Satisfaction With Life in IBS Is Associated With Psychological Burden Rather than Gastrointestinal Symptom Severity.

INTRODUCTION: Irritable bowel syndrome (IBS) has a major impact on emotional, social, and professional life. This study aimed to evaluate general life satisfaction, a subjective measure of well-being, in IBS patients, and to determine which factors are associated with higher life satisfaction. METHODS: IBS patients (n = 195, mean age 51.4 ± 16.5 years, 73.8% female) recruited from primary and secondary/tertiary care completed questionnaires regarding gastrointestinal symptoms, quality of life, psychological factors, and life satisfaction (Satisfaction With Life Scale, 5 items, range 5-35). A finite mixture model analysis was performed to identify latent classes. Multivariable linear regression was used to identify variables associated with life satisfaction. RESULTS: Overall, 71.3% of the patients were satisfied about their life (Satisfaction With Life Scale-score ≥21). Three latent subgroups could be identified with significantly higher life satisfaction in the subgroup with higher mental quality of life, fewer anxiety and depressive symptoms, lower gastrointestinal specific anxiety, and lower gastrointestinal symptom severity, compared with the other 2 groups. Multivariable linear regression showed that higher physical quality of life (B0.168, P < 0.001) and higher mental quality of life (B0.199, P < 0.001) were associated with higher life satisfaction. Using multivariable regression, no significant association was found between gastrointestinal symptom severity and life satisfaction. DISCUSSION: Higher physical and mental quality of life, but not gastrointestinal symptom severity, were independently associated with higher general life satisfaction in IBS. These findings reinforce the clinical need in IBS treatment to focus on the full extent of the disorder and not merely on gastrointestinal symptom improvement. ClinicalTrials.gov Identifier: NCT00775060.

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

BACKGROUND & AIMS: Irritable bowel syndrome (IBS) is associated with substantial costs to society. Extensive data on direct costs (health care consumption) and indirect costs (health-related productivity loss) are lacking. Hence, we examined the socioeconomic costs of IBS and assessed which patient characteristics are associated with higher costs. METHODS: Cross-sectional data from 3 Rome-defined Dutch IBS patient cohorts (n = 419) were collected. Bootstrapped mean direct and indirect costs were evaluated per patient with IBS using validated questionnaires (ie, medical cost questionnaire and productivity cost questionnaire, respectively). Multivariable regression analyses were performed to identify variables associated with higher costs. RESULTS: Quarterly mean total costs per patient were €2.156 (95% confidence interval (CI), €1793-€2541 [$2444]), consisting of €802 (95% CI, €625-€1010 [$909]) direct costs and €1.354 (95% CI, €1072-€1670 [$1535]) indirect costs. Direct costs consisted primarily of health care professional consultations, with costs related to gastrointestinal clinic visits accounting for 6% and costs related to mental health care visits for 20%. Higher direct costs were significantly associated with older age (P = .007), unemployment (P = .001), IBS subtypes other than constipation (P = .033), lower disease-specific quality of life (P = .027), and more severe depressive symptoms (P = .001). Indirect costs consisted of absenteeism (45%), presenteeism (42%), and productivity loss related to unpaid labor (13%) and were significantly associated with the male sex (P = .014) and more severe depressive symptoms (P = .047). CONCLUSIONS: Productivity loss is the main contributor to the socioeconomic burden of IBS. Direct costs were not predominantly related to gastrointestinal care, but rather to mental health care. Awareness of the nature of costs and contributing patient factors should lead to significant socioeconomic benefits for society.

Integrated fecal microbiome-metabolome signatures reflect stress and serotonin metabolism in irritable bowel syndrome.

