Functional bowel disorders

Digesting the Impact of Diet on Irritable Bowel Syndrome (IBS): Exploring Solutions for Controlling IBS

Irritable bowel syndrome (IBS) plagues nearly a fifth of the general population. It is a chronic illness that can significantly lower quality of life (QoL) and work productivity. The relationship between diet and the functional gastrointestinal (GI) symptoms present in IBS is gaining more and more attention. In addition to being a factor in the pathophysiology of IBS, diet also has a significant impact on symptoms and overall well-being. Recent research has also shown that short-chain fermentable carbohydrates increase colonic gas production and small intestine water volume, which in turn causes functional GI symptoms in those with visceral hypersensitivity. This review article has consolidated various studies highlighting the association between certain foods and the pathophysiology of IBS. It has also talked about how restricting certain food items from the diet of affected individuals can relieve symptoms and in some cases can be more effective than pharmacotherapy. Although the low reduced fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) diet (LFD) is a well-known method of treating IBS symptoms, over a third of individuals do not benefit from it. This article has also discussed the effectiveness and applicability of the LFD compared to other dietary therapies for the long-term management of IBS.

Functional Gastrointestinal Disorders

Functional gastrointestinal disorders (FGIDs) are an extremely common set of more than 50 disorders characterized by persistent and recurring gastrointestinal symptoms. Most of these patients can be diagnosed and managed by primary care physicians. Treatment includes patient education and reassurance, eliminating triggers, dietary modification, and pharmacologic management. Primary care physicians should consider referral to gastroenterologists when patients exhibit red flag symptoms such as blood in stool, abnormal laboratory findings, involuntary weight loss, age of presentation greater than 50 years, or certain concerning family history.

Does fecal calprotectin increase may be linked to lactose intolerance in patients with irritable bowel syndrome?

BACKGROUND

Irritable bowel syndrome (IBS) is a multifactorial condition without any specific investigation. Fecal calprotectin (FC) may be elevated in IBS without any explanation. In addition, some patients with IBS have symptoms related to lactose intolerance. Our main aim was to investigate whether an increase in FC could be related to lactose intolerance in patients with IBS.

METHODS

In this retrospective single-center study, all patients with IBS who have underwent a FC test and a lactose respiratory test within a period of less than 6 months were eligible. A FC greater than or equal to 50 μg/g was considered abnormal.

RESULTS

Severnty-six patients (48 females), mean age 38±15 years were included. Symptoms were respectively: bloating in 57%, diarrhea in 76% and abdominal pain in 46% of cases. Among the 76 patients: 22 (29%) had FC≥50 μg/g and 9/22 (41%) had a positive lactose test. No significant relationship could be identified between the increase in FC and the lactose test positivity. The value of the FC was also not related to the subtype of IBS or the positivity of the glucose test.

CONCLUSIONS

In our study, the increase in FC was not significantly related to the presence of lactose intolerance. Nevertheless, our work, despite its originality, is limited by its retrospective nature and small number of patients. Future studies including larger numbers of patients may identify the causes of elevated FC in patients with IBS to individualize different subgroups of patients to best adapt therapeutic management.

Revisiting the Intestinal Microbiome and Its Role in Diarrhea and Constipation

The gut microbiota represents a community of microorganisms (bacteria, fungi, archaea, viruses, and protozoa) that colonize the gut and are responsible for gut mucosal structural integrity and immune and metabolic homeostasis. The relationship between the gut microbiome and human health has been intensively researched in the past years. It is now widely recognized that gut microbial composition is highly responsible for the general health of the host. Among the diseases that have been linked to an altered gut microbial population are diarrheal illnesses and functional constipation. The capacity of probiotics to modulate the gut microbiome population, strengthen the intestinal barrier, and modulate the immune system together with their antioxidant properties have encouraged the research of probiotic therapy in many gastrointestinal afflictions. Dietary and lifestyle changes and the use of probiotics seem to play an important role in easing constipation and effectively alleviating diarrhea by suppressing the germs involved. This review aims to describe how probiotic bacteria and the use of specific strains could interfere and bring benefits as an associated treatment for diarrhea and constipation.

Research progress of colon-targeted oral hydrogel system based on natural polysaccharides

The quality of life is significantly impacted by colon-related diseases. There have been a lot of interest in the oral colon-specific drug delivery system (OCDDS) as a potential carrier to decrease systemic side effects and protect drugs from degradation in the upper gastrointestinal tract (GIT). Hydrogels are effective oral colon-targeted drug delivery carriers due to their high biodegradability, substantial drug loading, and great biocompatibility. Natural polysaccharides give the hydrogel system unique structure and function to effectively respond to the complex environment of the GIT and deliver drugs to the colon. In this paper, the physiological factors of colonic drug delivery and the pathological characteristics of common colonic diseases are summarized, and the latest advances in the design, preparation and characterization of natural polysaccharide hydrogels are reviewed, which are expected to provide new references for colon-targeted oral hydrogel systems using natural polysaccharides as raw materials.

Microbiota in Irritable Bowel Syndrome and Endometriosis: Birds of a Feather Flock Together-A Review

Endometriosis and irritable bowel syndrome (IBS) are chronic conditions affecting up to 10% of the global population, imposing significant burdens on healthcare systems and patient quality of life. Interestingly, around 20% of endometriosis patients also present with symptoms indicative of IBS. The pathogenesis of both these multifactorial conditions remains to be fully elucidated, but connections to gut microbiota are becoming more apparent. Emerging research underscores significant differences in the gut microbiota composition between healthy individuals and those suffering from either endometriosis or IBS. Intestinal dysbiosis appears pivotal in both conditions, exerting an influence via similar mechanisms. It impacts intestinal permeability, triggers inflammatory reactions, and initiates immune responses. Furthermore, it is entwined in a bidirectional relationship with the brain, as part of the gut-brain axis, whereby dysbiosis influences and is influenced by mental health and pain perception. Recent years have witnessed the development of microbiota-focused therapies, such as low FODMAP diets, prebiotics, probiotics, antibiotics, and fecal microbiota transplantation, designed to tackle dysbiosis and relieve symptoms. While promising, these treatments present inconsistent data, highlighting the need for further research. This review explores the evidence of gut dysbiosis in IBS and endometriosis, underscoring the similar role of microbiota in both conditions. A deeper understanding of this common mechanism may enable enhanced diagnostics and therapeutic advancements.

Association of low occlusal force as an oral hypofunction with the prevalence of irritable bowel syndrome in Japanese adults

BACKGROUND AND AIM

We investigated whether oral-dental conditions may be associated with the prevalence of irritable bowel syndrome (IBS) in a cross-sectional study in Japan.

METHODS

Information on lifestyle and abdominal symptoms was collected, and oral-dental examinations were performed from 2013 to 2017. To investigate the association between oral-dental conditions and IBS, this study used logistic regression analyses adjusted for relevant confounding factors, such as age, sex, BMI, stress, and eating between meals.

RESULTS

The prevalence of IBS was 484 (13.4%) among 3626 participants. The mean maximum occlusal force in the IBS group was significantly lower than that in the non-IBS group (0.306 ± 0.192 kN vs. 0.329 ± 0.205 kN, P = 0.014). The maximum occlusal force of the constipation-type IBS was significantly lower than that of other types of IBS without constipation type (0.269 ± 0.164 kN vs. 0.317 ± 0.198 kN, P = 0.010). Compared with those who had high values of maximum occlusal force (≧0.265 kN), those with a low value of maximum occlusal force (<0.265 kN) had a significantly greater risk for IBS (OR, 1.426; 95% CI, 1.135-1.792; P = 0.002), by multivariate analyses, across different categories of oral-dental condition in women, not in men. Women who had lowest third occlusal force (<0.206 kN) had approximately 35% significantly greater odds of having IBS compared with those who had highest third occlusal force (≧0.386 kN).

CONCLUSIONS

Results suggest that a reduction in the maximum occlusal force increases the risk of IBS in Japanese women.

Clinical outcome of disorders of gut-brain interaction in secondary care: A longitudinal study

BACKGROUND

Real-world data on the outcome of routine treatment for disorders of gut-brain interaction (DGBI) in secondary care are lacking.

METHOD

A longitudinal study of consecutive adult patients with various DGBI attending this institution's gastroenterology clinic was conducted. Following 2 years of treatment, the proportion of patients with symptom improvement, details of clinical therapy, factors associated with and the impact of 'no symptom improvement' were determined.

RESULTS

A total of 289 patients (median age 68 years; 64.7% females; 28.4% irritable bowel syndrome (IBS), 20.1% functional dyspepsia (FD), 8.7% functional constipation (FC), 42.9% overlap syndrome) were recruited. After 2 years, 66.1% patients reported symptom improvement. Patients with overlap syndrome were less likely to have symptomatic improvement compared to those with a single DGBI (Overlap 55.6% vs IBS 74.4% vs FD 72.4% vs FC 76.0%, p = 0.014). Reassurance was associated with symptom improvement (p < 0.001). On multivariate analysis, overlap syndrome remained significantly associated with a poorer outcome (OR 2.27, 95% CI 1.22-4.25, p = 0.010), while providing reassurance was associated with a positive outcome (OR 0.30, 95% CI 0.16-0.56, p < 0.001). Only 25.6% and 14.9% of patients were referred for a low FODMAP diet and psychiatric intervention respectively. DGBI patients who had 'no improvement' were more likely to seek further GI consultations and had more work absenteeism.

