Progress with treating the microbial dysbiosis associated with irritable bowel syndrome

PURPOSE OF REVIEW

Microbial dysbiosis is receiving increasing attention as possibly being important in the pathophysiology of irritable bowel syndrome. This review will summarize the most recent literature addressing attempts to explore and target the microbiome in patients with irritable bowel syndrome.

RECENT FINDINGS

Manipulation of the intestinal microbiota in irritable bowel syndrome is receiving increasing attention. Traditionally, dietary manipulation has been utilized. There is now evidence that a low fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet has not only been able to improve symptoms, but may have an effect on the gut microbiota. Probiotics are a safe and attractive option for the manipulation of the microbiota. There have been a number of well-designed trials examining the efficacy of certain strains of bacteria, and even yeasts are receiving attention. The role of antibiotics remains controversial and it seems likely that their use should currently be limited to those individuals with small intestinal bacterial overgrowth. Interest in the role of faecal microbiota transplantation for the treatment of a number of gastrointestinal conditions has intensified and irritable bowel syndrome is no exception.

SUMMARY

The manipulation of the microbial dysbiosis is gaining momentum. Further research, however, is required in order to identify the most appropriate treatment option for each individual patient.

Centrally Mediated Disorders of Gastrointestinal Pain

Centrally Mediated Abdominal Pain Syndrome (CAPS), formerly known as Functional Abdominal Pain Syndrome, can be distinguished from other functional GI disorders by its strong central component and relative independence from motility disturbances. CAPS is a result of central sensitization with disinhibition of pain signals rather than increased peripheral afferent excitability. A newly described condition, Narcotic Bowel Syndrome (NBS)/Opioid-Induced GI Hyperalgesia, is characterized by the paradoxical development of or increases in abdominal pain associated with continuous or increasing dosages of opioids. Patients only have relief when opioids are withdrawn. We define both conditions in the context of epidemiology, pathophysiology, clinical evaluation and treatment, emphasizing the importance of a physician-patient relationship in all aspects of care.

Immunoglobulin E in irritable bowel syndrome: another target for treatment? A case report and literature review

Irritable bowel syndrome (IBS) is notoriously difficult to treat and this situation is unlikely to change until the pathophysiology is better understood. There is no doubt that IBS is a multifactorial condition but it is likely that the relative contribution of the various factors involved varies from patient to patient. Consequently, in some individuals one mechanism may have such a strong effect that its elimination may lead to a substantial improvement in symptoms. This paper describes a patient with severe asthma and IBS where the administration of an anti-Immunoglobulin E (IgE) monoclonal antibody not only improved her asthma but also resulted in an almost complete resolution of her IBS symptoms. This observation suggests that some form of allergic process, which may be mediated by IgE, might be driving IBS in some patients and there is evidence from the literature that atopy is more common in this condition. Therefore, in patients with IBS and atopy where the response to standard treatment is poor, it may be worth considering targeting the allergic diathesis. Possible approaches include skin testing with food antigens followed by an appropriate exclusion diet or pharmacological mast cell stabilization.

The Intestinal Gas Questionnaire: development of a new instrument for measuring gas-related symptoms and their impact on daily life

BACKGROUND

Although gas-related symptoms (GRS) are common and intrusive, there are no questionnaires to quantitate this problem. This study aimed to develop an instrument to rectify this gap in our knowledge.

METHODS

Concepts were initially identified from the literature and interviews with gastroenterologists. Exploratory one-to-one interviews and focus groups with irritable bowel syndrome (IBS) patients (n = 28) and non-IBS subjects (n = 27) with GRS were conducted in UK, France, and Spain leading to a conceptual framework for the questionnaire. Last, iterative rounds of cognitive debriefing were performed with IBS (n = 16) and non-IBS subjects (n = 14).

KEY RESULTS

From the first three steps, nine GRS (bloating, distension, flatulence, odorous flatulence, difficult gas evacuation, stomach rumbling, belching, bad breath, and abdominal movement) were identified although abdominal movement was subsequently excluded. Twelve quality of life domains affected by these symptoms were identified as: Clothing, emotional, physical appearance, diet, daily living, work, social life, physical activity, relationships, sex life, sleep, and cognitive function. A 24-h recall for symptoms and a 7-day recall for impact assessment were supported by the qualitative findings. Cognitive debriefing confirmed the understanding of the instrument. Across the three languages, the instrument was conceptually and linguistically consistent.