To gain insight into the complex microbiome-gut-brain axis in irritable bowel syndrome (IBS), several modalities of biological and clinical data must be combined. We aimed to identify profiles of fecal microbiota and metabolites associated with IBS and to delineate specific phenotypes of IBS that represent potential pathophysiological mechanisms. Fecal metabolites were measured using proton nuclear magnetic resonance (1H-NMR) spectroscopy and gut microbiome using shotgun metagenomic sequencing (MGS) in a combined dataset of 142 IBS patients and 120 healthy controls (HCs) with extensive clinical, biological and phenotype information. Data were analyzed using support vector classification and regression and kernel t-SNE. Microbiome and metabolome profiles could distinguish IBS and HC with an area-under-the-receiver-operator-curve of 77.3% and 79.5%, respectively, but this could be improved by combining microbiota and metabolites to 83.6%. No significant differences in predictive ability of the microbiome-metabolome data were observed between the three classical, stool pattern-based, IBS subtypes. However, unsupervised clustering showed distinct subsets of IBS patients based on fecal microbiome-metabolome data. These clusters could be related plasma levels of serotonin and its metabolite 5-hydroxyindoleacetate, effects of psychological stress on gastrointestinal (GI) symptoms, onset of IBS after stressful events, medical history of previous abdominal surgery, dietary caloric intake and IBS symptom duration. Furthermore, pathways in metabolic reaction networks were integrated with microbiota data, that reflect the host-microbiome interactions in IBS. The identified microbiome-metabolome signatures for IBS, associated with altered serotonin metabolism and unfavorable stress response related to GI symptoms, support the microbiota-gut-brain link in the pathogenesis of IBS.

The estimation of a preference-based single index for the IBS-QoL by mapping to the EQ-5D-5L in patients with irritable bowel syndrome.

PURPOSE: The Irritable Bowel Syndrome Quality of Life (IBS-QoL) questionnaire is a commonly used and validated IBS-specific QoL instrument. However, this questionnaire is in contrast to the EQ-5D-5L, not preference-based and as such does not allow calculation of QALYs. The objective of this study was to describe the convergent- and known-group validity of both questionnaires and to develop a mapping algorithm from EQ-5D-5L which enable IBS-QoL scores to be transformed into utility scores for use in economic evaluations. METHODS: We used data from two multicenter randomized clinical trials, which represented the estimation and external validation dataset. The convergent validity was investigated by examining correlations between the EQ-5D-5L and IBS-QoL and the known-group validity by calculating effect sizes. Ordinary least squares (OLS), censored least absolute deviations (CLAD), and mixture models were used in this mapping approach. RESULTS: 283 IBS patients were included (n = 189 vs. n = 84). Mean IBS-QoL score was 71.13 (SD 15.66) and mean EQ-5D-5L utility score was 0.73 (SD 0.19). The overall sensitivity of the IBS-QoL and EQ-5D-5L to discriminate between patient and disease characteristics was similar. CLAD model 4, containing the total IBS-QoL score and squared IBS-SSS (IBS severity scoring system), was chosen as the most appropriate model to transform IBS-QoL scores into EQ-5D-5L utility scores. CONCLUSION: This study reports the development of an algorithm where the condition-specific questionnaire IBS-QoL can be used to calculate utility values for use in economic evaluations. Including a clinical measure, IBS-SSS, in the model improved the performance of the algorithm.

Evidence for engagement of the nucleus of the solitary tract in processing intestinal chemonociceptive input irrespective of conscious pain response in healthy humans.

ABSTRACT: Neuroimaging studies have revealed important pathomechanisms related to disorders of brain-gut interactions, such as irritable bowel syndrome and functional dyspepsia. More detailed investigations aimed at neural processing in the brainstem, including the key relay station of the nucleus of the solitary tract (NTS), have hitherto been hampered by technical shortcomings. To ascertain these processes in more detail, we used multiecho multiband 7T functional magnetic resonance imaging and a novel translational experimental model based on a nutrient-derived intestinal chemonociceptive stimulus. In a randomized cross-over fashion, subjects received duodenal infusion of capsaicin (the pungent principle in red peppers) and placebo (saline). During infusion, functional magnetic resonance imaging data and concomitant symptom ratings were acquired. Of 26 healthy female volunteers included, 18 were included in the final analysis. Significantly increased brain activation over time during capsaicin infusion, as compared with placebo, was observed in brain regions implicated in pain processing, in particular the NTS. Brain activation in the thalamus, cingulate cortex, and insula was more pronounced in subjects who reported abdominal pain (visual analogue scale > 10 mm), as compared with subjects who experienced no pain. On the contrary, activations at the level of the NTS were independent of subjective pain ratings. The current experimental paradigm therefore allowed us to demonstrate activation of the principal relay station for visceral afferents in the brainstem, the NTS, which was engaged irrespective of the conscious pain response. These findings contribute to understanding the fundamental mechanism necessary for developing novel therapies aimed at correcting disturbances in visceral afferent pain processing.

