A multi-omic brain gut microbiome signature differs between IBS subjects with different bowel habits

Alterations of the brain-gut-microbiome system (BGM) have been implicated in the pathophysiology of irritable bowel syndrome (IBS), yet bowel habit-specific alterations have not been elucidated. In this cross-sectional study, we apply a systems biology approach to characterize BGM patterns related to predominant bowel habit. Fecal samples and resting state fMRI were obtained from 102 premenopausal women (36 constipation-predominant IBS (IBS-C), 27 diarrhea-predominant IBS (IBS-D), 39 healthy controls (HCs)). Data integration analysis using latent components (DIABLO) was used to integrate data from the phenome, microbiome, metabolome, and resting-state connectome to predict HCs vs IBS-C vs IBS-D. Bloating and visceral sensitivity, distinguishing IBS from HC, were negatively associated with beneficial microbes and connectivity involving the orbitofrontal cortex. This suggests that gut interactions may generate aberrant central autonomic and descending pain pathways in IBS. The connection between IBS symptom duration, key microbes, and caudate connectivity may provide mechanistic insight to the chronicity of pain in IBS. Compared to IBS-C and HCs, IBS-D had higher levels of many key metabolites including tryptophan and phenylalanine, and increased connectivity between the sensorimotor and default mode networks; thus, suggestingan influence on diarrhea, self-related thoughts, and pain perception in IBS-D ('bottom-up' mechanism). IBS-C's microbiome and metabolome resembled HCs, but IBS-C had increased connectivity in the default mode and salience networks compared to IBS-D, which may indicate importance of visceral signals, suggesting a more 'top-down' BGM pathophysiology. These BGM characteristics highlight possible mechanistic differences for variations in the IBS bowel habit phenome. This article is part of the Special Issue on 'Microbiome & the Brain: Mechanisms & Maladies'.

Piezo2 channels expressed by colon-innervating TRPV1-lineage neurons mediate visceral mechanical hypersensitivity

Inflammatory and functional gastrointestinal disorders such as irritable bowel syndrome (IBS) and obstructive bowel disorder (OBD) underlie the most prevalent forms of visceral pain. Although visceral pain can be generally provoked by mechanical distension/stretch, the mechanisms that underlie visceral mechanosensitivity in colon-innervating visceral afferents remain elusive. Here, we show that virally mediated ablation of colon-innervating TRPV1-expressing nociceptors markedly reduces colorectal distention (CRD)-evoked visceromotor response (VMR) in mice. Selective ablation of the stretch-activated Piezo2 channels from TRPV1 lineage neurons substantially reduces mechanically evoked visceral afferent action potential firing and CRD-induced VMR under physiological conditions, as well as in mouse models of zymosan-induced IBS and partial colon obstruction (PCO). Collectively, our results demonstrate that mechanosensitive Piezo2 channels expressed by TRPV1-lineage nociceptors powerfully contribute to visceral mechanosensitivity and nociception under physiological conditions and visceral hypersensitivity under pathological conditions in mice, uncovering potential therapeutic targets for the treatment of visceral pain.

Associations of Fecal Short Chain Fatty Acids With Colonic Transit, Fecal Bile Acid, and Food Intake in Irritable Bowel Syndrome

INTRODUCTION

Short-chain fatty acids (SCFAs) correlate with colonic transit time (CTT) and may influence irritable bowel syndrome (IBS) pathophysiology. However, the clinical significance of fecal SCFAs, relationships between SCFAs and other metabolites (bile acids [BAs]), and real-time diet effects on SCFAs in IBS are uncertain. The aim was to evaluate fecal SCFA associations with IBS phenotype and mechanisms and explore effects of real-time diet.

METHODS

We conducted a prospective observational study of fecal SCFA, BAs, and CTT in healthy controls (HCs) and participants with IBS. We compared study end points across groups, analyzed relationships between end points, and evaluated the discriminative ability of SCFAs. Diet effects were explored in participants with dietary data.

RESULTS

Among 21 HCs and 43 participants with IBS, fecal SCFAs (total, individual) were inversely correlated with overall (all P < 0.01) and segmental (all P < 0.05) CTT; similar associations were observed within HC and IBS groups. The acetate-to-butyrate ratio correlated with slower overall and left CTT in all and in HCs (both P < 0.01). SCFAs (total, acetate) correlated with BAs (total, % primary) in all participants and in those with IBS with diarrhea. Logistic regression analyses demonstrated associations of acetate with slower transit (odds ratio = 0.988, P = 0.002) and BA diarrhea (BAD; odds ratio = 1.014, P = 0.001). Acetate accurately predicted delayed CTT (area under the receiving operating characteristic curve = 0.84) and BAD (area under the receiver operating characteristic curve = 0.79). Adjusting for diet strengthened correlations of total SCFAs with overall CTT ( R = [-0.46], P = 0.04) and SCFAs with transverse CTT (all P < 0.05).

DISCUSSION

Fecal SCFAs correlate with CTT and fecal BAs and reliably exclude delayed CTT and BAD. Accounting for diet strengthens SCFA associations with transit.

Comparison of biochemical, microbial and mucosal mRNA expression in bile acid diarrhoea and irritable bowel syndrome with diarrhoea

OBJECTIVE

There are altered mucosal functions in irritable bowel syndrome with diarrhoea (IBS-D); ~30% of patients with IBS-D have abnormal bile acid (BA) metabolism (ABAM) and diarrhoea (summarised as BAD).

AIM

To compare biochemical parameters, gastrointestinal and colonic transit, rectal sensation and pathobiological mechanisms in IBS-D without ABAM and in BAD (serum 7C4>52 ng/mL).

DESIGN

In patients with Rome III criteria of IBS-D, we compared biochemical features, colonic transit, rectal sensation, deep genotype of five BA-related genes, ileal and colonic mucosal mRNA (differential expression (DE) analysis) and stool dysbiosis (including functional analysis of microbiome). Results in BAD were compared with IBS-D without ABAM.

RESULTS

Compared with 161 patients with IBS-D without ABAM, 44 patients with BAD had significantly faster colonic transit, lower microbial alpha diversity, different compositional profile (beta diversity) and higher Firmicutes to Bacteroidetes ratio with evidence of decreased expression of bile acid thiol ligase (involved in transformation of primary to secondary BAs) and decreased sulfatases. In BAD (compared with IBS-D without ABAM), terminal ileal biopsies showed downregulation of SLC44A5 (a BA transporter), and ascending colon biopsies showed upregulation in barrier-weakening genes (CLDN2), serine protease inhibitors, immune activation, cellular differentiation and a cellular transporter (FABP6; BA binding). No DE of genes was documented in descending colon biopsies. The two groups had similar rectal sensation.

CONCLUSION

Though sharing clinical symptoms with IBS-D, BAD is associated with biological differences and mechanisms that have potential to enhance diagnosis and treatment targeting barrier dysfunction, inflammatory and microbial changes.

Gastrointestinal health: changes of intestinal mucosa and microbiota in patients with ulcerative colitis and irritable bowel syndrome from PM2.5-polluted regions of Ukraine

Here, clinical studies of patients were conducted to assess changes in patients with ulcerative colitis (UC) and irritable bowel syndrome (IBS) associated with air pollution by PM. A comparative study of 100 patients with UC and 75 with IBS from highly (HPRs) and low (LPRs) PM_2.5-polluted regions of Ukraine was conducted. Biopsy of the intestinal mucosa of patients with UC from HPRs showed severe cellular infiltration. Patients with IBS from HPRs had changes in the superficial epithelium (focal desquamation), and inflammatory-cellular infiltration of mucous membrane of the colon. In patients with UC, changes in mucus production were found, which were more significant in HPR patients. PAS response did not depend on the residence; the level of MUC2 was significantly lower in HPR patients with UC (1.12 vs 2.15 au). In patients with UC from HPRs, a decrease in Bacteroidetes (34.0 vs. 39.0 small intestinal bacterial overgrowth (SIBO), ppm) and an increase in Proteobacteria compared to LPRs were shown. In IBS patients, significant differences were found in the level of Proteobacteria, which was higher in HPRs. The level of regulatory flora Akkermansia muciniphila and Faecalibacterium prausnitzii reduced in patients with UC from HPRs. In patients from LPRs, the level of Akkermansia muciniphila raised above normal (2.8 vs 4.7 SIBO, ppm). Similar changes of regulatory flora have been identified in patients with IBS from different regions. Therefore, a more severe course of the disease (more pronounced cellular infiltration and violation of the microbiota) was shown in patients with UC from HPRs as compared to LPRs.

The Intake of Dicarbonyls and Advanced Glycation Endproducts as Part of the Habitual Diet Is Not Associated with Intestinal Inflammation in Inflammatory Bowel Disease and Irritable Bowel Syndrome Patients

A Western diet comprises high levels of dicarbonyls and advanced glycation endproducts (AGEs), which may contribute to flares and symptoms in inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). We therefore investigated the intake of dietary dicarbonyls and AGEs in IBD and IBS patients as part of the habitual diet, and their association with intestinal inflammation. Food frequency questionnaires from 238 IBD, 261 IBS as well as 195 healthy control (HC) subjects were used to calculate the intake of dicarbonyls methylglyoxal, glyoxal, and 3-deoxyglucosone, and of the AGEs Nε-(carboxymethyl)lysine, Nε-(1-carboxyethyl)lysine and methylglyoxal-derived hydroimidazolone-1. Intestinal inflammation was assessed using faecal calprotectin. The absolute dietary intake of all dicarbonyls and AGEs was higher in IBD and HC as compared to IBS (all p < 0.05). However, after energy-adjustment, only glyoxal was lower in IBD versus IBS and HC (p < 0.05). Faecal calprotectin was not significantly associated with dietary dicarbonyls and AGEs in either of the subgroups. The absolute intake of methylglyoxal was significantly higher in patients with low (<15 μg/g) compared to moderate calprotectin levels (15−<50 μg/g, p = 0.031). The concentrations of dietary dicarbonyls and AGEs generally present in the diet of Dutch patients with IBD or IBS are not associated with intestinal inflammation, although potential harmful effects might be counteracted by anti-inflammatory components in the food matrix.

