Global prevalence of irritable bowel syndrome according to Rome III or IV criteria: a systematic review and meta-analysis

A systematic review and meta-analysis of the correlation between polycystic ovary syndrome and irritable bowel syndrome

BACKGROUND

Research on the prevalence of irritable bowel syndrome (IBS) among polycystic ovary syndrome (PCOS) patients has gained significant momentum over the years. However, it remains unclear whether PCOS is related to a higher prevalence of IBS. The objective of this systematic review and meta-analysis was to fully study IBS correlation with PCOS.

METHODS

From inception until October 16th, 2022, all observational studies documenting IBS prevalence in PCOS patients were collected from the China national knowledge infrastructure(CNKI), China Science and Technology Journal Database(VIP), Wanfang database, PubMed, Embase, Web of Science, and Cochrane databases. The quality of case-control studies was assessed with Newcastle-Ottawa Scale. Review Manager 5.3 was used to determine the pooled odds ratio (OR) and 95% confidence interval (CI).

RESULTS

5 case-control studies involving 1268 individuals and one cross-sectional study involving 291 participants were included in our qualitative analysis. The quantitative analysis was conducted based on five case-control studies. Four case-control studies involving 1063 participants showed a higher prevalence of IBS in PCOS This meta-analysis revealed an almost twice higher risk of IBS in comparison with controls (OR = 2.23, 95%CI:1.58-3.14, p < 0.001; I²=41%, p = 0.150). Four sensitivity analyses validated the consistency of the aggregated findings.

CONCLUSION

This meta-analysis and systematic review demonstrated a significant association between PCOS and increased odds of IBS. However, more high-quality and well-controlled research is essential to increase the robustness of our conclusions.

Does sourdough bread provide clinically relevant health benefits?

During the last decade, scientific interest in and consumer attention to sourdough fermentation in bread making has increased. On the one hand, this technology may favorably impact product quality, including flavor and shelf-life of bakery products; on the other hand, some cereal components, especially in wheat and rye, which are known to cause adverse reactions in a small subset of the population, can be partially modified or degraded. The latter potentially reduces their harmful effects, but depends strongly on the composition of sourdough microbiota, processing conditions and the resulting acidification. Tolerability, nutritional composition, potential health effects and consumer acceptance of sourdough bread are often suggested to be superior compared to yeast-leavened bread. However, the advantages of sourdough fermentation claimed in many publications rely mostly on data from chemical and in vitro analyzes, which raises questions about the actual impact on human nutrition. This review focuses on grain components, which may cause adverse effects in humans and the effect of sourdough microbiota on their structure, quantity and biological properties. Furthermore, presumed benefits of secondary metabolites and reduction of contaminants are discussed. The benefits claimed deriving from in vitro and in vivo experiments will be evaluated across a broader spectrum in terms of clinically relevant effects on human health. Accordingly, this critical review aims to contribute to a better understanding of the extent to which sourdough bread may result in measurable health benefits in humans.

MicroRNA-29b-3p promotes intestinal permeability in IBS-D via targeting TRAF3 to regulate the NF-κB-MLCK signaling pathway

Irritable bowel syndrome with predominant diarrhea (IBS-D) is characterized by increased intestinal permeability. Previous studies have shown that the microRNA-29 gene is involved in the regulation of intestinal permeability in patients with IBS-D. NF-κB was proved to play a key role in inflammatory response of intestine and resultant disruption of tight junction integrity, whose activity could be inhibited by TNF Receptor-Associated Factor 3 (TRAF3). However, the exact mechanism that induces increased intestinal permeability in IBS-D patients has not been clarified. In this study, we found that microRNA-29b‑3p (miR-29b-3p) was significantly upregulated, while TRAF3 was decreased and the NF-κB-MLCK pathway was activated within the colonic tissue of IBS-D patients. Subsequently, we confirmed the targeting relationship between miR-29b-3p and TRAF3 through a double-luciferase reporter assay. Lentivirus transfection of NCM460 cells with miR-29b-3p-overexpressing and -silencing vectors demonstrated that the expression of TRAF3 was negatively correlated with the level of miR-29b-3p. The NF-κB/MLCK pathway was activated in the miR-29b-3p-overexpressing group and inhibited to some extent in the miR-29b-3p-silencing group. Results in WT and miR-29 knockout mice showed that miR-29b-3p levels were increased, TRAF3 levels were decreased, and the NF-κB/MLCK signaling was activated in the WT IBS-D group as compared with the WT control group. The protein levels of TRAF3 and TJs in the miR-29b-/- IBS-D group were partially recovered and NF-κB/MLCK pathway indicators were, to a certain extent, decreased as compared with the WT IBS-D group. These results suggested that miR-29b-3p deletion enhances the TRAF3 level in IBS-D mice and alleviates the high intestinal permeability. In brief, through the analysis of intestinal tissue samples from IBS-D patients and miR-29b-/- IBS-D mice, we showed that miR-29b-3p is involved in the pathogenesis of intestinal hyperpermeability in IBS-D via targeting TRAF3 to regulate the NF-κB-MLCK signaling pathway.

Associations and gastrointestinal symptoms in women with endometriosis in comparison to women with irritable bowel syndrome: a study based on a population cohort

BACKGROUND

Endometriosis and irritable bowel syndrome (IBS) have similar symptoms, pathogenesis, and risk factors. These diagnoses often coexist and are frequently misdiagnosed leading to diagnostic delays. This study of a population-based cohort aimed to investigate associations relating to endometriosis and IBS and to compare gastrointestinal symptoms between endometriosis and IBS.

METHOD

The study cohort included women from the Malmö Offspring Study with information about endometriosis and IBS diagnoses from the National Board of Health and Welfare. The participants answered a questionnaire about lifestyle habits, medical and drug history, and self-reported IBS. The visual analog scale for IBS was used to estimate gastrointestinal symptoms the past 2 weeks. Endometriosis diagnosis and self-reported IBS were used as dependent variables to study associations with age, body mass index (BMI), education, occupation, marital status, smoking, alcohol habits, and physical activity using logistic regression. Mann-Whitney U Test or Kruskal-Wallis tests were used to calculate the differences in symptoms between groups.

