A meta-analysis of the placebo response in complementary and alternative medicine trials of irritable bowel syndrome

Irritable bowel syndrome in children: the placebo response rate and influencing factors a meta-analysis

BACKGROUND

Irritable bowel syndrome is common in children and exhibits a high placebo response. This study was to explore the placebo response rate and its influencing factors in children with irritable bowel syndrome.

METHODS

A systematic search was performed on Pubmed, Embase, MEDLINE, Cochrane Library, CNKI, Wanfang, and CBM from database inception to March 2022. Randomized controlled trials of irritable bowel syndrome in children were included in the study. The primary outcome was the placebo response rate of improvement.

RESULTS

Thirteen studies were included, with 445 patients in the placebo group. The rate of improvement and abdominal pain disappearance were 28.2% (95% CI, 16.6-39.9%) and 5% (95% CI, 0-18.4%). The placebo response based on the abdominal pain score was 0.675 (95% CI, 0.203-1.147). The mode of administration (P < 0.01), dosing schedule (P < 0.01), and clinical outcome assessor (P = 0.04) have a significant impact on the magnitude of placebo effect.

CONCLUSIONS

The placebo response rate for pediatric irritable bowel syndrome was 28.2%. In clinical trials, reducing dosing frequency, selecting appropriate dosage forms, and using patient-reported outcomes can help mitigate the placebo effect.

IMPACT

This is the first meta-analysis to assess the placebo response rates for improvement and disappearance in children with IBS. The finding suggested that the mode of administration, dosing schedule, and clinical outcome assessor could potentially influence the magnitude of the placebo effect in children with IBS. This study would provide a basis for estimating sample size in clinical trial design with a placebo control.

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

BACKGROUND

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

METHODS

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

KEY RESULTS

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

CONCLUSIONS & INFERENCES

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

Efficacy of probiotics, prebiotics and synbiotics in irritable bowel syndrome: a systematic review and meta-analysis of randomized, double-blind, placebo-controlled trials

Introduction. Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that affects the quality of life of numerous people worldwide.Gap statement. The therapeutic role of gut microbiota modulation in IBS remains controversial.Aim. We aimed to assess the efficacy of probiotics, prebiotics or synbiotics in patients with IBS.Methodology. We searched MEDLINE and EMBASE up to 1 August 2023, to identify the randomized, double-blind, placebo-controlled trials investigating the effectiveness of probiotics, prebiotics or synbiotics among patients with IBS. Pooled analyses of the effects of probiotics in relieving IBS symptoms were calculated using a random-effects model. Further subgroup analyses were performed by different genera, doses and duration of treatment.Results. Our final analysis included 52 trials involving 6289 IBS patients. Probiotics significantly increased the overall response rate (RR:1.64; P<0.00001), subjective relief rate (RR:1.50; P=0.0002) and abdominal pain relief rate (RR:1.69; P<0.00001). As for specific genera, mixed probiotics (RR:1.41; P=0.0001), Bifidobacterium (RR:1.76; P<0.00001), Lactobacillus (RR:1.97; P=0.0004) and Saccharomyces (RR:1.31; P=0.0004) markedly relieved IBS symptoms. Mixed probiotics (RR:1.31; P=0.005), Lactobacillus (RR:2.22; P=0.04) and Bifidobacterium (RR:1.62; P<0.0001) elevated patients' subjective relief rate. Besides, probiotics effectively relieved the abdominal pain in IBS patients (RR:1.69; P<0.00001). Probiotics appeared to show a remarkable beneficial role at a dose of 109 c.f.u./day or above (RR:1.662; P<0.0001) and started to work at 4 weeks (RR 1.72; P<0.00001). Efficacy of prebiotics and synbiotics in IBS remained uncertain, due to the deficiency of available RCTs.Conclusions. Probiotics have a therapeutic role in IBS. However, the effect of different probiotics varies. The minimal effective dose of probiotics may be 109 c.f.u./day. With appropriate probiotic formula, the therapeutic effect can occur at 4 weeks. These data provide a basis for further research on the optimal probiotic therapy in IBS.

Meditation and Yoga for Irritable Bowel Syndrome: A Randomized Clinical Trial

INTRODUCTION

Delivered in person, yoga is effective in managing irritable bowel syndrome (IBS) symptoms. The evidence for efficacy, feasibility, and safety of virtually delivered yoga for patients with IBS is unknown.

METHODS

Adults diagnosed with IBS were randomized to either Hatha yoga intervention of 8 weekly online classes delivered virtually or an advice-only control group and assessed at baseline and postintervention. We used an unadjusted ANOVA to determine differences between and within groups on the primary outcome (decrease of ≥50 points in IBS Symptom Severity Scale [IBS-SSS]) and secondary outcomes (quality of life, anxiety and depression, fatigue, somatic symptoms, perceived stress, COVID-19 stress, and self-compassion). We assessed feasibility through recruitment and attrition rates, adherence, participant satisfaction, and safety (i.e., adverse events).

RESULTS

Seventy-nine people participated (mean age 45.4 years [SD = 14.0], 92% women, 20% attrition rate). IBS-SSS decreased significantly in the treatment group (Δ change = 54.7, P = 0.028), but not in the control group (Δ change = 22.6, P = 0.277). Fourteen patients (37%) in the yoga group reached a clinically relevant decrease of ≥50 points on the IBS-SSS postintervention compared with 8 patients (20%) in the control group ( P = 0.242). No significant difference was found between groups in IBS-SSS score postintervention ( P = 0.149), but significant differences in favor of the treatment group for quality of life ( P = 0.030), fatigue ( P = 0.035), and perceived stress ( P = 0.040) were identified. The yoga program demonstrated feasibility. Intention to practice yoga decreased significantly in both groups from baseline to postintervention ( P < 0.001). However, the decline in intention did not correlate with practice minutes.

DISCUSSION

Virtually delivered yoga is safe and feasible, and effective in reducing IBS symptoms. Based on the primary end point, the intervention was not superior to an advice-only control group.

Placebo Response Rates in Trials of Licensed Drugs for Irritable Bowel Syndrome With Constipation or Diarrhea: Meta-analysis

BACKGROUND & AIMS

There are several licensed drugs for irritable bowel syndrome (IBS) that have proven efficacy in randomized controlled trials (RCTs), but placebo response rates are high. We conducted a systematic review and meta-analysis of licensed drugs to estimate magnitude of placebo response rate according to Food and Drug Administration (FDA)-recommended endpoints and to assess how this varies with stringency of the endpoint used to define response.

METHODS

We searched MEDLINE, EMBASE CLASSIC and EMBASE, and the Cochrane central register of controlled trials (through January 2021) to identify RCTs comparing licensed drugs with placebo in adult IBS patients. Studies assessed efficacy according to at least one of composite response, abdominal pain response, or stool response. Data were extracted as intention-to-treat analyses, with dropouts assumed to be treatment failures and pooled using a random-effects model.

RESULTS

There were 17 RCTs of licensed drugs versus placebo in IBS with constipation (4603 patients placebo) and 17 trials in IBS with diarrhea (3908 patients placebo). In IBS with constipation, according to FDA criteria, pooled composite, abdominal pain, and stool response rates with placebo over ≥6 of 12 weeks were 18.9%, 34.6%, and 30.1%, respectively. Evaluating response rates over ≥9 of 12 weeks led to placebo response rates of 4.3% for the composite endpoint, 24.5% for abdominal pain, and 7.7% for stool. In IBS with diarrhea, pooled placebo response rates according to FDA criteria were 16.2% for the composite endpoint, 40.2% for abdominal pain, and 16.2% for stool. Increasing the threshold used to define abdominal pain response from ≥30% improvement to ≥40% or ≥50% led to lower placebo response rates of 34.5% and 23.4%.

CONCLUSIONS

Future RCTs should adhere to current FDA-recommended endpoints for IBS because these lead to lower placebo response rates. However, consideration should be given to further refining some of these to better differentiate between active drug and placebo.

Percutaneous Tibial Nerve Stimulation vs Sham Stimulation for Fecal Incontinence in Women: NeurOmodulaTion for Accidental Bowel Leakage Randomized Clinical Trial

INTRODUCTION

To determine whether percutaneous tibial nerve stimulation (PTNS) is superior to sham stimulation for the treatment of fecal incontinence (FI) in women refractory to first-line treatments.

METHODS

Women aged 18 years or older with ≥3 months of moderate-to-severe FI that persisted after a 4-week run-in phase were randomized 2:1 (PTNS:sham stimulation) to 12 weekly 30-minute sessions in this multicenter, single-masked, controlled superiority trial. The primary outcome was change from baseline FI severity measured by St. Mark score after 12 weeks of treatment (range 0-24; minimal important difference, 3-5 points). The secondary outcomes included electronic bowel diary events and quality of life. The groups were compared using an adjusted general linear mixed model.

