Placebo effect in patients with irritable bowel syndrome

Results from a Cross-Sectional Observational Study Examining Irritable Bowel Syndrome Patients Six Months After Finishing Their Participation in the ViIBS Trial

BACKGROUND/OBJECTIVES

A recent clinical (ViIBS) trial investigating the effects of a balanced multi-strain synbiotic in irritable bowel syndrome (IBS) patients showed that twelve weeks of treatment resulted in significant improvements across all major IBS symptoms. The current observational study pursued three aims: investigate patients' attitude towards the intake of pro- or synbiotics during the six months after finishing their trial participation, determine the severity of IBS symptoms, and assess IBS diagnosis scores.

METHODS

During a single six-month follow-up examination, patients were asked about the intake of probiotics or synbiotics. For the study, former placebo-group patients who abstained from taking probiotics were compared with synbiotic-group patients who continued taking the tested synbiotic. IBS symptom severity was assessed with the IBS-Severity of Symptoms Scale and the IBS diagnosis score with the IBS questionnaire of the World Gastroenterology Organisation.

RESULTS

The control group comprised 17 patients (out of 70 from the placebo group participating in the follow-up) and the treatment group 75 (out of 91 examined). IBS symptom severity was significantly lower in the treatment group (23.5 ± 33.1) than in the placebo group (232.6 ± 35.1). IBS diagnosis scores were 5.9 ± 2.5 and 21.2 ± 2.0 in the treatment and control group, respectively.

CONCLUSIONS

Measurement values for the treatment group indicate the absence of IBS. The results indicate that the prolonged administration of the balanced multi-strain synbiotic can potentially reduce IBS symptom severity and IBS diagnosis scores to levels indicating the absence of IBS, an observation to be followed up in a controlled clinical trial.

Positive Outcomes of Supplementation with Lecithin-Based Delivery Formulation of Curcuma longa and Boswellia serrata in IBS Subjects with Small Bowel Dysbiosis

BACKGROUND

Small bowel dysbiosis (SBD) is a frequent finding in subjects with irritable bowel syndrome (IBS). The sunflower lecithin (phytosome) formulation of Curcuma longa and Boswellia serrata demonstrated beneficial effects on intestinal microbiota. This study aimed to evaluate the impact of a lecithin-based delivery formulation of Curcuma longa and Boswellia serrata extracts (CUBO) on SBD in IBS subjects.

SUBJECTS

Forty-nine adult subjects with IBS and SBD were randomly supplemented for 30 days with CUBO and a low-FODMAP diet (LFD) (intervention) or with LFD and placebo (control group).

RESULTS

The intervention group showed a significant reduction in urinary indican (p < 0.001), which was the marker of SBD, and of abdominal bloating (p < 0.001) and abdominal pain (p < 0.001). The pre-post control group analysis did not evidence significant differences. The comparison between the two groups (net effect in intervention minus control subjects) showed that the changes differ significantly for urinary indican p < 0.001 (-42.88; 95% CI: -62.04 to -23.72), abdominal bloating p < 0.001 (-1.50; 95% CI: -1.93 to -1.07), and abdominal pain p < 0.001 (-2.37; 95% CI: -3.61 to -1.13) and for the global assessment of efficacy (p < 0.001). The efficacy was 20% greater in males than in females.

CONCLUSIONS

In IBS subjects, the intervention with CUBO and LFD shows a significantly higher reduction in SBD, abdominal pain, and bloating compared to LFD and placebo. Additional research is needed to confirm these data.

Doctors Speak: A Qualitative Study of Physicians' Prescribing of Antidepressants in Functional Bowel Disorders

Tricyclic antidepressants (TCAs) are frequently prescribed for chronic functional pain disorders. Although the mechanism of action targets pain perception, treating patients with TCAs for disorders conceptualized as "functional" can promote stigmatization in these patients because it hints at psychological dimensions of the disorder. The goal of this study was to understand how physicians prescribe TCAs in the face of this challenge. We interviewed eleven gastroenterologists in tertiary care clinics specializing in functional gastrointestinal disorders, such as irritable bowel syndrome. We found that the physicians interviewed (1) were aware of the stigma attached to taking antidepressants for a medical condition, (2) emphasized biological, as opposed to psychological, mechanisms of action, (3) while focusing on biological mechanisms, they nevertheless prescribed TCAs in a way that is highly attentive to the psychology of expectations, making specific efforts to adjust patients' expectations to be realistic and to reframe information that would be discouraging and (4) asked patients to persist in taking TCAs despite common and, at times, uncomfortable side effects. In this context of shared decision making, physicians described nuanced understanding and behaviours necessary for treating the complexity of functional disorders and emphasized the importance of a strong patient-provider relationship.