RESULTS

Of the 2,200 women with information from medical records, 72 participants had endometriosis; 21 (29.2%) of these had self-reported IBS. Of the 1,915 participants who had answered the questionnaire, 436 (22.8%) had self-reported IBS. Endometriosis was associated with IBS (OR:1.86; 95%CI:1.06-3.26; p = 0.029), as well as with age 50-59 years (OR:6.92; 95%CI:1.97-24.32; p = 0.003), age ≥ 60 years (OR:6.27; 95%CI:1.56-25.17; p = 0.010), sick leave (OR:2.43; 95%CI:1.08-5.48; p = 0.033), and former smoking (OR:3.02; 95%CI:1.19-7.68; p = 0.020). There was an inverse association with BMI (OR:0.36; 95%CI:0.14-4.91; p = 0.031). IBS was associated with endometriosis (OR:1.77; 95%CI:1.02-3.07; p = 0.041) and sick leave (OR:1.77; 95%CI:1.14-2.73; p = 0.010), with a tendency to association with smoking (OR:1.30; 95%CI:0.98-1.72; p = 0.071). When excluding participants using drugs associated with IBS, the condition was associated with current smoking (OR:1.39; 95%CI:1.03-1.89; p = 0.033) and inversely with age 50-59 years (OR:0.58; 95%CI:0.38-0.90; p = 0.015). There were differences in the gastrointestinal symptoms between IBS and healthy participants, but not between endometriosis and IBS or healthy participants.

CONCLUSION

There were associations between endometriosis and IBS, without differences in gastrointestinal symptoms. Both IBS and endometriosis were associated with smoking and sick leave. Whether the associations reflect causality or depend on common risk factors and pathogenesis remains to be determined.

Assessment of Sleep Quality Among Adolescents and Adults With Self-Diagnosed Irritable Bowel Syndrome, in Jeddah, Saudi Arabia

Background The frequency of irritable bowel syndrome (IBS) has increased significantly in the last ten years. Few studies were done in Saudi Arabia to assess the relationship between sleep quality and IBS. This study aims to assess the prevalence of IBS and its association with sleep quality among adolescents and adults in Saudi Arabia. Methods A cross-sectional study was done on 651 participants aged 15-65 years. An online questionnaire was used to collect data, including demographics; the Rome IV criteria (R4DQ) was used in the diagnosis of IBS, the IBS symptoms severity scale (IBS-SSS) assessed IBS symptoms and severity, and the Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. Results Based on the Rome IV criteria, 25.7% of the participants had IBS. Among them, 23.3%, 17.9%, 47.3%, and 11.5% had IBS types constipation (C), diarrhea (D), mixed bowel habits (M), and undefined subtype (U), respectively. Mild, moderate, and severe IBS were found among 43.1%, 39.5%, and 17.4% of IBS cases, respectively. About 46% had poor sleep quality, which was significantly higher among those with younger mean age, females, and students. Patients with IBS exhibited a considerably greater prevalence of poor sleep quality, and IBS-C had the highest prevalence. Conclusion A correlation was found between poor sleep quality and the positive status of IBS diagnosis among adolescents and adults. An evaluation of specific sleep disorders among IBS patients is needed.

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.

Pain Catastrophizing and Clinical Outcomes Among Patients Receiving a Novel Cognitive-Behavioral Therapy for Irritable Bowel Syndrome: An Experimental Therapeutics Approach

Irritable bowel syndrome (IBS) is the most common gastrointestinal (GI) condition treated by GI and primary care physicians. Although IBS symptoms (abdominal pain, bowel problems) are generally refractory to medical therapies, consistent research has shown that they improve following cognitive-behavioral therapy (CBT). Notwithstanding empirical support for CBT, there is less research explicating the reasons for why or how it works. Like other pain disorders, the focus on change mechanisms for behavioral pain treatments has focused on pain-specific cognitive-affective processes that modulate pain experience, few of which are more important than pain catastrophizing (PC). The fact that PC changes are seen across treatments of differing theoretical and technical orientation, including CBT, yoga, and physical therapy, suggests that it may be a nonspecific (vs. theory-based) change mechanism akin to therapeutic alliance and treatment expectancy. Therefore, the current study examined change in PC as a concurrent mediator of IBS symptoms severity, global GI symptom improvement, and quality of life among 436 Rome III-diagnosed IBS patients enrolled in a clinical trial undergoing two dosages of CBT versus a nonspecific comparator emphasizing education and support. Results from structural equation modeling parallel process mediation analyses suggest that reduction in PC during treatment are significantly associated with improvement in IBS clinical outcomes through 3-month follow-up. Results from the current study provide evidence that PC may be an important, albeit nonspecific change mechanism, during CBT for IBS. Overall, reducing the emotional unpleasantness of pain through cognitive processes is associated with improved outcomes for IBS.

Exploring the Role of Vitamin D and the Gut Microbiome: A Cross-Sectional Study of Individuals with Irritable Bowel Syndrome and Healthy Controls

Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction with multifaceted pathophysiology. Prior studies have demonstrated higher rates of vitamin D deficiency in individuals with IBS compared to healthy controls (HC), as well as associations of vitamin D concentration with IBS symptoms. A systematic review of 10 mouse and 14 human studies reported a positive association between vitamin D (serum levels and supplementation) and beta diversity of gut microbiome in a variety of conditions. The present retrospective case-control study aimed to compare vitamin D (25(OH)D) plasma concentrations and gut microbiome composition in adult women with IBS (n=99) and HC (n=62). Plasma concentrations of 25(OH)D were assessed using the Endocrine Society Guidelines definition of vitamin D deficiency (25(OH)D <20 ng/ml) and insufficiency (25(OH)D >20-<30 ng/ml). 16S rRNA microbiome gene sequencing data was available for 39 HC and 62 participants with IBS. Genus-level Bifidobacterium and Lactobacillus and phylum-level Firmicutes and Bacteroidetes relative abundances were extracted from microbiome profiles. Results showed vitamin D deficiency in 40.3% (n=25) vs. 41.4% (n=41), and insufficiency 33.9% (n=21) vs. 34.3% (n=34) in the HCs vs. IBS groups, respectively. The odds of IBS did not differ depending on 25(OH)D status (p=0.75 for deficient, p=0.78 for insufficient), and the average plasma vitamin D concentration did not differ between IBS (mean 24.8 ng/ml) and HCs (mean 25.1 ng/ml; p=0.57). We did not find evidence of an association between plasma 25(OH)D concentration and richness, Shannon index, Simpson index or specific bacterial abundances in either HCs or the IBS group.

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.

Emerging role of the gut microbiome in post-infectious irritable bowel syndrome: A literature review

Post-infectious irritable bowel syndrome (PI-IBS) is a particular type of IBS, with symptom onset after an acute episode of infectious gastroenteritis. Despite infectious disease resolution and clearance of the inciting pathogen agent, 10% of patients will develop PI-IBS. In susceptible individuals, the exposure to pathogenic organisms leads to a marked shift in the gut microbiota with prolonged changes in host-microbiota interactions. These changes can affect the gut-brain axis and the visceral sensitivity, disrupting the intestinal barrier, altering neuromuscular function, triggering persistent low inflammation, and sustaining the onset of IBS symptoms. There is no specific treatment strategy for PI-IBS. Different drug classes can be used to treat PI-IBS similar to patients with IBS in general, guided by their clinical symptoms. This review summarizes the current evidence for microbial dysbiosis in PI-IBS and analyzes the available data regarding the role of the microbiome in mediating the central and peripheral dysfunctions that lead to IBS symptoms. It also discusses the current state of evidence on therapies targeting the microbiome in the management of PI-IBS. The results of microbial modulation strategies used in relieving IBS symptomatology are encouraging. Several studies on PI-IBS animal models reported promising results. However, published data that describe the efficacy and safety of microbial targeted therapy in PI-IBS patients are scarce. Future research is required.