RESULTS

Of 199 women who entered the run-in period, 166 (of 170 eligible) were randomized, (111 in PTNS group and 55 in sham group); the mean (SD) age was 63.6 (11.6) years; baseline St. Mark score was 17.4 (2.7); and recording was 6.6 (5.5) FI episodes per week. There was no difference in improvement from baseline in St. Mark scores in the PTNS group when compared with the sham group (-5.3 vs -3.9 points, adjusted difference [95% confidence interval] -1.3 [-2.8 to 0.2]). The groups did not differ in reduction in weekly FI episodes (-2.1 vs -1.9 episodes, adjusted difference [95% confidence interval] -0.26 [-1.85 to 1.33]). Condition-specific quality of life measures did not indicate a benefit of PTNS over sham stimulation. Serious adverse events occurred in 4% of each group.

DISCUSSION

Although symptom reduction after 12 weeks of PTNS met a threshold of clinical importance, it did not differ from sham stimulation. These data do not support the use of PTNS as conducted for the treatment of FI in women.

Ayurvedic vs. Conventional Nutritional Therapy Including Low-FODMAP Diet for Patients With Irritable Bowel Syndrome-A Randomized Controlled Trial

Aims: To compare the effects of Ayurvedic and conventional nutritional therapy in patients with irritable bowel syndrome (IBS).

Methods: Sixty-nine patients with IBS were randomized to Ayurvedic (n = 35) or conventional nutritional therapy according to the recommendations of the German Nutrition Society including the low-FODMAP diet (n = 34). Study visits took place at baseline and after 1, 3, and 6 months. The primary outcome was IBS symptom severity (IBS-SSS) after 3 months; secondary outcomes included stress (CPSS), anxiety and depression (HADS), well-being (WHO-5) and IBS-specific quality of life (IBS-QOL). A repeated measures general linear model (GLM) for intent-to-treat-analyses was applied in this explorative study.

Results: After 3 months, estimated marginal means for IBS-SSS reductions were 123.8 [95% confidence interval (95% CI) = 92.8–154.9; p < 0.001] in the Ayurvedic and 72.7 (95% CI = 38.8–106.7; p < 0.001) in the conventional group. The IBS-SSS reduction was significantly higher in the Ayurveda group compared to the conventional therapy group (estimated marginal mean = 51.1; 95% CI = 3.8–98.5; p = 0.035) and clinically meaningful. Sixty-eight percentage of the variance in IBS-SSS reduction after 3 months can be explained by treatment, 6.5% by patients' expectations for their therapies and 23.4% by IBS-SSS at pre-intervention. Both therapies are equivalent in their contribution to the outcome variance. The higher the IBS-SSS score at pre-intervention and the larger the patients' expectations, the greater the IBS-SSS reduction. There were no significant group differences in any secondary outcome measures. No serious adverse events occurred in either group.

Conclusion: Patients with IBS seem to benefit significantly from Ayurvedic or conventional nutritional therapy. The results warrant further studies with longer-term follow-ups and larger sample sizes.

Clinical Trial Registration:https://clinicaltrials.gov/ct2/show/NCT03019861, identifier: NCT03019861.

Potential Benefit With Complementary and Alternative Medicine in Irritable Bowel Syndrome: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Patients with irritable bowel syndrome (IBS) may pursue complementary and alternative medicine (CAM). We conducted a comprehensive systematic review and meta-analysis examining efficacy of CAM vs. placebo or sham in adults with IBS.

METHODS

Publication databases were searched for randomized controlled trials of CAM therapies (herbal therapy, dietary supplements, mind-body based, body-based, and energy-healing) in adults with IBS. Data were extracted to obtain pooled estimates of mean improvement in abdominal pain (standardized mean difference [SMD]) and relative risk (RR) of overall response using random effects models. Sensitivity and subgroup analyses along with quality assessments were completed.

RESULTS

Among 2825 articles identified, 66 were included. Herbal therapy (SMD=0.47, 95% CI: 0.20 to 0.75, I²=82%) demonstrated significant benefit over placebo for abdominal pain (low confidence in estimates). Benefit with mind-body based therapy for abdominal pain was of borderline significance (SMD=0.29, 95% CI: -0.01 to 0.59, I²=78%). Herbal therapy (RR=1.57, 95% CI: 1.31 to 1.88, I²=77%), dietary supplements (RR=1.95, 95% CI: 1.02 to 3.73, I²=75%), and mind-body based therapy (RR=1.67, 95% CI: 1.13 to 2.49, I²=63%) showed benefit for overall response compared to placebo (low confidence in estimates). Body-based and energy healing therapies demonstrated no significant benefit over placebo or sham for abdominal pain or overall response.

CONCLUSIONS

CAM therapies such as herbal or dietary supplements and mind-body based approaches may be beneficial for abdominal pain and overall response in IBS. However, overall quality of evidence is low. Rigorous, high quality clinical trials are warranted to investigate CAM in IBS.

Pharmacologic Treatment in Functional Abdominal Pain Disorders in Children: A Systematic Review

CONTEXT

Functional abdominal pain disorders (FAPDs) are common in childhood, impacting quality of life and school attendance. There are several compounds available for the treatment of pediatric FAPDs, but their efficacy and safety are unclear because of a lack of head-to-head randomized controlled trials (RCTs).

OBJECTIVE

To systematically review the efficacy and safety of the pharmacologic treatments available for pediatric FAPDs.

DATA SOURCES

Electronic databases were searched from inception to February 2021.

STUDY SELECTION

RCTs or systematic reviews were included if the researchers investigated a study population of children (4-18 years) in whom FAPDs were treated with pharmacologic interventions and compared with placebo, no treatment, or any other agent.

DATA EXTRACTION

Two reviewers independently performed data extraction and assessed their quality. Any interresearcher disagreements in the assessments were resolved by a third investigator.

RESULTS

Seventeen articles representing 1197 children with an FAPD were included. Trials investigating antispasmodics, antidepressants, antibiotics, antihistaminic, antiemetic, histamine-2-receptor antagonist, 5-HT4-receptor agonist, melatonin, and buspirone were included. No studies were found on treatment with laxatives, antidiarrheals, analgesics, antimigraines, and serotonergics.

LIMITATIONS

The overall quality of evidence on the basis of the Grading of Recommendations, Assessment, Development and Evaluations system was very low to low.

CONCLUSIONS

On the basis of current evidence, it is not possible to recommend any specific pharmacologic agent for the treatment of pediatric FAPDs. However, agents such as antispasmodics or antidepressants can be discussed in daily practice because of their favorable treatment outcomes and the lack of important side effects. High-quality RCTs are necessary to provide adequate pharmacologic treatment. For future intervention trials, we recommend using homogenous outcome measures and instruments, a large sample size, and long-term follow-up.

A comparison using standardized measures for patients with irritable bowel syndrome: Trust in the gastroenterologist and reliance on the internet

BACKGROUND

Irritable bowel syndrome (IBS) patients' use of the Internet for health information interacts with the way they trust their gastroenterologist. No standardized measure has targeted IBS patients and gastroenterologists specifically, nor their use of the Internet. The aims of this paper were as follows: the development of a scale that measures an IBS patient's trust in their gastroenterologist, the development of a scale measuring an IBS patient's reliance on Internet health information, and testing the hypothesis that IBS patients, who use the Internet for IBS-related information, trust their gastroenterologist less than those who do not.

METHOD

A total of 82 patients (mean age 49, SD = 14.62) diagnosed with IBS completed two questionnaires: one about trust in their gastroenterologist and the other about the reliance on Internet health information regarding IBS. The two questionnaires were built using current literature as well as our previous qualitative research. The statistical computations were performed using the SPSS 20 program.

KEY RESULTS

Both questionnaires proved to be reliable in measuring gastroenterologist-IBS patient trust (alpha = 0.87) and Internet information reliance (alpha = 0.88), respectively. The IBS patients who did not look for information about IBS over the Internet had significantly higher trust in their gastroenterologist compared with those who did (U = 535.5; z = -2.26; P < 0.05).

CONCLUSIONS

We developed two ready-to-use scales to measure both the gastroenterologist-IBS patient's trust and the IBS patient's reliance on the Internet. Further studies will be able to explore the interaction among all variables in IBS patients' trust.

Effect of multispecies probiotic on gut microbiota composition in individuals with intestinal constipation: A double-blind, placebo-controlled randomized trial

OBJECTIVE

The aim of this study was to evaluate the effect of a multispecies probiotic on gut microbiota composition and constipation symptoms.