CONCLUSION

Two-thirds of DGBI patients in secondary care showed symptom improvement. Patients who were reassured had better symptom improvement, while those with an overlap syndrome were associated with a poorer outcome, resulting in greater healthcare consultation and work absenteeism.

What Is Unspecified Functional Bowel Disorder? A Commonly Seen, Rarely Recognized, and Poorly Understood Diagnosis

INTRODUCTION

Unspecified functional bowel disorder (FBD-U) is a Rome IV diagnosis of exclusion and occurs when patients report bowel symptoms but do not meet the criteria for other functional bowel disorders (FBD; irritable bowel syndrome [IBS], functional constipation [FC], functional diarrhea [FDr], or functional bloating). Previous research suggests that FBD-U is as/more common than IBS.

METHODS

One thousand five hundred one patients at a single-center tertiary care center completed an electronic survey. Study questionnaires included Rome IV Diagnostic Questionnaires, anxiety, depression, sleep, health care utilization, and bowel symptom severity measures.

RESULTS

Eight hundred thirteen patients met Rome IV criteria for a FBD and 194 patients (13.1%) met criteria for FBD-U, representing the second most common FBD after IBS. Severity of abdominal pain, constipation, and diarrhea were lower in FBD-U compared with other FBD, whereas health care utilization was similar among the groups. Scores on measures of anxiety, depression, and sleep disturbances were similar in FBD-U compared with FC and FDr but were less severe than IBS. Between 25% and 50% of patients with FBD-U did not meet Rome IV criteria for other FBD due to timing of onset of the target symptom (e.g., constipation for FC, diarrhea for FDr, and abdominal pain for IBS).

DISCUSSION

FBD-U, by Rome IV criteria, is highly prevalent in clinical settings. These patients are not represented in mechanistic studies or clinical trials for not having met Rome IV criteria for other FBD. Making future Rome criteria less stringent would minimize the number fulfilling criteria for FBD-U and maximize the true representation of FBD in clinical trials.

Shared genetic architecture between irritable bowel syndrome and psychiatric disorders reveals molecular pathways of the gut-brain axis

BACKGROUND

Irritable bowel syndrome (IBS) often co-occurs with psychiatric and gastrointestinal disorders. A recent genome-wide association study (GWAS) identified several genetic risk variants for IBS. However, most of the heritability remains unidentified, and the genetic overlap with psychiatric and somatic disorders is not quantified beyond genome-wide genetic correlations. Here, we characterize the genetic architecture of IBS, further, investigate its genetic overlap with psychiatric and gastrointestinal phenotypes, and identify novel genomic risk loci.

METHODS

Using GWAS summary statistics of IBS (53,400 cases and 433,201 controls), and psychiatric and gastrointestinal phenotypes, we performed bivariate casual mixture model analysis to characterize the genetic architecture and genetic overlap between these phenotypes. We leveraged identified genetic overlap to boost the discovery of genomic loci associated with IBS, and to identify specific shared loci associated with both IBS and psychiatric and gastrointestinal phenotypes, using the conditional/conjunctional false discovery rate (condFDR/conjFDR) framework. We used functional mapping and gene annotation (FUMA) for functional analyses.

RESULTS

IBS was highly polygenic with 12k trait-influencing variants. We found extensive polygenic overlap between IBS and psychiatric disorders and to a lesser extent with gastrointestinal diseases. We identified 132 independent IBS-associated loci (condFDR < 0.05) by conditioning on psychiatric disorders (n = 127) and gastrointestinal diseases (n = 24). Using conjFDR, 70 unique loci were shared between IBS and psychiatric disorders. Functional analyses of shared loci revealed enrichment for biological pathways of the nervous and immune systems. Genetic correlations and shared loci between psychiatric disorders and IBS subtypes were different.

CONCLUSIONS

We found extensive polygenic overlap of IBS and psychiatric and gastrointestinal phenotypes beyond what was revealed with genetic correlations. Leveraging the overlap, we discovered genetic loci associated with IBS which implicate a wide range of biological pathways beyond the gut-brain axis. Genetic differences may underlie the clinical subtype of IBS. These results increase our understanding of the pathophysiology of IBS which may form the basis for the development of individualized interventions.

A protease activity-based machine-learning approach as a complementary tool for conventional diagnosis of diarrhea-predominant irritable bowel syndrome

Irritable bowel syndrome (IBS) has no clinically accepted biomarkers even though it affects a large number of individuals worldwide. To address this lack of understanding, we evaluated peptidase activity in fecal samples from 35 patients with diarrheal IBS without symptom exacerbation (IBS-n) and 35 healthy subjects using a library of 384 fluorescent enzymatic substrate probes. IBS-n patients had high trypsin-like peptidase activity for cleavage of C-terminal lysine and arginine residues and low elastase-like activity for cleavage of C-terminal serine and glycine residues. These fluorescent probe library data, together with diagnostic machine-learning techniques, were able to accurately predict IBS-n. This approach can be used to diagnose diseases where no clinically accepted biomarkers exist, in which fecal enzyme activity is altered and also suggests that the development of new therapies targeting enzyme activities is possible.

Loose ends in the differential diagnosis of IBS-like symptoms

Two thirds of the patients we believed to have IBS in the 1970's have since been possible to diagnose with treatable conditions like bile acid diarrhea, inflammatory bowel disease, microscopic colitis, celiac disease, disaccharide malabsorption, exocrine pancreatic insufficiency, or rare genetic variants. Despite advances in diagnostic techniques a substantial proportion of patients continue suffering from IBS-like symptoms that cannot be explained by current knowledge. Although it is likely that further research will reveal small but important subgroups of patients with treatable mechanisms for IBS-like symptoms, we propose that only two large groups remain for being addressed in the clinic: those with connective tissue disorders such as Ehlers-Danlos syndrome or hypermobility spectrum disorders and those with autism spectrum disorders. Patients with connective tissue disorders exhibit identifiable disturbances of gut motor function and possibly increased gut permeability as underlying mechanisms for IBS-like symptoms. Autism spectrum disorders pose a much more difficult problem in the clinic. Disturbances of perception combined with anxiety and excessive worry about signals from the gut can lead to an endless but futile search for something being wrong. The search can involve large numbers of care givers, no one understanding the patient's suffering. Others may try to change their diet to lessen symptoms, only to find that almost all foods may cause worrying perceptions from the gut. Early recognition of autism spectrum disorders is essential for finding better ways to help patients with gastrointestinal and, as is often the case, extraintestinal symptoms.

Associations and gastrointestinal symptoms in women with endometriosis in comparison to women with irritable bowel syndrome: a study based on a population cohort

BACKGROUND

Endometriosis and irritable bowel syndrome (IBS) have similar symptoms, pathogenesis, and risk factors. These diagnoses often coexist and are frequently misdiagnosed leading to diagnostic delays. This study of a population-based cohort aimed to investigate associations relating to endometriosis and IBS and to compare gastrointestinal symptoms between endometriosis and IBS.

METHOD

The study cohort included women from the Malmö Offspring Study with information about endometriosis and IBS diagnoses from the National Board of Health and Welfare. The participants answered a questionnaire about lifestyle habits, medical and drug history, and self-reported IBS. The visual analog scale for IBS was used to estimate gastrointestinal symptoms the past 2 weeks. Endometriosis diagnosis and self-reported IBS were used as dependent variables to study associations with age, body mass index (BMI), education, occupation, marital status, smoking, alcohol habits, and physical activity using logistic regression. Mann-Whitney U Test or Kruskal-Wallis tests were used to calculate the differences in symptoms between groups.

RESULTS

Of the 2,200 women with information from medical records, 72 participants had endometriosis; 21 (29.2%) of these had self-reported IBS. Of the 1,915 participants who had answered the questionnaire, 436 (22.8%) had self-reported IBS. Endometriosis was associated with IBS (OR:1.86; 95%CI:1.06-3.26; p = 0.029), as well as with age 50-59 years (OR:6.92; 95%CI:1.97-24.32; p = 0.003), age ≥ 60 years (OR:6.27; 95%CI:1.56-25.17; p = 0.010), sick leave (OR:2.43; 95%CI:1.08-5.48; p = 0.033), and former smoking (OR:3.02; 95%CI:1.19-7.68; p = 0.020). There was an inverse association with BMI (OR:0.36; 95%CI:0.14-4.91; p = 0.031). IBS was associated with endometriosis (OR:1.77; 95%CI:1.02-3.07; p = 0.041) and sick leave (OR:1.77; 95%CI:1.14-2.73; p = 0.010), with a tendency to association with smoking (OR:1.30; 95%CI:0.98-1.72; p = 0.071). When excluding participants using drugs associated with IBS, the condition was associated with current smoking (OR:1.39; 95%CI:1.03-1.89; p = 0.033) and inversely with age 50-59 years (OR:0.58; 95%CI:0.38-0.90; p = 0.015). There were differences in the gastrointestinal symptoms between IBS and healthy participants, but not between endometriosis and IBS or healthy participants.

CONCLUSION

There were associations between endometriosis and IBS, without differences in gastrointestinal symptoms. Both IBS and endometriosis were associated with smoking and sick leave. Whether the associations reflect causality or depend on common risk factors and pathogenesis remains to be determined.

Overlap of disorders of gut-brain interaction: a systematic review and meta-analysis

BACKGROUND

Rome criteria differentiate distinct types of disorders of gut-brain interaction (DGBI); also known as functional gastrointestinal disorders. Overlap of symptom categories frequently occurs. This systematic review and meta-analysis aimed to define the prevalence of DGBI overlap and compare overlap in population-based, primary care or tertiary care health settings. Furthermore, we aimed to compare symptom severity of psychological comorbidities in DGBI with and without overlap.