Safety and efficacy of purified clinoptilolite-tuff treatment in patients with irritable bowel syndrome with diarrhea: Randomized controlled trial

BACKGROUND

Irritable bowel syndrome (IBS) is a highly prevalent gastrointestinal disorder with poor response to treatment. IBS with predominant diarrhea (IBS-D) is accompanied by abdominal pain as well as high stool frequency and urgency. Purified clinoptilolite-tuff (PCT), which is approved by the Food and Drug Administration for use as a dietary supplement with the brand name G-PUR^®, has previously shown therapeutic potential in other indications based on its physical adsorption capacity.

AIM

To assess whether symptoms of IBS-D can be ameliorated by oral treatment with PCT.

METHODS

In this randomized, placebo-controlled, double-blind pilot study, 30 patients with IBS-D diagnosis based on Rome IV criteria were enrolled. Following a 4-wk run-in phase, 14 patients were randomized to receive a 12-wk treatment with G-PUR^® (2 g three times daily), and 16 patients received placebo. The relief from IBS-D symptoms as measured by the proportion of responders according to the Subject’s Global Assessment (SGA) of Relief was assessed as the primary outcome. For the secondary outcomes, validated IBS-D associated symptom questionnaires, exploratory biomarkers and microbiome data were collected.

RESULTS

The proportions of SGA of Relief responders after 12 wk were comparable in both groups, namely 21% in the G-PUR^® group and 25% in the placebo group. After 4 wk of treatment, 36% of patients in the G-PUR^® group vs 0% in the placebo group reported complete or considerable relief. An improvement in daily abdominal pain was noted in 94% vs 83% (P = 0.0353), and the median number of days with diarrhea per week decreased by 2.4 d vs 0.3 d in the G-PUR^® and placebo groups, respectively. Positive trends were observed for 50% of responders in the Bristol Stool Form Scale. Positive trends were also noted for combined abdominal pain and stool consistency response and the Perceived Stress Questionnaire score. Only 64% in the G-PUR^® group compared to 86% in the placebo group required rescue medication intake during the study. Stool microbiome studies showed a minor increase in diversity in the G-PUR^® group but not in the placebo group. No PCT-related serious adverse events were reported.

CONCLUSION

In this randomized, double-blind, placebo-controlled study, the PCT product, G-PUR^®, demonstrated safety and clinical benefit towards some symptoms of IBS-D, representing a promising novel treatment option for these patients.

The association between irritable bowel syndrome and ischemic colitis: a systematic review and meta-analysis

INTRODUCTION

Studies have suggested an association between ischemic colitis and irritable bowel syndrome (IBS) although the results were inconsistent. This systematic review and meta-analysis were performed to comprehensively examine the association between IBS and ischemic colitis by identifying all available cohort and case-control studies and combining their effect estimates together.

EVIDENCE ACQUISITION

EMBASE, MEDLINE and Google Scholar databases were systematically reviewed up to June 2020. Eligible study had to be either cohort or case-control studies that evaluated whether patients with IBS have a higher risk of ischemic colitis than individuals without IBS. Point estimates and standard errors from each eligible study were combined together using the generic inverse variance method of DerSimonian and Laird.

EVIDENCE SYNTHESIS

The systematic review identified three cohort and eight case-control studies. The pooled analysis found a significantly higher risk of ischemic colitis among patient with IBS with the pooled odds ratio of 2.50 (95% CI, 2.00-3.14; I² 57%). Funnel plot was relatively symmetric and was not suggestive of presence of publication bias.

CONCLUSIONS

A significantly increased risk of ischemic colitis among patients with IBS was observed in this systematic review and meta-analysis.

Exocrine Pancreatic Insufficiency is Undiagnosed in Some Patients with Diarrhea-Predominant Irritable Bowel Syndrome Using the Rome IV Criteria

BACKGROUND AND AIMS

Irritable bowel syndrome (IBS) is one of the most frequent disorders in clinical practice, with a mean 7.6-10.8% worldwide prevalence. A study showed that 6.1% of patients with diarrhea-predominant IBS (IBS-D) had severe exocrine pancreatic insufficiency (EPI). We aimed to identify the prevalence of EPI based on fecal elastase stool testing (Fel-1) in IBS-D and the clinical characteristics that may predict the diagnosis of EPI.

METHODS

Patients aged > 18 years presenting to tertiary hospital outpatient clinics with IBS-D completed validated questionnaires and gave a stool sample where Fel-1 concentration was measured. Patients with Fel-1 < 100 µg/g represented EPI and > 100 to < 200 µg/g underwent testing for pancreatic pathology with laboratory and endoscopic ultrasound (EUS) evaluation.

RESULTS

One hundred forty patients (mean age 60 years, females 75.7%) were studied. EPI was found in 5% (95% CI 2.2-10.4), and pancreatic steatosis was the main EUS finding (71%). Dyspepsia was an independent factor associated with EPI (OR 34.7; 95% CI 4.95-366.37, p = 0.0007). After pancreatic enzyme replacement therapy (PERT), patients showed a significant improvement in the Bristol stool scale (p < 0.0001), bowel movements per day (p < 0.005), distension score (0.0009), pain score (0.0277) and IBS severity (0.0034).

CONCLUSION

EPI is present in 5% of patients who fulfill Rome IV criteria for D-IBS, and dyspepsia was an independent symptom strongly associated with EPI. Pancreatic steatosis was the main endoscopic ultrasound finding. After PERT therapy, patients had significantly improved stool frequency, stool consistency, abdominal pain, distension and IBS severity score.

Acupuncture for the Treatment of Diarrhea-Predominant Irritable Bowel Syndrome: A Pilot Randomized Clinical Trial

IMPORTANCE

Acupuncture is a promising therapy for irritable bowel syndrome (IBS), but the use of subjective scales as an assessment is accompanied by high placebo response rates.

OBJECTIVES

To preliminarily test the feasibility of using US Food and Drug Administration (FDA)-recommended end points to evaluate the efficacy of acupuncture in the treatment of IBS.

DESIGN, SETTING, AND PARTICIPANTS

This pilot, multicenter randomized clinical trial was conducted in 4 tertiary hospitals in China from July 1, 2020, to March 31, 2021, and 14-week data collection was completed in March 2021. Individuals with a diagnosis of IBS with diarrhea (IBS-D) were randomized to 1 of 3 groups, including 2 acupuncture groups (specific acupoints [SA] and nonspecific acupoints [NSA]) and a sham acupuncture group (non-acupoints [NA]) with a 1:1:1 ratio.

INTERVENTIONS

Patients in all groups received twelve 30-minute sessions over 4 consecutive weeks at 3 sessions per week (ideally every other day).

MAIN OUTCOMES AND MEASURES

The primary outcome was the response rate at week 4, which was defined as the proportion of patients whose worst abdominal pain score (score range, 0-10, with 0 indicating no pain and 10 indicating unbearable severe pain) decreased by at least 30% and the number of type 6 or 7 stool days decreased by 50% or greater.

RESULTS

Ninety patients (54 male [60.0%]; mean [SD] age, 34.5 [11.3] years) were enrolled, with 30 patients in each group. There were substantial improvements in the primary outcomes for all groups (composite response rates of 46.7% [95% CI, 28.8%-65.4%] in the SA group, 46.7% [95% CI, 28.8%-65.4%] in the NSA group, and 26.7% [95% CI, 13.0%-46.2%] in the NA group), although the difference between them was not statistically significant (P = .18). The response rates of adequate relief at week 4 were 64.3% (95% CI, 44.1%-80.7%) in the SA group, 62.1% (95% CI, 42.4%-78.7%) in the NSA group, and 55.2% (95% CI, 36.0%-73.0%) in the NA group (P = .76). Adverse events were reported in 2 patients (6.7%) in the SA group and 3 patients (10%) in NSA or NA group.

CONCLUSIONS AND RELEVANCE

In this pilot randomized clinical trial, acupuncture in both the SA and NSA groups showed clinically meaningful improvement in IBS-D symptoms, although there were no significant differences among the 3 groups. These findings suggest that acupuncture is feasible and safe; a larger, sufficiently powered trial is needed to accurately assess efficacy.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2000030670.

Diabetic Patients With Rosacea Increase the Risks of Diabetic Macular Edema, Dry Eye Disease, Glaucoma, and Cataract

PURPOSE

Inflammation plays a role in diabetic eye diseases, but the association between rosacea and eye diseases in patients with diabetes remains unknown.

DESIGN

This retrospective cohort study used claims data from the National Health Insurance Research Database in Taiwan to investigate the association between rosacea and eye diseases in patients with diabetes.

MATERIALS AND METHODS

Taiwanese patients diagnosed as having diabetes mellitus between January 1, 1997, and December 31, 2013, and using any hypoglycemic agents were included and divided into rosacea and nonrosacea groups. After applying 1:20 sex and age matching and exclusion criteria, 1:4 propensity score matching (PSM) was conducted to balance the covariate distribution between the groups. The risk of time-to-event outcome between rosacea and nonrosacea groups in the PSM cohort was compared using the Fine and Gray subdistribution hazard model.

RESULTS

A total of 4096 patients with rosacea and 16,384 patients without rosacea were included in the analysis. During a mean follow-up period of 5 years, diabetic patients with rosacea had significantly higher risks of diabetic macular edema [subdistribution hazard ratio (SHR): 1.31, 95% confidence interval (CI): 1.05-1.63], glaucoma with medical treatment (SHR: 1.11, 95% CI: 1.01-1.21), dry eye disease (SHR: 1.55, 95% CI: 1.38-1.75), and cataract surgery (SHR: 1.13, 95% CI: 1.02-1.25) compared with diabetic patients without rosacea. A cumulative incidence analysis performed up to 14 years after the index date revealed that the risks of developing ocular diseases consistently increased over time. No significant differences in diabetic retinopathy, age-related macular degeneration, retinal vascular occlusion, ischemic optic neuropathy, optic neuritis, uveitis, or retinal detachment were identified according to rosacea diagnosis. However, we observed significant associations between rosacea and psoriasis, irritable bowel syndrome, anxiety, and major depressive disorder among patients with diabetes.

CONCLUSIONS

Rosacea is associated with diabetic macular edema, glaucoma, dry eye disease, and cataract development in diabetic patients, as well as increased risks of psoriasis, irritable bowel syndrome, anxiety, and depression in diabetic patients.