METHODS

A randomized, double-blind, placebo-controlled clinical trial was conducted with 35 individuals with constipation for 30 days. The individuals were randomized into two groups: the control capsule (CC) and the probiotic capsule (PC) groups. Constipation symptoms were evaluated by the ROME IV criteria and by evacuation diaries. Fecal microbiota was analyzed by 16 S rRNA gene sequencing.

RESULTS

The majority of participants were women (85.7%). There was a significant reduction in the percent of participants who had incomplete defecation (P = 0.034), blockage sensation (P = 0.025), and rarely present liquid stools without the aid of laxatives (P = 0.046) only within the PC group (but no significant difference between groups). There was a significant increase in the relative abundance percentage of Blautia faecis and Ruminococcus torques in the CC group (P = 0.003 and P = 0.011, respectively), although there was no significant change in the PC group (P = 0.794 and P = 0.958, respectively), with a significant difference between groups (P = 0.029 and P 0.013, respectively), suggesting that probiotic treatment prevented the increase of percent relative abundance of these two species.

CONCLUSION

These results suggest that multispecies probiotics in capsule form may modulate gut microbiota by reducing the bacteria that are commonly increased in patients with constipation, contributing to the balance of microbiota and, consequently, to the well-being of the individual. Future studies with larger numbers of patients are required.

Improved gastrointestinal health for irritable bowel syndrome with metagenome-guided interventions

Irritable bowel syndrome (IBS) is the most prevalent functional gastrointestinal disorder worldwide, and the most common reason for referral to gastroenterology clinics. However, the pathophysiology is still not fully understood and consequently current management guidelines are very symptom-specific, leading to mixed results. Here we present a study of 88 individuals with IBS who had baseline sequencing of their gut microbiome (stool samples), received targeted interventions that included dietary, supplement, prebiotic/probiotic, and lifestyle recommendations for a 30-day period, and a follow-up sequencing of their gut microbiome. The study's objectives were to demonstrate unique metagenomic signatures across the IBS phenotypes and to validate whether metagenomic-guided interventions could lead to improvement of symptom scores in individuals with IBS. Enrolled subjects also completed a baseline and post-intervention questionnaire that assessed their symptom scores. The average symptom score of an individual with IBS at baseline was 160 and at the endpoint of the study the average symptom score of the cohort was 100.9. The mixed IBS subtype showed the most significant reduction in symptom scores across the different subtypes (average decrease by 102 points, P = 0.005). The metagenomics analysis reveals shifts in the microbiome post-intervention that have been cross-validated with the literature as being associated with improvement of IBS symptoms. Given the complex nature of IBS, further studies with larger sample sizes, more targeted analyses, and a broader population cohort are needed to explore these results further.

Efficacy of Lactobacillus paracasei HA-196 and Bifidobacterium longum R0175 in Alleviating Symptoms of Irritable Bowel Syndrome (IBS): A Randomized, Placebo-Controlled Study

Specific probiotic strains can alleviate the gastrointestinal (GI) symptoms and psychiatric comorbidities of irritable bowel syndrome (IBS). In this randomized, double-blind, placebo-controlled study, the efficacy of Lactobacillus paracasei HA-196 (L. paracasei) and Bifidobacterium longum R0175 (B. longum) in reducing the GI and psychological symptoms of IBS was evaluated in 251 adults with either constipation (IBS-C), diarrhea (IBS-D), or mixed-pattern (IBS-M). Following a 2-week run-in period, participants were randomized to one of three interventions: L. paracasei (n = 84), B. longum (n = 83) or placebo (n = 81). IBS symptoms, stool frequency and consistency and quality of life were assessed by questionnaires. The differences from baseline in the severity of IBS symptoms at 4 and 8 weeks were similar between groups. Participants in this study were classified, after randomization, into subtypes according to Rome III. Within the L. paracasei group, complete spontaneous and spontaneous bowel movement frequency increased in participants with IBS-C (n = 10) after 8 weeks of supplementation (both p < 0.05) and decreased in participants with IBS-D (n = 10, p = 0.013). Both L. paracasei and B. longum supplementation improved the quality of life in emotional well-being and social functioning compared with baseline (all p < 0.05). In conclusion, L. paracasei and B. longum may reduce GI symptom severity and improve the psychological well-being of individuals with certain IBS subtypes.

Lactobacillus acidophilus DDS-1 and Bifidobacterium lactis UABla-12 Improve Abdominal Pain Severity and Symptomology in Irritable Bowel Syndrome: Randomized Controlled Trial

This randomized, double-blind, placebo-controlled, multi-center study investigated the clinical efficacy of two probiotic strains on abdominal pain severity and symptomology in irritable bowel syndrome (IBS). Three hundred and thirty adults, aged 18 to 70 years, with IBS according to Rome IV criteria were allocated (1:1:1) to receive placebo, Lactobacillus acidophilus DDS-1 (1 × 1010 CFU/day) or Bifidobacterium animalis subsp. lactis UABla-12 (1 × 1010 CFU/day) over six weeks. The primary outcome was the change in Abdominal Pain Severity - Numeric Rating Scale (APS-NRS). Over the intervention period, APS-NRS was significantly improved in both probiotic groups vs. placebo in absolute terms (DDS-1: -2.59 ± 2.07, p = 0.001; UABla-12: -1.56 ± 1.83, p = 0.001) and in percentage of significant responders (DDS-1: 52.3%, p < 0.001); UABla-12 (28.2%, p = 0.031). Significant amelioration vs. placebo was observed in IBS Symptom Severity Scale (IBS-SSS) scores for L. acidophilus DDS-1 (-133.4 ± 95.19, p < 0.001) and B. lactis UABla-12 (-104.5 ± 96.08, p < 0.001) groups, including sub-scores related to abdominal pain, abdominal distension, bowel habits and quality of life. Additionally, a significant normalization was observed in stool consistency in both probiotic groups over time and as compared to placebo. In conclusion, L. acidophilus DDS-1 and B. lactis UABla-12 improved abdominal pain and symptom severity scores with a corresponding normalization of bowel habits in adults with IBS.

Placebo Responses and Placebo Effects in Functional Gastrointestinal Disorders

Much has been written about the placebo effects in functional gastrointestinal disorders (FGD), especially in irritable bowel syndrome (IBS), driven by the early hypothesis that in randomized controlled trials (RCTs) of IBS, the placebo effect might be specifically high and thus, corrupts the efficacy of novel drugs developed for this condition. This narrative review is based on a specific search method, a database (www.jips.online) developed since 2004 containing more than 4,500 papers (data papers, meta-analyses, systematic reviews, reviews) pertinent to the topic placebo effects/placebo response. Three central questions-deducted from the body of current literature-are addressed to explore the evidence behind this hypothesis: What is the size placebo effect in FGD, especially in IBS, and is it different from the placebo effect seen in other gastrointestinal disorders? Is the placebo effect in FGD different from other functional, non-intestinal disorders, e.g. in other pain syndromes? Is the placebo effect in FGD related to placebo effects seen in psychiatry, e.g. in depression, anxiety disorders, and alike? Following this discussion, a fourth question is raised as the result of the three: What are the consequences of this for future drug trials in FGD? In summary it is concluded that, contrary to common belief and discussion, the placebo effect seen in RCT in FGD is not specifically high and extraordinary as compared to other comparable (i.e. functional) disorders. It shares less than expected commonalities with the placebo effect in psychiatry, and very few predictors have yet been identified that determine its effect size, especially some that are driven by design features of the studies. Current practice of RCT in IBS seems to limit and control the placebo effect quite well, and future trial practice, e.g. head-to-head trial, still offers options to maintain this control, even in the absence of placebos used.

Placebo Response in Chronic Idiopathic Constipation: A Systematic Review and Meta-Analysis

OBJECTIVES

Chronic idiopathic constipation (CIC), like other functional gastrointestinal disorders, has been associated with a high placebo response rate. However, the placebo response in randomized controlled trials has not been described.

METHODS

We conducted a search of the medical literature following the protocol outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement using MEDLINE, EMBASE and EMBASE Classic, Web of Science, and the Cochrane Central Register of Controlled Trials for all drugs used for the treatment of CIC. Two independent reviewers performed eligibility assessment and data extraction. The mean response rate was examined for the following 2 responder endpoints: (i) greater than or equal to 3 complete spontaneous bowel movements (CSBMs)/wk (≥3 CSBMs/wk responders) and (ii) mean increase of ≥1 CSBM/wk compared with baseline (increase in ≥1 CSBM/wk responders).

