with disorders of gut-brain interaction, including functional dyspepsia (FD) or irritable bowel syndrome (IBS). We propose that postprandial symptoms arise via a distinct pathophysiological process. A physiological or psychological insult, for example, acute enteric infection, leads to loss of tolerance to a previously tolerated oral food antigen. This enables interaction of both the microbiota and the food antigen itself with the immune system, causing a localised immunological response, with activation of eosinophils and mast cells, and release of inflammatory mediators, including histamine and cytokines. These have more widespread systemic effects, including triggering nociceptive nerves and altering mood. Dietary interventions, including a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols, elimination of potential food antigens or gluten, IgG food sensitivity diets or salicylate restriction may benefit some patients with IBS or FD. This could be because the restriction of these foods or dietary components modulates this pathophysiological process. Similarly, drugs including proton pump inhibitors, histamine-receptor antagonists, mast cell stabilisers or even tricyclic or tetracyclic antidepressants, which have anti-histaminergic actions, all of which are potential treatments for FD and IBS, act on one or more of these mechanisms. It seems unlikely that food antigens driving intestinal immune activation are the entire explanation for postprandial symptoms in FD and IBS. In others, fermentation of intestinal carbohydrates, with gas release altering reflex responses, adverse reactions to food chemicals, central mechanisms or nocebo effects may dominate. However, if the concept that postprandial symptoms arise from food antigens driving an immune response in the gastrointestinal tract in a subset of patients is correct, it is paradigm-shifting, because if the choice of treatment were based on one or more of these therapeutic targets, patient outcomes may be improved.

Organization of Neurogastroenterology and Motility units with a multidisciplinary, patient-centered perspective

Neurogastroenterology and Motility is a Gastroenterology subspecialty dealing with the management of gastrointestinal (GI) motor diseases and disorders of gut-brain interaction (DGBI). Both types of conditions may impair the nutritional status of patients - In the case of motility disorders, because deficient gastrointestinal motility may impair appropriate food digestion and absorption; in DGBI because development of gastrointestinal symptoms may impair appropriate patient nutrition. In both cases, different studies have shown that patients start restrictive diets on their own, without supervision of a dietician, which leads to nutritional deficits in many cases. Likewise, psychological factors like stressful situations or anxiety may trigger gastrointestinal symptoms in these patients, mainly in those with DGBI. Recent studies comparing a patient-centered approach that includes medical treatment, dietary modifications, and behavioural interventions with gastroenterologist-only standard care have shown a greater proportion of improved symptoms, psychological status, and quality of life, as well as reduced costs in patients allocated to the multidisciplinary treatment arm. In conclusion, there is growing evidence in favour of dietary and behavioural interventions by specialized professionals, coupled with appropriate medical evaluation and treatment by a gastroenterologist. Hence the importance of developing reference units in which comprehensive, individualized management may be offered. Multidisciplinary models improve clinical outcomes and patient satisfaction, which should result in a reduction of direct and indirect costs.  .

Deciphering the brain-gut axis: elucidating the link between cerebral cortex structures and functional gastrointestinal disorders via integrated Mendelian randomization

Background

Observational studies have suggested associations between functional gastrointestinal disorders (FGIDs) and variations in the cerebral cortex. However, the causality of these relationships remains unclear, confounded by anxiety and depression. To clarify these causal relationships and explore the mediating roles of anxiety and depression, we applied univariate, multivariable, and mediation Mendelian randomization (MR) analyses.

Method

We utilized genome-wide association study (GWAS) summary data from the FinnGen database and the ENIGMA consortium, identifying genetic variants associated with irritable bowel syndrome (IBS), functional dyspepsia (FD), and cerebral cortex structures. Data on anxiety and depression came from FinnGen and a large meta-analysis. Utilizing a bidirectional univariate MR approach, we explored correlations between FD, IBS, and cortex variations. Then, independent effects were assessed through multivariable MR. A meta-analysis of these results, incorporating data from two cohorts, aimed to increase precision. We also explored the potential mediating roles of anxiety and depression.