Vitamin D improves irritable bowel syndrome symptoms: A meta-analysis

Background & aims

Approximately 5%-10% of the population in most geographical regions suffer from irritable bowel syndrome (IBS), which creates a significant burden on individual patients, their families, and society. Recent advances in IBS therapies have indicated that vitamin D supplementation is potential to relieve its symptoms, but evidence of this is lacking. This meta-analysis aimed to estimate the effect of vitamin D on gastrointestinal (GI) symptoms in IBS patients.

Methods

The PubMed, Embase, and Cochrane Central Register of Controlled Trials databases were searched from their inception to March 2022. Statistical analyses were performed with Stata 12.0 and Review Manager 5.4, and statistical significance was defined as P < 0.05. The pooled results are presented as weighted mean differences (WMD) and 95% confidence intervals (CI).

Results

The meta-analysis including 6 randomized controlled trials (RCT) with 572 patients found a significant difference in IBS symptom severity score (WMD, -34.88; 95% CI, -62.48 to -7.27; P = 0.013; random-effects model) but no significant difference in IBS quality of life score (WMD, 3.33; 95% CI, -5.12 to -11.77; P = 0.440; random-effects model).

Conclusions

Overall, IBS patients may benefit from vitamin D supplementation to reduce the GI symptoms.

Exercise habits that include exercise partners and irritable bowel syndrome in a young Japanese population: a cross-sectional study

OBJECTIVE

Evidence regarding the association between exercise habits and irritable bowel syndrome (IBS) remains scarce in a young population. It is also unknown whether the existence of an exercise partner affects this issue. The purpose of this study was to explore the association between exercise habits that include an exercise partner and IBS in a young Japanese population.

METHODS

This study enrolled 8923 Japanese university students and examined exercise frequency and intensity, and exercise partners using self-administered questionnaires. IBS and functional dyspepsia were defined according to the Rome III criteria.

RESULTS

The prevalence of IBS in this survey was 6.5%. Moderate frequency exercise was inversely related with IBS [adjusted odds ratio (aOR): 0.65 (95% confidence interval, CI: 0.51-0.83), P for trend = 0.005]. Moderate and high exercise intensities were independently and inversely related with IBS, respectively [aORs were moderate: 0.76 (95% CI: 0.61-0.95) and high: 0.62 (95% CI: 0.48-0.78), P for trend = 0.001]. Exercising with a group or with friends instead of alone was independently inversely related with IBS [aOR with groups: 0.53 (95% CI: 0.40-0.70) and with friends: aOR 0.71 (95% CI: 0.54-0.93)]. After excluding subjects with overlapping IBS and functional dyspepsia, an inverse association between high intensity of exercise or exercise in a group and IBS remained significant.

CONCLUSION

The frequency and intensity of exercise may be independently inversely related with IBS in a young Japanese population. Also, exercise with others may be important for preventing IBS.

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.

Diagnostic Implications of Irritable Bowel Syndrome Is an Independent Risk Factor for Undergoing Surgical Interventions in Patients with Inflammatory Bowel Disease

BACKGROUND

Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) can present with overlapping symptoms, making diagnosis and management challenging. Patients with IBD in remission may continue to experience IBS symptoms. Patients with IBS were found to have a disproportionately higher prevalence of abdominal and pelvic surgeries than the general population.

AIMS

The aim of this study was to determine whether IBS is a risk factor for undergoing surgical interventions in patients with IBD and explore the diagnostic implications of these findings.

METHODS

A population-based cohort analysis was performed using TriNetX. Patients with Crohn's disease + IBS (CD + IBS) and ulcerative colitis + IBS (UC + IBS) were identified. The control groups consisted of patients with CD or UC alone without IBS. The main outcome was to compare the risks of undergoing surgical interventions between the cohorts. The secondary outcomes were to compare the risks of developing gastrointestinal symptoms and IBD-related complications between the cohorts.

RESULTS

Patients with IBD who subsequently developed IBS were more likely to experience gastrointestinal symptoms than those without IBS (p < 0.0001). Patients with concomitant IBD and IBS were more likely to develop IBD-related complications, including perforation of the intestine, gastrointestinal bleeding, colon cancer, and abdominal abscess (p < 0.05). Patients with concomitant IBD and IBS were more likely to undergo surgical interventions than patients without IBS, including colectomy, appendectomy, cholecystectomy, exploratory laparotomy, and hysterectomy (p < 0.05).

CONCLUSIONS

IBS appears to be an independent risk factor for patients with IBD to develop IBD-related complications and undergo surgical interventions. Patients with concomitant IBD and IBS could represent a unique subgroup of IBD patients with more severe symptoms, highlighting the importance of accurate diagnosis and management in this population.

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.

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.

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.

Evaluation of the Symptom-Based Diagnostic Criteria for Irritable Bowel Syndrome in Conjunction With Clinical Examinations and Laboratory Investigations

Background Irritable bowel syndrome (IBS) is a chronic condition characterized by persistent abdominal pain or discomfort and impaired bowel function. Symptoms often vary in onset and severity, are worse during flare-ups, and affect the patient's quality of life. A positive diagnosis of IBS based on clinical symptoms may lead to a better outcome. There are different diagnostic criteria like Kruis score, Manning criteria, Rome I, II, III, and IV criteria, and each new one addresses the deficiencies of the previous ones. We analyze the effectiveness of the most commonly used diagnostic criteria associated with clinical examinations and laboratory tests in treating IBS in these studies. Methodology This is a retrospective study in which data from IBS subjects were collected by simple random sampling and compared using Manning criteria, Kruis score, and Rome IV criteria. Laboratory tests included complete blood count (CBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). Results Of the 130 patients, IBS is more prevalent in adults aged 30-50 years, with a male predominance. The Kruis score outperformed the Manning criterion in distinguishing between organic bowel disease and IBS. This, together with the Rome IV criteria, increases the likelihood of identifying IBS. Conclusions Differentiating IBS from functional and organic gastrointestinal problems is critical. Irritable bowel syndrome can be diagnosed using symptom-based diagnostic criteria. Clinical observation and physical examination should be supplemented with laboratory indicators.