Identification of putative transcriptomic biomarkers in irritable bowel syndrome (IBS): Differential gene expression and regulation of TPH1 and SERT by vitamin D

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders and affects approximately 4% of the global population. The diagnosis of IBS can be made based on symptoms using the validated Rome criteria and ruling out commonly occurring organic diseases. Although biomarkers exist for "IBS mimickers" such as celiac disease and inflammatory bowel disease (IBD), no such test exists for IBS. DNA microarrays of colonic tissue have been used to identify disease-associated variants in other gastrointestinal (GI) disorders. In this study, our objective was to identify biomarkers and unique gene expression patterns that may define the pathological state of IBS. Mucosal tissue samples were collected from the sigmoid colon of 29 participants (11 IBS and 18 healthy controls). DNA microarray analysis was used to assess gene expression profiling. Extraction and purification of RNA were then performed and used to synthesize cDNA. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) was employed to identify differentially expressed genes in patients diagnosed with IBS compared to healthy, non-IBS patient-derived cDNA. Additional testing probed vitamin D-mediated regulation of select genes associated with serotonergic metabolism. DNA microarray analyses led to the identification of 858 differentially expressed genes that may characterize the IBS pathological state. After screening a series of genes using a combination of gene ontological analysis and RT-qPCR, this spectrum of potential IBS biomarkers was narrowed to 23 genes, some of which are regulated by vitamin D. Seven putative IBS biomarkers, including genes involved in serotonin metabolism, were identified. This work further supports the hypothesis that IBS pathophysiology is evident within the human transcriptome and that vitamin D modulates differential expression of genes in IBS patients. This suggests that IBS pathophysiology may also involve vitamin D deficiency and/or an irregularity in serotonin metabolism.

Ratio of Omega-6/Omega-3 Polyunsaturated Fatty Acids Associated With Somatic and Depressive Symptoms in People With Painful Temporomandibular Disorder and Irritable Bowel Syndrome

Somatic symptom disturbance is among the strongest predictors of painful temporomandibular disorder (TMD). Related psychological constructs, such as anxiety and depression, respond therapeutically to omega-3 polyunsaturated fatty acids (PUFAs) in clinical trials. This cross-sectional study investigated associations between the omega-6/omega-3 PUFA ratio and somatic symptom disturbance and depressive symptoms in a community-based sample of 501 adults and determined whether these associations differed between adults with and without TMD or irritable bowel syndrome (IBS). Liquid chromatography tandem mass spectrometry quantified PUFAs in circulating erythrocytes. Somatic symptoms and depression were quantified using Symptom Checklist-90-Revised subscales. Presence or absence of TMD and IBS, respectively, were determined by clinical examination and Rome III screening questions. The standardized beta coefficient for the omega-6/omega-3 long-chain PUFA ratio was 0.26 (95% confidence limits (CL): 0.08, 0.43) in a multivariable linear regression model in which somatic symptom disturbance was the dependent variable. When modelling depressive symptoms as the dependent variable, the standardized beta coefficient was 0.17 (95% CL:0.01, 0.34). Both associations were stronger among TMD cases and IBS cases than among non-cases. Future randomized control trials that lower the omega-6/omega-3 PUFA ratio could consider somatic or depressive symptoms as a therapeutic target for TMD or IBS pain. PERSPECTIVE: In people with TMD or IBS, a high n-6/n-3 PUFA ratio was positively associated with somatic symptom disturbance and depressive symptoms. Both measures of psychological distress were elevated in people with painful TMD and IBS. Future randomized clinical trials will determine whether lowering the n-6/n-3 ratio is therapeutic for pain.

Psychosocial and Sensory Factors Contribute to Self-Reported Pain and Quality of Life in Young Adults with Irritable Bowel Syndrome

AIMS

Psychosocial and sensory factors, including anxiety, depression, and pressure pain threshold have been used to cluster chronic symptoms in irritable bowel syndrome (IBS). This study examined the contribution of psychosocial sensory factors on pain interference and quality of life (QOL) in this population.

DESIGN

We performed a cross-sectional analysis of baseline data from a randomized controlled trial.

SETTINGS

Two gastrointestinal clinics, general communities, and two large campuses of a public university in the Northeastern United States.

PARTICIPANTS/SUBJECTS

Eighty young adults with IBS aged 21 ± 2.57 years (76.25% female).

METHODS

Demographic and psychosocial factors including anxiety, depression, fatigue, cognition or general concerns, sleep disturbance, self-efficacy, coping, and food intake were measured as independent variables. Quantitative sensory testing was conducted to measure mechanical, thermal, and pressure pain thresholds. Self-reported pain measured by the brief pain inventory (BPI) and IBS-QOL were assessed as the outcome variables. Regression analysis and mediation analysis were conducted to determine the associated factors of IBS pain and QOL.

RESULTS

Age, sex, and psychosocial factors including coping, self-efficacy, alcohol intake, mechanical pain sensitivity, and cold pain threshold were significantly associated with pain interference (all p < 0.05). Coping, and self-efficacy were significantly associated with IBS-QOL (all p < 0.05). In the mediation analysis, coping catastrophizing and self-efficacy were indirectly associated with IBS-QOL mediated by fatigue.

CONCLUSIONS

Psychosocial factors including coping and self-efficacy, and quantitative sensory testing factors significantly correlate with self-reported pain and QOL among young adults with IBS. This preliminary research calls for further interventional studies that target personalized psychosocial and quantitative sensory factors to improve pain management and quality of life in IBS patients.

[Meta analysis of acupuncture and moxibustion for anxiety and depression in irritable bowel syndrome]

OBJECTIVE

To evaluate the effectiveness of acupuncture and moxibustion in the treatment of anxiety and depression in irritable bowel syndrome (IBS) by meta-analysis.

METHODS

China National Knowledge Infrastructure (CNKI), Wanfang Data, China Scientific Journal Database (VIP), China Biomedical Literature Service System (SinoMed), PubMed, Embase, and Cochrane Library were searched for randomized controlled trials (RCTs) on acupuncture and moxibustion in the treatment of IBS anxiety and depression from database inception to June 30, 2021. RevMan5.3 and Stata16.0 were used to conduct Meta-analysis of relevant outcome indicators.

RESULTS

A total of 11 RCTs were included in this study, involving 774 IBS patients (431 in the intervention group and 343 in the control group). Eight of them used manual acupuncture (MA) intervention, and the other three used electroacupuncture (EA) intervention. Meta-analysis showed that compared with the western medicine, MA improved the sedation-agitation scale (SAS) scores (MD=5.24, 95%CI=［3.49, 7.00］, P<0.000 01) and self-rating depression scale (SDS) scores (MD=8.50, 95%CI=［4.68, 12.32］, P<0.000 1) in IBS patients, and there was no significant difference between MA or EA and western medicine in the improvement of Hamilton anxiety rating scale (HAMA) scores (MD=1.10, 95%CI=［0.36, 2.56］, P=0.14) and Hamilton depression rating scale (HAMD) scores (MD=0.53, 95%CI=［0.89, 1.94］, P=0.47). In terms of total effective rates (RR=1.21, 95%CI=［1.12, 1.31］, P<0.000 01) and the irritable bowel syndrome severity scoring system (IBS-SSS) scores (MD=42.16, 95%CI=［27.40, 56.91］, P<0.000 01), both MA and EA therapy was superior to western medicine in alleviating gastrointestinal symptoms of IBS patients.

CONCLUSION

MA and EA can improve the anxiety and depression of IBS patients, while the influence of other acupuncture and moxibustion interventions needs to be deeply explored with more high-quality RCTs.

Are bowel symptoms and psychosocial features different in irritable bowel syndrome patients with abdominal discomfort compared to abdominal pain?

BACKGROUND

The Rome IV criteria eliminated abdominal discomfort for irritable bowel syndrome (IBS), which was previously included in Rome III. There are questions as to whether IBS patients with abdominal discomfort (seen in Rome III but not Rome IV) are different from those with abdominal pain (Rome IV).

AIM

To compare bowel symptoms and psychosocial features in IBS patients diagnosed with Rome III criteria with abdominal discomfort, abdominal pain, and pain & discomfort.

METHODS

We studied IBS patients meeting Rome III criteria. We administered the IBS symptom questionnaire, psychological status, and IBS quality of life. Patients were classified according to the predominant abdominal symptom associated with defecation into an only pain group, only discomfort group, and pain & discomfort group. We compared bowel symptoms, extraintestinal symptoms, IBS quality of life, psychological status and healthcare-seeking behaviors, and efficacy among the three groups. Finally, we tested risk factors for symptom reporting in IBS patients.

RESULTS

Of the 367 Rome III IBS patients enrolled, 33.8% (124 cases) failed to meet Rome IV criteria for an IBS diagnosis. There were no meaningful differences between the pain group (n = 233) and the discomfort group (n = 83) for the following: (1) Frequency of defecatory abdominal pain or discomfort; (2) Bowel habits; (3) Coexisting extragastrointestinal pain; (4) Comorbid anxiety and depression; and (5) IBS quality of life scores except more patients in the discomfort group reported mild symptom than the pain group (22.9% vs 9.0%). There is a significant tendency for patients to report their defecatory and non-defecatory abdominal symptom as pain alone, or discomfort alone, or pain & discomfort (all P < 0.001).

CONCLUSION

IBS patients with abdominal discomfort have similar bowel symptoms and psychosocial features to those with abdominal pain. IBS symptoms manifesting abdominal pain or discomfort may primarily be due to different sensation and reporting experience.

Successful low-dose corticosteroid treatment of aggressive pyoderma gangrenosum with irritable bowel syndrome: a case report

Pyoderma gangrenosum (PG) is a rare and chronic cutaneous disorder characterized by painful ulcers that progresses rapidly. The disease is thought to be immune-mediated. However, the exact etiopathogenesis of the disease has yet to be clearly established. The disease is often misdiagnosed as other cutaneous disorders, most notably infections such as cellulitis in its initial stage. Failure of antibiotic treatment is one of the signs when a diagnosis of PG should be considered. Due to its rampant lesion evolution, aggressive corticosteroid therapy has long been used as the mainstay treatment for PG. However, this can lead to side effects such as gastrointestinal bleeding, especially in patients with autoimmune diseases such as inflammatory bowel disease (IBD). We report the case of a 54-year-old female patient with PG that was initially misdiagnosed as cellulitis and furunculosis along with IBD. She was treated using a low-dose regimen of methylprednisolone, which resulted in significant clinical improvement and complete resolution after 2 months of therapy.