Results

Our findings indicate a negative causal correlation between FD and the thickness of the rostral anterior cingulate cortex (rACC) across both global and regional adjustments (β = -0.142, 95% confidence interval (CI): -0.209 to-0.074, P.FDR = 0.004; β = -0.112, 95%CI: -0.163 to-0.006, P.FDR = 0.003) and a positive causal correlation with the globally adjusted thickness of the superior frontal gyrus (SFG) (β = 0.107, 95%CI: 0.062 to 0.153, P.FDR = 0.001). The causal correlation with the rACC persisted after multiple variable adjustments (β = -0.137, 95% CI: -0.187 to-0.087, P.FDR = 1.81 × 10-5; β = -0.109, 95%CI: -0.158 to-0.06, P.FDR = 0.002). A significant causal association was found between globally adjusted surface area of the caudal anterior cingulate cortex (cACC) and IBS (odds ratio = 1.267, 95%CI: 1.128 to 1.424, P.FDR = 0.02). The analysis showed that neither anxiety nor depression mediated the relationship between FGIDs and cerebral cortex structures.

Conclusion

Our research provides significant MR evidence of a bidirectional causal relationship between FGIDs and the cerebral cortex structures. This evidence not only confirms the two-way communication along the brain-gut axis but also illuminates the underlying pathophysiology, paving the way for identifying potential therapeutic approaches.

Assessing 'response' to the low-FODMAP diet in irritable bowel syndrome: Should we be reporting harder primary endpoints?

BACKGROUND & AIMS

The low-FODMAP diet (LFD) has become almost synonymous with IBS care, yet the challenges associated with this rigorous therapeutic approach are often underacknowledged. Despite positive outcomes in RCTs, comparator groups frequently exhibit substantial response rates, raising questions about the definition of 'response'. Whilst the assessment of response in drug trials has evolved to utilize the more stringent FDA/EMA primary clinical endpoints, trials of the LFD have not yet followed. The aim of this article is to opine whether the current approach to the measurement of clinical response to the LFD in clinical trials should be reconsidered.

METHODS

A comprehensive literature review of LFD clinical trials from the past decade was conducted, focusing on recorded response metrics for primary clinical endpoints.

RESULTS

While response definitions vary, the 50-point IBS-SSS delta emerged as the predominant metric. Notably, no trials to date have adopted the more stringent primary clinical endpoints used in drug trials. Other response measures included binary response metrics (such as 'adequate clinical response'), changes in visual analogue scales or stool form/output, reductions in abdominal pain, as well as changes the magnitude of the IBS-SSS delta. Whether these metrics correspond to a clinically meaningful improvement for the patient is less clear, and as such aligning patient-clinician expectations can be challenging.

CONCLUSIONS

A paradigm shift in the conceptualization of 'response' coupled with an emphasis on harder clinical endpoints in the context of clinical trials may serve to better justify the trade-off between symptom-improvement and the inherent challenges associated with this burdensome therapeutic approach.

Utility of irritable bowel syndrome subtypes and most troublesome symptom in predicting disease impact and burden

BACKGROUND

Little is known about the characteristics of individuals with irritable bowel syndrome (IBS) according to stool subtype or the most troublesome symptom reported by the individual, or whether these are useful in predicting the impact of IBS.

METHODS

We collected demographic, gastrointestinal, and psychological symptoms, healthcare usage and direct healthcare costs, impact on work and activities of daily living, and quality of life data from individuals with Rome IV-defined IBS.

KEY RESULTS

We recruited 752 people with Rome IV IBS. Individuals with IBS-D reported a poorer disease-specific quality of life than those with IBS-C or IBS-M (mean (SD) IBS-QOL 45.3 (23.0) for IBS-D, vs. 52.3 (19.9) for IBS-C, vs. 49.4 (22.0) for IBS-M, p = 0.005). Mean (SD) IBS-QOL scores were also lower amongst those who reported diarrhea (44.8 (22.3)) or urgency (44.6 (22.3)) as their most troublesome symptom, compared with those reporting abdominal pain (52.2 (22.9)), constipation (49.5 (21.8)), or abdominal bloating or distension (50.4 (21.3)). However, there were no differences in mean EQ-5D scores, IBS severity, levels of anxiety, depression, somatoform symptom-reporting, or gastrointestinal symptom-specific anxiety. Direct healthcare costs of IBS were similar across all subtypes and all most troublesome symptom groups, although some differences in work productivity and social leisure activities were detected.