METHODS

For this systematic review and meta-analysis we searched MEDLINE (PubMed) and Embase electronic databases from inception until March 1, 2022, for original articles and conference abstracts of observational cross-sectional, case-controlled, or cohort design studies that reported the prevalence of DGBI overlap in adult participants (aged ≥18 years). We included only those studies where the diagnosis of DGBI was based on clinical assessment, questionnaire data, or specific symptom-based criteria. Studies were excluded if reporting on mixed populations of DGBI and organic diseases. Aggregate patient data were extracted from eligible published studies. The prevalence of DGBI overlap in all studies was pooled using the DerSimonian and Laird random effects model, and further analysis stratified by subgroups (care setting, diagnostic criteria, geographic region, and gross domestic product per capita). We also assessed the relationship between DGBI overlap with anxiety, depression, and quality of life symptom scores. This study was registered with PROSPERO (CRD42022311101).

FINDINGS

46 of 1268 screened studies, reporting on 75 682 adult DGBI participants, were eligible for inclusion in this systematic review and meta-analysis. Overall, 24 424 (pooled prevalence 36·5% [95% CI 30·7 to 42·6]) participants had a DGBI overlap, with considerable between-study heterogeneity (I2=99·51, p=0·0001). In the tertiary health-care setting, overlap among participants with DGBI was more prevalent (8373 of 22 617, pooled prevalence 47·3% [95% CI 33·2 to 61·7]) compared with population-based cohorts (11 332 of 39 749, pooled prevalence 26·5% [95% CI 20·5 to 33·4]; odds ratio 2·50 [95% CI 1·28 to 4·87]; p=0·0084). Quality of life physical component scores were significantly lower in participants with DGBI overlap compared with participants without overlap (standardised mean difference -0·47 [95% CI -0·80 to -0·14]; p=0·025). Participants with DGBI overlap had both increased symptom scores for anxiety (0·39 [95% CI 0·24 to 0·54]; p=0·0001) and depression (0·41 [0·30 to 0·51]; p=0·0001).

INTERPRETATION

Overlap of DGBI subtypes is frequent, and is more prevalent in tertiary care settings and associated with more severe symptom manifestations or psychological comorbidities. Despite the large sample size, the comparative analyses revealed substantial heterogeneity, and the results should be interpreted with caution.

FUNDING

National Health and Medical Research Council and Centre for Research Excellence.

The microbiome in adolescents with irritable bowel syndrome and changes with percutaneous electrical nerve field stimulation

BACKGROUND

Irritable bowel syndrome (IBS), a disorder of the gut-brain axis, is affected by the microbiome. Microbial studies in pediatric IBS, especially for centrally mediated treatments, are lacking. We compared the microbiome between pediatric IBS patients and healthy controls (HC), in relation to symptom severity, and with percutaneous electrical nerve field stimulation (PENFS), a non-invasive treatment targeting central pain pathways.

METHODS

We collected a stool sample, questionnaires and a 1-2 week stool and pain diary from 11 to 18 years patients with IBS. A patient subset completed 4 weeks of PENFS and repeated data collection immediately after and/or 3 months after treatment. Stool samples were collected from HC. Samples underwent metagenomic sequencing to evaluate diversity, composition, and abundance of species and MetaCyc pathways.

KEY RESULTS

We included 27 cases (15.4 ± 2.5 year) and 34 HC (14.2 ± 2.9 year). Twelve species including Firmicutes spp., and carbohydrate degradation/long-chain fatty acid (LCFA) synthesis pathways, were increased in IBS but not statistically significantly associated with symptom severity. Seventeen participants (female) who completed PENFS showed improvements in pain (p = 0.012), disability (p = 0.007), and catastrophizing (p = 0.003). Carbohydrate degradation and LCFA synthesis pathways decreased post-treatment and at follow-up (FDR p-value <0.1).

CONCLUSIONS AND INFERENCES

Firmicutes, including Clostridiaceae spp., and LCFA synthesis pathways were increased in IBS patients suggesting pain-potentiating effects. PENFS led to marked improvements in abdominal pain, functioning, and catastrophizing, while Clostridial species and LCFA microbial pathways decreased with treatment, suggesting these as potential targets for IBS centrally mediated treatments.

Symptoms and Prevalence of Constipation among Adult Population of Bangladesh

Background

Constipation is one of the most common gastrointestinal disorders. The prevalence of constipation is rapidly increasing globally. It has adverse effects on the patient's quality of life including productivity and results in a high financial hardship on the healthcare system. The aim of the study was to estimate the symptoms and prevalence of constipation among the adult population of Bangladesh.

Materials and methods

It was a cross-sectional observational study based on a structured questionnaire and a checklist. In this study, three criteria were used for the diagnosis of chronic constipation (self-reported perception, Rome III criteria, and Bristol's criteria). The study was conducted among 1,550 population between July 2019 and December 2019.

Result

The study population consisted of 1,550 respondents, among them 41.61% male and 58.39% female, and the mean age was 32.71 ± 9.72 years. In the study, 12.2% of the population was categorized to have constipation according to self-reported perception, 11.2% according to Rome III, and 10.3% reported to have been suffering from constipation according to Bristol chart.Female gender tends to have a greater prevalence than male. In multivariate analysis for constipation, betel nut chewer, alcohol consumer, diabetes mellitus, hypertension, GI surgery, and bronchial asthma were significantly (p < 0.001) associated with constipation. According to Bristol's criteria, the most common stool form was Type III (sausage-shaped with cracked surface) among the Bangladeshi population in this study.

Conclusion

Chronic constipation is a common problem worldwide. The findings of this study suggest that there is a high prevalence of constipation among the general population of Bangladesh. Decreasing modifiable risk factors of constipation can reduce its prevalence and burden of the disease. Bangladesh is markedly deficient in literature citing constipation prevalence and determinants. These findings may commence a call for setting priority as one of the major public health problems and demanding attention for both at the clinical and community levels.

How to cite this article

Ghosh DK, Sarkar DK, Nath M, et al. Symptoms and Prevalence of Constipation among Adult Population of Bangladesh. Euroasian J Hepato-Gastroenterol 2023;13(2):45-49.

Clinical Presentation of Small Intestinal Bacterial Overgrowth from Aerodigestive Tract Bacteria Versus Colonic-Type Bacteria: A Comparison Study

BACKGROUND

Small Intestinal Bacterial Overgrowth (SIBO) is a heterogenous syndrome from excessive bacteria in the small intestine lumen. It is unknown if differences in type of bacterial overgrowth lead to differences in symptoms.

METHODS

Patients with suspected SIBO were recruited prospectively. Exclusion criteria were probiotics, antibiotics, or bowel prep in preceding 30 days. Clinical characteristics, risk factors, and labs were collected. Proximal jejunal aspiration via upper enteroscopy was performed. Aerodigestive tract (ADT) SIBO was defined as > 10⁵ CFU/mL of oropharyngeal and respiratory bacteria. Colonic-type SIBO was defined as > 10⁴ CFU/mL of distal small bowel and colon bacteria. Aims were to compare symptom profiles, clinical complications, labs, and underlying risk factors between ADT and colonic-type SIBO.

KEY RESULTS

We consented 166 subjects. Aspiration was not obtained in 22 and SIBO was found in 69 (49%) of 144 subjects. Daily abdominal distention trended towards more prevalent in ADT SIBO versus colonic-type SIBO (65.2% vs 39.1%, p = 0.09). Patient symptom scores were similar. Iron deficiency was more prevalent in ADT SIBO (33.3% vs 10.3%, p = 0.04). Subjects with colonic-type SIBO were more likely to have a risk factor for colonic bacteria colonization (60.9% vs 17.4%, p = 0.0006). Subjects with ADT SIBO were more likely to have a risk factor for diminished gastric acid (91.3% vs 67.4%, p = 0.02).

CONCLUSIONS & INFERENCES

We found differences in iron deficiency and underlying risk factors between ADT and colonic-type SIBO. However, distinct clinical profiles remained elusive. Future research is needed to develop validated symptom assessment tools and distinguish cause from correlation.

Towards criteria and symptoms of constipation in people with severe or profound intellectual and multiple disabilities: A Delphi study

Background

Chronic constipation is common in people with intellectual disabilities, and seems to be highly prevalent in people with severe or profound intellectual and multiple disabilities (SPIMD). However, there is no current widely accepted definition for the constipation experienced by these individuals.

Aim

This Delphi study aims to compile a list of operationalized criteria and symptoms of constipation in people with SPIMD based on practical experiences of and consensus between experts supporting them.

Methods

A two-round Delphi study with an intermediate evaluation and analyses was conducted. Parents and relatives of persons with SPIMD and support professionals were included. The panel answered statements and open questions about symptoms and criteria of constipation. They were also requested to provide their opinion about classifying criteria and symptoms into domains. Answers to statements were analysed separately after both rounds with regard to consensus rate and displayed qualitatively; answers to open questions were analysed deductively.

Results

In the first Delphi round (n = 47), consensus was achieved on criteria within the domains 'Defecation' and 'Physical features', that were assigned to broader categories. Symptoms retrieved within the domain 'Behavioural/Emotional' were brought back to the panel as statements. After the second Delphi round (n = 38), consensus was reached on questions about domains, and for eight criteria (domain 'Defecation' n = 5; domain 'Physical features n = 3). Within the domain 'Behavioural/Emotional', consensus was achieved for five symptoms. Criteria and symptoms with consensus >70% were considered 'generic' and <70% as 'personal'. Symptoms mentioned in the text boxes were used to operationalize categories.