Efficacy and Safety of the Adjuvant Use of Probiotic Bacillus clausii Strains in Pediatric Irritable Bowel Syndrome: A Randomized, Double-Blind, Placebo-Controlled Study

OBJECTIVES

Current irritable bowel syndrome (IBS) treatments have limited efficacy and probiotics like Bacillus clausii (B. clausii) were found to be effective in the management of several gastrointestinal disorders. This phase III trial assessed the efficacy and safety of adding B. clausii (four strains: O/C, N/R, SIN, T), versus placebo, to conventional treatment of pediatric IBS in Mexico.

METHODS

Patients aged 6-17 years 11 months with IBS (Rome IV) for at least 2 months were randomized to receive either B. clausii (oral suspension, total dose 4 billion spores/day) or placebo once daily for 8 weeks. All patients also received conventional treatment. The primary endpoint was the difference in the proportion of patients with clinical improvements at Week 8 (Global Assessment Questions [GAQ]). Secondary endpoints included responders by Subject's Global Assessment of Relief for Children with IBS (SGARC); number/consistency of stools; abdominal distention/bloating; abdominal pain/intensity; and IBS behavior.

RESULTS

73.6% (95% confidence interval [CI] 67.3-80.0; B. clausii n = 129) and 78.5% (95% CI 72.5-84.4; placebo n = 130) of patients had symptom improvement (p = 0.8182). For Week 8 SGARC, 19.2% (B. clausii) and 20.9% (placebo) reported complete symptom relief. Stool evaluations, bloating, abdominal pain/intensity, and IBS behavior were similar between groups. Both treatments were well tolerated.

CONCLUSION

No significant differences in efficacy between B. clausii and placebo were demonstrated in addition to conventional treatment. The sample size calculation was based on an expected placebo/conventional treatment response of 30-40%. However, the actual treatment response observed was 80% and, thus, a study with larger population would be warranted. In addition, this study was conducted during the COVID-19 pandemic, when such controlled social conditions may have resulted in better diet, greater family stability, less psychological stress, and lower risk of infections exacerbating IBS, thereby improving symptoms in both groups.

EUDRACT NUMBER

2018-004519-31.

Factors Associated With Placebo Treatment Response in Functional Dyspepsia Clinical Trials

INTRODUCTION

Controlling for potential placebo effects is an important aspect of gaining an accurate estimate of how much the therapy alone changes patient symptoms or other end points. When the placebo effect is large, this can lead to only a small fraction of changes seen in the active therapy group being attributed to the therapy itself. This problem has been well studied in some disorders of brain-gut interaction but not in functional dyspepsia where placebo response rates of 40% and higher have been reported. Understanding risk factors for placebo response might lead to changes in trial design that could reduce the magnitude of the problem. This study sought to identify risk factors for the placebo effect in a functional dyspepsia clinical trial with a longer-term aim of suggesting trial design changes that might minimize the problem.

METHODS

A secondary analysis of the clinical trial data was undertaken using 2 arms deemed to involve placebo therapy. Potential predictors were drawn from a wide range of patient characteristics including psychological, clinical, and physiological features.

RESULTS

Predictors of a stronger placebo effect on the gastrointestinal symptom rating scale included higher functional dyspepsia symptom burden at baseline (b = -0.101), coexisting irritable bowel syndrome (b = -0.436), and higher scores on the Nepean Dyspepsia Index eat/drink domain (-0.005). Baseline symptom burden and coexisting irritable bowel syndrome were found to be independent placebo predictors, explaining 13% of the variance in change in gastrointestinal symptom rating scale. Anxiety, childhood sexual abuse, sleep amount, and frequent abdominal pain were also found to be predictors of change in individual symptom scores.

DISCUSSION

The findings of this study yield actionable insights into trial methodology that may help to reduce the magnitude of the placebo effect in future functional dyspepsia treatment trials.

Effects of treatment with eluxadoline on abdominal pain in patients with IBS-D: Additional post hoc analyses of Phase 3 trials

BACKGROUND

Recurring abdominal pain is a characteristic and often unpredictable and debilitating symptom of irritable bowel syndrome with diarrhea (IBS-D). Measuring the effects of IBS-D treatments on abdominal pain remains a significant challenge in clinical trials. Here, we aimed to examine the effect of eluxadoline through various post hoc analyses.