RESULTS

A total of 23 placebo-controlled trials met our inclusion criteria and were included in this meta-analysis. The placebo response in CIC trials ranged from 4% to 44%. The magnitude of the placebo response was 13% (95% confidence interval 11%-16%) with the ≥3 CSBM/wk responder endpoint and 28% (95% confidence interval 21%-30%) with the increase of ≥1 in the CSBM responder endpoint. Higher baseline CSBM, older age, and trials with more male participants were significantly associated with a stronger placebo response for both the ≥3 CSBMs/wk endpoint and increase in the ≥1 CSBM/wk endpoint. Trial characteristics such as location (Europe vs Asia/United States) and laxative class (prokinetic vs secretagogue) revealed key differences in the placebo response for both endpoints. The placebo response was not significantly affected by the number of study visits, study duration, year of publication, number of drop outs, or likelihood of receiving active drug.

DISCUSSION

The placebo response in CIC trials ranges from 4% to 44% depending on the endpoint. Modifying factors of the placebo response include multiple subject and trial characteristics.

Reinterpreting homoeopathy in the light of placebo effects to manage patients who seek homoeopathic care: A systematic review

Homoeopathy is widespread, and users claim to benefit from it. However, clear evidence of its efficacy over placebo is not available to date. As a consequence, a social separation between homoeopathy users and mainstream medicine exists, exposing these patients to many risks. Our primary objective is to assess homoeopathy efficacy by systematically reviewing existing systematic reviews and meta-analyses and to systematically review trials on open-label placebo (OLP) treatments. A secondary objective is to understand if homoeopathy as a whole may be considered as a placebo treatment. PubMed/Medline, Embase, Google Scholar, and Cochrane Library were systematically searched for systematic reviews and meta-analyses on homoeopathy efficacy, and 61 studies were included. Same databases plus Journal of Interdisciplinary Placebo Studies (JIPS) were also systematically searched for randomised controlled trials (RCTs) on OLP treatments, and 10 studies were included. Databases were searched up to 24 February 2018. Two authors independently screened all retrieved articles and selected studies eligible for inclusion. The quality of reviews of included studies was evaluated with a dedicated NIH tool in the first review, whereas the risk of bias of trials of included studies was assessed with the specific Cochrane tool in the second review. Qualitative syntheses show that homoeopathy efficacy can be considered comparable to placebo, and that OLP treatments may be effective in some health conditions. Placebo effects like placebo itself, treatment context, physician-patient relationship, and other nonspecific factors can define the idea of placebo treatments, which may be effective in some conditions. If homoeopathy efficacy is comparable to placebo, and if placebo treatments can be effective in some conditions, then homoeopathy as a whole may be considered as a placebo treatment. Reinterpreting homoeopathy as a placebo treatment would define limits and possibilities of this practice. This perspective shift suggests a strategy to manage patients who seek homoeopathic care and to reconcile them with mainstream medicine in a sustainable way.

Efficacy of the gluten free diet in the management of functional gastrointestinal disorders: a systematic review on behalf of the Italian Society of Paediatrics

BACKGROUND

Functional gastrointestinal disorders (FGIDs) are characterized by chronic/recurrent gastrointestinal symptoms not related to organic disorders. Due to the limited treatment options and to the perception of subjects with FGIDs suffering from a food intolerance, in recent years there has been an increase in the self-prescription of elimination diets, especially gluten free diet (GFD), for the treatment of these disorders. For this reason, we decided to perform this systematic review with the aim to evaluate the available evidence on the effects of a GFD on gastrointestinal symptoms, in subjects with FGIDs.

METHODS

Cochrane Library and MEDLINE (via PubMed) databases were searched, from inception to March 2018, using the MeSH terms "functional gastrointestinal disorder OR irritable bowel syndrome AND gluten". We included all the clinical trials published in English and evaluating the effects of a GFD in subjects with FGIDs diagnosed according to the Rome II, III, and IV criteria.

RESULTS

Eleven trials were eligible (3 prospective trials, 8 single or double-blind placebo-controlled trials), with 10/11 trials including adult subjects with irritable bowel syndrome (IBS) or FGIDs. Most of the prospective studies found an effect of GFD on gastrointestinal symptoms control. Nevertheless, 1 trial failed to find an association between gluten and GI symptoms when FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) content was simultaneously reduced in the diet, and 2 trials reported a worsening of symptoms during placebo administration. The results of the different trials are difficult to compare due to discrepancies in the study protocols regarding the amount and type of gluten administered, the duration of the gluten challenge, the type of placebo used, and the duration of the challenge itself.

CONCLUSIONS

According to our results, gluten may contribute to the occurrence of gastrointestinal symptoms in patients with FGIDs, particularly in those with IBS. Nevertheless, the results of the currently available trials are difficult to compare due to the lack of standardization in the study designs. For this reason, it is still not possible to recommend the use of the GFD in the routine management of FGIDs.

Factors Associated With Response to Placebo in Patients With Irritable Bowel Syndrome and Constipation

BACKGROUND & AIMS

A high proportion of patients with irritable bowel syndrome (IBS) respond to placebo in clinical trials (estimated at about 40%). We aimed to identify factors that contribute to the high placebo response rate using data from a placebo-controlled trial of patients with IBS.

METHODS

We performed a retrospective analysis of 599 women with IBS with constipation who were in the placebo group of a 12-week, randomized, double-blind, phase 3 trial of the experimental medication renzapride. Primary analyses evaluated frequency of abdominal pain in patients who received placebo, defined as ≥30% pain improvement from baseline for ≥6 of the 12 study weeks. We performed backward elimination regression with bootstrapping to identify factors associated with response to placebo.

RESULTS

In the placebo group, 29.0% of the patients had an abdominal pain response. Factors associated with a response to placebo were baseline variation in abdominal pain (odds ratio [OR], 1.71), maximum baseline pain severity (OR, 1.34), and placebo response in study week 2 (OR, 2.23) or week 3 (OR, 3.69). Factors associated with lack of response to placebo were number of baseline complete spontaneous bowel movements (OR, 0.73; P = .019) and final baseline pain ratings (OR, 0.73; P < .001).

CONCLUSIONS

We identified factors associated with a response in abdominal pain to placebo using original data from an IBS clinical trial. Baseline factors associated with the placebo response in women with IBS and constipation included variation in baseline pain symptoms, severity of baseline symptoms, and early improvement of abdominal pain. These findings have significant implications for clinical trial design.

A Meta-Analysis of the Clinical Use of Curcumin for Irritable Bowel Syndrome (IBS)

Irritable bowel syndrome (IBS) remains a prevalent and difficult-to-manage gastrointestinal condition. There is growing interest in the use of traditional medicine to manage IBS. In particular, curcumin, a biologically active phytochemical, has demonstrated anti-inflammatory and anti-oxidant properties and mucosal protective effects in rat models of colitis. This meta-analysis thus aimed to investigate the hypothesis that curcumin improves IBS symptoms. Using the keywords (curcumin OR turmeric OR Indian saffron OR diferuloylmethane OR curcuminoid) AND (irritable bowel syndrome OR IBS), a preliminary search on the PubMed, Medline, Embase, PsychINFO, Web of Science, and Google Scholar databases yielded 1080 papers published in English between 1 January 1988 and 1 May 2018. Five randomized, controlled trials were systematically reviewed and 3 were included in the final meta-analysis. Random-effects meta-analysis based on three studies and 326 patients found curcumin to have a beneficial albeit not statistically significant effect on IBS symptoms (pooled standardized mean difference from baseline IBS severity rating -0.466, 95% CI: -1.113 to 0.182, p = 0.158). This is the first meta-analysis to examine the use of curcumin in IBS. With its unique anti-oxidant and anti-inflammatory activities and ability to modulate gut microbiota, curcumin is a potentially useful addition to our armamentarium of agents for IBS. It also appears safe and well-tolerated, with no adverse events reported in the available trials. However, current findings are based on a considerably limited evidence base with marked heterogeneity. More robust clinical trials involving a standardized curcumin preparation and larger sample sizes should be encouraged.

Agomelatine, a novel therapeutic option for the management of irritable bowel syndrome

WHAT IS KNOWN AND OBJECTIVE

Irritable bowel syndrome (IBS) is a complex and chronic, relapsing gastrointestinal condition that affects more than 10% of the population worldwide. There is a pressing need for new therapeutic strategies in the management of IBS. Increasing research has shed light on the modulatory functions of melatonin on pain, local inflammation and motility in the gastrointestinal tract. However, melatonin's effects are limited by its extensive first-pass metabolism and short half-life.