Prevalence and impact of disorders of Gut-Brain interaction in Sweden

BACKGROUND

Previous epidemiologic studies in Sweden have only covered some of the disorders of gut-brain interaction (DGBI) and are not representative of the general population. This study aimed to define the prevalence and impact of DGBI in Sweden.

METHODS

We used Swedish data from the Rome Foundation Global Epidemiology Study which include information on DGBI diagnoses, psychological distress, quality of life (QoL), healthcare utilization, and the impact of stress on GI symptoms.

KEY RESULTS

The prevalence of having any DGBI was 39.1% (95% CI 37.0-41.2); esophageal disorders 6.1% (5.1-7.3), gastroduodenal disorders 10.7% (9.3-12.0), bowel disorders 31.6% (29.6-33.6), and anorectal disorders 6.0% (5.1-7.2). Subjects with a DGBI more commonly reported anxiety and/or depression, reduced mental and physical QoL, and more frequent doctor visits due to health problems. Subjects with a DGBI reported bothersome gastrointestinal (GI) symptoms to a greater extent and more than 1/3 had visited a doctor due to GI problems and of those 1/3 had seen multiple doctors. Prescription medications were available among 36.4% (31.0-42.0) who had bothersome GI symptoms and a DGBI, with sufficient symptom relief in 73.2% (64.0-81.1). Psychological factors and eating were reported to worsen GI symptoms and stress during the last month was greater in subjects with a DGBI.

CONCLUSIONS AND INFERENCES

DGBI prevalence and its impact in Sweden is in line with global data, including increased healthcare utilization. GI symptoms are commonly affected by psychological factors and eating, and a high proportion of those on prescription medication report sufficient GI symptom relief.

Understanding neuroimmune interactions in disorders of gut-brain interaction: from functional to immune-mediated disorders

Functional gastrointestinal disorders-recently renamed into disorders of gut-brain interaction-such as irritable bowel syndrome and functional dyspepsia are highly prevalent conditions with bothersome abdominal symptoms in the absence of structural abnormalities. While traditionally considered as motility disorders or even psychosomatic conditions, our understanding of the pathophysiology has evolved significantly over the last two decades. Initial observations of subtle mucosal infiltration with immune cells, especially mast cells and eosinophils, are since recently being backed up by mechanistic evidence demonstrating increased release of nociceptive mediators by immune cells and the intestinal epithelium. These mediators can activate sensitised neurons leading to visceral hypersensitivity with bothersome symptoms. The interaction between immune activation and an impaired barrier function of the gut is most likely a bidirectional one with alterations in the microbiota, psychological stress and food components as upstream players in the pathophysiology. Only few immune-targeting treatments are currently available, but an improved understanding through a multidisciplinary scientific approach will hopefully identify novel, more precise treatment targets with ultimately better outcomes.

Functional gastrointestinal disorders among healthcare professionals at a tertiary Australian hospital

Background and Aim

The aim of this study was to determine the frequency, characteristics, and associations of functional gastrointestinal disorders (FGIDs) among healthcare professionals.

Methods

A qualitative survey was conducted among the staff at a tertiary Australian hospital between January 2017 and June 2018. Rome III criteria (excluding endoscopic) were used to define FGID. Multivariable logistic regression was used to explore associations.

Results

Of the 274 respondents (17% doctors, 66% nurses, 17% others; 77% female), 54% had experienced GI symptoms ≥3 times per week and 23% were diagnosed with FGIDs (2% IBS, 19% FD, 2% both). GI symptoms were more common in females (58% vs. 38%), Caucasians versus Asians (59% vs. 35%), respondents who were easily (67% vs. 40%) or often stressed (58% vs. 37%), and had irregular working hours (62% vs. 46%, each P < 0.05). Independent predictors of GI symptoms included being easily stressed (OR 2.7) and female sex (OR 2.4), while Asian ethnicity was protective (OR 0.42, each P < 0.05). FGIDs were more prevalent in respondents who often felt stressed (27% vs. 10%), felt easily stressed (29% vs. 17%), and in nurses compared to others (27% vs. 16%; each P < 0.05). The only independent predictor of FGID was being often stressed (OR 4.1, P = 0.011).

Conclusions

FGIDs and GI symptoms are prevalent among hospital workers. Stress, female sex, irregular working hours, and non-Asian ethnicity appeared to be associated with GI symptoms and FGIDs.

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.

The Prevalence, Humanistic Burden, and Health Care Impact of Irritable Bowel Syndrome Among United States Veterans

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) in veterans is understudied. This study sought to investigate (1) prevalence of IBS; (2) phenotypic, environmental, and psychosocial factors associated with IBS; and (3) associations of IBS with health-related quality of life and health care use.

METHODS

From June 2018 to April 2020, we invited veterans to complete the Rome IV IBS questionnaire; Short Form-12; posttraumatic stress disorder (PTSD) checklist; Hospital Anxiety and Depression Scale; and questionnaires on general health, antibiotic use, infectious enteritis (IE), and health care use.

RESULTS

Among 858 veteran respondents, 244 (28.4%) met Rome IV IBS criteria (47.5% IBS with diarrhea, 16.8% IBS with constipation, 33.6% mixed IBS). IBS was associated with greater anxiety and depression and lower quality of life (all P < .001). Provisional PTSD, IE, and bowel problems after antibiotics were more common in IBS (all P < .001) as were multiple doctor visits (P < .01) and hospitalizations (P = .04). Comparisons across non-IBS and IBS subgroups revealed overall associations of psychological comorbidities (P < .01), multiple doctor visits (P < .01), hospitalizations (P = .03), IE (P < .01), and bowel problems after IE (P = .03) or antibiotics (P < .01) with subgroup. Highest anxiety and depression scores, PTSD, multiple doctor visits, hospitalizations, and bowel problems after IE were observed in IBS with constipation. In adjusted analyses, IBS was associated (all P < .001) with anxiety (odds ratio [OR], 3.47), depression (OR, 2.88), lower quality of life, PTSD (OR, 3.09), IE (OR, 4.44), bowel problems after antibiotics (OR, 1.84), multiple doctor visits (OR, 2.08), and hospitalizations (OR, 1.78).

CONCLUSIONS

IBS is prevalent among veterans and has a measurable impact on individuals and health care resources. Veterans with IBS may experience significant psychological impairment.

Characteristics and properties of a polysaccharide isolated from Wolfiporia cocos as potential dietary supplement for IBS

Introduction

As low FODMAP (Fermentable oligosaccharides, disaccharides, monosaccharides and polyols) diet therapy is recommended for most of Irritable Bowel Syndrome (IBS) patients, the consequent insufficient of dietary fibers (DFs) intake exert an adverse impact on intestinal health. It is necessary to find suitable DFs for IBS patients.