CONCLUSIONS & INFERENCES

The International Gas Questionnaire is a 2-part instrument, developed rigorously and simultaneously in three languages assessing seven symptoms (17 items) and their impact on 12 domains (26 items) in IBS and general population. It is now undergoing psychometric validation and should provide a unique tool for epidemiological surveys and clinical trials for developing new treatments for these symptoms.

Managing irritable bowel syndrome in primary care

The classic symptoms of irritable bowel syndrome (IBS) are abdominal pain, bloating and some form of bowel dysfunction. The pain is typically colicky in nature and can occur at any site although most commonly it is on the left side. The abdomen feels flat in the morning and then gradually becomes more bloated as the day progresses reaching a peak by late afternoon or evening. It then subsides again over night. Traditionally IBS is divided into diarrhoea, constipation or alternating subtypes. IBS patients frequently complain of one or more non-colonic symptoms, these include constant lethargy, low backache, nausea, bladder symptoms suggestive of an irritable bladder, chest pain and dyspareunia in women. The traditional view that IBS is a largely psychological condition is no longer tenable. Rectal bleeding, a family history of malignancy and a short history in IBS should always be treated with suspicion. Both pain and bowel dysfunction are often made worse by eating. It is recommended that a coeliac screening test is undertaken to rule out this condition. Other routine tests should include inflammatory markers such as CRP or ESR. Calprotectin is a marker for leukocytes in the stools and detects gastrointestinal inflammation. A negative test almost certainly rules out inflammatory bowel disease, especially in conjunction with a normal CRP. Fermentable carbohydrates can have a detrimental effect on IBS and this has led to the introduction of the low FODMAP diet.

Hypnotherapy for irritable bowel syndrome: an audit of one thousand adult patients

BACKGROUND

Gut-focused hypnotherapy improves the symptoms of irritable bowel syndrome (IBS) with benefits being sustained for many years. Despite this, the technique has not been widely adopted by healthcare systems, possibly due to relatively small numbers in published studies and uncertainty about how it should be provided.

AIM

To review the effect of hypnotherapy in a large cohort of refractory IBS patients.

METHODS

One thousand IBS patients fulfilling Rome II criteria, mean age 51.6 years (range 17-91 years), 80% female, receiving 12 sessions of hypnotherapy over 3 months, were studied. The primary outcome was a 50 point reduction in the IBS Symptom Severity Score. The fall in scores for Noncolonic Symptoms, Quality of Life and Anxiety or Depression, were secondary outcomes. The Federal Drug Administration's recommended outcome of a 30% or more reduction in abdominal pain was also recorded.

RESULTS

Overall, 76% met the primary outcome which was higher in females (females: 80%, males: 62%, P < 0.001) and those with anxiety (anxious: 79%, non-anxious: 71%, P = 0.010). The mean reduction in other scores was: IBS Symptom Severity Score, 129 points (P < 0.001), Noncolonic Symptom Score, 65 (P < 0.001) and Quality of Life Score, 66 (P < 0.001). Sixty-seven per cent reported a 30% or more reduction in abdominal pain scores. Pain days fell from 18 to 9 per month. Patients with anxiety and depression fell from 63% to 34% and 25% to 12% respectively (P < 0.001). Outcome was unaffected by bowel habit subtype.

CONCLUSION

These results provide further evidence that gut-focused hypnotherapy is an effective intervention for refractory IBS.

Faecal incontinence-the hidden scourge of irritable bowel syndrome: a cross-sectional study

OBJECTIVE

Faecal incontinence (FI) is a devastating condition which is well recognised in the elderly and those with certain conditions such as inflammatory bowel disease. However, there is surprisingly little information on its prevalence in irritable bowel syndrome (IBS), especially in relation to bowel habit subtype, and this study aimed to answer this question.

DESIGN

500 consecutive new and follow-up secondary care IBS outpatients (399 female, 101 male, age range 15-87, mean age 46) fulfilling Rome III criteria without any significant concomitant disease were studied. They completed a series of questionnaires documenting FI, IBS severity, IBS subtype, non-colonic symptoms, quality of life, anxiety, depression and any other factors that might be associated with FI.

RESULTS

285 patients (57%) reported FI, which was mild in 68 (23.9%), moderate in 99 (34.7%) and severe in 91 (31.9%) and in response to laxatives in 27 (9.5%) with an equal prevalence in males and females. The prevalence of FI in patients classified as having mild, moderate or severe IBS was 62%, 49.5% and 61%, respectively. The prevalence of incontinence was 65.2% in diarrhoea IBS, 63.7% in alternating IBS and, surprisingly, 37.9% in constipation IBS, where it was in response to laxatives in 35.8%. Compared to continent patients, those with FI had a significantly higher prevalence of urinary incontinence, previous abdominal surgery, pregnancy and vaginal as opposed to caesarean delivery. 23.3% had not disclosed their incontinence to anyone and only 50.6% had told their general practitioner. 66% always carried a change of clothes and 30% used incontinence pads on a regular basis.