CONCLUSIONS AND INFERENCES

There appears to be limited variation in the characteristics of individuals with Rome IV IBS based on both stool subtypes and most troublesome symptom reported, suggesting that gastrointestinal symptoms alone have limited ability to predict disease impact and burden.

A double-blind, randomized, placebo-controlled study assessing the impact of probiotic supplementation on the symptoms of irritable bowel syndrome in females

BACKGROUND

A previous exploratory study demonstrated the ability of the Lab4 probiotic to alleviate the symptoms of IBS, and post hoc data analysis indicated greatest improvements in the female subgroup. The aim of this study is to confirm the impact of this multistrain probiotic on IBS symptom severity in females.

METHODS

An 8-week, single-center, randomized, double-blinded, placebo-controlled, superiority study in 70 females with Rome IV-diagnosed irritable bowel syndrome (IBS) receiving the Lab4 probiotic (25 billion colony-forming units) daily or a matched placebo. Changes from baseline in the IBS-symptom severity score (IBS-SSS), daily bowel habits, anxiety, depression, IBS-related control, and avoidance behavior, executive function, and the fecal microbiota composition were assessed. The study was prospectively registered: ISRCTN 14866272 (registration date 20/07/22).

KEY RESULTS

At the end of the study, there were significant between-group reductions in IBS-SSS (-85.0, p < 0.0001), anxiety and depression scores (-1.9, p = 0.0002 and -2.4, p < 0.0001, respectively), and the IBS-related control and avoidance behavior score (-7.5, p = 0.0002), all favoring the probiotic group. A higher proportion of the participants in the probiotic group had normal stool form (p = 0.0106) and/or fewer defecations with loose stool form (p = 0.0311). There was little impact on the overall diversity of the fecal microbiota but there were significant differences in Roseburia, Holdemanella, Blautia, Agathobacter, Ruminococcus, Prevotella, Bacteroides, and Anaerostipes between the probiotic and placebo groups at the end of the study.

CONCLUSIONS & INFERENCES

Daily supplementation with this probiotic may represent an option to be considered in the management of IBS.

Risk factors for irritable bowel syndrome: A review

Irritable bowel syndrome (IBS) is one of the most common diseases of the digestive tract from the group of disorders of interaction in the gut-brain axis. IBS has a negative impact of on patients' quality of life and the significant social and economic burden of the disease due to the low effectiveness of available treatment strategies, which are only symptomatic, without impacting factors and mechanisms of intestinal dysfunction. From this perspective, it is critical to study the factors contributing to the onset and persistence of IBS symptoms to improve the early diagnosis of the disease and implement targeted prevention technology in at-risk groups. The objective of this paper is to systematize data on the main risk factors for IBS, including hereditary predisposition, stress and psycho-emotional state, diet and eating habits, and acute intestinal infections.

Systematic Review and Meta-analysis: Efficacy of Mesalamine in Irritable Bowel Syndrome

BACKGROUND & AIMS

Some patients with irritable bowel syndrome (IBS) demonstrate low-grade inflammation in the intestine. Mesalamine, which has anti-inflammatory effects, may be an efficacious treatment for IBS, but studies are conflicting. We conducted a systematic review and meta-analysis to assess efficacy and safety of mesalamine in IBS.

METHODS

We searched the medical literature up to September 14, 2022, to identify randomized controlled trials (RCTs) of mesalamine in IBS. We judged efficacy and safety using dichotomous assessments of effect on global IBS symptoms, abdominal pain, bowel habit or stool frequency, and occurrence of any adverse event. We pooled data using a random effects model, with efficacy and safety reported as pooled relative risks (RRs) with 95% confidence intervals (CIs).