METHODS

Data from two eluxadoline Phase 3 trials were pooled over 26 weeks, comparing eluxadoline 100 mg twice daily to placebo. Worst abdominal pain (WAP) was measured daily on a 0-10 scale. WAP responder criteria were prospectively defined as a ≥30% improvement in daily WAP score on ≥50% of days. Pairwise, two-sided Cochran-Mantel-Haenszel tests assessed treatment effects. Cumulative distribution functions were used to plot WAP response rates using variations on the response criteria.

KEY RESULTS

Of 1615 patients with IBS-D (66% female, mean age 46 years), 806 received eluxadoline and 809 received placebo; 48.3% and 44.0% were WAP responders (≥30% improvement), respectively (P value not significant). When the response threshold was increased to 50% daily WAP improvement from baseline, a significantly greater percentage of eluxadoline-treated patients versus placebo-treated patients were WAP responders (38.7% vs 32.5%, respectively; P = .009). At Week 26, average WAP changes from baseline were -3.4 and -3.0 points, respectively (P = .002).

CONCLUSIONS AND INFERENCES

Despite small effect sizes, eluxadoline demonstrated consistent and sustained improvement in WAP compared to placebo across a range of prospective and post hoc analyses. Assessing WAP response across a range of measures is important for fully understanding a treatment's efficacy.

Understanding the Scope of Do-It-Yourself Fecal Microbiota Transplant

OBJECTIVES

Fecal microbiota transplantation (FMT) has emerged as an effective treatment option for Clostridioides difficile infection (CDI) and is considered an investigational therapy for a number of other diseases. Social media has facilitated widespread exposure of the public to the gut microbiome and FMT, ultimately acting as a catalyst for the Do-It-Yourself (DIY)-FMT movement. The aims of this study were to identify factors that influenced willingness to pursue DIY-FMT including common indications, screening processes, sample preparation, and self-reported efficacy and safety outcomes.

METHODS

A twenty-five-point cross-sectional survey was posted online through the websites and social media pages of the Peggy Lillis Foundation, The Fecal Transplant Foundation, and The Power of Poop. Responses were cataloged through the Research Electronic Data Capture tool, and descriptive analyses were performed.

RESULTS

Eighty-four respondents completed the survey between January 2018 and February 2019. The majority were female (71%) and white (92%). Most (80%) reported performing FMT on themselves; 87% used Internet resources to assist in the process, and 92% knew their stool donor. Inflammatory bowel disease (35%) and irritable bowel syndrome (29%) were the 2 most common conditions that respondents attempted to treat. Only 12% reported adverse events, whereas 82% reported improvement in their condition.

DISCUSSION

DIY-FMT is being used for many indications, including those for which there is little evidence. There was a high self-reported success rate among respondents with few adverse events. There is a need for increased awareness around DIY-FMT and research around this phenomenon, which may impact public health.

Efficacy and safety of Achillea wilhelmsii C. Koch capsules on symptom severity and quality of life in patients with irritable bowel syndrome: a randomized, placebo-controlled clinical trial

Background Irritable bowel syndrome (IBS) is one of the most common digestive diseases. The aim of this clinical trial was to determine the effectiveness of Achillea wilhelmsii C. Koch on the symptom severity and quality of life (QOL) in patients with IBS. Methods The patients were randomized into two groups of 45 each. The QOL and symptom severity of the patients were evaluated at baseline and at completion of the treatments by means of IBS-QOL and IBS severity index. Results The mean severity of clinical symptoms in the Achillea wilhelmsii C. Koch receiving groups before and after the treatment was 282.56 ± 103.57 and 178.06 ± 88.40, and in the placebo group was 265.93 ± 93.56 and 197.74 ± 106.26, respectively. The mean QOL in the Achillea wilhelmsii C. Koch receiving group before and after treatment was 51.49 ± 11.98 and 50.44 ± 13.39 and in the placebo group was 60.71 ± 11.97 and 58.39 ± 11.67, respectively. In both groups, there was a significant difference in the recovery rate in each group (p<0.05). However, the mean difference between the two groups before and after intervention was not significantly different (p>0.05). Also, no patient reported any adverse events during the trial. Although the symptom severity and QOL in both groups were improved compared to those before intervention, there was no significant difference between the two groups. Conclusion It is recommended to conduct future studies with larger sample size and longer treatment periods, and also investigate the efficacy on the IBS subtypes, separately.

Efficacy of bio-optimized extracts of turmeric and essential fennel oil on the quality of life in patients with irritable bowel syndrome

BACKGROUND

The use of herbal products to treat irritable bowel syndrome (IBS), a disease that frequently affects the quality of life (QoL), is still under evaluation. This open pilot study assessed the efficacy of bio-optimized extracts of turmeric and essential fennel oil (Enterofytol®) in IBS patients.