CONCLUSIONS

The prevalence of FI in these relatively young patients approached that observed in elderly care homes. Hopefully, recognition of this problem will lead to improved management and reduce the trivialisation that unfortunately still continues to surround this condition.

Irritable bowel syndrome: a comparison of subtypes

BACKGROUND AND AIM

Irritable bowel syndrome (IBS) is traditionally divided into subtypes depending on the bowel habit abnormality, but there is little clarity in the literature about whether these subtypes differ symptomatically or psychologically. Furthermore, there are conflicting reports on the relationship between symptom severity and psychological status. The aim of this study was to address these issues in a large cohort of patients defined by bowel habit.

METHODS

One thousand IBS patients were divided into diarrhea (IBS-D), constipation (IBS-C), and mixed (IBS-M) bowel habit subtypes and completed a series of validated questionnaires capturing symptom severity, non-colonic symptomatology (somatization), quality of life, and anxiety or depression levels. Comparisons were made using SPSS version 20.

RESULTS

There were no significant differences between the three subtypes with respect to symptom severity, abdominal pain intensity, non-colonic symptomatology, quality of life, and anxiety or depression scores (all Ps > 0.05). In addition, there was only a small but statistically significant correlation between IBS symptom severity and both anxiety or depression, as well as quality of life (highest r = 0.34), while the relationship between somatization and disease severity was moderate (r = 0.42).

CONCLUSION

This study suggests that there are no differences in the symptom profiles and anxiety or depression scores between different subtypes of IBS. In addition, anxiety and depression do not appear to be strongly associated with symptom severity, although this does not exclude the possible interplay between these and other psychological drivers of severity, such as poor coping skills.

Conducting multinational, cross-cultural research in the functional gastrointestinal disorders: issues and recommendations. A Rome Foundation working team report

BACKGROUND

Cross-cultural, multinational research can advance the field of functional gastrointestinal disorders (FGIDs). Cross-cultural comparative research can make a significant contribution in areas such as epidemiology, genetics, psychosocial modulators, symptom reporting and interpretation, extra-intestinal co-morbidity, diagnosis and treatment, determinants of disease severity, health care utilisation, and health-related quality of life, all issues that can be affected by geographical region, culture, ethnicity and race.

AIMS

To identify methodological challenges for cross-cultural, multinational research, and suggest possible solutions.

METHODS

This report, which summarises the full report of a working team established by the Rome Foundation that is available on the Internet, reflects an effort by an international committee of FGID clinicians and researchers. It is based on comprehensive literature reviews and expert opinion.

RESULTS

Cross-cultural, multinational research is important and feasible, but has barriers to successful implementation. This report contains recommendations for future research relating to study design, subject recruitment, availability of appropriate study instruments, translation and validation of study instruments, documenting confounders, statistical analyses and reporting of results.

CONCLUSIONS

Advances in study design and methodology, as well as cross-cultural research competence, have not matched technological advancements. The development of multinational research networks and cross-cultural research collaboration is still in its early stages. This report is intended to be aspirational rather than prescriptive, so we present recommendations, not guidelines. We aim to raise awareness of these issues and to pose higher standards, but not to discourage investigators from doing what is feasible in any particular setting.

Avoiding analgesic escalation and excessive healthcare utilization in severe irritable bowel syndrome: a role for intramuscular anticholinergics?

OBJECTIVES

In patients with severe irritable bowel syndrome (IBS), abdominal pain can be the predominant symptom impacting on all aspects of their lives and resulting in excessive healthcare utilization. Furthermore, the use of analgesics can become excessive in this group of patients, sometimes leading to opiate dependency. Typically, the pain is often described as spastic in nature and we have speculated that parenteral anticholinergics might provide effective relief when all other measures have failed. For several years, we have therefore been asking general practitioners to consider teaching such patients to administer intramuscular hyoscine butylbromide for pain episodes and this study is an audit of this approach.

METHODS

Patients in whom the use of intramuscular hyoscine butylbromide had been recommended to their general practitioner in the last three years were interviewed over the telephone in order to document the efficacy of this approach as well as any potential disadvantages.