COMMENT

Agomelatine, a naphthalene analog of melatonin, is a novel melatonergic drug with a longer half-life and a comparatively greater affinity for MT1 and MT2 melatonin receptors than melatonin itself. Agomelatine also shows serotonin 5-HT3 receptor antagonist activity, which is theoretically of benefit for patients with IBS with diarrhoea (IBS-D) as it regulates gastrointestinal motility and visceral sensory mechanisms. Although only one clinical study of agomelatine use in patients with IBS exists, we believe that agomelatine is a safe and efficacious multimodal agent with untapped potential in the management of IBS.

WHAT IS NEW AND CONCLUSION

Numerous comorbidities are associated with IBS, including chronic pain syndromes and psychiatric disorders. Coupled with its antidepressant actions, agomelatine could serve as an effective adjunct therapeutic. Agomelatine should be considered in our therapeutic armamentarium for IBS management.

The Management of Paediatric Functional Abdominal Pain Disorders: Latest Evidence

Recurrent abdominal pain (RAP) is one of the most common health complaints in both children and adults. Although RAP is considered a functional disorder rather than an organic disease, affected children and their families can still experience anxiety and concerns that can interfere with school, sports, and regular daily activities and lead to frequent attendances at pediatric emergency departments or pediatric gastroenterology clinics. Our review shows experts do not agree on a universally proven management that will work on every child presenting with functional abdominal pain (FAP). Treatment strategies include both non-pharmacological and pharmacological options. Non-pharmacological treatments are usually very well accepted by both children and their parents and are free from medication side effects. Nevertheless, they may be as effective as the pharmacological interventions; therefore, according to many experts and based on the majority of current evidence, a non-pharmacological approach should be the first intervention attempt in children with RAP. In particular, the importance of the bio-psychosocial approach is highlighted, as a majority of children will improve with counselling and reassurance that no serious organic pathologies are suspected, especially when the physician establishes a trustful relationship with both the child and their family. Placebo and pharmacological interventions could be attempted when the bio-psychosocial approach is not applicable or not efficacious. In some difficult cases, finding an effective treatment for FAP can be a challenge, and a number of strategies may need to be tried before symptoms are controlled. In these cases, a multidisciplinary team, comprising a pediatric gastroenterologist, dietician, psychologist, and psychotherapist, is likely to be successful.

Effectiveness of Menthacarin on symptoms of irritable bowel syndrome

Irritable bowel syndrome (IBS) and functional dyspepsia (FD) are common functional gastrointestinal disorders with overlapping symptoms. Effectiveness and safety of Menthacarin (Menthacarin® is the active ingredient of the product Carmenthin® [Dr. Willmar Schwabe GmbH & Co. KG, Karlsruhe, Germany]) in FD treatment were already demonstrated. We assessed the effectiveness of Menthacarin in reducing concomitant IBS-associated symptoms in FD patients. A systematic search to identify eligible double-blind, randomized controlled trials (RCTs) investigating Menthacarin in FD patients and focusing on IBS-associated symptoms was performed. Three out of five identified RCTs included a total of 111 eligible subjects, which allowed for summary statistics and inclusion into subgroup analysis for FD patients with IBS-associated symptoms. With pain intensity values decreasing by 50–75% on average during 28 days of treatment in patients with accompanying IBS, the subgroup analysis indicates beneficial treatment effects of Menthacarin that are similar to those found for FD patients in the primary analyses. The reduction of IBS-associated symptoms in FD patients suggests Menthacarin as a treatment option for IBS patients.

Pediatric irritable bowel syndrome and other functional abdominal pain disorders: an update of non-pharmacological treatments

Functional abdominal pain disorders, including irritable bowel syndrome, are common in children and treatment can often be difficult. Pharmacological therapies and complementary treatments are widely used, despite the limited data in pediatrics. Areas covered: This review provides an overview of the available data for the use of diet, probiotics, percutaneous electrical nerve stimulation, and psychosocial interventions, including hypnotherapy, yoga, cognitive and behavioral therapy, and mind-body interventions for the treatment of functional abdominal pain disorders in children. The literature review included a PubMed search by each therapy, children, abdominal pain, and irritable bowel syndrome. Relevant articles to this review are discussed. Expert commentary: The decision on the use of pharmacological and complementary therapies should be based on clinical findings, evidence, availability, and in-depth discussion with the patient and family. The physician should provide education on the different interventions and their role on the treatment in an empathetic and warm manner providing ample time for the family to ask questions.

Nocebo Effects and Experimental Models in Visceral Pain

Despite its clinical relevance and the potential to extend insights into the processing and modulation of pain derived from investigations of placebo phenomena, the nocebo effect has received comparably little attention over the past decades. Research from experimental and clinical studies is only beginning to unravel the behavioral, functional, and psychoneurobiological mechanisms underlying the nocebo effect. Herein, we summarize current evidence regarding nocebo effects in the field of pain, with a particular emphasis on visceral pain. We provide an overview over behavioral and neuroimaging findings on the impact of expectations and learning and propose promising future directions to help fostering the transition of experimental research from bench to bedside.

Food Therapy in Sinosphere Asia

Traditional Chinese Food Therapy has long been an integral part of dietary practices in Sinosphere Asia. This therapy is defined by the classification of foods into cooling (Yin) and heaty (Yang) and the manipulation of dietary intake of these foods as a therapeutic strategy for chronic diseases. Both functional dyspepsia (FD) and irritable bowel syndrome (IBS) are chronic, functional gut disorders widely prevalent in Sinosphere Asia. Diet is increasingly recognized as a symptom trigger in FD and IBS, and the evidence suggesting the utility of diet therapies as front-line management is growing, particularly in the West. Specifically, a diet low in Fermentable, Oligosaccharides, Disaccharides, Monosaccharides, and Polyols is an efficacious therapy for patients with IBS. In contrast, a proportion of patients with IBS in Sinosphere Asia utilize Chinese Food Therapy for symptom management. Chinese Food Therapy provides an attractive target for integration with evidence-based Western dietary therapies as a management strategy in FD and IBS. However, significant gaps in research exist with the utility of Chinese Food Therapy that first need to be addressed. This includes a lack of standardization for heaty and cooling classification, limited mechanistic rationale or clinical studies supporting its efficacy in FD and IBS, and the lack of an ideal practitioner for implementation of Chinese Food Therapy. Hence, the review provides a summary of the role of diet and nutrition in Sinosphere Asia with an emphasis on FD and IBS, and an examination of how modern dietary practices may be able to be integrated into practices in this region.

The plan of enrichment designs for dealing with high placebo response

To deal with high placebo response in clinical trials for psychiatric and other diseases, different enrichment designs, such as the sequential parallel design, two-way enriched design, and sequential enriched design, have been proposed and implemented recently. Depending on the historical trial information and the trial sponsors' resources, detailed design elements are needed for determining which design to adopt. To assist in making more suitable decisions, we perform evaluations for selecting required design elements in terms of power optimization and sample size planning. We also discuss the implementation of the interim analysis related to its applicability.

Studying brain-regulation of immunity with optogenetics and chemogenetics; A new experimental platform

The interactions between the brain and the immune system are bidirectional. Nevertheless, we have far greater understanding of how the immune system affects the brain than how the brain affects immunity. New technological developments such as optogenetics and chemogenetics (using DREADDs; Designer Receptors Exclusively Activated by Designer Drugs) can bridge this gap in our understanding, as they enable an unprecedented mechanistic and systemic analysis of the communication between the brain and the immune system. In this review, we discuss new experimental approaches for revealing neuronal circuits that can participate in regulation of immunity. In addition, we discuss methods, specifically optogenetics and chemogenetics, that enable targeted neuronal manipulation to reveal how different brain regions affect immunity. We describe how these techniques can be used as an experimental platform to address fundamental questions in psychoneuroimmunology and to understand how neuronal circuits associate with different psychological states can affect physiology.

Can a science-based definition of acupuncture improve clinical outcomes?

Research on acupuncture has been muddled by attempts to bridge the ancient with the modern. Barriers to effectiveness research are reflected in recurring conflicts that include disagreement on use of the most basic terms, lack of standard intervention controls, and the absence of functional measures for assessing treatment effect. Acupuncture research has stalled at the "placebo barrier" wherein acupuncture is "no better than placebo." The most widely recognized comparative effectiveness research in acupuncture does not compare acupuncture treatment protocols within groups, thereby, mutating large scale effectiveness studies into large scale efficacy trials. Too often research in acupuncture attempts to tie outcomes to traditional belief systems thereby limiting usefulness of the research. The acupuncture research paradigm needs to focus more closely on a scientific definition of treatments and outcomes that compare protocols in terms of prevalent clinical issues such as relative effectiveness for treating pain.