Digital Instruments for Reporting of Gastrointestinal Symptoms in Clinical Trials: Comparison of End-of-Day Diaries Versus the Experience Sampling Method.

BACKGROUND: Questionnaires are necessary tools for assessing symptoms of disorders of the brain-gut interaction in clinical trials. We previously reported on the excellent adherence to a smartphone app used as symptom diary in a randomized clinical trial on irritable bowel syndrome (IBS). Other sampling methods, such as the experience sampling method (ESM), are better equipped to measure symptom variability over time and provide useful information regarding possible symptom triggers, and they are free of ecological and recall bias. The high frequency of measurements, however, could limit the feasibility of ESM in clinical trials. OBJECTIVE: This study aimed to compare the adherence rates of a smartphone-based end-of-day diary and ESM for symptom assessment in IBS and functional dyspepsia (FD). METHODS: Data from 4 separate studies were included. Patients with IBS participated in a randomized controlled trial, which involved a smartphone end-of-day diary for a 2+8-week (pretreatment + treatment) period, and an observational study in which patients completed ESM assessments using a smartphone app for 1 week. Patients with FD participated in a randomized controlled trial, which involved a smartphone end-of-day diary for a 2+12-week (pretreatment + treatment) period, and an observational study in which patients completed ESM assessments using a smartphone app for 1 week. Adherence rates were compared between these 2 symptom sampling methods. RESULTS: In total, 25 patients with IBS and 15 patients with FD were included. Overall adherence rates for the end-of-day diaries were significantly higher than those for ESM (IBS: 92.7% vs 69.8%, FD: 90.1% vs 61.4%, respectively). CONCLUSIONS: This study demonstrates excellent adherence rates for smartphone app-based end-of-day diaries as used in 2 separate clinical trials. Overall adherence rates for ESM were significantly lower, rendering it more suitable for intermittent sampling periods rather than continuous sampling during longer clinical trials.

A trial-based economic evaluation of peppermint oil for the treatment of irritable bowel syndrome.

BACKGROUND: Irritable Bowel Syndrome (IBS) is a prevalent, chronic gastrointestinal disorder that imposes a substantial socioeconomic burden. Peppermint oil is a frequently used treatment for IBS, but evidence about cost-effectiveness is lacking. OBJECTIVE: We aimed to assess cost-effectiveness of small-intestinal release peppermint oil versus placebo in IBS patients. METHODS: In a multicenter randomized placebo-controlled trial, cost-effectiveness was evaluated from a societal perspective. The incremental cost-effectiveness ratios (ICERs) were expressed as (1) incremental costs per Quality Adjusted Life Years (QALY), and (2) incremental costs per successfully treated patient, that is per abdominal pain responder (according to FDA definitions), both after an eight-week treatment period with placebo versus peppermint oil. Cost-utility and uncertainty were estimated using non-parametric bootstrapping. Sensitivity analyses were performed. RESULTS: The analysis comprised 126 patients (N = 64 placebo, N = 62 small-intestinal release peppermint oil). Peppermint oil was a dominant treatment compared to placebo in 46% of bootstrap replications. Peppermint oil was also more effective but at higher cost in 31% of replications. The net-benefit acceptability curve showed that peppermint oil has a 56% probability of being cost-effective at a conservative willingness-to-pay threshold of €10.000/QALY. Peppermint oil was also a dominant treatment per additional successfully treated patient according to FDA definitions, that is in 51% of replications. In this case, the acceptability curve showed an 89% probability of being cost-effective. CONCLUSIONS: In patients with IBS, small-intestinal release peppermint oil appears to be a cost-effective treatment although there is uncertainty surrounding the ICER. When using abdominal pain responder as outcome measure for the ICER, peppermint oil has a high probability of being cost-effective. The use of peppermint oil, which is a low-cost treatment, can be justified by the modest QALY gains and slightly higher proportion of abdominal pain responders. More research and long-term data are necessary to confirm the cost-effectiveness of peppermint oil. NCT02716285.