RESULTS

A total of 122 general practitioners were advised to try this approach, with 58 agreeing to teach the technique and prescribe the medication. Of the 58 patients who used the medication, 50 (86%) found it gave them pain relief, which was complete in six (10%), substantial in 36 (62%) and mild in eight (14%), with 15 (26%) decreasing the use of analgesics and 13 (32%) of the 41 taking opiates able to reduce or stop them completely. Side effects were few and largely consisted of those associated with anticholinergics. Only four patients stopped medication because of side effects and no major skin reactions were reported.

CONCLUSIONS

The use of intramuscular hyoscine butylbromide shows promise in the management of IBS when severe unmanageable abdominal pain is a major problem. This approach appears to be safe and has the potential to reduce analgesic escalation, opiate dependency and attendances at accident and emergency departments.

Rome III functional constipation and irritable bowel syndrome with constipation are similar disorders within a spectrum of sensitization, regulated by serotonin

BACKGROUND & AIMS

Patients with irritable bowel syndrome with constipation (IBS-C) and patients with functional constipation (FC) have similar symptoms, and these disorders overlap in their diagnostic features. Little is known about their overlap in physiology or the involvement of serotonin signaling. We investigated relationships between platelet-depleted plasma concentrations of serotonin, gastrointestinal symptoms, and motor-sensory function in patients with FC or IBS-C compared with healthy volunteers (controls).

METHODS

We measured platelet-depleted plasma concentrations of serotonin in fasting and fed individuals with IBS-C (n = 23; 19-50 years old), FC (n = 11; 25-46 years old), and controls (n = 23; 20-49 years old) recruited in Manchester, UK. We also quantified abdominal and bowel-related symptoms, rectal sensitivity, oro-cecal transit, and colonic (whole intestine) transit.

RESULTS

Patients with IBS-C or FC had similar baseline symptoms, bowel habits, oro-cecal and colonic transit, and fasting concentrations of serotonin and response to meal ingestion. Only patients with IBS-C had increased symptoms after ingestion of a meal (P < .001)-these patients tended to have lower sensory thresholds than patients with FC. Defecation frequency in the combined group of patients with IBS-C or FC correlated inversely with serotonin concentration (r = -0.4; P = .03). Serotonin concentration also correlated with pain threshold (r = 0.4; P = .02) and stool threshold (r = 0.5; P = .06), which correlated inversely with defecation frequency (r = -0.3; P = .10).

CONCLUSIONS

FC and IBS-C, based on Rome III criteria, are not distinct disorders, symptomatically or physiologically. Instead, they appear to lie in a spectrum of visceral sensitivity modulated by serotonin signaling. Symptom response to meal ingestion should be considered in patient classification.

Identifying and testing candidate genetic polymorphisms in the irritable bowel syndrome (IBS): association with TNFSF15 and TNFα

OBJECTIVES

The postinfectious irritable bowel syndrome (PI-IBS) suggests that impaired resolution of inflammation could cause IBS symptoms. The authors hypothesised that polymorphisms in genes whose expression were altered by gastroenteritis might be linked to IBS with diarrhoea (IBS-D) which closely resembles PI-IBS.

DESIGN

Part 1: 25 healthy volunteers (HVs), 21 patients 6 months after Campylobacter jejuni infection, 37 IBS-D and 19 IBS with constipation (IBS-C) underwent rectal biopsy for gene expression analysis and peripheral blood mononuclear cell cytokine production assessment. Part 2: Polymorphisms in genes whose expression was altered in Part 1 were assessed in 179 HV, 179 IBS-D, 122 IBS-C and 41 PI-IBS.

RESULTS

Part 1: Mucosal expression of seven genes was altered in IBS: CCL11, CCL13, Calpain 8 and TNFSF15 increased while NR1D1, GPR161 and GABRE decreased with similar patterns after infection with C jejuni. Part 2: The authors assessed 21 known single nucleotide polymorphisms (SNPs) in these seven genes and one SNP in each of the TNFα and IL-10 genes. Three out of five TNFSF15 SNPs (rs6478108, rs6478109 and rs7848647) showed reduced minor allele frequency (MAF) (0.28, 0.27 and 0.27) in subjects with IBS-D compared with HV (0.38, 0.36 and 0.37; p=0.007, 0.015 and 0.007, respectively) confirming others recent findings. The authors also replicated the previously reported association of the TNFα SNP rs1800629 with PI-IBS which showed an increase in the MAF at 0.30 versus 0.19 for HV (p=0.04).

CONCLUSION

IBS-D and PI-IBS patients are associated with TNFSF15 and TNFα genetic polymorphisms which also predispose to Crohn's disease suggesting possible common underlying pathogenesis.