Effect of a Multistrain Probiotic on Leaky Gut in Patients with Diarrhea-Predominant Irritable Bowel Syndrome: A Pilot Study

BACKGROUND

A probiotic mixture prevented epithelial barrier impairment in various experimental models. The objective was to evaluate its effects in patients suffering from IBS with diarrhea (IBS-D) with confirmed leaky gut.

METHODS

IBS-D patients with increased intestinal permeability measured by radionuclide tracers were enrolled in this pilot, open-label, prospective, interventional, single-center, Phase IV study. Patients received two capsules of a multistrain probiotic a day for 30 days and were evaluated by repeated intestinal permeability tests, the Bristol Stool Scale, and patient-perceived quality of life and satisfaction.

RESULTS

Of the 30 enrolled patients (mean age: 42.1 [SD: 13.1] years; female: 60%), 27 completed the study (full analysis set [FAS]), and 18 had no major protocol violation (per protocol set [PPS]). On D30, an improvement of intestinal permeability was observed in 81.5% of patients in FAS, normalization being observed in 37% of the participants (44% in PPS). The mean intestinal permeability was significantly decreased: baseline minus D30, 3.4 (95% CI: 1.7, 5.2); the IBS-QOL total score was significantly increased: D30 minus baseline, 8.0 (95% CI: 3.0, 12.9); and stool consistency was significantly improved. On D15 and D30, 96.3% of patients claimed that their IBS symptoms had been satisfactory alleviated, and a significant improvement was reported for the following VAS-IBS items: abdominal pain, diarrhea, and impact of gastrointestinal problems in daily life. Compliance and tolerance were satisfactory.

CONCLUSION

The multistrain probiotic tested may reduce intestinal permeability in a considerable proportion of patients and may improve abdominal pain, stool consistency, and quality of life. These results pave the way for larger, placebo-controlled clinical studies.

Association between body mass index and fecal calprotectin levels in children and adolescents with irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common pediatric functional gastrointestinal disorder. It is characterized by recurrent abdominal pain and changes in bowel habits and is more prevalent in obese patients. We investigated the association between obesity and IBS in pediatric patients through fecal calprotectin testing. Patients under 18 years of age with IBS who underwent fecal calprotectin testing from January 2015 through April 2020 were retrospectively investigated. The patients were divided into groups based on body mass index (BMI): group I (BMI < 85th percentile) and group II (BMI ≥ 85th percentile). Group II was divided into group IIa, overweight (85th percentile ≤ BMI < 95th percentile), and group IIb, obese (BMI ≥ 95th percentile). Among 277 included patients, 202 (72.9%) were in group I, and 75 (27.1%) were in group II (mean calprotectin levels, 75.60 ± 103.48 vs 45.89 ± 66.57 µg/g, respectively; P = .006). There were significant differences in mean calprotectin levels between groups I and IIa (75.60 ± 103.48 vs 45.45 ± 63.38 µg/g, respectively; P = .028) and groups I and IIb (75.60 ± 103.48 vs 46.22 ± 69.59 µg/g, respectively; P = .025). There was a significant difference in mean calprotectin levels between groups I and II (85.69 ± 142.13 vs 32.04 ± 28.17 µg/g, respectively; P = .029) among patients between 6 and 12 years of age but not among adolescents aged between 12 and 18 years (P = .139). Fecal calprotectin was lower when moderate-to-severe fatty livers were observed by ultrasound compared with normal livers (68.52 ± 97.22 vs 18.53 ± 18.56 µg/g, respectively; P = .017). Fecal calprotectin levels were higher in normal-weight pediatric IBS patients than in their obese counterparts, and this difference was more prominent in younger patients. In young children, IBS symptoms are thought to be influenced more by factors other than intestinal inflammation.

Helicobacter pylori Infection—A Risk Factor for Irritable Bowel Syndrome? An Updated Systematic Review and Meta-Analysis

Nowadays, the relationship between Helicobacter pylori infection (HPI) and irritable bowel syndrome (IBS) remains controversial. Objective: The aim of this study is to investigate the relationship between HPI and IBS through a systematic review and meta-analysis based on the current evidence. Methods: We performed a systematic literature search in electronic databases (PubMed, EMBASE, and the Cochrane library) by computer to identify all reports published before 8 August 2021. The odds ratio (OR) and confidence interval (CI) were calculated to evaluate the association between HPI and IBS. Subgroup analyses were conducted for further assessment and exploration of heterogeneity sources. In addition, we assessed publication bias through funnel plots, Egger’s test, and Begg’s test. Finally, we conducted a sensitivity analysis to evaluate the robustness of the results. Results: Thirteen studies with 13,173 participants were included in the meta-analysis. The pooled OR of the association between HPI and IBS was 1.03 (95% CI [0.80,1.31]; p = 0.84). The adjusted OR of the association between HPI and IBS after excluding the studies with confounding factors defined by our team was 1.29 (95% CI [1.03,1.62]; p = 0.03). We found a positive association between HPI and IBS-D (diarrhea subtype) (OR: 1.54; 95% CI [1.22,1.95]; p = 0.0003). The OR of the relationship between cytotoxin-associated gene A (Cag A) positive HPI and IBS was 4.3 (95% CI [0.51,36.17]; p = 0.18). Conclusions: The likelihood of HPI in IBS patients is relatively higher than that of non-IBS participants but not statistically significant, implying that HPI is not significantly associated with IBS, albeit we may underestimate this association. Moreover, we found a positive association between HPI and IBS-D. We also observed an increased likelihood of Cag-A positive HPI in IBS patients than that of non-IBS participants but not statistically significant.

Practical approach to irritable bowel syndrome-diarrhea beyond low-FODMAP diet

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by abdominal pain and altered defecation, usually accompanied by abdominal bloating or distension. The integrated model of bidirectional interaction between the central, autonomic, enteric nervous system, the microbiome, and the gut barrier allows a better understanding of the pathophysiology of IBS, as well as consideration of potential therapeutic strategies. IBS with predominant diarrhea (IBS-D) represents a therapeutic challenge. Dietary changes or restrictions are most commonly used by patients in an attempt at symptom control. Therefore, a number of diets, especially low-FODMAP diet, have increasingly gained interest as a therapy for IBS-D or mixed IBS. However, this kind of diet, while effective, is not exempt of problems. It is therefore necessary that other therapeutic options be considered while bearing pathophysiological mechanisms and general symptom management in mind.

Somatosensory Profiles Differentiate Pain and Psychophysiological Symptoms Among Young Adults With Irritable Bowel Syndrome: A Cluster Analysis

OBJECTIVE

The aim of this study was to investigate if somatosensory profiles can differentiate pain and psychophysiological symptoms among young adults with irritable bowel syndrome (IBS).

METHODS

We performed a cluster analysis of data collected from a randomized clinical trial of 80 IBS patients and 21 age-matched healthy controls (HCs) to stratify pain and symptoms among young adults with IBS by their peripheral sensory profiles. Data of quantitative sensory testing and IBS-related pain and symptoms were collected at baseline and 6-week and 12-week follow-ups.

RESULTS

Using the K-means method, IBS patients were classified into 2 clusters, the "IBS normal threshold" (IBS-NT) and the "IBS increased threshold" (IBS-IT). The IBS-NT cluster had a similar pain threshold as the HCs, and the IBS-IT cluster had an increased threshold of somatic pain perception (lower cold pain threshold, higher heat pain threshold, and higher pressure pain threshold, all P<0.001) than HCs. Compared with the IBS-NT cluster, the IBS-IT cluster reported higher levels of IBS-related pain intensity, anxiety, fatigue, and sleep disturbance over the 3 visits (all P<0.05).

DISCUSSION

Young adults with IBS fell into 2 clusters, one with a similar sensory threshold as the HCs and another with an increased pain threshold, who reported higher pain intensity and more severe symptoms. Somatic sensory profiles should be integrated into further personalized self-management intervention among patients with IBS.

AGA Clinical Practice Guideline on the Pharmacological Management of Irritable Bowel Syndrome With Constipation

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction associated with significant disease burden. This American Gastroenterological Association guideline is intended to support practitioners in decisions about the use of medications for the pharmacological management of IBS-C and is an update of a prior technical review and guideline.

METHODS

The Grading of Recommendations Assessment, Development and Evaluation framework was used to assess evidence and make recommendations. The technical review panel prioritized clinical questions and outcomes according to their importance for clinicians and patients and conducted an evidence review of the following agents: tenapanor, plecanatide, linaclotide, tegaserod, lubiprostone, polyethylene glycol laxatives, tricyclic antidepressants, selective serotonin reuptake inhibitors, and antispasmodics. The Guideline Panel reviewed the evidence and used the Evidence-to-Decision Framework to develop recommendations.

CONCLUSIONS

The panel agreed on 9 recommendations for the management of patients with IBS-C. The panel made a strong recommendation for linaclotide (high certainty) and conditional recommendations for tenapanor, plecanatide, tegaserod, and lubiprostone (moderate certainty), polyethylene glycol laxatives, tricyclic antidepressants, and antispasmodics (low certainty). The panel made a conditional recommendation against the use of selective serotonin reuptake inhibitors (low certainty).

AGA Clinical Practice Guideline on the Pharmacological Management of Irritable Bowel Syndrome With Diarrhea

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder associated with significant disease burden. This American Gastroenterological Association Guideline is intended to support practitioners in decisions about the use of medications for the pharmacological management of IBS with predominant diarrhea (IBS-D) and is an update of a prior technical review and guideline.

METHODS

The Grading of Recommendations Assessment, Development and Evaluation framework was used to assess evidence and make recommendations. The technical review panel prioritized clinical questions and outcomes according to their importance for clinicians and patients and conducted an evidence review of the following agents: eluxadoline, rifaximin, alosetron, loperamide, tricyclic antidepressants, selective serotonin reuptake inhibitors, and antispasmodics. The guideline panel reviewed the evidence and used the Evidence-to-Decision Framework to develop recommendations.