The Placebo Response in Pediatric Abdominal Pain-Related Functional Gastrointestinal Disorders: A Systematic Review and Meta-Analysis

OBJECTIVE

To investigate the magnitude and determinants of the placebo response in studies with pediatric abdominal pain-related functional gastrointestinal disorders.

STUDY DESIGN

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and CINAHL were searched for systematic reviews and randomized placebo-controlled trials concerning children 4-18 years of age with an abdominal pain-related functional gastrointestinal disorder. The primary outcome was the pooled proportion of subjects assigned to placebo with improvement as defined by the authors. The effect of trial characteristics on the magnitude of the placebo response was investigated using univariate meta-regression analysis.

RESULTS

Twenty-one trials were identified. The pooled proportion of subjects with improvement was 41% (95% CI, 34%-49%; 17 studies) and with no pain was 17% (95% CI, 8%-32%; 7 studies). The pooled standardized mean difference on the Faces Pain Scales compared with baseline was -0.73 (95% CI, -1.04 to -0.42; 8 studies). There was significant heterogeneity across studies with respect to both outcomes. Lower dosing frequency (P = .04), positive study (P = .03), longer duration of treatment (P < .001), and higher placebo dropout (P < .001) were associated with higher report of no pain. Response on Faces Pain Scales was greater in studies conducted in the Middle East (P = .002), in studies that did not report the randomization schedule (P = .02), and in studies with a higher percentage of females (P = .04).

CONCLUSIONS

Approximately 41% of children with abdominal pain-related functional gastrointestinal disorders improve on placebo. Several trial characteristics are correlated significantly with the proportion of patients with no pain on placebo and with the magnitude of the placebo response on Faces Pain Scales. These data could be valuable for the design of future studies.

Medical comorbidity and distress in patients with irritable bowel syndrome: The moderating role of age

OBJECTIVES

Irritable bowel syndrome (IBS) affects people across the age spectrum and is highly comorbid with other medical conditions. The aim of this study was to determine the moderating effect of age on the relationship between medical comorbidity and health outcomes in IBS patients.

METHODS

Patients (n=384) across the age spectrum (18 to 70) completed questionnaires regarding medical comorbidities, anxiety, depression, IBS symptom severity, and IBS quality of life (QOL).

RESULTS

The mean age was 41 (SD=15). Age interacted with medical comorbidities to predict anxiety, F(7,354)=5.82, p=0.009, R(2)=0.10. Results revealed significant main effects for education, β=-0.16, p<0.05, age, β=-0.15, p<0.05, medical comorbidities, β=0.25, p<0.05, and a significant interaction, β=-0.15, p<0.01. Anxiety was greater among patients with many comorbidities, with this effect being more pronounced for younger adults. Depression, also predicted by the interaction between age and comorbidities, showed the same pattern as anxiety. There was no significant interaction between age and medical comorbidities in predicting IBS symptom severity or IBS QOL.

CONCLUSION

Distress among IBS patients with medical comorbidities varies with age, with higher levels of anxiety and depression among younger adults than their older counterparts. Medical comorbidity may have a more selective impact on psychological distress as compared to IBS symptom severity and quality of life for younger adults with IBS. Distress may increase IBS burden for these patients and complicate its medical management.

Electroacupuncture for patients with diarrhea-predominant irritable bowel syndrome or functional diarrhea: A randomized controlled trial

Diarrhea-predominant irritable bowel syndrome (IBS-D) and functional diarrhea (FD) are highly prevalent, and the effectiveness of acupuncture for managing IBS-D and FD is still unknown.The aim of this study was to compare the effectiveness of electroacupuncture with loperamide.It was a prospective, randomized, parallel group controlled trial.A total of 448 participants were randomly assigned to He electroacupuncture group (n = 113), Shu-Mu electroacupuncture group (n = 111), He-Shu-Mu electroacupuncture group (n = 112), or loperamide group (n = 112). Participants in the 3 acupuncture groups received 16 sessions of electroacupuncture during a 4-week treatment phase, whereas participants in the loperamide group received oral loperamide 2 mg thrice daily. The primary outcome was the change from baseline in stool frequency at the end of the 4-weeks treatment. The secondary outcomes were the Bristol scale, the MOS 36-item short form health survey (SF-36), the weekly average number of days with normal defecations and the proportion of adverse events.Stool frequency was significantly reduced at the end of the 4-week treatment in the 4 groups (mean change from baseline, 5.35 times/week). No significant difference was found between the 3 electroacupuncture groups and the loperamide group in the primary outcome (He vs. loperamide group [mean difference 0.6, 95% CI, -1.2 to 2.4]; Shu-Mu vs. loperamide group [0.4, 95% CI, -1.4 to 2.3]; He-Shu-Mu vs. loperamide group [0.0, 95% CI, -1.8 to 1.8]). Both electroacupuncture and loperamide significantly improved the mean score of Bristol scale and increased the weekly average number of days with normal defecations and the mean scores of SF-36; they were equivalent in these outcomes. However, the participants in electroacupuncture groups did not report fewer adverse events than those in the loperamide group. Similar results were found in a subgroup analysis of separating patients with IBS-D and FD patients.Electroacupuncture is equivalent to loperamide for reducing stool frequency in IBS-D and FD patients. Further studies on cost effectiveness of acupuncture are warranted.

Moxibustion for Diarrhea-Predominant Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background. The complementary and alternative medicines in treatment of diarrhea-predominant irritable bowel syndrome (IBS-D) are controversial. Methods. We searched PubMed, Ovid Embase, Web of Science, Cochrane Library databases, CNKI, Wanfang Database, CBM, VIP, and AMED for randomized controlled trials (RCTs) of moxibustion compared with pharmacological medications in patients with IBS-D. A meta-analysis was performed using both fixed and random-effects models based on heterogeneity across studies. Results. In total, 568 patients in 7 randomized controlled trials were randomly treated with moxibustion and pharmacological medications. The improvement of global IBS-D symptoms and overall scores was significant (P = 0.0001 and P < 0.0001, resp.) in patients treated by moxibustion only compared to pharmacological medications. The specific IBS-D symptoms of abdominal pain, abdominal distension, abnormal stool, and defecation frequency were alleviated in patients treated by moxibustion compared to pharmacological medications, but no significance was found except for abdominal distension and defecation frequency (P = 0.03 and P = 0.02, resp.). There were no serious adverse events related to moxibustion. Conclusions. Moxibustion appears to be effective in treating IBS-D compared with pharmacological medications. However, further large, rigorously designed trials are warranted due to insufficient methodological rigor in the included trials.

Efficacy of Lactobacillus casei Shirota for patients with irritable bowel syndrome

BACKGROUND AND AIMS

Meta-analyses point to a modest but significant effect of probiotics on symptoms in irritable bowel syndrome (IBS). We aimed to assess the effect of the probiotic Lactobacillus casei Shirota (LcS) on symptoms and quality of life in IBS patients in a randomized, double-blind, placebo-controlled intervention study.

MATERIALS AND METHODS

IBS patients (Rome II) between 18 and 65 years of age were included. The study consisted of an 8-week intervention period in which the participants received probiotic (LcS) or placebo twice daily, followed by an 8-week follow-up period. Symptom diaries and quality of life were scored at weeks 0, 8 and 16. The primary outcome parameter was a decrease of at least 30% in a composite mean symptom score (MSS) at week 8 on the basis of an intention-to-treat analysis.

RESULTS

Thirty-nine individuals (67% women) were included in the probiotic group and 41 individuals (71% women) were included in the placebo group. After the intervention period, the mean relative improvement did not reach 30% for MSS or any individual symptom score. After follow-up (week 16), a mean improvement of at least 30% was achieved for MSS in the probiotic group, but no significant difference was found between both treatment groups (mean±SD: 34±7%; 13±8%, P=0.06).

CONCLUSION

After probiotic treatment with LcS, no improvement of 30% in MSS was observed after 8 weeks.