Does Day-to-Day Variability in Stool Consistency Link to the Fecal Microbiota Composition?

Introduction: Stool consistency has been associated with fecal microbial composition. Stool consistency often varies over time, in subjects with and without gastrointestinal disorders, raising the question whether variability in the microbial composition should be considered in microbiota studies. We evaluated within-subject day-to-day variability in stool consistency and the association with the fecal microbiota in irritable bowel syndrome (IBS) and healthy subjects, over seven days. Methods: Twelve IBS patients and 12 healthy subjects collected fecal samples during seven consecutive days. Stool consistency was determined by the patient-reported Bristol Stool Scale (BSS) and fecal dry weight percentage. 16S rRNA V4 gene sequencing was performed and microbial richness (alpha diversity; Chao1 index, observed number of species, effective Shannon index) and microbial community structure (beta diversity; Bray-Curtis distance, generalized UniFrac, and taxa abundance on family level) were determined. Results: Linear mixed-effects models showed significant associations between stool consistency and microbial richness, but no time effect. This implies that between-subject but not within-subject variation in microbiota over time can partially be explained by variation in stool consistency. Redundancy analysis showed a significant association between stool consistency and microbial community structure, but additional linear mixed-effects models did not demonstrate a time effect on this. Conclusion: This study supports an association between stool consistency and fecal microbiota, but no effect of day-to-day fluctuations in stool consistency within seven days. This consolidates the importance of considering stool consistency in gut microbiota research, though confirms the validity of single fecal sampling to represent an individual's microbiota at a given time point. NCT00775060.

A putative anti-inflammatory role for TRPM8 in irritable bowel syndrome-An exploratory study.

BACKGROUND: Chronic and recurring pain is a characteristic symptom in irritable bowel syndrome (IBS). Altered signaling between immune cells and sensory neurons within the gut may promote generation of pain symptoms. As transient receptor potential melastatin 8 (TRPM8) agonists, such as L-menthol in peppermint oil, have shown to attenuate IBS pain symptoms, we began investigating potential molecular mechanisms. METHODS: Colonic biopsy tissues were collected from patients with IBS and controls, in two separate cohorts. Immunohistochemistry was performed to identify TRPM8 localization. Quantitative PCR was performed to measure mucosal mRNA levels of TRPM8. In addition, functional experiments with the TRPM8 agonist icilin were performed ex vivo to examine cytokine release from biopsies. Daily diaries were collected to ascertain pain symptoms. RESULTS: In biopsy tissue from IBS patients, we showed that TRPM8 immunoreactivity is colocalized with immune cells predominantly of the dendritic cell lineage, in close approximation to nerve endings, and TRPM8 protein and mRNA expression was increased in IBS patients compared to controls (p < 0.001). TRPM8 mRNA expression showed a significant positive association with abdominal pain scores (p = 0.015). Treatment of IBS patient biopsies with icilin reduced release of inflammatory cytokines IL-1ß, IL-6, and TNF-α (p < 0.05). CONCLUSIONS AND INFERENCES: These data indicate TRPM8 may have important anti-inflammatory properties and by this virtue can impact neuro-immune disease mechanisms in IBS.

Examining the optimal cutoff values of HADS, PHQ-9 and GAD-7 as screening instruments for depression and anxiety in irritable bowel syndrome.

BACKGROUND: Self-rating scales are frequently used to screen for anxiety and depression in patients with irritable bowel syndrome (IBS). Different cutoff values are recommended in literature, and guidelines have suggested the use of other screening instruments over time. The aim of this study was to assess the correlation between the most commonly used psychological screening instruments for anxiety and depression in IBS and to compare custom cutoff scores for these instruments. METHODS: Irritable bowel syndrome patients (n = 192) completed several questionnaires including the Hospital Anxiety and Depression Scale (HADS, HADS-A and HADS-D subscale), Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7). Agreement at different cutoff points, for depressive and anxiety disorder, was assessed by use of the Gwet AC1 coefficient. KEY RESULTS: Hospital Anxiety and Depression Scale (HADS)-D and PHQ-9 scores, and HADS-A and GAD-7 scores showed high correlations (rs  = 0.735 and rs  = 0.805, respectively). For depressive disorder, a Gwet AC1 value of 0.829 was found when recommended cutoff points from literature were compared (PHQ-9 cutoff ≥10, HADS-D cutoff ≥8). For anxiety disorder, a Gwet AC1 value of 0.806 was found when recommended cutoff points from literature were compared (GAD-7 cutoff ≥10, HADS-A cutoff ≥8). Even higher agreements were found when higher HADS cutoff values were chosen, with impact on sensitivity and specificity. CONCLUSIONS & INFERENCES: Custom cutoff values deem the HADS subscales (HADS-D and HADS-A) concordant to PHQ-9 and GAD-7 scores. The choice of a cutoff value has substantial impact on sensitivity/specificity and is dependent on patient population, setting, and the purpose of use.