CONCLUSIONS

The panel agreed on 8 recommendations for the management of patients with IBS-D. The panel made conditional recommendations for eluxadoline, rifaximin, alosetron, (moderate certainty), loperamide (very low certainty), tricyclic antidepressants, and anstispasmodics (low certainty). The panel made a conditional recommendation against the use of selective serotonin reuptake inhibitors (low certainty).

Duodenal eosinophilia is associated with symptomatic erosive gastro-oesophageal reflux disease, presence of co-morbidities, and ethnicity but not undifferentiated functional dyspepsia: A retrospective Malaysian study

BACKGROUND

Duodenal eosinophilia is postulated to play a key role in the pathogenesis of functional dyspepsia, a common condition responsible for considerable impairment of quality of life. Our objective was to evaluate the relative strength of the associations between duodenal eosinophilia, functional dyspepsia, symptomatic erosive gastroesophageal reflux disease (GERD), the presence of co-morbidities, and a number of other variables.

METHODS

Eosinophil counts of archived endoscopic duodenal biopsies of 289 subjects were determined by a pathologist blinded to the clinical data. Duodenal eosinophilia was defined by a count of more than 15 per 5 high power fields. Clinical charts were reviewed by a gastroenterologist blinded to the histology review.

RESULTS

In the study sample, the primary diagnosis was functional dyspepsia (undifferentiated by subtypes) in 45, symptomatic erosive GERD in 29, gall stone disease in 17, irritable bowel syndrome in 23, and an alternative or undetermined diagnosis in 175 subjects, respectively. On logistic regression analyses, eosinophil counts were positively associated with symptomatic erosive GERD (Odds Ratio, OR 1.03, 95% Confidence Interval, 95%CI: 1.00, 1.05; p=0.035) but not functional dyspepsia. Pre-defined duodenal eosinophilia was associated with symptomatic erosive gastro-oesophageal reflux disease (OR 3.36, 95%CI 1.18,-9.60; p=0.023), the presence of co-morbidities (OR 2.00, 95%CI 1.10, 3.62; p=0.022), and Chinese (as compared to Malay and Indian) ethnicity but not with either functional dyspepsia, irritable bowel syndrome, gallstone disease, Helicobacter pylori infection, or gender.

CONCLUSION

Duodenal eosinophilia was associated with symptomatic erosive GERD, the presence of co-morbidities, and Chinese ethnicity but not with undifferentiated functional dyspepsia.

A therapeutic guide on pediatric irritable bowel syndrome and functional abdominal pain-not otherwise specified

Disorders of the gut-brain interaction negatively impact quality of life and carry a substantial socioeconomic burden. Irritable bowel syndrome (IBS) and functional abdominal pain-not otherwise specified (FAP-NOS) are common functional abdominal pain disorders in childhood. The pathophysiology is not fully understood, and high-quality intervention trials and international guidelines are missing. Therefore, the management of these disorders remains challenging. This review aims to provide an up-to-date overview of therapeutic possibilities for pediatric IBS or FAP-NOS and recommends management strategies. To prevent unnecessary referrals and extensive costs, it is fundamental to make a positive diagnosis of IBS or FAP-NOS in children with chronic abdominal pain with only minimal investigations. A tailor-made approach for each patient, based on the accompanying physical and psychological symptoms, is proposed to date.

CONCLUSION

Shared decision-making including non-pharmacological and pharmacological interventions should be considered and discussed with the family.

WHAT IS KNOWN

• Irritable bowel syndrome and functional abdominal pain-not otherwise specified are common in childhood. • Although the number of treatment options has grown recently, managing these disorders can be challenging and unsatisfactory, and no evidence-based international management guidelines are available.

WHAT IS NEW

• We suggest using a stepwise individualized approach to management, where after first-line management, both non-pharmacological and pharmacological interventions should be discussed.

Persistence of gastrointestinal symptoms in irritable bowel syndrome and ulcerative colitis: study protocol for a three-arm randomised controlled trial (SOMA.GUT-RCT)

INTRODUCTION

Ulcerative colitis (UC) and irritable bowel syndrome (IBS) are distressing chronic diseases associated with abdominal pain and altered bowel habits of unknown aetiology. Results from previous studies indicate that, across both diseases, increased levels of illness-related anxiety and dysfunctional symptom expectations contribute to symptom persistence. Thus, comparing both disorders with regard to common and disease-specific factors in the persistence and modification of gastrointestinal symptoms seems justified. Our primary hypothesis is that persistent gastrointestinal symptoms in UC and IBS can be improved by modifying dysfunctional symptom expectations and illness-related anxiety using expectation management strategies.

METHODS AND ANALYSIS

To assess the extent to which persistent somatic symptoms are modifiable in adult patients with UC and IBS, we will conduct an observer-blinded, three-arm randomised controlled trial. A total of 117 patients with UC and 117 patients with IBS will be randomised into three groups of equal size: targeted expectation management aiming to reduce illness-related anxiety and dysfunctional symptom expectations in addition to standard care (SC, intervention 1), non-specific supportive treatment in addition to SC (intervention 2) or SC only (control). Both active intervention groups will comprise three individual online consultation sessions and a booster session after 3 months. The primary outcome is baseline to postinterventional change in gastrointestinal symptom severity.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee of the Hamburg Medical Association (2020-10198-BO-ff). The study will shed light onto the efficacy and mechanisms of action of a targeted expectation management intervention for persistent gastrointestinal symptoms in patients with UC and IBS. Furthermore, the detailed analysis of the complex biopsychosocial mechanisms will allow the further advancement of aetiological models and according evidence-based intervention strategies.

TRIAL REGISTRATION NUMBER

ISRCTN30800023.

Cost-Effectiveness of Linaclotide Compared to Osmotic Laxatives in the Treatment of Irritable Bowel Syndrome with Constipation in China

INTRODUCTION

Linaclotide, a selective agonist of guanylate cyclase C, was highly recommended for the treatment of irritable bowel syndrome with constipation (IBS-C). However, the cost-effectiveness of linaclotide in Chinese is not known, and this study aimed to assess the cost-effectiveness of linaclotide for patients with IBS-C.

METHODS

An economic evaluation was conducted with a Markov model from a societal perspective. The Markov model was structured to simulate the discontinuation and continuation of medication in IBS-C patients in clinical practice, as well as the revisit and non-visit of non-responding patients. The cycle of the model was 4 weeks, and the time horizon was 1 year. The efficacy data in the model was from the risk ratios obtained by the meta-analysis and the calculation of the response rate of the three medications. The utility, discontinuation rate of the medication, and revisit rate data were from published literature, while the cost data were obtained from experts' opinions and published literature. A series of sensitivity analyses was performed on parameters potentially having impact on the model outputs.

RESULTS

The QALYs (quality-adjusted life years) gained for 1-year treatment with linaclotide, polyethylene glycol, and lactulose were 0.821, 0.795, and 0.781, respectively. The corresponding total costs were CNY 7,721 (USD 1,120), CNY 8,797 (USD 1,276) and CNY 9,481 (USD 1,375). In both comparisons, linaclotide was dominant. Compared with polyethylene glycol and lactulose, the likelihood of linaclotide being cost-effective was 100% for both, using 1 times per capita GDP per QALY as willingness-to-pay threshold.

CONCLUSIONS

IBS-C seriously affects the quality of life of patients with IBS-C, and linaclotide can improve symptoms and quality of life at less cost.

Effects of linaclotide in the treatment of chronic constipation and irritable bowel syndrome with constipation: a meta-analysis

OBJECTIVE

Linaclotide is a guanylate cyclase-C (GCC) agonist that is found in intestinal epithelial cells and is used when treating chronic constipation (CC) and irritable bowel syndrome with constipation (IBS-C). Several randomized controlled trials (RCTs) were conducted for evaluating its efficacy and safety.

METHODS

The PubMed, EMBASE, and Cochrane databases and the Web of Science were searched to find multiple RCTs of patients with CC or IBS-C. The Jadad scoring system was used for evaluating each study's methodological quality, and RevMan5.3 was used for meta-analysis. The composite endpoint reaction approved by the FDA, abdominal pain and discomfort relief, symptom improvement, and diarrhea-related adverse reactions were chosen as observation indicators, and relative risk (RR) and 95% confidence interval (CI) were obtained for quantitative and comprehensive evaluation.

RESULTS

Eleven randomized controlled studies were included, consisting of 5 cases of CC and 6 cases of IBS-C. Linaclotide reached the composite endpoint response approved by FDA in the treatment of CC (RR = 3.26, 95% CI: 2.45-4.33), and the composite endpoint response approved by FDA for the treatment of IBS-C (RR = 2.26, 95% CI: 1.86-2.74) was greater than the placebo (both p < 0.00001). The main adverse reactions of linaclotide were gastrointestinal, mostly diarrhea, which was higher than that of the placebo when treating CC (RR = 3.56, 95% CI: 2.76-4.60) and IBS-C (RR = 8.23, 95% CI: 5.69-11.90) (both p < 0.00001).

CONCLUSION

Linaclotide proved to be effective and safe for the treatment of CC and IBS-C compared to the placebo. However, diarrhea is the primary adverse reaction.

Diet Quality and Dietary Inflammatory Index in Dutch Inflammatory Bowel Disease and Irritable Bowel Syndrome Patients

Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) share common culprit foods and potential pathophysiological factors. However, how diet may contribute to disease course and whether this differs between both entities is unclear. We therefore investigated the association of dietary indices with intestinal inflammation and gastrointestinal symptoms in both IBD and IBS patients. Food frequency questionnaires from 238 IBD, 261 IBS and 195 healthy controls (HC) were available to calculate the overall diet quality by the Dutch Healthy Diet-Index 2015 (DHD-2015) and its inflammatory potential by the Adapted Dietary Inflammatory Index (ADII). Intestinal inflammation and symptoms were evaluated by faecal calprotectin and the Gastrointestinal Symptom Rating Scale, respectively. The DHD-2015 was lower in IBD and IBS versus HC (p < 0.001), being associated with calprotectin levels in IBD (b = −4.009, p = 0.006), and with abdominal pain (b = −0.012, p = 0.023) and reflux syndrome (b = −0.016, p = 0.004) in IBS. ADII scores were comparable between groups and were only associated with abdominal pain in IBD (b = 0.194, p = 0.004). In this side-by-side comparison, we found a lower diet quality that was differentially associated with disease characteristics in IBD versus IBS patients. Longitudinal studies are needed to further investigate the role of dietary factors in the development of flares and predominant symptoms.