Age and sex as moderators of the placebo response – an evaluation of systematic reviews and meta-analyses across medicine

Predictors of the placebo response (PR) in randomized controlled trials (RCT) have been searched for ever since RCT have become the standard for testing novel therapies and age and gender are routinely documented data in all trials irrespective of the drug tested, its indication, and the primary and secondary end points chosen. To evaluate whether age and gender have been found to be reliable predictors of the PR across medical subspecialties, we extracted 75 systematic reviews, meta-analyses, and meta-regressions performed in major medical areas (neurology, psychiatry, internal medicine) known for high PR rates. The literature database used contains approximately 2,500 papers on various aspects of the genuine PR. These ‘meta-analyses’ were screened for statistical predictors of the PR across multiple RCT, including age and gender, but also other patient-based and design-based predictors of higher PR rates. Retrieved papers were sorted for areas and disease categories. Only 15 of the 75 analyses noted an effect of younger age to be associated with higher PR, and this was predominantly in psychiatric conditions but not in depression, and internal medicine but not in gastroenterology. Female gender was associated with higher PR in only 3 analyses. Among the patient-based predictors, the most frequently noted factor was lower symptom severity at baseline, and among the design- based factors, it was a randomization ratio that selected more patients to drugs than to placebo, more frequent study visits, and more recent trials that were associated with higher PR rates. While younger age may contribute to the PR in some conditions, sex does not. There is currently no evidence that the PR is different in the elderly. PR are, however, markedly influenced by the symptom severity at baseline, and by the likelihood of receiving active treatment in placebo- controlled trials.

Gender differences in irritable bowel syndrome: the interpersonal connection

BACKGROUND

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.

METHODS

A total of 283 (M age = 41 years, F = 80%), Rome III-diagnosed IBS patients completed a test battery that included the IBS Symptom Severity Scale, McGill Pain Questionnaire, Inventory of Interpersonal Problems (IIP), interpersonal support evaluation list (social support), Negative Interactions Scale, Brief Symptom Inventory (distress), Beck Depression Inventory, Anxiety Sensitivity Inventory, and IBS-Quality of Life as part of baseline assessment of an NIH trial.

KEY RESULTS

Males scored higher on two IIP scales reflecting a hostile-dominant interpersonal pattern, and reported less social support. The quality of relationship problems (more interpersonal difficulties, lower support) correlated with IBS symptom severity as measured mainly by gastroenterologists.

CONCLUSIONS & INFERENCES

Male, not female, IBS patients reported more interpersonal difficulties. Male patients-a population for whom little is known-are characterized by hostile-dominant interpersonal problems. This finding has clinical importance, given that relationship problems may influence MDs' estimation of IBS symptom severity and undermine the physician-patient relationship.

Placebo effects and their determinants in gastrointestinal disorders

Placebo effects in clinical trials have sparked an interest in the placebo phenomenon, both in randomized controlled trials (RCTs) and in experimental gastroenterology. RCTs have demonstrated similar short-term and long-term placebo response rates in gastrointestinal compared to other medical diagnoses. Most mediators and moderators of placebo effects in gastrointestinal diseases are also of similar type and size to other medical diagnoses and not specific for gastrointestinal diagnoses. Other characteristics such as an increase in the placebo response over time and the placebo-enhancing effects of unbalanced randomization were not seen, at least in IBS. Experimental placebo and nocebo studies underscore the 'power' of expectancies and conditioning processes in shaping gastrointestinal symptoms not only at the level of self-reports, but also within the brain and along the brain-gut axis. Brain imaging studies have redressed earlier criticism that placebo effects might merely reflect a response bias. These findings raise hope that sophisticated trials and experiments designed to boost positive expectations and minimize negative expectations could pave the way for a practical and ethically sound use of placebo knowledge in daily practice. Rather than focusing on a 'personalized' choice of drugs based on biomarkers or genes, it might be the doctor-patient communication that needs to be tailored.

The efficacy of Shugan Jianpi Zhixie therapy for diarrhea-predominant irritable bowel syndrome: a meta-analysis of randomized, double-blind, placebo-controlled trials

Background

Shugan Jianpi Zhixie therapy (SJZT) has been widely used to treat diarrhea-predominant irritable bowel syndrome (IBS-D), but the results are still controversial. A meta-analysis of randomized, double-blind, placebo-controlled trials was performed to assess the efficacy and tolerability of SJZT for IBS-D.

Methods

The MEDLINE, EMBASE, Cochrane Library, the China National Knowledge Infrastructure database, the Chinese Biomedical Literature database and the Wanfang database were searched up to June 2014 with no language restrictions. Summary estimates, including 95% confidence intervals (CI), were calculated for global symptom improvement, abdominal pain improvement, and Symptom Severity Scale (BSS) score.

Results

Seven trials (N=954) were included. The overall risk of bias assessment was low. SJZT showed significant improvement for global symptom compared to placebo (RR 1.61; 95% CI 1.24, 2.10; P =0.0004; therapeutic gain = 33.0%; number needed to treat (NNT) = 3.0). SJZT was significantly more likely to reduce overall BSS score (SMD –0.67; 95% CI –0.94, –0.40; P < 0.00001) and improve abdominal pain (RR 4.34; 95% CI 2.64, 7.14; P < 0.00001) than placebo. The adverse events of SJZT were no different from those of placebo.

Conclusions

This meta-analysis suggests that SJZT is an effective and safe therapy option for patients with IBS-D. However, due to the high clinical heterogeneity and small sample size of the included trials, further standardized preparation, large-scale and rigorously designed trials are needed.

Optimal management of constipation associated with irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common chronic functional disorder of the gastrointestinal tract, meanly characterized by recurrent abdominal pain or discomfort and altered bowel habit. It is a complex disorder involving biological, environmental, and psychosocial factors. The diagnosis is achieved according to the Rome III criteria provided that organic causes have been excluded. Although IBS does not constitute a life-threatening condition, it has a remarkable prevalence and profoundly reduces the quality of life with burdening socioeconomic costs. One of the principal concerns about IBS is the lack of effective therapeutic options. Up to 40% of patients are not satisfied with any available medications, especially those suffering from chronic constipation. A correct management of IBS with constipation should evolve through a global approach focused on the patient, starting with careful history taking in order to assess the presence of organic diseases that might trigger the disorder. Therefore, the second step is to examine lifestyle, dietary habits, and psychological status. On these bases, a step-up management of disease is recommended: from fiber and bulking agents, to osmotic laxative drugs, to new molecules like lubiprostone and linaclotide. Although new promising tools for relief of bowel-movement-related symptoms are being discovered, a dedicated doctor-patient relationship still seems to be the key for success.

The efficacy of paroxetine and placebo in treating anxiety and depression: a meta-analysis of change on the Hamilton Rating Scales

BACKGROUND

Previous meta-analyses of published and unpublished trials indicate that antidepressants provide modest benefits compared to placebo in the treatment of depression; some have argued that these benefits are not clinically significant. However, these meta-analyses were based only on trials submitted for the initial FDA approval of the medication and were limited to those aimed at treating depression. Here, for the first time, we assess the efficacy of a selective serotonin reuptake inhibitor (SSRI) in the treatment of both anxiety and depression, using a complete data set of all published and unpublished trials sponsored by the manufacturer.

METHODS AND FINDINGS

GlaxoSmithKline has been required to post the results for all sponsored clinical trials online, providing an opportunity to assess the efficacy of an SSRI (paroxetine) with a complete data set of all trials conducted. We examined the data from all placebo-controlled, double-blind trials of paroxetine that included change scores on the Hamilton Rating Scale for Anxiety (HRSA) and/or the Hamilton Rating Scale for Depression (HRSD). For the treatment of anxiety (k = 12), the efficacy difference between paroxetine and placebo was modest (d = 0.27), and independent of baseline severity of anxiety. Overall change in placebo-treated individuals replicated 79% of the magnitude of paroxetine response. Efficacy was superior for the treatment of panic disorder (d = 0.36) than for generalized anxiety disorder (d = 0.20). Published trials showed significantly larger drug-placebo differences than unpublished trials (d's = 0.32 and 0.17, respectively). In depression trials (k = 27), the benefit of paroxetine over placebo was consistent with previous meta-analyses of antidepressant efficacy (d = 0.32).

CONCLUSIONS

The available empirical evidence indicates that paroxetine provides only a modest advantage over placebo in treatment of anxiety and depression. Treatment implications are discussed.

Traditional Chinese medicine (Shun-Qi-Tong-Xie Granule) for irritable bowel syndrome: study protocol for a randomised controlled trial

Background

Irritable bowel syndrome (IBS) is a common gastrointestinal functional disorder with no effective therapy. Traditional Chinese medicine (TCM) is one of the most common complementary therapies in China. We designed this study to evaluate the efficacy and safety of Shun-Qi-Tong-Xie Granule (SQTX Granule), a TCM treatment, in patients with IBS with diarrhea (IBS-D).

Methods/Design

A randomised, double-blinded, placebo-controlled, multi-centre, superiority clinical trial to evaluate the efficacy and safety of SQTX Granule is proposed. Eligible patients (Rome III) with IBD-S will be randomly assigned into SQTX Granule group and the placebo group. Patients will receive a 28-day treatment and a 2-month follow-up. The primary outcome measures include the scores of IBS-quality of life (IBS-QOL) rating scale and IBS-symptom severity scale (IBS-SSS) rating scale. The secondary outcome measures include the improvement of symptom scores, and the duration of abdominal pain and diarrhea.

