Darren M. Brenner

The utility of probiotics in the treatment of irritable bowel syndrome: a systematic review.

OBJECTIVES:Irritable bowel syndrome (IBS) is a common disorder and available therapies have limited efficacy. Mucosal inflammation and alterations in gut microflora may contribute to the development of IBS symptoms, and researchers have hypothesized that probiotics might improve these symptoms. The aim of this study was to perform a systematic review of randomized controlled trials (RCTs) evaluating the efficacy, safety, and tolerability of probiotics in the treatment of IBS.METHODS:Comprehensive literature searches of multiple databases were performed. Study selection criteria were as follows: (i) RCTs, (ii) adults with IBS defined by Manning or Rome II criteria, (iii) single or combination probiotic vs. placebo, and (iv) improvement in IBS symptoms and/or decrease in frequency of adverse events reported. Data about study design and results were extracted in duplicate using standardized data extraction forms. Owing to variability in outcome measures, quantitative pooling of data was not feasible.RESULTS:A total of 16 RCTs met selection criteria. Of those, 11 studies showed suboptimal study design with inadequate blinding, inadequate trial length, inadequate sample size, and/or lack of intention-to-treat analysis. None of the studies provided quantifiable data about both tolerability and adverse events. Bifidobacterium infantis 35624 showed significant improvement in the composite score for abdominal pain/discomfort, bloating/distention, and/or bowel movement difficulty compared with placebo (P<0.05) in two appropriately designed studies. No other probiotic showed significant improvement in IBS symptoms in an appropriately designed study.CONCLUSIONS:B. infantis 35624 has shown efficacy for improvement of IBS symptoms. Most RCTs about the utility of probiotics in IBS have not used an appropriate study design and do not adequately report adverse events. Therefore, there is inadequate data to comment on the efficacy of other probiotics. Future probiotic studies should follow Rome II recommendations for appropriate design of an RCT.

Efficacy of pharmacological therapies for the treatment of opioid-induced constipation: Systematic review and meta-analysis

OBJECTIVES:There has been no definitive synthesis of the evidence for any benefit of available pharmacological therapies in opioid-induced constipation (OIC). We conducted a systematic review and meta-analysis to address this deficit.METHODS:We searched MEDLINE, EMBASE, EMBASE Classic, and the Cochrane central register of controlled trials through to December 2012 to identify placebo-controlled trials of μ-opioid receptor antagonists, prucalopride, lubiprostone, and linaclotide in the treatment of adults with OIC. No minimum duration of therapy was required. Trials had to report a dichotomous assessment of overall response to therapy, and data were pooled using a random effects model. Effect of pharmacological therapies was reported as relative risk (RR) of failure to respond to therapy, with 95% confidence intervals (CIs).RESULTS:Fourteen eligible randomized controlled trials (RCTs) of μ-opioid receptor antagonists, containing 4,101 patients, were identified. These were superior to placebo for the treatment of OIC (RR of failure to respond to therapy=0.69; 95% CI 0.63–0.75). Methylnaltrexone (six RCTs, 1,610 patients, RR=0.66; 95% CI 0.54–0.84), naloxone (four trials, 798 patients, RR=0.64; 95% CI 0.56–0.72), and alvimopan (four RCTs, 1,693 patients, RR=0.71; 95% CI 0.65–0.78) were all superior to placebo. Total numbers of adverse events, diarrhea, and abdominal pain were significantly commoner when data from all RCTs were pooled. Reversal of analgesia did not occur more frequently with active therapy. Only one trial of prucalopride was identified, with a nonsignificant trend toward higher responder rates with active therapy. Two RCTs of lubiprostone were found, with significantly higher responder rates with lubiprostone in both, but reporting of data precluded meta-analysis.CONCLUSIONS:μ-Opioid receptor antagonists are safe and effective for the treatment of OIC. More data are required before the role of prucalopride or lubiprostone in the treatment of OIC are clear.

Type, rather than number, of mental and physical comorbidities increases the severity of symptoms in patients with irritable bowel syndrome.

BACKGROUND & AIMS Irritable bowel syndrome (IBS) has significant mental and physical comorbidities. However, little is known about the day-to-day burden these comorbidities place on quality of life (QOL), physical and mental function, distress, and symptoms of patients. METHODS We collected cross-sectional data from 175 patients with IBS, which was diagnosed on the basis of Rome III criteria (median age, 41 years; 78% women), who were referred to 2 specialty care clinics. Patients completed psychiatric interviews, a physical comorbidity checklist, the IBS Symptom Severity Scale, the IBS-QOL instrument, the Brief Symptom Inventory, the abdominal pain intensity scale, and the Short Form-12 Health Survey. RESULTS Patients with IBS reported an average of 5 comorbidities (1 mental, 4 physical). Subjects with more comorbidities reported worse QOL after adjusting for confounding variables. Multiple linear regression analyses indicated that comorbidity type was more consistently and strongly associated with illness burden indicators than disease counts. Of 10,296 possible physical-mental comorbidity pairs, 6 of the 10 most frequent dyads involved specific conditions (generalized anxiety, depression, back pain, agoraphobia, tension headache, and insomnia). These combinations were consistently associated with greater illness and symptom burdens (QOL, mental and physical function, distress, more severe symptoms of IBS, and pain). CONCLUSIONS Comorbidities are common among patients with IBS. They are associated with distress and reduced QOL. Specific comorbidities are associated with more severe symptoms of IBS.