Methods

This study extracted a water-insoluble polysaccharide from Wolfiporia cocos (WIP) by alkali-extraction and acid-precipitation method. Its molecular weight was detected by high performance gel permeation chromatography (HPGPC) analysis. The structure of WIP was analyzed by Fourier transform infrared (FT-IR) spectrum, Nuclear Magnetic Resonance (NMR) spectra and X-ray diffraction (XRD). The properties related to stability, digestion, viscosity, osmotic activity, adsorption and fermentation were investigated, aimed to explore the feasibility of WIP as a new DF supplement for patients with IBS. In addition, 16S rRNA sequencing analysis was conducted to explore its effects on IBS-related gut microbiota.

Results and Discussion

The results showed that WIP had a single homogeneous composition and the molecular weight was 8.1 × 103 Da. WIP was indicated as a kind of pyranose form with β anomeric configuration and the main chain of WIP was 1,3-β-glucan with amorphous structure. In addition to good thermal stability, WIP also has low bioavailability and can reach the colon mostly without being digested. Moreover, the low viscosity and osmotic activity, the high water- swelling and water/oil-holding capacity, fructose adsorption capacity and poor fermentation performance of WIP demonstrated that it is suitable for IBS patients. It is worth noting that WIP regulates IBS associated gut microbiota effectively, such as the abundance of Lachnospiraceae and Prevotella. These findings provide a theoretical basis for the development of WIP as a dietary supplement for IBS patients with low FODMAP diet therapy.

GRAPHICAL ABSTRACT

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.

Consumption of Solnul™ Resistant Potato Starch Produces a Prebiotic Effect in a Randomized, Placebo-Controlled Clinical Trial

The effects of resistant starch at high doses have been well-characterized, but the potential prebiotic effects of resistant starch at doses comparable to oligosaccharide prebiotics have not been evaluated. A three-arm randomized, double-blind, placebo-controlled clinical trial was conducted to evaluate the effect of 3.5 g and 7 g daily doses of Solnul^™ resistant potato starch (RPS) on beneficial populations of gut bacteria and stool consistency after a 4-week period. The relative abundance of Bifidobacterium and Akkermansia was determined by employing 16Sv4 sequencing of stool samples. To assess the effect of RPS on laxation and bowel movements, stools were recorded and scored using the Bristol Stool Form Scale. Participants consuming 3.5 g/day of RPS experienced significantly greater changes in Bifidobacterium and Akkermansia compared to the placebo after 4 weeks. The number of diarrhea- and constipation-associated bowel movements were both significantly lower in the 3.5 g RPS arm compared to the placebo group. Participants consuming 7 g of RPS responded similarly to those in the 3.5 g arm. Our analyses demonstrate that Solnul^™ RPS has a prebiotic effect when consumed for 4 weeks at the 3.5 g per day dose, stimulating increases in beneficial health-associated bacteria and reducing diarrhea- and constipation-associated bowel movements when compared to the placebo group.

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.

A Tritordeum-Based Diet for Female Patients with Diarrhea-Predominant Irritable Bowel Syndrome: Effects on Abdominal Bloating and Psychological Symptoms

Most female patients with irritable bowel syndrome (IBS) complain of abdominal bloating rather than abdominal pain and diarrhea. The higher incidence in women could be due to the so-called dysfunctional gas handling. Since diet seems the most effective and durable strategy for managing IBS symptoms, we aimed to evaluate the effects of a 12 week diet based on a relatively new cereal, Tritordeum (TBD), on gastrointestinal (GI) symptoms, anthropometric and bioelectrical impedance parameters, and psychological profiles in 18 diarrhea-predominant IBS (IBS-D) female patients with abdominal bloating as the dominant symptom. The IBS Severity Scoring System (IBS-SSS), the Symptom Checklist-90 Revised, the Italian version of the 36-Item Short-Form Health Survey, and the IBS-Quality of Life questionnaire were administered. The TBD reduces the IBS-SSS “Intensity of abdominal bloating” with a concomitant improvement in the anthropometric profile. No correlation was found between “Intensity of abdominal bloating” and “Abdominal circumference”. Anxiety, depression, somatization, interpersonal sensitivity, and phobic and avoidance manifestations were significantly reduced after TBD. Lastly, anxiety was correlated with “Intensity of abdominal bloating”. Overall, these results suggest the possibility of lowering abdominal bloating and improving the psychological profile of female IBS-D patients using a diet based on an alternative grain such as Tritordeum.

Epigenetic mechanisms underlying stress-induced visceral pain: Resilience versus vulnerability in a two-hit model of early life stress and chronic adult stress

BACKGROUND

Women with a history of early life stress (ELS) have a higher risk of developing irritable bowel syndrome (IBS). In addition, chronic stress in adulthood can exacerbate IBS symptoms such as abdominal pain due to visceral hypersensitivity. We previously showed that sex and the predictability of ELS determine whether rats develop visceral hypersensitivity in adulthood. In female rats, unpredictable ELS confers vulnerability and results in visceral hypersensitivity, whereas predictable ELS induces resilience and does not induce visceral hypersensitivity in adulthood. However, this resilience is lost after exposure to chronic stress in adulthood leading to an exacerbation of visceral hypersensitivity. Evidence suggests that changes in histone acetylation at the promoter regions of glucocorticoid receptor (GR) and corticotrophin-releasing factor (CRF) in the central nucleus of the amygdala (CeA) underlie stress-induced visceral hypersensitivity. Here, we aimed to investigate the role of histone acetylation in the CeA on visceral hypersensitivity in a two-hit model of ELS followed by chronic stress in adulthood.

METHODS

Male and female neonatal rats were exposed to unpredictable, predictable ELS, or odor only (no stress control) from postnatal days 8 to 12. In adulthood, rats underwent stereotaxic implantation of indwelling cannulas. Rats were exposed to chronic water avoidance stress (WAS, 1 h/day for 7 days) or SHAM stress and received infusions of vehicle, the histone deacetylase inhibitor trichostatin A (TSA) or the histone acetyltransferase inhibitor garcinol (GAR) after each WAS session. 24 h after the final infusion, visceral sensitivity was assessed and the CeA was removed for molecular experiments.

RESULTS

In the two-hit model (ELS + WAS), female rats previously exposed to predictable ELS, showed a significant reduction in histone 3 lysine 9 (H3K9) acetylation at the GR promoter and a significant increase in H3K9 acetylation at the CRF promoter. These epigenetic changes were associated with changes in GR and CRF mRNA expression in the CeA and an exacerbation of stress-induced visceral hypersensitivity in female animals. TSA infusions in the CeA attenuated the exacerbated stress-induced visceral hypersensitivity, whereas GAR infusions only partially ameliorated ELS+WAS induced visceral hypersensitivity.