RESULTS

We identified 8 eligible RCTs (820 patients). Mesalamine was more efficacious than placebo for global IBS symptoms (RR of global symptoms not improving, 0.86; 95% CI, 0.79-0.95; number needed to treat = 10; 95% CI, 6-27), but not for abdominal pain or bowel habit or stool frequency. Subgroup analyses demonstrated efficacy of mesalamine in IBS with diarrhea for global IBS symptoms (RR, 0.88; 95% CI, 0.79-0.99), but not patients with other predominant bowel habits or those with post-infection IBS. Adverse event rates were no higher with mesalamine (RR, 1.20; 95% CI, 0.89-1.63) but were reported in only 5 trials.

CONCLUSIONS

Mesalamine may be modestly efficacious for global symptoms in IBS, particularly IBS with diarrhea, but quality of evidence was low. Adequately powered high quality RCTs of mesalamine in IBS are needed.

Clinical trial: predictive factors for response to gut-directed hypnotherapy for refractory irritable bowel syndrome, a post hoc analysis

BACKGROUND

Gut-directed hypnotherapy is effective for patients with irritable bowel syndrome (IBS). Despite its considerable evidence base, gut-directed hypnotherapy is not widely available and remains a limited resource. This emphasises the need to select patients who are most likely to benefit.

AIM

To determine whether baseline patient characteristics were predictive of response to gut-directed hypnotherapy in patients with IBS METHODS: We conducted a secondary analysis of outcomes of 448 patients with refractory Rome III IBS who participated in a randomised study confirming non-inferiority of 6 compared to 12 sessions of gut-directed hypnotherapy. We compared baseline patient characteristics, including age, sex, IBS subtype, quality of life and IBS-Symptom Severity Scale (IBS-SSS), non-colonic symptom score and Hospital Anxiety and Depression (HAD) score between responders and non-responders. We defined response as ≥50-point decrease in IBS-SSS or ≥30% reduction in pain severity scores.

RESULTS

Overall, 76.3% achieved ≥50-point decrease in IBS-SSS. Responders had a higher baseline non-colonic symptom score (p = 0.005). Those who achieved ≥30% improvement in abdominal pain scores (59.8%) had higher baseline IBS-SSS (p = 0.03), and lower baseline HAD-depression score (p = 0.012). Fifty-four patients (12%) dropped out of gut-directed hypnotherapy. Compared to completers, dropouts had higher baseline HAD-anxiety score (p = 0.034).

CONCLUSIONS

These data suggest that patients with a higher burden of gastrointestinal and extraintestinal symptoms are most likely to benefit from gut-specific behavioural intervention for refractory IBS. Clinical assessment of gastrointestinal, somatic and psychological symptom profiles may play a role in selecting patients for gut-directed hypnotherapy.

Efficacy of the Enteroadsorbent Silicol®gel in Adults with Irritable Bowel Syndrome Subtypes IBS-D or Mixed: Observational Open-Label Study

Background

Irritable bowel syndrome (IBS) is a common chronic gut-brain interaction disorder with limited effective treatment options. Intestinal adsorbents have a high adsorption capacity for gut irritants and may provide nonpharmacological alternatives.

Objectives

This post marketing study is aimed at providing up-to-date evidence to support the safety and efficacy in normal use of an established medical device for IBS treatment.

Methods

In this open-label, observational study, adults with IBS with predominant diarrhoea (IBS-D) or IBS with mixed bowel habits (IBS-M), according to Rome IV criteria, received 4 weeks of treatment with the enteroadsorbent Silicol®gel, a CE-certified, licenced, medical device containing colloidal silicic acid. Eligible participants were assessed at baseline (visit 1; in-clinic) and after 1 (visit 2; telephone), 2 (visit 3; telephone), and 4 (visit 4; in-clinic) weeks of treatment. The primary endpoint was the proportion of participants with an overall reduction in the IBS severity scoring system (IBS SSS) > 50, representing clinically meaningful improvement. Key secondary endpoints were a reduction in common IBS symptoms and improved quality of life (QoL).