The Irritable Bowel Syndrome Outcome Study (IBSOS): Rationale and design of a randomized, placebo-controlled trial with 12 month follow up of self- versus clinician-administered CBT for moderate to severe irritable bowel syndrome☆

Irritable bowel syndrome is a common, oftentimes disabling, gastrointestinal disorder whose full range of symptoms has no satisfactory medical or dietary treatment. One of the few empirically validated treatments includes a specific psychological therapy called cognitive behavior therapy which, if available, is typically administered over several months by trained practitioners in tertiary care settings. There is an urgent need to develop more efficient versions of CBT that require minimal professional assistance but retain the efficacy profile of clinic based CBT. The Irritable Bowel Syndrome Outcome Study (IBSOS) is a multicenter, placebo-controlled randomized trial to evaluate whether a self-administered version of CBT is, at least as efficacious as standard CBT and more efficacious than an attention control in reducing core GI symptoms of IBS and its burden (e.g. distress, quality of life impairment, etc.) in moderately to severely affected IBS patients. Additional goals are to assess, at quarterly intervals, the durability of treatment response over a 12 month period; to identify clinically useful patient characteristics associated with outcome as a way of gaining an understanding of subgroups of participants for whom CBT is most beneficial; to identify theory-based change mechanisms (active ingredients) that explain how and why CBT works; and evaluate the economic costs and benefits of CBT. Between August 2010 when IBSOS began recruiting subjects and February 2012, the IBSOS randomized 171 of 480 patients. Findings have the potential to improve the health of IBS patients, reduce its social and economic costs, conserve scarce health care resources, and inform evidence-based practice guidelines.

Psychosocial predictors of self-reported fatigue in patients with moderate to severe irritable bowel syndrome

The objective of this study was to assess the level, impact, and predictors of fatigue in patients with moderate to severe irritable bowel syndrome (IBS). One hundred seventy five patients meeting Rome III criteria for IBS completed a variety of measures including the vitality scale of the SF-12, IBS-Symptom Severity Scale, IBS-QOL, Brief Symptom Inventory-18, Screening for Somatoform Symptoms (SOMS-7), and a semi structured clinical interview (IBS-PRO) as part of a pretreatment evaluation of an NIH funded clinical trial of cognitive behavior therapy for IBS. Fatigue was the third most common somatic complaint, reported by 61% of the patients. Levels of fatigue were associated with both somatic (more severe IBS symptoms, greater number of unexplained medical symptoms), behavioral (frequency of restorative experiences) and psychological (e.g., trait anxiety, depression) outcomes after holding constant confounding variables. The final model in multiple regression analyses accounted for 41.6% of the variance in self-reported fatigue scores with significant predictors including anxiety sensitivity, perceived stress, IBS symptom severity, restorative activities and depression. The clinical implications of data as they relate to both IBS and CBT in general are discussed in the context of attention restoration theory.

Negative Aspects of Close Relationships are More Strongly Associated than Supportive Personal Relationships with Illness Burden of Irritable Bowel Syndrome

OBJECTIVE This study assessed the relative magnitude of associations between IBS outcomes and different aspects of social relationships (social support, negative interactions). METHOD Subjects included 235 Rome III diagnosed IBS patients (M age=41yrs, F=78%) without comorbid GI disease. Subjects completed a testing battery that included the Interpersonal Support Evaluation List (Social Support or SS), Negative Interaction (NI) Scale, IBS Symptom Severity Scale (IBS-SSS), IBS-QOL, BSI Depression, STAI Trait Anxiety, SOMS-7 (somatization), Perceived Stress Scale, and a medical comorbidity checklist. RESULTS After controlling for demographic variables, both SS and NI were significantly correlated with all of the clinical variables (SS rs=.20 to .36; NI rs=.17 to .53, respectively; ps<.05) save for IBS symptom severity (IBS-SSS). NI, but not SS, was positively correlated with IBS-SSS. After performing r-to-z transformations on the correlation coefficients and then comparing z-scores, the correlation between perceived stress, and NI was significantly stronger than with SS. There was no significant difference between the strength of correlations between NI and SS for depression, somatization, trait anxiety, and IBSQOL. A hierarchical linear regression identified both SS and NI as significant predictors of IBS-QOL. CONCLUSIONS Different aspects of social relationships - support and negative interactions - are associated with multiple aspects of IBS experience (e.g. stress, QOL impairment). Negative social relationships marked by conflict and adverse exchanges are more consistently and strongly related to IBS outcomes than social support.