CONCLUSION

The two-hit model of ELS followed by WAS in adulthood revealed that epigenetic dysregulation occurs after exposure to stress in two important periods of life and contributes to the development of visceral hypersensitivity. These aberrant underlying epigenetic changes may explain the exacerbation of stress-induced abdominal pain in IBS patients.

Is Personalized Dietary Therapy Effective for Individuals With Irritable Bowel Syndrome?

Introduction: Adverse reactions to foods and food additives have a critical role in clinical manifestations of irritable bowel syndrome (IBS). Personalized dietary modifications conducted under the supervision of a qualified health practitioner could considerably impact the clinical care and course of the condition. Objective: To investigate the clinical effectiveness of the Lifestyle Eating and Performance (LEAP) program based on the Leukocyte Activation Assay-MRT (LAA-MRT^®) results in improving IBS symptoms and quality of life. Methods: The retrospective study included de-identified client records (n = 146) from private group practices seen by registered dietitians. The eligibility criteria were adults aged > 18 years old with an established diagnosis of IBS. Results: Participants were 46.7 ± 12.6 years old and had a BMI of 26.7 ± 6.1 kg/m²; the majority were female (87.0%) and followed-up by a registered dietitian for 10.1 ± 6.4 weeks. There was a significant reduction post-dietary intervention in overall Global Gastrointestinal Symptom Survey Scores (P < 0.001) and improvement in quality of life (P < 0.001). Conclusion: This study generates real-world evidence of an alternative treatment option for IBS using a personalized dietary approach. A more precise understanding of the effect of food intake reactions is vital for clinical improvements and enhancing health outcomes in IBS.

The Prevalence of Irritable Bowel Syndrome after Severe Acute Respiratory Syndrome Coronavirus 2 Infection and Their Association: A Systematic Review and Meta-Analysis of Observational Studies

AIM

Investigate the prevalence of irritable bowel syndrome (IBS) after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and assess the association between IBS and SARS-CoV-2 infection.

METHODS

A systematic literature search for PubMed, Web of Science, Embase, Scopus, and the Cochrane Library was performed to identify all reports published before 31 December 2022. The confidence interval (CI), estimation effect (ES) of prevalence, and risk ratios (RR) were calculated to evaluate the prevalence of IBS after SARS-CoV-2 infection and their association. Individual results were pooled by the random-effects (RE) model. Subgroup analyses conducted a further investigation of the results. We employed funnel plots, Egger's test, and Begg's test to evaluate publication bias. Sensitivity analysis was performed for the assessment of the robustness of the result.

RESULTS

The data on IBS prevalence after SARS-CoV-2 infection were extracted from two cross-sectional studies and ten longitudinal studies from nineteen countries with 3950 individuals. The IBS prevalence after SARS-CoV-2 infection ranges from 3% to 91% in different countries, and the overall pooled prevalence of IBS following SARS-CoV-2 infection is 15% (ES: 0.15; 95% CI, 0.11-0.20; p = 0.000). The data on the association between IBS and SARS-CoV-2 infection were extracted from six cohort studies from fifteen countries with 3595 individuals. The risk of IBS increased following SARS-CoV-2 infection but was not significant (RR: 1.82; 95% CI, 0.90-3.69; p = 0.096).

CONCLUSIONS

In conclusion, the overall pooled prevalence of IBS following SARS-CoV-2 infection was 15%, and SARS-CoV-2 infection increased the overall risk of IBS but was not statistically significant. Further extra high-quality epidemiological evidence and studies to clarify the underlying mechanism of IBS following SARS-CoV-2 infection are needed.

Low FODMAP Diet Relieves Visceral Hypersensitivity and Is Associated with Changes in Colonic Microcirculation in Water Avoidance Mice Model

(1) Background: Irritable bowel syndrome (IBS) is a global public health problem, the pathogenesis of which has not been fully explored. Limiting fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) can relieve symptoms in some patients with IBS. Studies have shown that normal microcirculation perfusion is necessary to maintain the primary function of the gastrointestinal system. Here, we hypothesized that IBS pathogenesis might be related to abnormalities in colonic microcirculation. A low-FODMAP diet could alleviate visceral hypersensitivity (VH) by improving colonic microcirculation; (2) Methods: C57BL/6 mice were raised to establish an IBS-like rodent model using water avoidance (WA) stress or SHAM-WA as a control, one hour per day for ten days. The mice in the WA group were administered different levels of the FODMAP diet: 2.1% regular FODMAP (WA-RF), 10% high FODMAP diet (WA-HF), 5% medium FODMAP diet (WA-MF), and 0% low FODMAP diet (WA-LF) for the following 14 days. The body weight and food consumption of the mice were recorded. Visceral sensitivity was measured as colorectal distention (CRD) using the abdominal withdrawal reflex (AWR) score. Colonic microcirculation was assessed using laser speckle contrast imaging (LCSI). Vascular endothelial-derived growth factor (VEGF) was detected using immunofluorescence staining; (3) Results: The threshold values of CRD pressure in the WA-RF, WA-HF, and WA-MF groups were significantly lower than those in the SHAM-WA group. Moreover, we observed that colonic microcirculation perfusion decreased, and the expression of VEGF protein increased in these three groups of mice. Interestingly, a low-FODMAP dietary intervention could reverse this situation. Specifically, a low-FODMAP diet increased colonic microcirculation perfusion, reduced VEGF protein expression in mice, and increased the threshold of VH. There was a significant positive correlation between colonic microcirculation and threshold for VH; (4) Conclusions: These results demonstrate that a low-FODMAP diet can alter VH by affecting colonic microcirculation. Changes in intestinal microcirculation may be related to VEGF expression.

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.

Prevalence of irritable bowel syndrome and its association with colorectal cancer: a systematic review and meta-analysis

BACKGROUND

This study evaluates the risk of colorectal cancer (CRC) in patients with Irritable Bowel Syndrome (IBS).

METHODS

A literature search was performed on MEDLINE, EMBASE, SCOPUS, and Google Scholar from inception to 31st January 2020 without any limitations on article type or language for studies reporting data on CRC on patients with IBS. A meta-analysis was performed to estimate the prevalence of CRC among patients with IBS. Data extraction was according to the PRISMA guidelines. The quality of the included studies was assessed according to the Newcastle Ottawa Scale.

RESULTS

Twenty-one articles were eligible for data extraction and quantitative analysis. Of them, 11 were included in the meta-analysis (IBS n = 284 366, no-IBS n = 8 390 509). The pooled prevalence of CRC in patients with IBS was 0.96% (95% CI-0.184%-2.344%). The prevalence was lowest in the constipation-predominant IBS (pooled prevalence 1.126%. Patients with IBS-D and IBS-U had an equal pooled prevalence of CRC (2.49%). Eleven studies compared the prevalence of CRC in patients with IBS with a control population. The pooled OR was 2.8 (CI 2.305-3.294).