Results

Among the 67 treated participants (IBS-D: 37; IBS-M: 30), 65 completed the study. At visit 4, 83.6% (56/67) of participants achieved a reduction in IBS SSS > 50. The mean (standard deviation [SD]) IBS SSS was 323.4 (55.7) at visit 1 and 160.3 (90.3) at visit 4 (overall change: -163.1 (101.7); 95% confidence interval [CI] 138.3, 187.9, p < 0.001). Compared with visit 1, significant reductions in the severity of all key IBS symptoms and overall improvement in QoL were observed at visit 4 (p < 0.001), with improvements observed from visits 1 and 2.

Conclusions

In this open-label study of participants with IBS-D and IBS-M, Silicol®gel provided clinically significant improvement in IBS symptoms, demonstrating that enteroadsorbents may be clinically beneficial in this population.

Amitriptyline at Low-Dose and Titrated for Irritable Bowel Syndrome as Second-Line Treatment in primary care (ATLANTIS): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Most patients with irritable bowel syndrome (IBS) are managed in primary care. When first-line therapies for IBS are ineffective, the UK National Institute for Health and Care Excellence guideline suggests considering low- dose tricyclic antidepressants as second-line treatment, but their effectiveness in primary care is unknown, and they are infrequently prescribed in this setting.

METHODS

This randomised, double-blind, placebo-controlled trial (Amitriptyline at Low-Dose and Titrated for Irritable Bowel Syndrome as Second-Line Treatment [ATLANTIS]) was conducted at 55 general practices in England. Eligible participants were aged 18 years or older, with Rome IV IBS of any subtype, and ongoing symptoms (IBS Severity Scoring System [IBS-SSS] score ≥75 points) despite dietary changes and first-line therapies, a normal full blood count and C-reactive protein, negative coeliac serology, and no evidence of suicidal ideation. Participants were randomly assigned (1:1) to low-dose oral amitriptyline (10 mg once daily) or placebo for 6 months, with dose titration over 3 weeks (up to 30 mg once daily), according to symptoms and tolerability. Participants, their general practitioners, investigators, and the analysis team were all masked to allocation throughout the trial. The primary outcome was the IBS-SSS score at 6 months. Effectiveness analyses were according to intention-to-treat; safety analyses were on all participants who took at least one dose of the trial medication. This trial is registered with the ISRCTN Registry (ISRCTN48075063) and is closed to new participants.

FINDINGS

Between Oct 18, 2019, and April 11, 2022, 463 participants (mean age 48·5 years [SD 16·1], 315 [68%] female to 148 [32%] male) were randomly allocated to receive low-dose amitriptyline (232) or placebo (231). Intention-to-treat analysis of the primary outcome showed a significant difference in favour of low-dose amitriptyline in IBS-SSS score between groups at 6 months (-27·0, 95% CI -46·9 to -7·10; p=0·0079). 46 (20%) participants discontinued low-dose amitriptyline (30 [13%] due to adverse events), and 59 (26%) discontinued placebo (20 [9%] due to adverse events) before 6 months. There were five serious adverse reactions (two in the amitriptyline group and three in the placebo group), and five serious adverse events unrelated to trial medication.

INTERPRETATION

To our knowledge, this is the largest trial of a tricyclic antidepressant in IBS ever conducted. Titrated low-dose amitriptyline was superior to placebo as a second-line treatment for IBS in primary care across multiple outcomes, and was safe and well tolerated. General practitioners should offer low-dose amitriptyline to patients with IBS whose symptoms do not improve with first-line therapies, with appropriate support to guide patient-led dose titration, such as the self-titration document developed for this trial.

FUNDING

National Institute for Health and Care Research Health Technology Assessment Programme (grant reference 16/162/01).

Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis

BACKGROUND & AIMS

Some probiotics may be beneficial in irritable bowel syndrome (IBS), but differences in species and strains used, as well as endpoints reported, have hampered attempts to make specific recommendations as to which should be preferred. We updated our previous meta-analysis examining this issue.