Effect of Obesity on the Expression of Nutrient Receptors and Satiety Hormones in the Human Colon.

BACKGROUND: Receptors located on enteroendocrine cells (EECs) of the colon can detect nutrients in the lumen. These receptors regulate appetite through a variety of mechanisms, including hormonal and neuronal signals. We assessed the effect of obesity on the expression of these G-protein coupled receptors (GPCRs) and hormones at both mRNA and protein level. METHODS: qPCR and immunohistochemistry were used to examine colonic tissue from cohorts of patients from the Netherlands (proximal and sigmoid tissue) and the United Kingdom (tissue from across the colon) and patients were grouped by body mass index (BMI) value (BMI < 25 and BMI ≥ 25). RESULTS: The mRNA expression of the hormones/signaling molecules serotonin, glucagon, peptide YY (PYY), CCK and somatostatin were not significantly different between BMI groups. GPR40 mRNA expression was significantly increased in sigmoid colon samples in the BMI ≥ 25 group, but not proximal colon. GPR41, GPR109a, GPR43, GPR120, GPRC6A, and CaSR mRNA expression were unaltered between low and high BMI. At the protein level, serotonin and PYY containing cell numbers were similar in high and low BMI groups. Enterochromaffin cells (EC) showed high degree of co-expression with amino acid sensing receptor, CaSR while co-expression with PYY containing L-cells was limited, regardless of BMI. CONCLUSIONS: While expression of medium/long chain fatty acid receptor GPR40 was increased in the sigmoid colon of the high BMI group, expression of other nutrient sensing GPCRs, and expression profiles of EECs involved in peripheral mechanisms of appetite regulation were unchanged. Collectively, these data suggest that in human colonic tissue, EEC and nutrient-sensing receptor expression profiles are not affected despite changes to BMI.

Correction: Smart Data Collection for the Assessment of Treatment Effects in Irritable Bowel Syndrome: Observational Study.

[This corrects the article DOI: 10.2196/19696.].

Age-Related Decrease in Abdominal Pain and Associated Structural- and Functional Mechanisms: An Exploratory Study in Healthy Individuals and Irritable Bowel Syndrome Patients.

Introduction: The world population is ageing, resulting in increased prevalence of age-related comorbidities and healthcare costs. Limited data are available on intestinal health in elderly populations. Structural and functional changes, including altered visceroperception, may lead to altered bowel habits and abdominal symptoms in healthy individuals and irritable bowel syndrome (IBS) patients. Our aim was to explore age-related changes in gastrointestinal symptoms and underlying mechanisms. Methods: In total, 780 subjects (IBS patients n = 463, healthy subjects n = 317) from two separate studies were included. Subjects were divided into different age groups ranging from young adult to elderly. Demographics and gastrointestinal symptom scores were collected from all participants using validated questionnaires. A subset of 233 IBS patients and 103 controls underwent a rectal barostat procedure to assess visceral hypersensitivity. Sigmoid biopsies were obtained from 10 healthy young adults and 10 healthy elderly. Expression of the visceral pain-associated receptors transient receptor potential (TRP) Ankyrin 1 (TRPA1) and Vanilloid 1 (TRPV1) genes were investigated by quantitative RT-PCR and immunofluorescence. Results: Both elderly IBS and healthy individuals showed significantly lower scores for abdominal pain (p < 0.001) and indigestion (p < 0.05) as compared to respective young adults. Visceral hypersensitivity was less common in elderly than young IBS patients (p < 0.001). Relative TRPA1 gene transcription, as well as TRPA1 and TRPV1 immunoreactivity were significantly lower in healthy elderly versus healthy young adults (p < 0.05). Conclusions: Our findings show an age-related decrease in abdominal pain perception. This may in part be related to decreased TRPA1 and/or TRPV1 receptor expression. Further studies are needed to reveal precise underlying mechanisms and the associations with intestinal health.