Rome IV Criteria-Defined Irritable Bowel Syndrome in Atopic Patients and the Effect of Anxiety and Depression: A Case-Control Study

BACKGROUND

Numerous studies report an increased prevalence of irritable bowel syndrome in patients with atopic diseases such as allergic rhinitis, allergic asthma, and chronic urticaria. Both disease groups have a higher incidence of psychological disorders. In this study, we aimed to examine the relationship of irritable bowel syndrome with the presence and severity of allergic diseases and accom- panying anxiety and depression.

METHODS

One hundred sixty-two patients (56 with AR, 34 with AA, and 72 with CU) and 43 healthy volunteers were included in the study. Demographic and clinical data, along with disease duration and severity, was analyzed. Irritable bowel syndrome was diagnosed using Rome IV criteria. Hospital Anxiety and Depression Scale was used to evaluate anxiety and depression. All statistical analyses were performed using Statistic Program for Social Sciences 23.0.

RESULTS

Irritable bowel syndrome prevalence in the control group was 9.3% and 56% in atopic patients (P < .0001). Hospital Anxiety and Depression Scale anxiety scores of 11 and above increased the odds of IBS approximately 14 times, and independently, the presence of allergic disease increased the odds 10 times. In the allergic patient subgroup, Hospital Anxiety and Depression Scale anxiety scores of 11 and above increased the risk of irritable bowel syndrome approximately 18 times.

CONCLUSION

In this first study using Rome IV criteria to examine the relationship of irritable bowel syndrome, allergic diseases, and anxiety and depression, irritable bowel syndrome was more frequent in allergic patients, especially in patients with anxiety. Awareness of a disease cluster where these 3 disease groups intersect will guide clinicians from different disciplines involved in patients' treatment and follow-up.

Irritable Bowel Syndrome and Long-Term Risk of Cancer: A Prospective Cohort Study Among 0.5 Million Adults in UK Biobank

INTRODUCTION

To investigate the prospective association of irritable bowel syndrome (IBS) with long-term risk of overall, site-specific cancer and cancer-specific mortality in general population.

METHODS

Participants free of inflammatory bowel disease, celiac disease, and any cancer at baseline from the UK Biobank were included, with patients with IBS as the exposure group and non-IBS patients as the reference group. The primary outcome was the incidence of overall cancer and cancer-specific mortality. Secondary outcomes included site-specific cancers and types of digestive cancers. The Cox proportional hazard model was used to investigate the associated risk of incident malignancies and related mortality.

RESULTS

Among 449,595 participants, 22,338 (5.0%) were diagnosed with IBS. During a median of 12.2-year follow-up, 2,937 cases of incident cancer were identified in patients with IBS (11.47 per 1,000 person-years), compared with 60,556 cases in reference individuals (12.51 per 1,000 person-years). Of these cases, 512 and 12,282 cancer-specific deaths occurred in IBS and non-IBS groups. Compared with non-IBS, the adjusted hazard ratio for overall cancer and cancer-specific mortality was 0.97 (95% confidence interval: 0.93-1.00, P = 0.062) and 0.83 (0.76-0.91, P < 0.001) among patients with IBS. Specifically, decreased risk of digestive (0.79 [0.71-0.89]), particularly colon (0.75 [0.62-0.90]) and rectal (0.68 [0.49-0.93]), cancers was observed in patients with IBS. Further sensitivity analysis and subgroup analysis by age and sex indicated similar results.

DISCUSSION

Compared with the general population, IBS does not increase the overall risk of cancer. Conversely, IBS is associated with lower risk of incident colorectal cancer and cancer-specific mortality.

Psychiatric Morbidity in Irritable Bowel Syndrome

Psychiatric morbidity is frequent among outpatients with Irritable Bowel Syndrome (IBS) attending gastroenterology clinics. The lifetime prevalence of major depressive and anxiety disorders in IBS patients are up to 76% and 54% respectively. The point prevalence of Major depressive disorder and Anxiety disorders in IBS patients are ranged 9.6 to 54% and from 11.1 to 52.4% respectively. IBS is not usually life-threatening but it has a significant impact on quality of life. So, screening for psychiatric disorders in IBS patients attending Gastroenterology clinics is worthwhile. The objective of this study was to evaluate psychiatric morbidity among the patients with IBS. This cross sectional comparative study was conducted in the Department of Psychiatry, Sylhet MAG Osmani Medical College Hospital, Sylhet, Bangladesh during the period from January 2012 to June 2012. Inclusion criteria were patients of irritable bowel syndrome fulfilling the Rome-III criteria, age between 18 to 60 years irrespective of sex. Patients with any red flag sign, serious cognitive impairment such as dementia, schizophrenia, mania, delusional disorder, prior history of abdominal surgery and other chronic diseases were excluded. One hundred and ten patients with IBS were selected according to inclusion and exclusion criteria and categorized as IBS group. Another 110 age and sex matched subjects were selected as control group. The mean±SD age of the patients was 34.3±12.2 years which was almost identical to control group (p=0.820). Most of the patients (66.4%) were below the age of 40 years. There were 64 (58.2%) male and 46 (41.8%) female which was similar to control group (p=0.643). Psychiatric co-morbidity was most frequent in IBS patients (56.4%) as compared to control group (16.4%) p value <0.001. The most common psychiatric disorders were Anxiety disorders (22.7%), followed by major depressive disorder (19.1%) and somatization disorder (14.5%). The results of this study suggest that a significant number of patients with IBS suffer from psychiatric disorders than control, which are similar to the IBS group in age and gender.

The Prevalence and Incidence of Irritable Bowel Syndrome and Inflammatory Bowel Disease in Depression and Bipolar Disorder: A Systematic Review and Meta-Analysis

OBJECTIVE

The increased prevalence and incidence of affective disorders among patients with gastrointestinal disease have been well established. However, few studies have investigated the inverse relationship. We aimed to identify all pieces of evidence of the prevalence and incidence of irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) in people with depression and bipolar disorder.

METHODS

We conducted a systematic review of studies reporting the association between affective disorders (exposure) and IBS or IBD (outcome) in adults. Evidence was evaluated for quality using Joanna Briggs Institute Critical Appraisal tools. Where suitable data were available, meta-analyses were performed.

RESULTS

We identified 18 studies that met the selection criteria, of which 11 provided data on IBS, 5 on IBD, and 2 on both. Overall, people with depression were significantly more likely to have comorbid IBS (risk ratio = 2.42, 95% confidence interval = 1.98-2.96) and to develop new-onset IBS (risk ratio = 1.90, 95% confidence interval = 1.41-2.56) compared with people without depression. They were also more likely to have and develop IBD, and among patients with IBD, significantly increased rates of depression were observed as early as 5 years before diagnosis. Bipolar disorder was not consistently associated with risk of either condition.

CONCLUSIONS

People with depression are at an increased risk of both having and developing lower gastrointestinal disorders. These findings have important implications for how we understand, manage, and prevent this comorbidity in clinical practice. Further studies are needed to improve our understanding of the relationship between bipolar disorder and bowel disease as well as the role of psychotropic medication, particularly selective serotonin reuptake inhibitors.

Cognitive Behavioral Therapy-Based Comprehensive Self-Management Program Improves Presenteeism in Persons with Irritable Bowel Syndrome: A Secondary Data Analysis

Individuals with irritable bowel syndrome (IBS) are more likely to miss work (absenteeism), have reduced work effectiveness (presenteeism) and experience activity impairment. This study compared the effect of a comprehensive self-management (CSM) intervention program (incorporating cognitive behavioral therapy, diet education and relaxation) versus usual care on work- and activity-impairments in adults with IBS. This secondary data analysis used daily diaries and Work Productivity and Activity Impairment in Irritable Bowel Syndrome (WPAI-IBS) questionnaire data collected at baseline, 3, 6 and 12 months post-randomization from 160 adults with IBS. Mixed-effects modeling was used to compare the effect of CSM versus usual care on work- and activity-related outcomes. The effect of CSM was shown to be superior to usual care in improving WPAI-IBS and diary-measured presenteeism, overall work productivity loss and activity impairment with sustained effects up to 12 months post-randomization (all p < 0.05). Moreover, the CSM intervention was found to be particularly beneficial for IBS patients with greater baseline work and activity impairments (all p < 0.05). The CSM intervention may bring benefits to individuals and society through improving symptoms and reducing presenteeism associated with IBS.

Efficacy and safety of Qinghua Zhixie Decoction against diarrhea-predominate irritable bowel syndrome: A protocol for a randomized controlled trial

BACKGROUND

Diarrhea-predominant irritable bowel syndrome (D-IBS) is the main subtypes of irritable bowel syndrome (IBS). In recent years, more than half of IBS patients have received complementary and alternative medicine. Traditional Chinese herbal formula is widely used in Asia, and clinical studies have also found that Chinese herbal formula could significantly improve abdominal pain and diarrhea. We plan to carry out a randomized, controlled, double blind, clinical studies to observe the clinical efficacy of Qinghua Zhixie decoction in the treatment of D-IBS.

METHODS

Four hundred sixty-four participants will be randomly assigned to the treatment group and control group. Patients in both groups would take medications and stimulations simultaneously. The outcomes of IBS symptom severity score, quality of life, psychological states, and recurrence rate will be recorded. Statistics will be analyzed with the SPSS 22.0.

CONCLUSIONS

The findings of the study will identify the safety and efficacy of Qinghua Zhixie decoction in the treatment of D-IBS.

TRIAL REGISTRATION OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/C8MHW.

Prevalence of Microscopic Colitis in Diarrhea-predominant Irittable Bowel Syndrome Patients: Cohort Study From Upper Egypt

BACKGROUND AND AIM

There is controversy about colonoscopy and taking biopsy from the normal colonic mucosa in patients with a clinical diagnosis of diarrhea-predominant irritable bowel syndrome (D-IBS). This study aims to estimate the prevalence of microscopic colitis (MC) in D-IBS patients and to select patients without the well-known alarming features who will benefit from colonoscopy and biopsies from the normal colonic mucosa.