Discussion

According to TCM theory, SQTX Granule has a regulating effect on abdominal pain, diarrhea and the syndrome of liver-spleen disharmony, which is similar to the symptoms of IBS-D. This study will provide objective evidence to evaluate the efficiency and safety of SQTX Granule in IBS-D treatment.

Trial registration

ChiCTR-TRC-14004241.

Date of registration: 9 February 2014.

Placebo effect in clinical trial design for irritable bowel syndrome

Ongoing efforts to improve clinical trial design in irritable bowel syndrome have been hindered by high placebo response rates and ineffective outcome measures. We assessed established strategies to minimize placebo effect as well as the various approaches to placebo effect which can affect trial design. These include genetic markers such as catechol-O-methyltransferase, opioidergic and dopaminergic neurobiologic theory, pre-cebo effect centered on expectancy theory, and side effect unblinding grounded on conditioning theory. We reviewed endpoints used in the study of IBS over the past decade including adequate relief and subjective global relief, emphasizing their weaknesses in fully evaluating the IBS condition, specifically their motility effects based on functional net value and relative benefit-harm based on dropouts due to adverse events. The focus of this review is to highlight ongoing efforts to improve clinical trial design which can lead to better outcomes in a real-world setting.

How positive and negative expectations shape the experience of visceral pain

Knowledge from placebo and nocebo research aimed at elucidating the role of treatment expectations and learning experiences in shaping the response to visceral pain fills an important research gap. First, chronic abdominal pain, such as in irritable bowel syndrome (IBS), is highly prevalent, with detrimental individual and socioeconomic impact and limited effective treatment options. At the same time, IBS patients show high placebo response rates in clinical trials and benefit from placebo interventions. Second, psychological factors including emotions and cognitions in the context of visceral pain have been implicated in the pathophysiology of IBS and other conditions characterized by medically unexplained somatic symptoms. Hence, the study of nocebo and placebo effects in visceral pain constitutes a model to assess the contribution of psychological factors. Herein, the clinical relevance of visceral pain is introduced with a focus on IBS as a bio-psycho-social disorder, followed by a review of existing clinical and experimental work on placebo and nocebo effects in IBS and in clinically relevant visceral pain models. Finally, emerging research trends are highlighted along with an outlook regarding goals for ongoing and future research.

Randomized clinical trial: the clinical effects of herb-partitioned moxibustion in patients with diarrhoea-predominant irritable bowel syndrome

Objective. To explore the efficacy of Herb-partitioned moxibustion in treating IBS-D patients. Method. 210 IBS-D patients were randomly assigned on a 3 : 3 : 2 basis to group HM, group FM, or group PB for 4-week treatment. The change of GSRS total score at weeks 4 and 8, the changes of GSRS specific scores, and adverse events were evaluated. Results. Patients in group HM and group FM had lower GSRS total score at week 4 (1.98 ± 0.303, 2.93 ± 0.302 versus 3.73 ± 0.449) and at week 8 (2.75 ± 0.306, 3.56 ± 0.329 versus 4.39 ± 2.48) as compared with patients' score in group PB. However, there was no significant difference of GSRS total score between group HM and group FM. The effect of HM was significantly greater than that of orally taking PB in ameliorating the symptoms of rugitus (0.38 versus 0.59, P < 0.05), abdominal pain (0.28 versus 0.57, P < 0.01), abdominal distension (0.4 versus 0.7, P < 0.01), and increased passage of stools (0.06 versus 0.25, P < 0.01) at the end of treatment period. In the follow-up period, patients' therapeutic effect in group HM remained greater than that in group FM (in abdominal pain, abdominal distension, and increased passage of stools) and that in group PB (in loose stools). Conclusions. HM appears to be a promising, efficacious, and well-tolerated treatment for patients with IBS-D.

Prediction of symptomatic improvement after exposure-based treatment for irritable bowel syndrome

BACKGROUND

Several studies show that psychological treatments relieve symptoms for patients suffering from irritable bowel syndrome (IBS). However, there are no consistent findings that show what patient characteristics make a psychological treatment more or less likely to result in improvement. We have previously conducted a study of a newly developed internet-delivered cognitive behavioral therapy (ICBT) that emphasized exposure to IBS symptoms and IBS-related situations and reduced symptom-related avoidance. The study showed that the treatment led to improvement in IBS symptoms compared to a waiting list and that treatment gains were maintained over a 15-18 month follow-up period. The aim of the present study was to investigate several possible predictors of short- and long-term treatment outcome in terms of symptom improvement, based on data collected in the previously conducted treatment trial.

METHODS

Demographics, comorbid psychological distress, IBS-related fear and avoidance behaviors, and IBS-related disability were investigated as predictors of treatment outcome in the sample consisting of 79 participants diagnosed with IBS who had undergone 10 weeks of ICBT. Predictors that were significantly correlated with symptom levels at post-treatment and follow-up were entered into multiple regression analyses that controlled for pre-treatment symptom levels.

RESULTS

There were measures within each domain, i.e., comorbid psychological distress, IBS-related fear and avoidance behaviors, and IBS-related disability, with the exception of demographic data, that were correlated with the symptom levels at post-treatment and follow-up. However, when these were entered into a multiple regression analyses that controlled for pre-treatment levels, none remained a significant predictor of the post-treatment and follow-up symptomatic status.

CONCLUSIONS

The study did not find any individual characteristics that made patients more or less likely to respond to the exposure-based ICBT. The finding that comorbid psychological distress did not predict outcome is in accordance with previous studies. Reliable predictors for response to any type of psychological treatment for IBS remain to be established.

Acupuncture for irritable bowel syndrome: diagnosis and treatment of patients in a pragmatic trial

OBJECTIVE

The aim of this study was to evaluate the treatments delivered during a pragmatic effectiveness study of acupuncture for irritable bowel syndrome (IBS) and to explore the roles of Traditional Chinese Medicine (TCM) diagnoses and preferences of the acupuncturists in treatment design.

METHODS

Patients allocated to an acupuncture arm of a study were offered up to ten sessions of acupuncture over 3 months. Acupuncturists followed a flexible treatment protocol that allowed for treatment individualization, use of additional therapies such as moxa, and provision of lifestyle advice. All treatments were recorded in logbooks and analyzed by content analysis.

RESULTS

Seven primary and eight secondary TCM patterns were identified among the 113 patients with IBS, and were combined in various ways to produce unique diagnoses for 84% patients. Liver Qi Stagnation and Damp Heat were the most commonly reported patterns. Of the 126 acupuncture points used, a distinct core and supporting group of points was associated with each primary pattern. Each practitioner also utilized a distinct core and supporting group of points that reflected his/her preferences. Use of additional therapies (e.g., moxa) and provision of lifestyle advice (e.g., diet) were generally consistent with a particular practitioner.

CONCLUSIONS

Data suggest that a patient's TCM diagnosis, the practitioner's preferences, and a patient's individual characteristics beyond his/her diagnosis influence treatment delivery. In particular, TCM diagnoses appear to influence the acupuncture (i.e., point selection) aspect of treatment more than the selection of additional therapies and lifestyle advice. From another perspective, the treatments incorporated pragmatic, individualized, and disease-specific approaches with combinations that produced both treatment commonalities and diversities.

Catechol-O-methyltransferase val158met polymorphism predicts placebo effect in irritable bowel syndrome

Identifying patients who are potential placebo responders has major implications for clinical practice and trial design. Catechol-O-methyltransferase (COMT), an important enzyme in dopamine catabolism plays a key role in processes associated with the placebo effect such as reward, pain, memory and learning. We hypothesized that the COMT functional val158met polymorphism, was a predictor of placebo effects and tested our hypothesis in a subset of 104 patients from a previously reported randomized controlled trial in irritable bowel syndrome (IBS). The three treatment arms from this study were: no-treatment (“waitlist”), placebo treatment alone (“limited”) and, placebo treatment “augmented” with a supportive patient-health care provider interaction. The primary outcome measure was change from baseline in IBS-Symptom Severity Scale (IBS-SSS) after three weeks of treatment. In a regression model, the number of methionine alleles in COMT val158met was linearly related to placebo response as measured by changes in IBS-SSS (p = .035). The strongest placebo response occurred in met/met homozygotes treated in the augmented placebo arm. A smaller met/met associated effect was observed with limited placebo treatment and there was no effect in the waitlist control. These data support our hypothesis that the COMT val158met polymorphism is a potential biomarker of placebo response.