Discussion and conclusion

It was possible to compile a list of generic criteria related to the domains 'Defecation' (n = 5) and 'Physical features' (n = 3) supplemented with generic symptoms related to the domain 'Behavioural/Emotional' (n = 5). We propose using both generic as well as personal criteria and symptoms resulting in a personal profile for an individual with SPIMD. Based on the current results, we recommend follow-up research to develop a screening tool to be used by relatives and professional caregivers, and a definition of constipation. This may support reciprocal collaboration and lead to timely identification of constipation in people with SPIMD.

Consumption of 2 Green Kiwifruits Daily Improves Constipation and Abdominal Comfort-Results of an International Multicenter Randomized Controlled Trial

INTRODUCTION

Consumption of green kiwifruit is known to relieve constipation. Previous studies have also reported improvements in gastrointestinal (GI) comfort. We investigated the effect of consuming green kiwifruit on GI function and comfort.

METHODS

Participants included healthy controls (n = 63), patients with functional constipation (FC, n = 60), and patients with constipation-predominant irritable bowel syndrome (IBS-C, n = 61) randomly assigned to consume 2 green kiwifruits or psyllium (7.5 g) per day for 4 weeks, followed by a 4-week washout, and then the other treatment for 4 weeks. The primary outcome was the number of complete spontaneous bowel movements (CSBM) per week. Secondary outcomes included GI comfort which was measured using the GI symptom rating scale, a validated instrument. Data (intent-to-treat) were analyzed as difference from baseline using repeated measures analysis of variance suitable for AB/BA crossover design.

RESULTS

Consumption of green kiwifruit was associated with a clinically relevant increase of ≥ 1.5 CSBM per week (FC; 1.53, P < 0.0001, IBS-C; 1.73, P = 0.0003) and significantly improved measures of GI comfort (GI symptom rating scale total score) in constipated participants (FC, P < 0.0001; IBS-C, P < 0.0001). No significant adverse events were observed.

DISCUSSION

This study provides original evidence that the consumption of a fresh whole fruit has demonstrated clinically relevant increases in CSBM and improved measures of GI comfort in constipated populations. Green kiwifruits are a suitable dietary treatment for relief of constipation and associated GI comfort.

Randomized Placebo-Controlled Phase 3 Trial of Vibrating Capsule for Chronic Constipation

BACKGROUND & AIMS

Despite therapeutic advances, effective treatments for chronic constipation remain an unmet need. The vibrating capsule is a nonpharmacologic, orally ingested, programmable capsule that vibrates intraluminally to induce bowel movements. We aimed to determine the efficacy and safety of the vibrating capsule in patients with chronic constipation.

METHODS

We conducted a phase 3, double-blind, placebo-controlled trial of patients with chronic constipation, who were randomized to receive either a vibrating or placebo capsule, once daily, 5 days a week for 8 weeks. The primary efficacy end points were an increase of 1 or more complete spontaneous bowel movements per week (CSBM1 responder) or 2 or more CSBMs per week (CSBM2) from baseline during at least 6 of the 8 weeks. Safety analyses were performed.

RESULTS

Among 904 patients screened, 312 were enrolled. A greater percentage of patients receiving the vibrating capsule achieved both primary efficacy end points compared with placebo (39.3% vs 22.1%, P = .001 for CSBM1; 22.7% vs 11.4% P = .008 for CSBM2). Significantly greater improvements were seen with the vibrating capsule for the secondary end points of straining, stool consistency, and quality-of-life measures compared with placebo. Adverse events were mild, gastrointestinal in nature, and similar between groups, except that a mild vibrating sensation was reported by 11% of patients in the vibrating capsule group, but none withdrew from the trial.

CONCLUSIONS

In patients with chronic constipation, the vibrating capsule was superior to placebo in improving bowel symptoms and quality of life. The vibrating capsule was safe and well tolerated. (Clinical trials.gov, Number: NCT03879239).

Effects of a Low-FODMAP Diet on Irritable Bowel Syndrome in Both Children and Adults-A Narrative Review

Irritable bowel syndrome is a typical gastrointestinal disease that causes bloating, flatulence, abdominal pain, diarrhoea, constipation, or alteration of the last two in adults and children. A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) is one of the potential treatment strategies to reduce abdominal symptoms and increase the quality of life. The present narrative review aims to present a general overview of current studies that have evaluated the efficacy of a low-FODMAP diet against other diets in gastrointestinal symptoms, nutrient intake in adults and children, and lifestyle quality. The research was performed using seven searchable databases, which included the Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews (CDSR), Excerpta Medica Database (EMBASE), Medline, PubMed, Scopus, and Web of Science, up to March 2023. In conclusion, there is significant evidence that the follow-up of a low-FODMAP diet might be a feasible first-line therapeutic strategy to reduce stomach discomfort, pain, bloating, and quality of life for patients with irritable bowel syndrome.

Eluxadoline-Loaded Eudragit Nanoparticles for Irritable Bowel Syndrome with Diarrhea: Formulation, Optimization Using Box-Behnken Design, and Anti-Diarrheal Activity

Eluxadoline (ELD), a recently approved drug, exhibits potential therapeutic effects in the management and treatment of IBS-D. However, its applications have been limited due to poor aqueous solubility, leading to a low dissolution rate and oral bioavailability. The current study's goals are to prepare ELD-loaded eudragit (EG) nanoparticles (ENPs) and to investigate the anti-diarrheal activity on rats. The prepared ELD-loaded EG-NPs (ENP1-ENP14) were optimized with the help of Box-Behnken Design Expert software. The developed formulation (ENP2) was optimized based on the particle size (286 ± 3.67 nm), PDI (0.263 ± 0.01), and zeta potential (31.8 ± 3.18 mV). The optimized formulation (ENP2) exhibited a sustained release behavior with maximum drug release and followed the Higuchi model. The chronic restraint stress (CRS) was successfully used to develop the IBS-D rat model, which led to increased defecation frequency. The in vivo studies revealed a significant reduction in defecation frequency and disease activity index by ENP2 compared with pure ELD. Thus, the results demonstrated that the developed eudragit-based polymeric nanoparticles can act as a potential approach for the effective delivery of eluxadoline through oral administration for irritable bowel syndrome diarrhea treatment.

Young adults with major depression show altered microbiome

There is growing basic and clinical evidence that major depressive disorder (MDD) is associated with gut microbiome alterations, but clinical studies have tended not to adjust for confounding factors. And few studies on the gut microbiome focused on young adults with MDD. Here we performed a pilot study to compare the gut microbiome of young adults with MDD with healthy controls. Shotgun metagenomic sequencing was performed on stool samples obtained from 40 young adults with MDD and 42 healthy controls. After controlling for confounding factors including sex, age, BMI, alcohol or cigarette consumption, bowel movement quality, exercise or defecation frequency, we compared microbiome diversity between groups, identified differentially abundant taxa, and further compared functional differences through gut-brain and gut-metabolic module analysis. There were no significant differences in overall gut microbiome structure and function in young adults with MDD compared with controls. Abundance of Sutterellaceae and species belonging to Clostridium, Eubacterium, and Ruminococcus were significantly different between groups. The cysteine degradation I pathway was increased in MDD. After controlling for most confounding factors, this pilot study provides new evidence on the specific, often subtle gut dysbiosis affecting young adults with depression.

Effect of Bifidobacterium bifidum G9-1 on the Intestinal Environment and Diarrhea-Predominant Irritable Bowel Syndrome (IBS-D)-like Symptoms in Patients with Quiescent Crohn's Disease: A Prospective Pilot Study

Diarrhea-predominant irritable bowel syndrome (IBS-D)-like symptoms are distressing for patients with quiescent Crohn's disease (qCD) and worsen their quality of life. In the present study, we assessed the effect of the probiotic Bifidobacterium bifidum G9-1 (BBG9-1) on the intestinal environment and clinical features in patients with qCD. Eleven patients with qCD, who met the Rome III diagnostic criteria for IBS-D, received BBG9-1 (24 mg) orally three times daily for 4 weeks. Indices of the intestinal environment (fecal calprotectin level and gut microbiome) and clinical features (CD/IBS-related symptoms, quality of life and stool irregularities) were evaluated before and after treatment. Treatment with BBG9-1 tended to reduce the IBS severity index in the studied patients (p = 0.07). Among gastrointestinal symptoms, abdominal pain and dyspepsia tended to be improved by the BBG9-1 treatment (p = 0.07 and p = 0.07, respectively), and IBD-related QOL showed a significant improvement (p = 0.007). With regard to mental status, the patient anxiety score was significantly lower at the endpoint of BBG9-1 treatment than at the baseline (p = 0.03). Although BBG9-1 treatment did not affect the fecal calprotectin level, it suppressed the serum MCP-1 level significantly and increased the abundance of intestinal Bacteroides in the study patients. The probiotic BBG9-1 is able to improve IBD-related QOL with a reduction of anxiety score in patients with quiescent CD and IBS-D-like symptoms.

Misfolded α-Synuclein Assessment in the Skin and CSF by RT-QuIC in Isolated REM Sleep Behavior Disorder

BACKGROUND AND OBJECTIVES

Real-time quaking-induced conversion (RT-QuIC) assay detects misfolded α-synuclein (AS) in the skin and CSF of patients with the synucleinopathies Parkinson disease and dementia with Lewy bodies. Isolated REM sleep behavior disorder (IRBD) constitutes the prodromal stage of these synucleinopathies. We aimed to compare the ability of RT-QuIC to identify AS in the skin and CSF of patients with IRBD.