PATIENTS AND METHODS

We performed a cohort cross-sectional study over 6 months duration in a total of 129 patients with Rome III criteria of D-IBS after excluding cases with features of organic diseases. Cases were subjected to colonoscopy and biopsies from the colonic mucosa that seemed normal.

RESULTS

Histopathologic examination of biopsies taken from cases with normal colonic mucosa revealed 86 (71.66%) cases with nonspecific colitis, 26 (21.66%) cases with MC and 8 (6.66%) cases with ulcerative colitis. Concomitant immunologic diseases (P=0.00005) and triggering drugs intake (P=0.006) were significantly more common in the MC group. The mean duration of diarrhea in MC patients was significantly longer than that of nonspecific colitis and ulcerative colitis patients (P=0.0006).

CONCLUSIONS

Prevalence of MC in D-IBS patients from Upper Egypt is relatively high (21.66%). Concomitant immunologic diseases, possible triggering drugs intake, and long duration of diarrhea are significant risk factors for undiagnosed MC in D-IBS patients.

The relationship between hidradenitis suppurativa and irritable bowel syndrome: a cross-sectional study

BACKGROUND

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder in which one experiences abdominal pain, tension, cramping, bloating, and changes in the form and frequency of defecation, without an underlying organic disease. Many skin diseases have been reported to be more common in people with functional bowel disease. To our knowledge, however, no previous study investigated the potential relationship between hidradenitis suppurativa (HS) and IBS. In this study, we aimed to examine the potential association between IBS and HS.

METHODS

Patients with HS and healthy subjects were enrolled in this cross-sectional study. All participants were assessed for the presence of IBS. ROME IV criteria were used to identify IBS cases. Hurley staging, modified Sartorius score, and physician's global assessment score were applied to define clinical severity and staging of HS.

RESULTS

According to the Rome IV diagnostic criteria, 54 (67.50%) of 80 HS patients and 23 (28.75%) of 80 control group were diagnosed with IBS. The frequency of IBS was statistically significantly higher in the patient group than in the control group (P < 0.001). No statistically significant difference was found between the two groups in terms of abnormal stool frequency and family history of IBS (P = 0.28, P = 0.862, respectively). Abnormal stool form, mucus in stool, abdominal distension, feeling of incomplete evacuation were statistically significantly higher in HS patients compared to the controls (P = 0.01, P = 0.02, P < 0.001, P = 0.001, respectively).

Impact of COVID-19 on Individuals With Irritable Bowel Syndrome and Comorbid Anxiety and/or Depression

GOALS

The goal of this study was to describe the influence of the COVID-19 pandemic on ability to engage in activities and the influence on psychological distress and gastrointestinal symptoms among individuals with irritable bowel syndrome (IBS) and comorbid anxiety and/or depression.

BACKGROUND

Individuals with IBS and comorbid anxiety and/or depression report increased symptoms and decreased quality of life compared with individuals with IBS alone. The current COVID-19 pandemic has the potential to further influence symptoms among individuals with IBS and comorbid anxiety and/or depression.

STUDY

Individuals who met the Rome-IV IBS criteria and reported mild to severe anxiety and/or depression were included. Participants completed an online survey with questions about anxiety, depression, impact of COVID on activities and symptoms, and demographics.

RESULTS

Fifty-five individuals participated in the study. The COVID-19 pandemic most commonly influenced their ability to spend time with friends and family, shop for certain types of food, and access health care. Participants also reported increased stress (92%), anxiety (81%), and depressive symptoms (67%). Finally, around half the sample reported increases in abdominal pain (48%), diarrhea (45%), or constipation (44%).

CONCLUSIONS

The COVID-19 pandemic is related to self-reported increases in psychological distress and gastrointestinal symptoms among individuals with IBS and comorbid anxiety and/or depression. Additional research is needed to intervene on these symptoms.

AhR/IL-22 pathway as new target for the treatment of post-infectious irritable bowel syndrome symptoms

Alterations in brain/gut/microbiota axis are linked to Irritable Bowel Syndrome (IBS) physiopathology. Upon gastrointestinal infection, chronic abdominal pain and anxio-depressive comorbidities may persist despite pathogen clearance leading to Post-Infectious IBS (PI-IBS). This study assesses the influence of tryptophan metabolism, and particularly the microbiota-induced AhR expression, on intestinal homeostasis disturbance following gastroenteritis resolution, and evaluates the efficacy of IL-22 cytokine vectorization on PI-IBS symptoms. The Citrobacter rodentium infection model in C57BL6/J mice was used to mimic Enterobacteria gastroenteritis. Intestinal homeostasis was evaluated as low-grade inflammation, permeability, mucosa-associated microbiota composition, and colonic sensitivity. Cognitive performances and emotional state of animals were assessed using several tests. Tryptophan metabolism was analyzed by targeted metabolomics. AhR activity was evaluated using a luciferase reporter assay method. One Lactococcus lactis strain carrying an eukaryotic expression plasmid for murine IL-22 (L. lactisIL-22) was used to induce IL-22 production in mouse colonic mucosa. C. rodentium-infected mice exhibited persistent colonic hypersensitivity and cognitive impairments and anxiety-like behaviors after pathogen clearance. These post-infectious disorders were associated with low-grade inflammation, increased intestinal permeability, decrease of Lactobacillaceae abundance associated with the colonic layer, and increase of short-chain fatty acids (SCFAs). During post-infection period, the indole pathway and AhR activity were decreased due to a reduction of tryptophol production. Treatment with L. lactisIL-22 restored gut permeability and normalized colonic sensitivity, restored cognitive performances and decreased anxiety-like behaviors. Data from the video-tracking system suggested an upgrade of welfare for mice receiving the L.lactisIL-22 strain. Our findings revealed that AhR/IL-22 signaling pathway is altered in a preclinical PI-IBS model. IL-22 delivering alleviate PI-IBS symptoms as colonic hypersensitivity, cognitive impairments, and anxiety-like behaviors by acting on intestinal mucosa integrity. Thus, therapeutic strategies targeting this pathway could be developed to treat IBS patients suffering from chronic abdominal pain and associated well-being disorders.

Olorinab (APD371), a peripherally acting, highly selective, full agonist of the cannabinoid receptor 2, reduces colitis-induced acute and chronic visceral hypersensitivity in rodents

ABSTRACT

Abdominal pain is a key symptom of inflammatory bowel disease and irritable bowel syndrome, for which there are inadequate therapeutic options. We tested whether olorinab-a highly selective, full agonist of the cannabinoid receptor 2 (CB2)-reduced visceral hypersensitivity in models of colitis and chronic visceral hypersensitivity (CVH). In rodents, colitis was induced by intrarectal administration of nitrobenzene sulfonic acid derivatives. Control or colitis animals were administered vehicle or olorinab (3 or 30 mg/kg) twice daily by oral gavage for 5 days, starting 1 day before colitis induction. Chronic visceral hypersensitivity mice were administered olorinab (1, 3, 10, or 30 mg/kg) twice daily by oral gavage for 5 days, starting 24 days after colitis induction. Visceral mechanosensitivity was assessed in vivo by quantifying visceromotor responses (VMRs) to colorectal distension. Ex vivo afferent recordings determined colonic nociceptor firing evoked by mechanical stimuli. Colitis and CVH animals displayed significantly elevated VMRs to colorectal distension and colonic nociceptor hypersensitivity. Olorinab treatment significantly reduced VMRs to control levels in colitis and CVH animals. In addition, olorinab reduced nociceptor hypersensitivity in colitis and CVH states in a concentration- and CB2-dependent manner. By contrast, olorinab did not alter VMRs nor nociceptor responsiveness in control animals. Cannabinoid receptor 2 mRNA was detected in colonic tissue, particularly within epithelial cells, and dorsal root ganglia, with no significant differences between healthy, colitis, and CVH states. These results demonstrate that olorinab reduces visceral hypersensitivity through CB2 agonism in animal models, suggesting that olorinab may provide a novel therapy for inflammatory bowel disease- and irritable bowel syndrome-associated abdominal pain.

Moxibustion for diarrhea-predominant irritable bowel syndrome: A protocol for systematic review and network meta-analysis

BACKGROUND

Irritable bowel syndrome (IBS) is commonly accompanied by intestinal dysfunction, and diarrhea-predominant irritable bowel syndrome accounts for approximately 23.4% of all cases of IBS. The purpose of this study was to evaluate the efficacy and safety of moxibustion in the treatment of diarrhea-predominant irritable bowel syndrome.

METHODS

According to the retrieval strategies, randomized controlled trials (RCTs) on moxibustion therapies for IBS-D will be obtained from the China National Knowledge Infrastructure, WanFang Data, Chinese Scientific Journals Database, PubMed, Embase, and Cochrane Library, regardless of publication date or language. Studies will be screened based on inclusion and exclusion criteria, and the Cochrane risk bias assessment tool will be used to evaluate the quality of the literature. The network meta-analysis will be performed with the Markov chain Monte Carlo method and carried out with Stata 14.2 and WinBUGS 1.4.3 software. Ultimately, the quality of the evidence obtained from the results will be evaluated.

RESULTS

This study will evaluate whether moxibustion therapy can effectively treat diarrhea-predominant irritable bowel syndrome.

CONCLUSION

This study will provide evidence for whether moxibustion therapy is beneficial to the treatment of human diarrhea-predominant irritable bowel syndrome.

INPLASY REGISTRATION NUMBER

INPLASY202180003.

Fecal microbiota profiling in irritable bowel syndrome and inflammatory bowel disease patients with irritable bowel syndrome-type symptoms

BACKGROUND

The intestinal microbiota is thought to be involved in the occurrence of inflammatory bowel disease in remission with irritable bowel syndrome (IBS)-type symptoms, but the specific distinct profile of these bacteria remains unclear. This cross-sectional study aims to investigate the fecal microbiota profiling in patients with these diseases.

METHODS

Fecal samples from 97 subjects, including Crohn's disease patients in remission with IBS-type symptoms (CDR-IBS+) or without IBS-type symptoms (CDR-IBS-), ulcerative colitis patients in remission with IBS-type symptoms (UCR-IBS+) or without IBS-type symptoms (UCR-IBS-), IBS patients and healthy controls, were collected and applied 16S ribosomal DNA (rDNA) gene sequencing. The V4 hypervariable regions of 16S rDNA gene were amplified and sequenced by the Illumina MiSeq platform. The differences in the sample diversity index in groups were analyzed with R software.