METHODS

MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched (up to March 2023). Randomized controlled trials (RCTs) recruiting adults with IBS, comparing probiotics with placebo were eligible. Dichotomous symptom data were pooled to obtain a relative risk of global symptoms, abdominal pain, or abdominal bloating or distension persisting after therapy, with a 95% confidence interval (CI). Continuous data were pooled using a standardized mean difference with a 95% CI. Adverse events data were also pooled.

RESULTS

We identified 82 eligible trials, containing 10,332 patients. Only 24 RCTs were at low risk of bias across all domains. For global symptoms, there was moderate certainty in the evidence for a benefit of Escherichia strains, low certainty for Lactobacillus strains and Lactobacillus plantarum 299V, and very low certainty for combination probiotics, LacClean Gold S, Duolac 7s, and Bacillus strains. For abdominal pain, there was low certainty in the evidence for a benefit of Saccharomyces cerevisae I-3856 and Bifidobacterium strains, and very low certainty for combination probiotics, Lactobacillus, Saccharomyces, and Bacillus strains. For abdominal bloating or distension there was very low certainty in the evidence for a benefit of combination probiotics and Bacillus strains. The relative risk of experiencing any adverse event, in 55 trials, including more than 7000 patients, was not significantly higher with probiotics.

CONCLUSIONS

Some combinations of probiotics or strains may be beneficial in IBS. However, certainty in the evidence for efficacy by GRADE criteria was low to very low across almost all of our analyses.

Outcome-Specific Efficacy of Different Probiotic Strains and Mixtures in Irritable Bowel Syndrome: A Systematic Review and Network Meta-Analysis

Irritable bowel syndrome (IBS) is a common gastrointestinal disease. The efficacy of different probiotics in treating IBS remains controversial. This network meta-analysis aimed to compare and rank the outcome-specific efficacy of different probiotic strains or combinations in adults with IBS. We searched the literature up to June 2023. Randomized controlled trials (RCTs) that evaluated the efficacy of probiotics in IBS were included. A frequentist framework was used to perform this study. In total, 9253 participants from 81 RCTs were included in the study. Four probiotic strains and five mixtures were significantly superior to placebo in improving IBS Symptom Severity Scale, among which Lactobacillus acidophilus DDS-1 ranked first (surface under the cumulative ranking, SUCRA, 92.9%). A mixture containing five probiotics (SUCRA, 100%) ranked first in improving the IBS-Quality of life. Bacillus coagulans MTCC 5856 (SUCRA, 96.9%) and Bacillus coagulans Unique IS2 (SUCRA, 92.6%) were among the most effective probiotics for improving abdominal pain. Three probiotic strains and two mixtures were effective in alleviating abdominal bloating. Four probiotic strains and a mixture were significantly superior to placebo in reducing the bowel movement frequency in diarrhea-predominant IBS (IBS-D). Bacillus coagulans MTCC 5856 (SUCRA, 99.6%) and Saccharomyces cerevisiae CNCM I-3856 (SUCRA, 89.7%) were among the most effective probiotics for improving the Bristol stool form scale of IBS-D. Only some probiotics are effective for particular outcomes in IBS patients. This study provided the first ranking of outcome-specific efficacy of different probiotic strains and combinations in IBS. Further studies are needed to confirm these results.

Irritable bowel syndrome and mental health comorbidity - approach to multidisciplinary management

Irritable bowel syndrome (IBS) affects 5-10% of the global population. Up to one-third of people with IBS also experience anxiety or depression. Gastrointestinal and psychological symptoms both drive health-care use in people with IBS, but psychological comorbidity seems to be more important for long-term quality of life. An integrated care approach that addresses gastrointestinal symptoms with nutrition and brain-gut behaviour therapies is considered the gold standard. However, best practice for the treatment of individuals with IBS who have a comorbid psychological condition is unclear. Given the rising prevalence of mental health disorders, discussion of the challenges of implementing therapy for people with IBS and anxiety and depression is critical. In this Review, we draw upon our expertise in gastroenterology, nutrition science and psychology to highlight common challenges that arise when managing patients with IBS and co-occurring anxiety and depression, and provide recommendations for tailoring clinical assessment and treatment. We provide best practice recommendations, including dietary and behavioural interventions that could be applied by non-specialists and clinicians working outside an integrated care model.