METHODS

This was a cross-sectional study where consecutive patients with polysomnographic-confirmed IRBD and age-matched controls without RBD underwent skin biopsy and lumbar puncture the same day. Three-millimeter skin punch biopsies were obtained bilaterally in the cervical region from dorsal C7 and C8 dermatomes and in distal legs. RT-QuIC assessed AS in these 6 skin sites and the CSF.

RESULTS

We recruited 91 patients with IRBD and 41 controls. In the skin, sensitivity to detect AS was 76.9% (95% CI 66.9-85.1), specificity 97.6% (95% CI 87.1-99.9) positive predictive value 98.6% (95% CI 91.0-99.8), negative predictive value 65.6% (95% CI 56.6-73.6), and accuracy 83.3% (95% CI 75.9-89.3). In the CSF, the sensitivity was 75.0% (95% CI 64.6-83.6), the specificity was 97.5% (95% CI 86.8-99.9), the positive predictive value was 98.5% (95% CI 90.5-99.8), the negative predictive value was 63.9% (95% CI 55.2-71.9), and the accuracy was 82.0% (95% CI 74.3-88.3). Results in the skin and CSF samples showed 99.2% agreement. Compared with negative patients, RT-QuIC AS-positive patients had a higher likelihood ratio of prodromal Parkinson disease (p < 0.001) and showed more frequently hyposmia (p < 0.001), dopamine transporter imaging single-photon emission CT deficit (p = 0.002), and orthostatic hypotension (p = 0.014). No severe or moderate adverse effects were reported. There was no difference between the percentage of participants reporting mild adverse events secondary to skin biopsy or lumbar puncture (9.1% vs 17.2%; p = 0.053). One hundred and ten (83%) and 104 (80%) participants, respectively, stated they would accept to undergo skin biopsy and lumbar puncture again for research purposes.

DISCUSSION

Our study in IRBD shows that (1) RT-QuIC detects AS in the skin and CSF with similar high sensitivity, specificity, and agreement, (2) AS RT-QuIC positivity is associated with supportive features and biomarkers of synucleinopathy, and (3) skin punch biopsy and lumbar puncture have comparable mild adverse effects, tolerance, and acceptance. RT-QuIC in the skin or CSF might represent a patient selection strategy for future neuroprotective trials targeting AS in IRBD.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that RT-QuIC-detected AS in the skin and CSF distinguishes patients with IRBD from controls.

Exploration of associations among dietary tryptophan, microbiome composition and function, and symptom severity in irritable bowel syndrome

BACKGROUND

Imbalance of the tryptophan (TRP) pathway may influence symptoms among patients with irritable bowel syndrome (IBS). This study explored relationships among different components that contribute to TRP metabolism (dietary intake, stool metabolite levels, predicted microbiome metabolic capability) in females with IBS and healthy controls (HCs). Within the IBS group, we also investigated relationships between TRP metabolic determinants, Bifidobacterium abundance, and symptoms of IBS.

METHODS

Participants with IBS (Rome III) and HCs completed a 28-day diary of gastrointestinal symptoms and a 3-day food record for TRP intake. They provided a stool sample for shotgun metagenomics, 16 S rRNA analyses, and quantitative measurement of TRP by mass spectrometry.

RESULTS

Our cohort included 115 females, 69 with IBS and 46 HCs, with a mean age of 28.5 years (SD 7.4). TRP intake (p = 0.71) and stool TRP level (p = 0.27) did not differ between IBS and HC. Bifidobacterium abundance was lower in the IBS group than in HCs (p = 0.004). Predicted TRP metabolism gene content was higher in IBS than HCs (FDR-corrected q = 0.006), whereas predicted biosynthesis gene content was lower (q = 0.045). Within the IBS group, there was no association between symptom severity and TRP intake or stool TRP, but there was a significant interaction between Bifidobacterium abundance and TRP intake (q = 0.029) in predicting stool character.

CONCLUSIONS

Dietary TRP intake, microbiome composition, and differences in TRP metabolism constitute a complex interplay of factors that could modulate IBS symptom severity.

Characteristics of disorders of gut-brain interaction in the Japanese population in the Rome Foundation Global Epidemiological Study

BACKGROUND

The aims were to use Japanese data from the Rome Foundation Global Epidemiological Study (RFGES) to test the hypotheses that severity of gastrointestinal (GI) symptoms and psychosocial disturbance are ordered as Rome IV irritable bowel syndrome (IBS) > Rome III IBS > DGBI, not IBS > others.

METHODS

Subjects were 2504 Japanese in the RFGES. We assessed DGBI/IBS diagnoses with Rome IV/III, IBS Symptom Severity Scale (IBS-SSS), Patient Health Questionnaire (PHQ) for anxiety/depression and non-GI somatic symptoms, PROMIS-10 for quality of life (QOL), Work Productivity and Activity Impairment (WPAI) Questionnaire, parts of Self-reported IBS Questionnaire (SIBSQ) for meal effect and stress effect, Food Frequency Questionnaire, and medication questions.

KEY RESULTS

The prevalence of Rome IV DGBI was as follows; IBS-C 0.5%, IBS-D 0.8%, IBS-M 0.8%, IBS-U 0.1%, unspecified functional bowel disorder 10.7%, postprandial distress syndrome 2.2%, and epigastric pain syndrome 0.3%. Rome III IBS prevalence; IBS-C 3.0%, IBS-D 3.1%, IBS-M 2.7%, and IBS-U 0.6%. Comparison among Rome IV IBS (n = 54), Rome III IBS (n = 197), other DGBI (n = 746), others (n = 1389) revealed significant order as Rome IV IBS > Rome III IBS > other DGBI > others in IBS-SSS, anxiety/depression, activity impairment, non-GI symptoms, physical QOL, mental QOL, exacerbated symptoms by meals and perceived stress (all p < 0.001).

CONCLUSIONS & INFERENCES

These findings support the study hypotheses. Data from Japan as a culturally homogenous country suggest Rome IV IBS is more severe and hence has more gut-brain psychobehavioral involvement than Rome III IBS.

Effects of Bifidobacterium longum CLA8013 on bowel movement improvement: a placebo-controlled, randomized, double-blind study

A placebo-controlled, randomized, double-blind study was conducted to evaluate the effect of taking 25 billion colony-forming units of heat-killed Bifidobacterium longum CLA8013 over 2 weeks on bowel movements in constipation-prone healthy individuals. The primary endpoint was the change in defecation frequency between the baseline and 2 weeks after the intake of B. longum CLA8013. The secondary endpoints were the number of days of defecation, stool volume, stool consistency, straining during defecation, pain during defecation, feeling of incomplete evacuation after defecation, abdominal bloating, fecal water content, and the Japanese version of the Patient Assessment of Constipation Quality of Life. A total of 120 individuals were assigned to two groups, 104 (control group, n=51; treatment group, n=53) of whom were included in the analysis. After 2 weeks of consuming the heat-killed B. longum CLA8013, defecation frequency increased significantly in the treatment group compared with that in the control group. Furthermore, compared with the control group, the treatment group showed a significant increase in stool volume and significant improvement in stool consistency, straining during defecation, and pain during defecation. No adverse events attributable to the heat-killed B. longum CLA8013 were observed during the study period. This study revealed that heat-killed B. longum CLA8013 improved the bowel movements of constipation-prone healthy individuals and confirmed that there were no relevant safety issues.

Face-to-face interviews versus Internet surveys: Comparison of two data collection methods in the Rome foundation global epidemiology study: Implications for population-based research

BACKGROUND AND AIMS

The Rome Foundation Global Epidemiology Study (RFGES) assessed the prevalence, burden, and associated factors of Disorders of Gut-Brain Interaction (DGBI) in 33 countries around the world. Achieving worldwide sampling necessitated use of two different surveying methods: In-person household interviews (9 countries) and Internet surveys (26 countries). Two countries, China and Turkey, were surveyed with both methods. This paper examines the differences in the survey results with the two methods, as well as likely reasons for those differences.

METHODS

The two RFGES survey methods are described in detail, and differences in DGBI findings summarized for household versus Internet surveys globally, and in more detail for China and Turkey. Logistic regression analysis was used to elucidate factors contributing to these differences.

RESULTS

Overall, DGBI were only half as prevalent when assessed with household vs Internet surveys. Similar patterns of methodology-related DGBI differences were seen within both China and Turkey, but prevalence differences between the survey methods were dramatically larger in Turkey. No clear reasons for outcome differences by survey method were identified, although greater relative reduction in bowel and anorectal versus upper gastrointestinal disorders when household versus Internet surveying was used suggests an inhibiting influence of social sensitivity.

CONCLUSIONS

The findings strongly indicate that besides affecting data quality, manpower needs and data collection time and costs, the choice of survey method is a substantial determinant of symptom reporting and DGBI prevalence outcomes. This has important implications for future DGBI research and epidemiological research more broadly.