METHODS

A total of 211 patients (14% diarrhea-predominant, IBS-D; 24% constipation-predominant, IBS-C; 62% mixed, IBS-M) were enrolled by general practitioners and completed questionnaires measuring symptom severity and QoL before and after Enterofytol®, two capsules b.i.d. for one month, followed by two capsules q.d. for another month.

RESULTS

IBS severity index and QoL were inversely related. A significant reduction in the severity index and an improvement in QoL were evident following treatment in all IBS subgroups. IBS-D patients showed the worst clinical picture at entry, with the highest IBS severity index and the lowest QoL score, compared with IBS-C and IBS-M subtypes. IBS-D patients, however, also showed the most pronounced response to therapy, considering both scores. The improvement in the IBS severity index was independent of age and sex.

CONCLUSIONS

Results from this "real-life" study show that the combination of turmeric and essential fennel oil over two months improves both symptoms and QoL in IBS patients, irrespectively of age, sex, initial severity of symptoms and IBS-subtypes, suggesting a potential role for the natural treatment of IBS.

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.

Efficacy and safety of PPC-5650 on experimental rectal pain in patients with irritable bowel syndrome

PPC-5650 is a new pharmacological agent that can modulate acid-sensing ion channel activity, leading to a reduction in the pain signal under up-regulated conditions. The non-clinical programme for PPC-5650 supported a role for this novel agent in the treatment of pain in patients with irritable bowel syndrome (IBS). In patients with IBS, the aims of the study were: (1) to assess the efficacy of a single bolus of PPC-5650 locally applied in the rectum using multi-modal stimulations of the recto sigmoid and (2) to assess the safety profile of PPC-5650. The study was a randomized, double-blind, placebo-controlled, cross-over trial in patients with IBS, excluding females of child-bearing potential. The study consisted of a training visit, study visit 1 and 2 and a follow-up visit. Rectosigmoid electrical, thermal and mechanical stimulations were performed, pain perception was rated on a pain intensity scale and referred pain areas were assessed. All adverse events were registered. Twenty-five patients with IBS were enrolled and completed the study (9 women and 16 men; mean age 50.4 ± 12.7 years). No effects of the study drug were found on any of the rectal stimulations or for referred pain areas (all p > 0.05). No significant or clinically relevant treatment-related differences were seen for the laboratory safety variables or any other reported adverse event. In conclusion, in patients with IBS on rectal sensitivity to multi-modal stimulations, PPC-5650 did not produce efficacy relative to placebo. The overall safety and tolerability of PPC-5650 was acceptable.

Pharmacologic treatment of pediatric headaches: a meta-analysis

OBJECTIVE To assess the effectiveness of prophylactic headache treatment in children and adolescents. DATA SOURCES PubMed, EMBASE, Cochrane Database of Clinical Trials, and bibliography of retrieved articles through August 11, 2012. STUDY SELECTION Randomized trials of headache treatment among children and adolescents (&lt;18 years old). INTERVENTION Any placebo-controlled trial or comparisons between 2 or more active medications. MAIN OUTCOME MEASURE Number of headaches per month. RESULTS Among 21 included trials, there were 13 placebo-controlled and 10 active comparator trials (2 also included placebo). Twenty trials focused on episodic migraines and 1 on chronic daily headaches. Drugs more effective than placebo for episodic migraines (&lt;15 headaches per month) included topiramate (difference in headaches per month, -0.71; 95% CI, -1.19 to -0.24) and trazodone (-0.60; 95% CI, -1.09 to -0.11). Ineffective drugs included clonidine, flunarizine, pizotifen, propranolol, and valproate. A single trial of fluoxetine for chronic daily headaches found it ineffective. Patients given placebo experienced a significant (P = .03) decline in headaches, from 5.6 (95% CI, 4.52-6.77; Q = 8.14 [Cochran Q is a measure of the heterogeneity of the included studies]) to 2.9 headaches per month (95% CI, 1.66-4.08; Q = 4.72). Among the 10 active comparator trials, flunarizine was more effective than piracetam (difference in headaches per month, -2.20; 95% CI, -3.93 to -0.47) but no better than aspirin, dihydroergotamine, or propranolol. Propranolol was compared with valproate as well as behavioral treatment, and 2 studies compared different doses of topiramate; none of these trials showed significant differences. CONCLUSIONS Topiramate and trazodone have limited evidence supporting efficacy for episodic migraines. Placebo was effective in reducing headaches. Other commonly used drugs have no evidence supporting their use in children and adolescents. More research is needed.