CONCLUSIONS

There was an increased risk of CRC among patients diagnosed with IBS, primarily in the first year after IBS diagnosis.

REGISTRATION

The review was registered on PROSPERO (CRD42021236707).

Evaluation of abdominal gas by plain abdominal radiographs

BACKGROUND

Our aim was to determine the reliability of plain abdominal radiographs for the evaluation of abdominal gas content in patients with functional digestive symptoms.

METHODS

Abdominal CT scan scout views, mimicking a conventional plain abdominal radiograph, were obtained from 30 patients both during episodes of abdominal distension and basal conditions. Physicians (n = 50) were instructed to rate the estimated volume of gas in the 60 images presented in random sequence using a scale graded from 0 to ≥600 ml.

KEY RESULTS

The gas volumes estimated in the scout views differed from those measured by CT by a median of 90 (95% CI 70-102) ml, and the misestimation was not related to the absolute volume in the image. The accuracy of the observers, measured by their mean misestimation, was not related to their specialty or the training status (misestimation by 96 (95% CI 85-104) ml in staff vs 78 (70-106) ml in residents; p = 0.297). The accuracy was independent of the order of presentation of the images. Gas volume measured by CT in the images obtained during episodes of abdominal distension differed by a median of 39 (95% CI 29-66) ml from those during basal conditions, and this difference was misestimated by a median of 107 (95% CI 94-119) ml. The accuracy of these estimations was not related to the absolute gas volumes (R = -0.352; p < 0.001) or the magnitude of the differences.

CONCLUSIONS & INFERENCES

Plain abdominal radiographs have limited value for the evaluation of abdominal gas volume in patients with functional gut disorders.

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.

Visible abdominal distension in functional gut disorders: Objective evaluation

BACKGROUND

Visible abdominal distension has been attributed to: (A) distorted perception, (B) intestinal gas accumulation, or (C) abdominophrenic dyssynergia (diaphragmatic push and anterior wall relaxation).

METHODS

A pool of consecutive patients with functional gut disorders and visible abdominal distension included in previous studies (n = 139) was analyzed. Patients (61 functional bloating, 74 constipation-predominant irritable bowel syndrome and 4 with alternating bowel habit) were evaluated twice, under basal conditions and during a self-reported episode of visible abdominal distension; static abdominal CT images were taken in 104 patients, and dynamic EMG recordings of the abdominal walls in 76, with diaphragmatic activity valid for analysis in 35.

KEY RESULTS

(A) Objective evidence of abdominal distension was obtained by tape measure (increase in girth in 138 of 139 patients), by CT imaging (increased abdominal perimeter in 96 of 104 patients) and by abdominal EMG (reduced activity, i.e., relaxation, in 73 of 76 patients). (B) Intestinal gas volume was within ±300 ml from the basal value in 99 patients, and above in 5 patients, who nevertheless exhibited a diaphragmatic descent. (C) Diaphragmatic contraction was detected in 34 of 35 patients by EMG (increased activity) and in 82 of 103 patients by CT (diaphragmatic descent).

CONCLUSIONS AND INFERENCES

In most patients complaining of episodes of visible abdominal distention: (A) the subjective claim is substantiated by objective evidence; (B) an increase in intestinal gas does not justify visible abdominal distention; (C) abdominophrenic dyssynergia is consistently evidenced by dynamic EMG recording, but static CT imaging has less sensitivity.

Ameliorative effect of buckwheat polysaccharides on colitis via regulation of the gut microbiota

Plant polysaccharides act as prebiotics by modulating gut microbiota. However, the functional characteristics of buckwheat Fagopyrum tataricum polysaccharides (FTP) and F. esculentum polysaccharides (FEP) on colitis prevention are not valid. This study evaluated the ameliorative effects of FTP and FEP against TNBS-induced colitis via gut microbiota modulation in rats. The characterizations of FTP and FEP were analyzed, including FTIR, TGA, DSC, and monosaccharide composition. In addition, the pathological features of colon length and symptoms in TNBS-induced colitis were improved via the intragastric preadministration of FTP and FEP. The results showed that prefeeding with FTP and FEP decreased inflammatory cytokines (IL-6, IL-1β, and TNF-α), β-glucuronidase, and mucinase, as well as increasing superoxide dismutase, catalase, and glutathione peroxidase levels, in TNBS-induced rats. A decrease in inflammatory signaling-associated proteins (NF-κB, MAPK, COX-2, and iNOS) improved the treatment of TNBS-induced colitis by buckwheat polysaccharides. Moreover, prefeeding with buckwheat polysaccharides increased the Firmicutes/Bacteroidetes ratio and short-chain fatty acid (SCFA) production and decreased the abundance of inflammation-related bacteria (Oscillospiraceae and Oscillibacter). In conclusion, FTP and FEP strongly improved TNBS-induced colitis through antioxidant, anti-inflammatory, and microbiota modulation properties, especially in the high-dose FEP group. Buckwheat polysaccharides have the potential for utilization in functional ingredients or food development.

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.

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.

Identification of irritable bowel syndrome in the Swedish National Patient Register: a validation study

BACKGROUND AND OBJECTIVE

National patient registers are valuable in epidemiological studies. To ensure high-quality data for studies of irritable bowel syndrome (IBS), this study aimed to validate the ICD-10 code for IBS in the Swedish National Patient Register.

METHODS

The positive predictive values (PPV) for IBS defined by the Rome criteria were calculated based on a review of medical records of randomly selected individuals with a first-ever diagnostic listing of IBS in the Swedish National Patient register in the year 2005 (Rome II criteria) or 2010 (Rome III criteria).

KEY RESULTS

340 medical records were reviewed (172 from 2005 and 168 from 2010). The majority of patients were females (74%), and the mean age was 42 years. IBS used in any type of department had a PPV of 76% (95% confidence interval 71-80%), which increased to 80% (76-84%) when we included individuals likely to have IBS but where information about some aspects of the Rome criteria was lacking in the medical record. Two highly specialized gastroenterological departments had the best PPV, 96%, while departments of internal medicine in general had a PPV of 82% (80-95%). The PPV for the IBS subtype was 62% (55-67%). The PPVs were not significantly different comparing the two time periods investigated.

CONCLUSION AND INFERENCES

The validity of a register-based definition of IBS in the Swedish National Patient register is high and can be used to identify patients with IBS in observational research. The data source, i.e., type of hospital and department, influences reliability.

Negative experiences with public bathrooms and chronic illness-related shame

INTRODUCTION

The use of public bathrooms is a challenge for everyone, but especially for those who are affected by a bathroom-dependent condition. Being dependent on bathrooms is linked with different negative emotions. One of them is a clinically relevant emotion: shame associated with the chronic condition.