Effect of Bacillus coagulans Unique IS2 with Lactulose on Functional Constipation in Adults: a Double-Blind Placebo Controlled Study

In the present double-blind randomised study, the efficacy of combination of Bacillus coagulans Unique IS2 and lactulose was evaluated in the treatment of functional constipation in adults. One-fifty participants diagnosed with functional constipation (Rome III criteria) were randomised (1:1:1) and supplemented daily with 15 mL suspension of probiotic (B. coagulans Unique IS2, 2 × 10⁹ spores) with lactulose (10 g) (group 1) or lactulose (10 g) (group 2) or placebo (water) (group 3) for 4 weeks. The primary (stool frequency) and secondary outome measures (stool consistency, sensation of incomplete evacuation, defecation- and abdominal-pain) were recorded weekly for up to 4 weeks. Bacillus coagulans Unique IS2 with lactulose showed significant changes in stool frequency as compared to lactulose treatment; however, at the end of the trial, it was found insignificant due to the gradual increase of stool frequency score of lactulose treatment. The changes observed in stool consistency were early (2nd week) and remained consistent up to end of the trial. The significant reduction of sensation of incomplete evacuation, defecation-, and abdominal-pain correlated with the strains ability to produce short-chain fatty acids. No adverse events were observed in any of the groups, and all the vital parameters were normal during the course of the study. Overall, results indicated that B. coagulans Unique IS2 addition to lactulose reduced time required to relieve constipation as compared to lactulose alone. In conclusion, B. coagulans Unique IS2 with lactulose is more effective than lactulose alone to relieve symptoms of constipation in a shorter period. Trial registration: CTRI/2018/11/016399, dated 22/11/2018.

Effect of osteopathic visceral manipulation for individuals with functional constipation and chronic nonspecific low back pain: Randomized controlled trial

OBJECTIVE

To investigate the effect of osteopathic visceral manipulation (OVM) on disability and pain intensity in individuals with functional constipation and chronic nonspecific low back pain.

METHODS

This study is a randomized controlled trial with a blinded assessor. Seventy-six volunteers with functional constipation and chronic nonspecific low back pain were randomized to two groups: OVM and sham OVM. The primary clinical outcome was pain intensity measured using a numeric rating scale (NRS) and disability measured using the Oswestry Disability Index (ODI). The secondary outcomes were electromyographic signals measured during the flexion-extension cycle, the finger-to-floor distance during complete flexion of the trunk and the Fear-Avoidance Beliefs Questionnaire (FABQ). All outcomes were determined after six weeks of treatment as well as three months after randomization.

RESULTS

The OVM group reported a reduction in pain intensity after six weeks of treatment and at the three-month evaluation (p < .0002) and the sham group reported a reduction in pain intensity after three-month evaluation (p < .007). For the ODI was also found in the OVM group six weeks after the end of treatment (treatment effect = -6.59, 95% CI: -12.01 to -1.17, p = .01) and at the three-month evaluation (treatment effect = -6.02, 95% CI: -11.55 to -0.49, p = .03). Significant differences were also found for paravertebral muscle activity during the dynamic phases (flexion and extension) six-week evaluations.

CONCLUSIONS

The OVM group demonstrated a reduction in pain intensity and improvement in disability after six-weeks and three-month follow-up while the sham group reduction in pain three-month follow-up.

Baseline gut microbial profiles are associated with the efficacy of Bacillus subtilis and Enterococcus faecium in IBS-D

OBJECTIVE

Little is known about association between the efficacy of probiotics and baseline gut microbiota in irritable bowel syndrome (IBS). We aimed to explore gut microbiota in diarrhea-predominant IBS (IBS-D) and whether baseline gut microbiota was related to the efficacy of Bacillus subtilis and Enterococcus faecium (BE).

METHODS

This study recruited 19 healthy controls (HC) and 50 IBS-D patients, among whom 19 patients were administrated 500 mg BE orally three times daily for 2 weeks. Clinical data and fecal samples were collected from patients before and after treatment. 16S rRNA sequencing was performed to obtain fecal bacterial data.

RESULTS

There was no significant difference of alpha diversity, beta diversity, profiles of microbial phyla and genera between HC and IBS. BE improved IBS-SSS (IBS severity scoring system) and stool consistency, and altered Enterococcus, Blautia, Lachnoclostridium and Fusobacterium without significant impact on microbial structure in IBS-D. Notably, baseline fecal bacterial composition differed between non-responders and responders to BE concerning abdominal pain and bloating, with Atopobium, Pyramidobacter, Ruminococcus gnavus and Peptostreptococcus enriched in responders in terms of abdominal pain. There was reduced abundance of Prevotella, Ruminococcaceae UCG, Eubacterium eligens, Faecalibacterium and Eubacterium coprostanoligenes in responders compared with non-responders. Furthermore, BE increased beneficial bacteria including Faecalibacterium, Blautia and Butyricicoccus, decreased Lachnoclostridium and Bilophila, and influenced some microbial metabolic pathways in responders, such as mineral absorption, metabolism of arachidonic acid, d-arginine, D-ornithine, phenylalanine and vitamin B6.

CONCLUSION

Baseline fecal microbiome is associated with the efficacy of BE in attenuating abdominal pain and bloating in IBS-D.

The Rome Foundation Global Epidemiology study: Conception, implementation, results, and future potential

BACKGROUND

Methodological problems have impeded successful epidemiological research into disorders of gut-brain interactions (DGBI), as previous studies were limited in terms of study population, diagnostic criteria, number of disorders assessed, data collection methods, and geographic area. Most prevalence estimates were based on pooling data from heterogeneous studies using inappropriate pooling methods, seriously limiting the relevance of the results. The Rome Foundatiion Global Epidemiology Study (RFGES) aimed to rectify these limitations using rigorous methodology to survey the prevalence of 22 DGBI in large population samples in 33 countries. Its aims were to conduct a comprehensive, multinational epidemiological study using rigorous research methodology, gain a better understanding of the burden of the DGBI, gain reliable regional estimates of DGBI prevalence, and advance our understanding of the pathophysiology of IBS. The study questionnaire consisted of the 89-item Rome IV Adult Diagnostic Questionnaire enabling the diagnosis of 22 DGBI, and an 80-item supplemental questionnaire that enabled analyses of the association of multiple factors with DGBI diagnoses.

PURPOSE FOR REVIEW ARTICLE

This review paper introduces a special issue on the Rome Foundation Global Epidemiology study (RFGES) with a narrative description of its conception, development, and implementation, its outcomes to date, and its potential contribution to neurogastroenterology. It includes 15 papers that reflect the range of RFGES studies from single country papers to intra-regional studies, to inter-regional studies, and one global study.

A Review of Colonoscopy in Intestinal Diseases

Since the development of the fiberoptic colonoscope in the late 1960s, colonoscopy has been a useful tool to diagnose and treat various intestinal diseases. This article reviews the clinical use of colonoscopy for various intestinal diseases based on present and future perspectives. Intestinal diseases include infectious diseases, inflammatory bowel disease (IBD), neoplasms, functional bowel disorders, and others. In cases of infectious diseases, colonoscopy is helpful in making the differential diagnosis, revealing endoscopic gross findings, and obtaining the specimens for pathology. Additionally, colonoscopy provides clues for distinguishing between infectious disease and IBD, and aids in the post-treatment monitoring of IBD. Colonoscopy is essential for the diagnosis of neoplasms that are diagnosed through only pathological confirmation. At present, malignant tumors are commonly being treated using endoscopy because of the advancement of endoscopic resection procedures. Moreover, the characteristics of tumors can be described in more detail by image-enhanced endoscopy and magnifying endoscopy. Colonoscopy can be helpful for the endoscopic decompression of colonic volvulus in large bowel obstruction, balloon dilatation as a treatment for benign stricture, and colon stenting as a treatment for malignant obstruction. In the diagnosis of functional bowel disorder, colonoscopy is used to investigate other organic causes of the symptom.

Efficacy of Fecal Microbiota Transplant on Behavioral and Gastrointestinal Symptoms in Pediatric Autism: A Systematic Review

Background and Aims: There is a high prevalence of gastrointestinal-related (GI) symptoms among children with autism spectrum disorder (ASD), which is associated with the severity of behavioral symptoms. Fecal microbiota transplantation (FMT) is a proposed therapeutic strategy that aims to address the dysregulation of the gut microbiome among children with ASD. Our study performed the first systematic review aimed to evaluate the benefits of FMT on the behavioral and gastrointestinal symptoms of pediatric patients with autism. Methods: A literature search was performed using variations of the keywords "pediatrics" and "fecal microbiota transplantation" in PubMed, EMBASE, CINAHL, Cochrane, and Web of Science from inception to 30 June 2022. Four studies that met the eligibility criteria were included in the systematic review. The efficacy of FMT on behavioral symptoms was measured by the difference in Aberrant Behavior Checklist (ABC) and Child Autism Rating Scale (CARS) scores before and after FMT. Results: We found a statistically significant improvement (p < 0.05) in ABC and CARS scores following FMT, with a statistically significant decrease in scores observed across all studies. In addition, substantial improvements in gastrointestinal symptoms were observed across all studies. Conclusion: Our findings suggest that FMT may offer a promising intervention for treating both behavioral and gastrointestinal symptoms in pediatric patients with autism.

Rifaximin Treatment for Individual and Multiple Symptoms of Irritable Bowel Syndrome With Diarrhea: An Analysis Using New End Points

PURPOSE

Rifaximin is indicated for the treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults. The current aim was to evaluate rifaximin efficacy on individual and composite IBS-D symptoms using definitions not previously examined.

METHODS

Phase III post hoc analyses of two randomized, double-blind, placebo-controlled trials and the open-label phase of a randomized, double-blind, placebo-controlled trial were conducted. Adults with IBS-D received a 2-week course of rifaximin 550 mg TID. Individual and composite responses for abdominal pain (mean weekly improvements from baseline of ≥30%, ≥40%, or ≥50%), bloating (mean weekly improvements from baseline of ≥1 or ≥2 points; or ≥30%, ≥40%, or ≥50%), stool consistency (mean weekly average stool consistency score <3 or <4), and urgency (improvement from baseline of ≥30% or ≥40% in percentage of days with urgency) for ≥2 of the first 4 weeks after treatment, and weekly for 12 weeks, were assessed.