RESULTS

The richness of the intestinal microbiota in the CDR-IBS group was markedly lower than those in the control and IBS groups based on the analysis of observed species and the Chao index (P < 0.05). The observed species index in the CDR-IBS+ group was higher than that in the CDR-IBS- group (median index: 254.8 vs 203, P = 0.036). No difference was found in alpha diversity between UCR patients with IBS-type symptoms and those without related symptoms. At the genus level, the number of Faecalibacterium in CDR patients with IBS-type symptoms increased significantly, while Fusobacterium decreased versus those without such symptoms (mean relative abundance of Faecalibacterium: 20.35% vs 5.18%, P < 0.05; Fusobacterium: 1.51% vs 5.2%, P < 0.05). However, compared with the UCR-IBS- group, the number of Faecalibacterium in the UCR-IBS+ group decreased, while the number of Streptococcus increased, but there was no significant difference in the genus structure. The abundance and composition of the microbiota of IBS patients were not distinct from those of healthy controls.

CONCLUSIONS

The IBS-type symptoms in CD patients in remission may be related to an increase in Faecalibacterium and a decrease in Fusobacterium. The IBS-type symptoms in UC patients in remission cannot be explained by changes in the abundance and structure of the intestinal microbiota.

Irritable bowel syndrome and risk of glaucoma: An analysis of two independent population-based cohort studies

OBJECTIVE

Irritable bowel syndrome (IBS) is a chronic disorder associated with an abnormal gastrointestinal microbiome. Microbiome-host interactions are known to influence organ function including in the central nervous system; thus, we sought to identify whether IBS may be a risk factor for the development of glaucoma.

DESIGN

Two prospective cohort studies.

SUBJECTS

The 1958 United Kingdom Birth Cohort (UKBC; 9091 individuals) and the Danish National Registry of Patients (DNRP; 62,541 individuals with IBS and 625,410 matched general population cohort members).

METHODS

In the UKBC, participants were surveyed throughout life (including at ages 42 and 50). The DNRP contains records of hospital-based contacts and prescription data from the national prescription database.

MAIN OUTCOME MEASURE

The main outcome measure was incidence of glaucoma. In the UKBC, incident glaucoma at age 50 (n = 48) was determined through comparison of survey responses at ages 42 and 50 years. In the DNRP, glaucoma was assessed by hospital diagnosis (n = 1510), glaucoma surgery (n = 582) and initiation of glaucoma medications (n = 1674).

RESULTS

In the UKBC, the odds ratio (OR) of developing glaucoma between ages 42 and 50 in persons with a chronic IBS diagnosis was increased [OR: 5.84, 95% confidence interval (CI): 2.26-15.13]. People with an IBS diagnosis in the DNRP had a hazard ratio (HR) of 1.35 for developing physician-diagnosed glaucoma (95% CI: 1.16-1.56), an HR of 1.35 for undergoing glaucoma surgery (95% CI: 1.06-1.70) and an HR of 1.19 for initiating glaucoma medication (95% CI: 1.03-1.38).

CONCLUSIONS

In two large European cohort studies, IBS is a risk factor for glaucoma.

Theories behind the effect of starch‑ and sucrose‑reduced diets on gastrointestinal symptoms in irritable bowel syndrome (Review)

Increased amounts of starch and sugar have been added to the diet in the Western world during the last decades. Undigested carbohydrates lead to bacterial fermentation and gas production with diffusion of water, causing abdominal bloating, pain and diarrhea. Therefore, dietary advice is the first line of treatment of irritable bowel syndrome (IBS), a disease characterized by abdominal pain and altered bowel habits without any organic findings. Recently, a diet with a reduction of starch and sucrose led to a marked effect on gastrointestinal (GI) symptoms. The mechanism is unknown, but three possible mechanisms are presented in the present review. First, functional variants of the enzyme sucrase‑isomaltase (SI) have been described in IBS. A subgroup of patients with IBS may thus suffer from partial SI deficiency with reduced digestion of starch and sucrose. Second, fructose absorption is less efficient than glucose absorption, which may lead to a physiological fructose malabsorption when ingesting high amounts of sucrose. A third mechanism is that high‑sugar diets causing hyperglycemia, hyperinsulinemia and weight gain have led to painful neuropathy in animal models; whereas, improved metabolic control in humans has led to improvement of neuropathy. Starch‑ and sucrose‑reduced diets lead to decreased levels of C‑peptide, insulin, gastric inhibitory peptide, leptin and weight reduction. These metabolic changes may reduce the excitability of the hypersensitive nervous system often found in IBS and, thereby, lead to the reduced symptoms found after the diet. In conclusion, further studies are needed to investigate the pathophysiology behind development of symptoms after starch and sucrose intake, and the mechanisms behind symptom relief after reduced intake.

The Dilemma of Persistent Irritable Bowel Syndrome Symptoms in Patients with Quiescent Inflammatory Bowel Disease

Irritable bowel syndrome and inflammatory bowel disease differ in their natural evolution, etiopathogenesis, diagnostic criteria, and therapeutic approach. However, recent evidence has suggested some similarities in mechanisms underlying symptom development and progression. There is a relevant role for alterations in the microbiome-brain-gut axis in both diseases. The presence of irritable bowel syndrome symptoms in patients with quiescent inflammatory bowel disease is common in clinical practice. To determine the cause of irritable bowel syndrome symptoms in patients with quiescent inflammatory bowel disease is a clinical challenge. This review aims to illustrate possible causes and solutions for these patients.

Open-label placebo vs double-blind placebo for irritable bowel syndrome: a randomized clinical trial

ABSTRACT

It is commonly believed that blinding to treatment assignment is necessary for placebos to have an effect. However, placebos administered without concealment (ie, open-label placebos [OLPs]) have recently been shown to be effective in some conditions. This study had 2 objectives: first, to determine whether OLP treatment is superior to no-pill control (NPC) in irritable bowel syndrome (IBS) and, second, to compare the efficacy of OLP against double-blind placebo (DBP). In a 6-week, 3-arm, randomized clinical trial, participants were randomized in equal proportions to 3 arms: OLP, DBP, or NPC. Two hundred sixty-two adults (72.9% women), with a mean age of 42.0 (SD = 18.1) years, participated in the primary study. The mean improvement on the IBS Severity Scoring System from baseline to the 6-week end point was significantly greater in OLP compared with that in NPC (90.6 vs 52.3, P = 0.038). Open-label placebo and DBP did not differ significantly on IBS Severity Scoring System improvement (100.3 vs 90.6, P = 0.485). Standardized effect sizes were moderate for OLP vs NPC (d = 0.43) and small for OLP vs DBP (d = 0.10). Participants treated with OLP reported clinically meaningful improvements in IBS symptoms that were significantly greater than those on NPC. Open-label placebo and DBP had similar effects that did not differ significantly, suggesting that blinding may not be necessary for placebos to be effective and that OLP could play a role in the management of patients with refractory IBS.

Pain and psyche in a patient with irritable bowel syndrome: chicken or egg? A time series case report

BACKGROUND

Irritable bowel syndrome (IBS) appears to have a bidirectional interaction with both depressive and anxiety-related complaints. However, it remains unclear how exactly the psychological complaints, at the individual level, are related to somatic symptoms on a daily basis. This single case study investigates how somatic and psychological variables are temporally related in a patient with irritable bowel syndrome.

CASE REPORT

The patient was a woman in her mid-twenties with an IBS diagnosis. She reported frequent soft bowel movements (5-6 times per day), as well as flatulence and abdominal pain. She resembled a typical IBS patient; however, a marked feature of the patient was her high motivation for psychosomatic treatment as well as her willingness to try new strategies regarding the management of her symptoms. As an innovative approach this single case study used a longitudinal, observational, time series design. The patient answered questions regarding somatic and psychological variables daily over a period of twelve weeks with an online diary. The diary data was analysed using an autoregressive (VAR) modeling approach. Time series analyses showed that in most variables, strong same-day correlations between somatic (abdominal pain, daily impairment) and psychological time series (including coping strategies) were present. The day-lagged relationships indicated that higher values in abdominal pain on one day were predictive of higher values in the psychological variables on the following day (e.g. nervousness, tension, catastrophizing, hopelessness). The use of positive thinking as a coping strategy was helpful in reducing the pain on the following days.

CONCLUSION

In the presented case we found a high correlation between variables, with somatic symptoms temporally preceding psychological variables. In addition, for this patient, the use of positive thoughts as a coping strategy was helpful in reducing pain.

Systematic review and network meta-analysis: efficacy of licensed drugs for abdominal bloating in irritable bowel syndrome with constipation

BACKGROUND

Although bloating is a highly prevalent and troublesome symptom in irritable bowel syndrome with constipation (IBS-C), treatment is empirical with no specific guidelines for its management.

AIM

To conduct a pairwise and network meta-analysis, using a frequentist approach, of Food and Drug Administration-licensed drugs for IBS-C comparing their efficacy for abdominal bloating as a specific endpoint.

METHODS

We searched the medical literature through December 2020 to identify randomised controlled trials (RCTs) in IBS-C, with abdominal bloating reported as a dichotomous assessment. Efficacy of each drug was reported as a pooled relative risk (RR) with 95% confidence intervals (CIs) to summarise effect of each comparison tested. Treatments were ranked according to their P-score.

RESULTS

We identified 13 eligible RCTs, containing 10 091 patients. Linaclotide 290 µg o.d., lubiprostone 8 µg b.d., tenapanor 50 mg b.d. and tegaserod 6 mg b.d. were all superior to placebo for abdominal bloating in patients with IBS-C, in both pairwise and the network meta-analyses. Linaclotide demonstrated the greatest improvement in abdominal bloating in both pairwise and network meta-analysis (RR of failure to achieve an improvement in abdominal bloating = 0.78; 95% CI 0.74-0.83, number needed to treat = 7, P-score 0.97). Indirect comparison revealed no significant differences between individual drugs.

CONCLUSIONS

We found all licensed drugs for IBS-C to be superior to placebo for abdominal bloating. Linaclotide appeared to be the most efficacious at relieving abdominal bloating. Further research is needed to assess long-term efficacy of these agents and to better understand the precise mechanism of improving bloating.