How positive and negative expectations shape the experience of visceral pain: an experimental pilot study in healthy women

BACKGROUND

In order to elucidate placebo and nocebo effects in visceral pain, we analyzed the effects of positive and negative expectations on rectal pain perception, rectal pain thresholds, state anxiety and cortisol responses in healthy women.

METHODS

Painful rectal distensions were delivered at baseline, following application of an inert substance combined with either positive instructions of pain relief (placebo group, N = 15), negative instructions of pain increase (nocebo group, N = 17), or neutral instructions (control, N = 15). Perceived pain intensity, unpleasantness/aversion and urge-to-defecate, state anxiety and serum cortisol were determined at baseline, immediately following group-specific instructions and on a second study day after the same instructions (test day). Rectal pain thresholds were determined at baseline and on the test day.

KEY RESULTS

Whereas perceived pain intensity was significantly decreased in the placebo group, the nocebo group revealed significantly increased pain intensity ratings, along with significantly greater anticipatory anxiety on the test day (all P < 0.05 vs controls). Cortisol concentrations were significantly increased in the nocebo group following treatment but not on the test day.

CONCLUSIONS & INFERENCES

The experience of abdominal pain can be experimentally increased or decreased by inducing positive or negative expectations. Nocebo effects involve a psychological stress response, characterized by increased anticipatory anxiety. These findings further underscore the role of cognitive and emotional factors in the experience of visceral pain, which has implications for the pathophysiology and treatment of patients with chronic abdominal complaints.

Perceived treatment group affects behavioral and neural responses to visceral pain in a deceptive placebo study

BACKGROUND

To assess effects of perceived treatment (i.e. drug vs placebo) on behavioral and neural responses to rectal pain stimuli delivered in a deceptive placebo condition.

METHODS

This fMRI study analyzed the behavioral and neural responses during expectation-mediated placebo analgesia in a rectal pain model. In N = 36 healthy subjects, the blood oxygen level-dependent (BOLD) response during cued anticipation and painful stimulation was measured after participants were informed that they had a 50% chance of receiving either a potent analgesic drug or an inert substance (i.e., double-blind administration). In reality, all received placebo. We compared responses in subjects who retrospectively indicated that they received the drug and those who believed to have received placebo.

KEY RESULTS

55.6% (N = 20) of subjects believed that they had received a placebo, whereas 36.1% (N = 13) believed that they had received a potent analgesic drug. Subjects who were uncertain (8.3%, N = 3) were excluded. Rectal pain-induced discomfort was significantly lower in the perceived drug treatment group (P < 0.05), along with significantly reduced activation of the insular, the posterior and anterior cingulate cortices during pain anticipation, and of the anterior cingulate cortex during pain (all P < 0.05 in regions-of-interest analyses).

CONCLUSIONS & INFERENCES

Perceived treatment constitutes an important aspect in placebo analgesia. A more refined understanding of individual treatment expectations and perceived treatment allocation has multiple implications for the design and interpretation of clinical trials and experimental studies on placebo and nocebo effects.

Intestinal microbiota, pathophysiology and translation to probiotic use in patients with irritable bowel syndrome

Probiotic agents have received growing attention in recent years as an alternative therapeutic tool in the management of irritable bowel syndrome. In this article, we will discuss the rationale that support this indication, including the role of intestinal microbiota in gastrointestinal function in both human and animal models, potential links between an impaired microbiota imbalance and the psycho-immunopathophysiology of irritable bowel syndrome, and the results of the available clinical trials to date.

Gut memories: towards a cognitive neurobiology of irritable bowel syndrome

The brain and the gut are engaged in continual crosstalk along a number of pathways collectively termed the 'brain-gut axis'. Over recent years it has become increasingly clear that dysregulation of the axis at a number of levels can result in disorders such as irritable bowel syndrome (IBS). With recent advances in neuroimaging technologies, insights into the neurobiology of IBS are beginning to emerge. However the cognitive neurobiology of IBS has remained relatively unexplored to date. In this review we summarise the available data on cognitive function in IBS. Moreover, we specifically address three key pathophysiological factors, namely; stress, immune activation and chronic pain, together with other factors involved in the manifestation of IBS, and explore how each of these components may impact centrally, what neurobiological mechanisms might be involved, and consider the implications for cognitive functioning in IBS. We conclude that each factor addressed could significantly impinge on central nervous system function, supporting the view that future research efforts must be directed towards a detailed assessment of cognitive function in IBS.