FINDINGS

Overall, 1258 patients from the double-blind trials (rifaximin [n = 624]; placebo [n = 634]) and 2438 from an open-label trial were analyzed. The percentage of bloating or urgency responders was significantly greater with double-blind rifaximin versus placebo (P ≤ 0.03). A significantly greater percentage of the double-blind group were composite abdominal pain and bloating responders versus placebo for all thresholds analyzed (P < 0.05). A significantly greater percentage of the double-blind group were tri-symptom composite end point responders (abdominal pain, bloating, and fecal urgency) versus placebo (P = 0.001). A significantly greater percentage of patients achieved response (≥30% composite tri-symptom threshold) with double-blind rifaximin versus placebo as early as 1 week posttreatment, with significance maintained through ≥5 weeks after treatment. Open-label results were consistent with those of the double-blind study.

IMPLICATIONS

Rifaximin significantly improved multiple, concurrent IBS-D symptoms, using clinically relevant definitions of treatment response. Using a novel tri-symptom composite end point (ie, abdominal pain, bloating, fecal urgency), adults with IBS-D treated with a 2-week course of rifaximin were significantly more likely to be composite end point responders than those receiving placebo (≥30% or ≥40% threshold) for the three symptoms. Thus, rifaximin not only met current standard thresholds used for adjudication of responders in clinical trials but also achieved higher thresholds for many of these symptoms, suggesting potential for even more robust clinical improvements.

CLINICALTRIALS

gov identifiers: NCT00731679, NCT00724126, and NCT01543178. (Clin Ther. 2023;45:XXX-XXX) © 2023 Elsevier HS Journals, Inc.

The role of psychological factors in functional gastrointestinal disorders: a systematic review and meta-analysis

PURPOSE

To systematically reevaluate the role of psychological factors in functional gastrointestinal disorders (FGIDs) and thus provide a scientific basis for the psychological treatment of FGIDs.

METHODS

A literature search was conducted using the PubMed, Embase, Web of Science, and Cochrane Library databases from January 2018 to August 2022 for researches on psychological factors affecting patients with functional gastrointestinal disorders. Meta-analysis was carried out with Stata17.0 after the screening, extraction, and evaluation of article quality.

RESULTS

The search included 22 articles with 2430 patients in the FGIDs group and 12,397 patients in the healthy controls. Meta-analysis showed anxiety [(pooled SMD = 0.74, 95%CI: 0.62 ~ 0.86, p < 0.000) (pooled OR = 3.14, 95%CI: 2.47 ~ 4.00, p < 0.000)], depression [(pooled SMD = 0.79, 95%CI: 0.63 ~ 0.95, p < 0.000) (pooled OR = 3.09, 95%CI: 2.12 ~ 4.52, p < 0.000)], mental disorders (pooled MD =  -5.53, 95%CI: -7.12 ~  -3.95, p < 0.05), somatization (pooled SMD = 0.92, 95%CI: 0.61 ~ 1.23, p < 0.000), and sleep disorders (pooled SMD = 0.69, 95%CI: 0.04 ~ 1.34, p < 0.05) are risk factors for functional gastrointestinal disorders.

CONCLUSION

There is a significant association between psychological factors and FGIDs. Interventions such as anti-anxiety drugs, antidepressants, and behavioral therapy are of great clinical significance in reducing FGIDs risk and improving prognosis.

Defecation status, intestinal microbiota, and habitual diet are associated with the fecal bile acid composition: a cross-sectional study in community-dwelling young participants

PURPOSE

Bile acid (BA) metabolism by intestinal bacteria is associated with the risk of gastrointestinal diseases; additionally, its control has become a modern strategy for treating metabolic diseases. This cross-sectional study investigated the influence of defecation status, intestinal microbiota, and habitual diet on fecal BA composition in 67 community-dwelling young participants.

METHODS

Feces were collected for intestinal microbiota and BA analyses; data about defecation status and dietary habits were collected using the Bristol stool form scales and a brief-type self-administered diet history questionnaire, respectively. The participants were categorized into four clusters based on their fecal BA composition, according to cluster analysis, and tertiles based on deoxycholic acid (DCA) and lithocholic acid (LCA) levels.

RESULTS

The high primary BA (priBA) cluster with high fecal cholic acid (CA) and chenodeoxycholic acid (CDCA) levels had the highest frequency of normal feces, whereas the second BA (secBA) cluster with high levels of fecal DCA and LCA had the lowest. Alternately, the high-priBA cluster had a distinct intestinal microbiota, with higher Clostridium subcluster XIVa and lower Clostridium cluster IV and Bacteroides. The low-secBA cluster with low fecal DCA and LCA levels had the lowest animal fat intake. Nevertheless, the insoluble fiber intake of the high-priBA cluster was significantly higher than that of the high-secBA cluster.

CONCLUSION

High fecal CA and CDCA levels were associated with distinct intestinal microbiota. Conversely, high levels of cytotoxic DCA and LCA were associated with increased animal fat intake and decreased frequency of normal feces and insoluble fiber intake.

CLINICAL TRIAL REGISTRY

University Hospital Medical Information Network (UMIN) Center system (UMIN000045639); date of registration: 15/11/2019.

The efficacy of exogenous melatonin supplement in ameliorating irritable bowel syndrome severity: A meta-analysis of randomized controlled trials

BACKGROUND

Irritable bowel syndrome (IBS) was found in 11% of the general population worldwide. The current pharmacologic management of IBS was unsatisfactory, and it was accompanied by a number of adverse events. Melatonin was found to play an important role in gastrointestinal smooth muscle motility. Dysregulation of endogenous melatonin secretion has been found in IBS patients. Exogenous melatonin supplement has become one alternative treatment for IBS, but the evidence is inconclusive. The current meta-analysis sought to determine the efficacy of exogenous melatonin supplement in improving IBS severity in IBS patients.

METHODS

We included randomized controlled trials (RCTs) that investigated the efficacy of exogenous melatonin supplement in ameliorating IBS severity in IBS patients. This meta-analysis was conducted using a random effects model. The primary target outcomes were changes in IBS severity associated with melatonin or placebo.

RESULTS

This meta-analysis of 4 RCTs and 115 participants revealed that exogenous melatonin supplement was associated with significantly better improvement in overall IBS severity than placebo (k = 4, Hedges' g = 0.746, 95% confidence intervals = 0.401-1.091, p < 0.001). The subgroup without concurrent medication had the same result (p < 0.001). In addition, exogenous melatonin supplement was also associated with significantly better improvement in IBS pain severity (p < 0.001) and quality of life (p = 0.007) than placebo, but not in abdominal distension (p = 0.111) or sleep quality (p = 0.142). Finally, melatonin was associated with similar safety profiles with placebo.

CONCLUSION

This meta-analysis provides evidence for the use of exogenous melatonin in IBS patients to ameliorate overall IBS severity, IBS pain severity, and quality of life.

TRIAL REGISTRATION

PROSPERO CRD42021269451.

A multi-omic brain gut microbiome signature differs between IBS subjects with different bowel habits

Alterations of the brain-gut-microbiome system (BGM) have been implicated in the pathophysiology of irritable bowel syndrome (IBS), yet bowel habit-specific alterations have not been elucidated. In this cross-sectional study, we apply a systems biology approach to characterize BGM patterns related to predominant bowel habit. Fecal samples and resting state fMRI were obtained from 102 premenopausal women (36 constipation-predominant IBS (IBS-C), 27 diarrhea-predominant IBS (IBS-D), 39 healthy controls (HCs)). Data integration analysis using latent components (DIABLO) was used to integrate data from the phenome, microbiome, metabolome, and resting-state connectome to predict HCs vs IBS-C vs IBS-D. Bloating and visceral sensitivity, distinguishing IBS from HC, were negatively associated with beneficial microbes and connectivity involving the orbitofrontal cortex. This suggests that gut interactions may generate aberrant central autonomic and descending pain pathways in IBS. The connection between IBS symptom duration, key microbes, and caudate connectivity may provide mechanistic insight to the chronicity of pain in IBS. Compared to IBS-C and HCs, IBS-D had higher levels of many key metabolites including tryptophan and phenylalanine, and increased connectivity between the sensorimotor and default mode networks; thus, suggestingan influence on diarrhea, self-related thoughts, and pain perception in IBS-D ('bottom-up' mechanism). IBS-C's microbiome and metabolome resembled HCs, but IBS-C had increased connectivity in the default mode and salience networks compared to IBS-D, which may indicate importance of visceral signals, suggesting a more 'top-down' BGM pathophysiology. These BGM characteristics highlight possible mechanistic differences for variations in the IBS bowel habit phenome. This article is part of the Special Issue on 'Microbiome & the Brain: Mechanisms & Maladies'.

The Prevalence of Irritable Bowel Syndrome after Severe Acute Respiratory Syndrome Coronavirus 2 Infection and Their Association: A Systematic Review and Meta-Analysis of Observational Studies

AIM

Investigate the prevalence of irritable bowel syndrome (IBS) after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and assess the association between IBS and SARS-CoV-2 infection.