Smart Data Collection for the Assessment of Treatment Effects in Irritable Bowel Syndrome: Observational Study.

BACKGROUND: End-of-day symptom diaries are recommended by drug regulatory authorities to assess treatment response in patients with irritable bowel syndrome. We developed a smartphone app to measure treatment response. OBJECTIVE: Because the employment of an app to measure treatment response in irritable bowel syndrome is relatively new, we aimed to explore patients' adherence to diary use and characteristics associated with adherence. METHODS: A smartphone app was developed to serve as a symptom diary. Patients with irritable bowel syndrome (based on Rome IV criteria) were instructed to fill out end-of-day diary questionnaires during an 8-week treatment. Additional online questionnaires assessed demographics, irritable bowel syndrome symptom severity, and psychosocial comorbidities. Adherence rate to the diary was defined as the percentage of days completed out of total days. Adherence to the additional web-based questionnaires was also assessed. RESULTS: Overall, 189 patients were included (age: mean 34.0 years, SD 13.3 years; female: 147/189, 77.8%; male: 42/189, 22.2%). The mean adherence rate was 87.9% (SD 9.4%). However, adherence to the diary decreased over time (P<.001). No significant association was found between adherence and gender (P=.84), age (P=.22), or education level (lower education level: P=.58, middle education level: P=.46, versus high education level), while higher anxiety scores were associated with lower adherence (P=.03). Adherence to the online questionnaires was also high (>99%). Missing data due to technical issues were limited. CONCLUSIONS: The use of a smartphone app as a symptom diary to assess treatment response resulted in high patient adherence. The data-collection framework described led to standardized data collection with excellent completeness and can be used for future randomized controlled trials. Due to the slight decrease in adherence to diary use throughout the study, this method might be less suitable for longer trials.

Efficacy and Safety of Peppermint Oil in a Randomized, Double-Blind Trial of Patients With Irritable Bowel Syndrome.

BACKGROUND & AIMS: Peppermint oil is frequently used to treat irritable bowel syndrome (IBS), despite a lack of evidence for efficacy from high-quality controlled trials. We studied the efficacy and safety of small-intestinal-release peppermint oil in patients with IBS and explored the effects of targeted ileocolonic-release peppermint oil. METHODS: We performed a double-blind trial of 190 patients with IBS (according to Rome IV criteria) at 4 hospitals in The Netherlands from August 2016 through March 2018; 189 patients were included in the intent-to-treat analysis (mean age, 34.0 years; 77.8% female; 57.7% in primary care), and 178 completed the study. Patients were randomly assigned to groups given 182 mg small-intestinal-release peppermint oil, 182 mg ileocolonic-release peppermint oil, or placebo for 8 weeks. The primary endpoint was abdominal pain response, as defined by the US Food and Drug Administration: at least a 30% decrease in the weekly average of worst daily abdominal pain compared with baseline in at least 4 weeks. The co-primary endpoint was overall relief of IBS symptoms, as defined by the European Medicines Agency. Secondary endpoints included abdominal pain, discomfort, symptom severity, and adverse events. RESULTS: Abdominal pain response did not differ significantly between the peppermint oil and placebo groups: 29 of 62 patients in the small-intestinal-release peppermint oil group had a response (46.8%, P = .170 vs placebo), 26 of 63 patients in the ileocolonic-release peppermint oil group had a response (41.3%, P = .385 vs placebo), and 22 of 64 patients in the placebo group had a response (34.4%). We did not find differences among the groups in overall relief (9.7%, P = .317 and 1.6%, P = .351 vs 4.7% for placebo). The small intestinal peppermint oil did, however, produce greater improvements than placebo in secondary outcomes of abdominal pain (P = .016), discomfort (P = .020), and IBS severity (P = .020). Adverse events, although mild, were more common in both peppermint oil groups (P < .005). CONCLUSIONS: In a randomized trial of patients with IBS, we found that neither small-intestinal-release nor ileocolonic-release peppermint oil (8 weeks) produced statistically significant reductions in abdominal pain response or overall symptom relief, when using US Food and Drug Administration/European Medicines Agency recommended endpoints. The small-intestinal-release peppermint oil did, however, significantly reduce abdominal pain, discomfort, and IBS severity. These findings do not support further development of ileocolonic-release peppermint oil for treatment of IBS. Clinicaltrials.gov, Number: NCT02716285.