Molecular characterization of systemic sclerosis esophageal pathology identifies inflammatory and proliferative signatures

IntroductionEsophageal involvement in patients with systemic sclerosis (SSc) is common, but tissue-specific pathological mechanisms are poorly understood. There are no animal scleroderma esophagus models and esophageal smooth muscle cells dedifferentiate in culture prohibiting in vitro studies. Esophageal fibrosis is thought to disrupt smooth muscle function and lead to esophageal dilatation, but autopsy studies demonstrate esophageal smooth muscle atrophy and the absence of fibrosis in the majority of SSc cases. Herein, we perform a detailed characterization of SSc esophageal histopathology and molecular signatures at the level of gene expression.MethodsEsophageal biopsies were prospectively obtained during esophagogastroduodenoscopy in 16 consecutive SSc patients and 7 subjects without SSc. Upper and lower esophageal biopsies were evaluated for histopathology and gene expression.ResultsIndividual patient’s upper and lower esophageal biopsies showed nearly identical patterns of gene expression. Similar to skin, inflammatory and proliferative gene expression signatures were identified suggesting that molecular subsets are a universal feature of SSc end-target organ pathology. The inflammatory signature was present in biopsies without high numbers of infiltrating lymphocytes. Molecular classification of esophageal biopsies was independent of SSc skin subtype, serum autoantibodies and esophagitis.ConclusionsProliferative and inflammatory molecular gene expression subsets in tissues from patients with SSc may be a conserved, reproducible component of SSc pathogenesis. The inflammatory signature is observed in biopsies that lack large inflammatory infiltrates suggesting that immune activation is a major driver of SSc esophageal pathogenesis.

The accuracy of patient-reported measures for GI symptoms: a comparison of real time and retrospective reports.

Obtaining accurate information about gastrointestinal (GI) symptoms is critical to achieving the goals of clinical research and practice. The accuracy of patient data is especially important for functional GI disorders (e.g., IBS) whose symptoms lack a biomarker and index illness severity and treatment response. Retrospective patient‐reported data are vulnerable to forgetting and various cognitive biases whose impact has not been systematically studied in patients with GI disorders. The aim of this study was to document the accuracy of patient‐reported GI symptoms over a reporting period (1 week) most representative of the time frame used in research and clinical care.

Gender differences in irritable bowel syndrome: the interpersonal connection

While irritable bowel syndrome (IBS) affects women more than men, the reasons are unclear. Research on the female preponderance of IBS has focused on gender differences in sex‐linked biological processes; much less attention has been paid to the role of psychosocial factors. Interpersonal difficulties may be one source of stress that may significantly impact on women with IBS. Because of the importance that women attach to relationships, we suspected they would be more reactive to interpersonal stress.

Analysis of opioid-mediated analgesia in Phase III studies of methylnaltrexone for opioid-induced constipation in patients with chronic noncancer pain.

Background Subcutaneous methylnaltrexone is efficacious and well tolerated for opioid-induced constipation (OIC) but may theoretically disrupt opioid-mediated analgesia. Methods Opioid use, pain intensity, and opioid withdrawal (Objective Opioid Withdrawal Scale [OOWS] and Subjective Opiate Withdrawal Scale [SOWS] scores) were reported in a randomized, double-blind trial with an open-label extension (RCT) and an open-label trial (OLT) evaluating safety in adults with chronic noncancer pain. In the RCT, patients taking ≥50 mg of oral morphine equivalents daily with <3 rescue-free bowel movements weekly received methyl naltrexone 12 mg once daily (n=150), every other day (n=148), or placebo (n=162) for 4 weeks, followed by open-label methylnaltrexone 12 mg (as needed [prn]; n=364) for 8 weeks. In the OLT, patients (n=1,034) on stable opioid doses with OIC received methylnaltrexone 12 mg prn for up to 48 weeks. Results Minimal fluctuations of median morphine equivalent dose from baseline (BL) were observed in the RCT double-blind period (BL, 154.8–161.0 mg/d; range, 137.1–168.0 mg/d), RCT open-label period (BL, 156.3–174.6; range, 144.0–180.0) and OLT (BL, 120 mg/d; range, 117.3–121.1 mg/d). No significant change from BL in pain intensity score occurred in any group at weeks 2 or 4 (both P≥0.1) of the RCT double-blind period, and scores remained stable during the open-label period and in the OLT (mean change, −0.2 to 0.1). Changes from BL in OOWS and SOWS scores during the double-blind period were not significantly impacted by methylnaltrexone exposure at weeks 2 or 4 (P>0.05 for all). Conclusion Methylnaltrexone did not affect opioid-mediated analgesia in patients with chronic noncancer pain and OIC.