MATERIALS AND METHODS

In a cross-sectional survey study (n = 193) of people who suffer a bathroom-dependent condition we asked about health conditions, well-being, and shame related to chronic condition outcomes.

RESULTS

We show a link between negative public bathroom experiences, and diminished well-being and feelings of shame related to chronic illness. We found that this relationship between negative experiences with public bathrooms and shame is not specific to the different conditions.

CONCLUSION

We conclude that the negative experiences which people with different gastrointestinal illnesses face is an environmental stressor associated with more embarrassment as a result of the condition suffered.

Gastroesophageal reflux disease incidence among male patients with irritable bowel syndrome: A single-center cross-sectional study in southern Iran

Background and Aim

Gastrointestinal reflux disease (GERD) and irritable bowel syndrome (IBS) are among the most common gastrointestinal disorders in which the overlap of these diseases and their syndromes has been frequently reported. In this study, we aimed to evaluate GERD incidence among IBS patients and the related risk factors.

Methods

Male patients aged 18-60 years with an impression of IBS and referred to the gastrointestinal clinic from March 2019 to 2020 in Shiraz, Iran, were included in this study.

Results

Among the 163 enrolled patients with an average age of 31.53 ± 9.38 years, 64 (39.3%) were diagnosed with GERD. Based on statistical analysis, there was a significant association between GERD and the IBS patients' age (P = 0.006), smoking (P = 0.011), and alcohol consumption (P = 0.043). Also, GERD among IBS patients was significantly associated with the type of IBS (P < 0.001), with IBS-D having the lowest incidence (19.4%) and IBS-M the highest incidence of GERD (66.7%). Based on multivariate analysis, smoking had a reverse and significant correlation with lower incidence of GERD (OR = -1.364; P = 0.002).

Conclusion

Our results demonstrate that among male IBS patients, younger age, smoking, and alcohol consumption were among the risk factors for GERD. These findings may provide further insight into the best approach to treating these diseases.

Impact of Rome IV criteria on the prevalence of post-infection irritable bowel syndrome

BACKGROUND

The Rome IV irritable bowel syndrome (IBS) criteria include changes to the description and frequency of abdominal pain. Existing studies have demonstrated a lower prevalence and greater severity in IBS patients identified using Rome IV than Rome III criteria. Our aim was to investigate the prevalence of post-infection IBS (PI-IBS) using Rome IV criteria in a population-based cohort of laboratory-confirmed C. jejuni infection cases.

METHODS

The Minnesota Department of Health (MDH) requires notification of Campylobacter cases and interviews patients to gather information on clinical symptoms. For this study, the Rome IV diagnostic questionnaire was utilized 6-9 months after infection to determine the development of PI-IBS. The survey responses were analyzed for the prevalence of IBS and symptom severity.

KEY RESULTS

Surveys were completed by 391 participants (31% response rate). Twenty-three patients had pre-existing IBS, and 18 did not complete enough questions to categorize their case status. Of the 350 remaining participants, 58 (17%) met Rome IV criteria. An additional 47 patients would have met the Rome III IBS criteria for pain frequency, driving the cumulative prevalence to 30%. The mean IBS Symptom Severity Score (IBS-SSS) in Rome IV patients was significantly higher than in Rome III (p < 0.05). With Rome IV, IBS-diarrhea was the most common subtype.

CONCLUSIONS & INFERENCES

Rome IV criteria resulted in a 19% lower prevalence of PI-IBS than earlier reported Rome III-based prevalence in a similar population. Rome IV defined PI-IBS patients have greater symptom severity but similar distribution of IBS subtypes.

Impaired Intestinal Permeability of Tricellular Tight Junctions in Patients with Irritable Bowel Syndrome with Mixed Bowel Habits (IBS-M)

BACKGROUND

The underlying pathophysiology of irritable bowel syndrome (IBS) is still unclear. Our aim was to investigate the pathophysiological mechanisms of diarrhea, constipation, and antigen uptake in mixed-type IBS (IBS-M).

METHODS

Colonoscopic biopsies were obtained from IBS-M patients. Epithelial transport and barrier function of colonic mucosae were characterized in Ussing chambers using impedance spectroscopy. Mucosal permeability to macromolecules was measured. Western blotting for tight junction (TJ) proteins was performed and their subcellular localization was visualized by confocal microscopy. RNA-sequencing was performed for gene expression and signaling pathway analysis.

RESULTS

In IBS-M, epithelial resistance and ENaC-dependent sodium absorption were unchanged, while short-circuit current reflecting chloride secretion was reduced. Concomitantly, epithelial permeability for fluorescein and FITC-dextran-4000 increased. TJ protein expression of occludin decreased, whereas claudins were unaltered. Confocal microscopy revealed the de-localization of tricellulin from tricellular TJs. Involved pathways were detected as proinflammatory cytokine pathways, LPS, PGE2, NGF, and vitamin D.

CONCLUSIONS

Decreased anion secretion explains constipation in IBS-M, while ion permeability and sodium absorption were unaltered. Reduced occludin expression resulted in the delocalization of tricellulin from the tricellular TJ, leading to increased macromolecular permeability that contributes to antigen influx into the mucosa and perpetuates a low-grade inflammatory process.

Randomised clinical trial: effects of MD-7246 on irritable bowel syndrome with diarrhoea

BACKGROUND

MD-7246, a delayed-release formulation of linaclotide, is designed to target the ileocaecal junction and caecum with the aim of relieving abdominal pain independently of bowel function.

AIMS

To evaluate the efficacy, safety and dose-response of MD-7246 in patients with irritable bowel syndrome with diarrhoea (IBS-D).

METHODS

A randomised, double-blind, phase 2 clinical trial enrolled adult patients with IBS-D (Rome IV criteria). Patients were randomised to placebo or once-daily oral MD-7246 300, 600 or 1200 μg for 12 weeks. Abdominal and bowel symptoms were assessed daily. Key efficacy endpoints were change from baseline in abdominal pain and responder rates for a 30% reduction in abdominal pain in 6/12 weeks. Additional abdominal pain responder and exploratory bowel function endpoints were also assessed.

RESULTS

Among the 388 randomised patients, there was no significant difference in mean change from baseline in abdominal pain between the MD-7246 300 μg, 600 μg and 1200 μg groups and placebo (-1.93, -1.58, -1.95 and - 2.01, respectively; p > 0.05 for each group vs placebo). The abdominal pain responder rates in the MD-7246 groups were similar to or lower than those in the placebo group. All doses of MD-7246 had a minimal effect on bowel function and were generally well tolerated.

CONCLUSIONS

MD-7246 at the doses studied did not improve abdominal pain relative to placebo in an IBS-D patient population. Similarly, most additional efficacy endpoints showed no improvement with MD-7246 relative to placebo.

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.

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.