Reduction in IBS symptom severity is not paralleled by improvement in quality of life in patients with irritable bowel syndrome.

BACKGROUND: Irritable bowel syndrome (IBS) is a brain-gut disorder, of which the natural course varies between patients and is difficult to predict. This study aimed to evaluate symptom evolution over a 5-year follow-up period and to identify baseline predictors for symptom severity and quality of life (QoL) at follow-up. METHODS: Maastricht IBS cohort participants completed questionnaires upon inclusion regarding demographics and lifestyle, gastrointestinal (GI) symptoms, anxiety and depression, and QoL. The same questionnaires, in addition to others, were completed after 5 years. Rome criteria were confirmed face-to-face at initial enrollment and through telephonic interviews at follow-up. KEY RESULTS: At a mean follow-up of 4.7 years, 379 patients were approached of whom 203 (53.7%) responded. Of these, 161 were reached by telephone and analyzed; 49 (30.4%) did not fulfill the Rome III criteria at follow-up and had lower levels of GI symptoms and GI-specific anxiety compared to those remaining Rome III-positive (P < 0.001). However, Rome III-negative patients had comparable levels of QoL and life satisfaction, comorbid anxiety and depression, work absenteeism, and impaired productivity. No baseline predictors were found for being Rome III-positive or Rome III-negative. However, greater age and lower baseline physical QoL predicted lower physical QoL at follow-up (P < 0.005 and P < 0.01, respectively), while lower baseline mental QoL predicted lower mental QoL at follow-up (P = 0.005). Additionally, higher anxiety and depression scores at follow-up were associated with lower QoL and life satisfaction at follow-up (P < 0.001). CONCLUSIONS AND INFERENCES: Long-term QoL and general well-being might depend on concurrent psychological symptoms, rather than GI symptom improvement.

A Novel Ileocolonic Release Peppermint Oil Capsule for Treatment of Irritable Bowel Syndrome: A Phase I Study in Healthy Volunteers.

INTRODUCTION: Peppermint oil (PO) has been shown to reduce abdominal pain in patients with irritable bowel syndrome (IBS). PO is assumed to induce intestinal smooth muscle relaxation and desensitization of nociceptive nerve afferents. To increase colonic PO concentration, an ileocolonic release peppermint oil (IC-PO) capsule has been developed. The aim of this study was to compare pharmacokinetic parameters of the currently available small intestinal release PO (SI-PO) and the novel IC-PO. METHODS: In this randomized, double-blind, crossover study, subjects received 182 mg of either SI-PO or IC-PO in a crossover design with a washout period of more than 14 days. Blood samples were collected to determine menthol glucuronide concentrations. RESULTS: Eight healthy volunteers (50% female, median age 22) were included. The time to reach the maximum concentration (Tmax) of IC-PO was significantly longer compared to SI-PO with a median (IQR) of 360 (360-405) versus 180 (120-180) min. The lag time (Tlag) was significantly longer with a median (IQR) of 225 (204-284) for IC-PO compared to 37 (6-65) min for SI-PO. The areas under the menthol glucuronide plasma concentration-time curves were significantly smaller with a median (IQR) of 2331 µg h/L (2006-2510) for IC-PO compared to 2623 µg h/L (2471-2920) for SI-PO. No significant differences were found in peak concentrations and elimination half-lives. CONCLUSION: IC-PO has a significantly delayed peak menthol glucuronide concentration and Tlag, both pointing to the release of PO in the more distal part of the intestine. This may enhance therapeutic efficacy as it results in increased exposure of colonic mucosal afferents to the PO. A randomized controlled trial investigating the efficacy of SI and IC-PO in IBS is currently ongoing. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02291445, EudraCT database 2014-004195-32.