The Manchester Colour Wheel: Enhancing its Utility

The Manchester Colour Wheel was developed to investigate the role of colour in the perception of illness in gastroenterology. During validation it was found that positive, neutral, or negative connotations of the shade of a colour were more important than the colour itself. However, when asked to relate mood to a colour, the response rate was greater in individuals with mood disorders than healthy controls. This study assessed whether response rate could be made more uniform by changing the wording of the question. Mood / colour choice was compared, using two slightly different questions, in 105 and 203 healthy volunteers, resulting in response rates of 39% and 95% respectively, with the latter not associated with increased false positive responses. These results show that adjustment of the wording of a mood-related question may allow equal response rates irrespective of the mood status of participants.

Intestinal microbiota in functional bowel disorders: a Rome foundation report

It is increasingly perceived that gut host-microbial interactions are important elements in the pathogenesis of functional gastrointestinal disorders (FGID). The most convincing evidence to date is the finding that functional dyspepsia and irritable bowel syndrome (IBS) may develop in predisposed individuals following a bout of infectious gastroenteritis. There has been a great deal of interest in the potential clinical and therapeutic implications of small intestinal bacterial overgrowth in IBS. However, this theory has generated much debate because the evidence is largely based on breath tests which have not been validated. The introduction of culture-independent molecular techniques provides a major advancement in our understanding of the microbial community in FGID. Results from 16S rRNA-based microbiota profiling approaches demonstrate both quantitative and qualitative changes of mucosal and faecal gut microbiota, particularly in IBS. Investigators are also starting to measure host-microbial interactions in IBS. The current working hypothesis is that abnormal microbiota activate mucosal innate immune responses which increase epithelial permeability, activate nociceptive sensory pathways and dysregulate the enteric nervous system. While we await important insights in this field, the microbiota is already a therapeutic target. Existing controlled trials of dietary manipulation, prebiotics, probiotics, synbiotics and non-absorbable antibiotics are promising, although most are limited by suboptimal design and small sample size. In this article, the authors provide a critical review of current hypotheses regarding the pathogenetic involvement of microbiota in FGID and evaluate the results of microbiota-directed interventions. The authors also provide clinical guidance on modulation of gut microbiota in IBS.

Refractory inflammatory bowel disease-could it be an irritable bowel?

Patients with IBD who are apparently in remission-as indicated by normal blood tests, endoscopic findings and ultrasonography results-often continue to experience symptoms. Furthermore, despite these negative findings, there is a temptation to increase their anti-inflammatory medication in the hope that this approach would lead to some improvement. However, this strategy often seems to fail and can sometimes lead to adverse events. Consequently, when evidence of continuing inflammatory activity is lacking it might be appropriate to consider the possibility of co-existent IBS in these patients and to treat them for this condition. Dietary manipulation, antispasmodic agents, antidepressants (especially of the tricyclic variety) and even behavioural treatments might result in a worthwhile improvement of symptoms.

The Manchester Color Wheel: validation in secondary school pupils

BACKGROUND

As part of our research programme into facilitating improved ways of communicating with patients, especially about more sensitive clinical issues, we have been investigating whether there are any non-verbal methods that might aid this process. One such approach is to ask patients to choose a color in response to a particular question, for instance about health or psychological status, and for this purpose we developed the Manchester Color Wheel (MCW). This instrument consists of positive, neutral and negative colors and its validation in normal adults and those with anxiety or depression showed that it is responsive to change and reproducible. It also has the capacity to identify a positive frame of mind. We concluded that it might be a particularly useful instrument in adolescents and therefore this study aimed to validate it in a secondary school.

METHODS

620 pupils (aged 11-17 years, mean age 14.0 years, 298 (48.1%) males, 322 (51.9%) females) at Sale Grammar School in Greater Manchester were asked to relate their mood to a MCW color and also complete the Hospital Anxiety Depression (HAD) questionnaire. To give these pupils an experience in science, 197 were divided into four subgroups for an 'experiment' to ascertain whether, compared to controls, a change in mood color choice could be induced by participation in sport, music or art activities.

RESULTS

Although mood color and HAD depression score are unlikely to be measuring exactly the same psychological state, a negative mood color was chosen by 62.5% of HAD depressed compared to only 14.5% of HAD normal pupils (p < 0.001). In contrast, a positive mood color was chosen by 48.9% of normal and only 18.8% of depressed pupils (p < 0.001). In the 'experiment', compared to controls, all activities resulted in an increased choice of positive mood colors which reached significance for sport and music.

CONCLUSION

This study confirms the potential utility of the MCW to rapidly and easily assess a variety of health issues in large populations, including adolescents. Some of our results should also be of interest to educationalists.