The Socioeconomic Impact of Irritable Bowel Syndrome: An Analysis of Direct and Indirect Health Care Costs

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) is associated with substantial costs to society. Extensive data on direct costs (health care consumption) and indirect costs (health-related productivity loss) are lacking. Hence, we examined the socioeconomic costs of IBS and assessed which patient characteristics are associated with higher costs.

METHODS

Cross-sectional data from 3 Rome-defined Dutch IBS patient cohorts (n = 419) were collected. Bootstrapped mean direct and indirect costs were evaluated per patient with IBS using validated questionnaires (ie, medical cost questionnaire and productivity cost questionnaire, respectively). Multivariable regression analyses were performed to identify variables associated with higher costs.

RESULTS

Quarterly mean total costs per patient were €2.156 (95% confidence interval (CI), €1793-€2541 [$2444]), consisting of €802 (95% CI, €625-€1010 [$909]) direct costs and €1.354 (95% CI, €1072-€1670 [$1535]) indirect costs. Direct costs consisted primarily of health care professional consultations, with costs related to gastrointestinal clinic visits accounting for 6% and costs related to mental health care visits for 20%. Higher direct costs were significantly associated with older age (P = .007), unemployment (P = .001), IBS subtypes other than constipation (P = .033), lower disease-specific quality of life (P = .027), and more severe depressive symptoms (P = .001). Indirect costs consisted of absenteeism (45%), presenteeism (42%), and productivity loss related to unpaid labor (13%) and were significantly associated with the male sex (P = .014) and more severe depressive symptoms (P = .047).

CONCLUSIONS

Productivity loss is the main contributor to the socioeconomic burden of IBS. Direct costs were not predominantly related to gastrointestinal care, but rather to mental health care. Awareness of the nature of costs and contributing patient factors should lead to significant socioeconomic benefits for society.

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.

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.

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.

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.

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.

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.

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.

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.

Multi-omics for biomarker approaches in the diagnostic evaluation and management of abdominal pain and irritable bowel syndrome: what lies ahead

Reliable biomarkers for common disorders of gut-brain interaction characterized by abdominal pain, including irritable bowel syndrome (IBS), are critically needed to enhance care and develop individualized therapies. The dynamic and heterogeneous nature of the pathophysiological mechanisms that underlie visceral hypersensitivity have challenged successful biomarker development. Consequently, effective therapies for pain in IBS are lacking. However, recent advances in modern omics technologies offer new opportunities to acquire deep biological insights into mechanisms of pain and nociception. Newer methods for large-scale data integration of complementary omics approaches have further expanded our ability to build a holistic understanding of complex biological networks and their co-contributions to abdominal pain. Here, we review the mechanisms of visceral hypersensitivity, focusing on IBS. We discuss candidate biomarkers for pain in IBS identified through single omics studies and summarize emerging multi-omics approaches for developing novel biomarkers that may transform clinical care for patients with IBS and abdominal pain.

Microbiota-Pain Association; Recent Discoveries and Research Progress

The relationship between gut microbiota and pain, such as visceral pain, headaches (migraine), itching, prosthetic joint infection (PJI), chronic abdominal pain (CAP), joint pain, etc., has received increasing attention. Several parts of the evidence suggest that microbiota is one of the most important pain modulators and they can regulate pain in the central and peripheral nervous systems. Any alteration in microbiota by diet or antibiotics mediation may characterize a novel therapeutic strategy for pain management. The present study includes the most up-to-date and influential scientific findings on the association of microbiota with pain, despite the fact that the underlying mechanism is not identified in most cases. According to recent research, identifying the molecular mechanisms of the microbiota-pain pathway can have a unique perspective in treating many diseases, even though there is a long way to reach the ideal point. This study will stress the influence of microbiota on the common diseases that can stimulate the pain with a focus on underlying mechanisms.

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.