METHODS

A systematic literature search for PubMed, Web of Science, Embase, Scopus, and the Cochrane Library was performed to identify all reports published before 31 December 2022. The confidence interval (CI), estimation effect (ES) of prevalence, and risk ratios (RR) were calculated to evaluate the prevalence of IBS after SARS-CoV-2 infection and their association. Individual results were pooled by the random-effects (RE) model. Subgroup analyses conducted a further investigation of the results. We employed funnel plots, Egger's test, and Begg's test to evaluate publication bias. Sensitivity analysis was performed for the assessment of the robustness of the result.

RESULTS

The data on IBS prevalence after SARS-CoV-2 infection were extracted from two cross-sectional studies and ten longitudinal studies from nineteen countries with 3950 individuals. The IBS prevalence after SARS-CoV-2 infection ranges from 3% to 91% in different countries, and the overall pooled prevalence of IBS following SARS-CoV-2 infection is 15% (ES: 0.15; 95% CI, 0.11-0.20; p = 0.000). The data on the association between IBS and SARS-CoV-2 infection were extracted from six cohort studies from fifteen countries with 3595 individuals. The risk of IBS increased following SARS-CoV-2 infection but was not significant (RR: 1.82; 95% CI, 0.90-3.69; p = 0.096).

CONCLUSIONS

In conclusion, the overall pooled prevalence of IBS following SARS-CoV-2 infection was 15%, and SARS-CoV-2 infection increased the overall risk of IBS but was not statistically significant. Further extra high-quality epidemiological evidence and studies to clarify the underlying mechanism of IBS following SARS-CoV-2 infection are needed.

Cinnamon (Cinnamomum cassia) water extract improves diarrhea symptoms by changing the gut environment: a randomized controlled trial

Cinnamon is a spice obtained from the bark of Cinnamomum and contains anti-inflammatory ingredients such as coumarin, cinnamaldehyde, and cinnamic acid. This study evaluated the effect of cinnamon water extract (CWE) on the symptoms of subjects with diarrhea in an 8-week randomized controlled trial. Seventy subjects with diarrhea symptoms were randomized and received three capsules of 400 mg CWE or placebo twice daily for 8 weeks. CWE intake significantly increased colonic transit time (p = 0.019) and fecal isobutyric acid (p = 0.008) and spermidine (p = 0.009) contents compared to placebo intake. In contrast, CWE decreased fecal indole (p = 0.032) and agmatine (p = 0.018) contents. Gut microbiota analysis showed increased alpha diversity and significant changes in strains such as Bifidobacterium longum ATCC 55813 (LDA = 1.38) in the CWE group compared with the placebo group. Bifidobacterium longum ATCC 55813 showed a positive correlation with colon transit time and stool phenol and spermidine contents. CWE improved diarrhea symptoms and changed the composition of stools and the gut microbiota. These results indicate that cinnamon intake relieves diarrhea symptoms through metabolic changes due to changes in intestinal microbial groups.

The relationship between fermentable carbohydrates and post-prandial bowel symptoms in patients with functional bowel disorders

Background and aims

A low fermentable oligosaccharide, disaccharide, monosaccharide, and polyols (FODMAP) diet alleviates symptoms of irritable bowel syndrome (IBS). We aimed to investigate the relationship between habitual FODMAP intake and post-prandial bowel symptoms in adults with IBS, functional diarrhoea (FD), or constipation (FD) (functional bowel disorders), and in healthy adults (controls).

Methods

292 participants (173 with functional bowel disorders and 119 controls) completed a food and symptom times diary. Estimated meal portion sizes were entered into the Monash FODMAP Calculator to analyse FODMAP content. Wilcoxon and ANOVA tests were used to investigate the relationship between FODMAP intake and post-prandial bowel symptoms.

Results

IBS participants experienced more post-prandial bowel symptoms compared to participants with other functional bowel disorders or controls. Meals associated with abdominal pain contained on average increased excess fructose (0.31 g vs. 0.18 g, p < 0.05), sorbitol (0.27 g vs. 0.10 g, p < 0.01), and total FODMAP (3.46 g vs. 2.96 g, p < 0.05) compared to meals not associated with pain. Abdominal swelling was associated with increased sorbitol (0.33 g vs. 0.11 g, p < 0.01), and total FODMAP (3.26 g vs. 3.02 g, p < 0.05) consumption. Abdominal bloating was associated with increased galacto oligosaccharide consumption (0.18 g vs. 0.14 g, p < 0.05).

Conclusion

These findings support the role of FODMAP in post-prandial bowel symptom onset, however, the amount and type of FODMAP triggering symptoms vary between individuals. Future research should investigate the relationship between the effect of individual FODMAP consumption on post-prandial bowel symptoms for each subtype, the interaction of FODMAP with differing functional bowel disorders and whether longitudinally symptoms and dietary intake are stable.

Factors associated with lower disease-specific and generic health-related quality of life in Rome IV irritable bowel syndrome

BACKGROUND

Little is known about associations with reduced quality of life in irritable bowel syndrome (IBS) or impact of IBS on quality of life compared with other chronic conditions.

METHODS

We collected demographic, gastrointestinal and psychological symptoms, healthcare usage, direct healthcare costs, impact on work and activities of daily living data from 752 individuals with Rome IV-defined IBS. We used the irritable bowel syndrome quality of life (IBS-QOL) and the EQ-5D-5L questionnaires to examine characteristics associated with lower quality of life.

RESULTS

The mean IBS-QOL among all 752 individuals with Rome IV IBS was 48.4 (SD 22.3) and the mean EQ-5D score was 0.570 (SD 0.283), the latter being comparable to people with stroke, leg ulcers or chronic obstructive pulmonary disease. Lower levels of both disease-specific and generic quality of life were associated with severe IBS symptom scores, abnormal anxiety or depression scores, and higher somatoform symptom-reporting and gastrointestinal symptom-specific anxiety scores (p < 0.001 for all analyses). Those with lower quality of life had significantly higher healthcare usage and direct healthcare costs and more impairment in work and activities of daily living (p < 0.01 for all analyses). Avoidance of alcohol, lower educational level, abnormal anxiety, depression or somatoform symptom-reporting scores, and impairment in social leisure activities, home management or maintaining close relationships were all independently associated with lower quality of life.

CONCLUSION

IBS has a substantial impact on the quality of life of those affected, and worse than observed in some severe chronic organic conditions.

Sex-specific brain microstructural reorganization in irritable bowel syndrome

ABSTRACT

Preliminary evidence suggests that there are sex differences in microstructural brain organization among individuals with irritable bowel syndrome (IBS). The aim of this study was to further investigate sex-dependent differences in brain microstructure and organization in a large sample of well-phenotyped participants with IBS compared with healthy controls. We hypothesized that female patients with IBS would show evidence for increased axonal strength and myelination within and between brain regions concerned with pain and sensory processing, when compared with males with IBS. We also hypothesized that female compared with male IBS subjects show greater levels of somatic awareness and sensory sensitivity consistent with multisystem sensory sensitivity. Diffusion tensor images and clinical assessments were obtained in 100 healthy controls (61 females) and 152 IBS (107 females) on a 3T Siemens Trio. Whole brain voxel-wise differences in fractional anisotropy, mean, radial and axial diffusivity, and track density as differences in somatic awareness and sensory sensitivity were assessed using the general linear model. Female compared with male IBS participants showed extensive microstructural alterations in sensorimotor, corticothalamic, and basal ganglia circuits involved in pain processing and integration of sensorimotor information. Together with the observed increases in symptom severity, somatic awareness, and sensory sensitivity, the findings support the hypotheses that the etiology and maintenance of symptoms in females with IBS may be driven by greater central sensitivity for multiple sensory stimuli.

Visible abdominal distension in functional gut disorders: Objective evaluation

BACKGROUND

Visible abdominal distension has been attributed to: (A) distorted perception, (B) intestinal gas accumulation, or (C) abdominophrenic dyssynergia (diaphragmatic push and anterior wall relaxation).

METHODS

A pool of consecutive patients with functional gut disorders and visible abdominal distension included in previous studies (n = 139) was analyzed. Patients (61 functional bloating, 74 constipation-predominant irritable bowel syndrome and 4 with alternating bowel habit) were evaluated twice, under basal conditions and during a self-reported episode of visible abdominal distension; static abdominal CT images were taken in 104 patients, and dynamic EMG recordings of the abdominal walls in 76, with diaphragmatic activity valid for analysis in 35.

KEY RESULTS

(A) Objective evidence of abdominal distension was obtained by tape measure (increase in girth in 138 of 139 patients), by CT imaging (increased abdominal perimeter in 96 of 104 patients) and by abdominal EMG (reduced activity, i.e., relaxation, in 73 of 76 patients). (B) Intestinal gas volume was within ±300 ml from the basal value in 99 patients, and above in 5 patients, who nevertheless exhibited a diaphragmatic descent. (C) Diaphragmatic contraction was detected in 34 of 35 patients by EMG (increased activity) and in 82 of 103 patients by CT (diaphragmatic descent).

CONCLUSIONS AND INFERENCES

In most patients complaining of episodes of visible abdominal distention: (A) the subjective claim is substantiated by objective evidence; (B) an increase in intestinal gas does not justify visible abdominal distention; (C) abdominophrenic dyssynergia is consistently evidenced by dynamic EMG recording, but static CT imaging has less sensitivity.

Association of Central Sensitization Inventory Scores With Pain Outcomes After Endometriosis Surgery

IMPORTANCE

A subset of people who undergo surgery for endometriosis have persistent pain, suggesting that other factors besides the endometriosis, such as central sensitization, may play a role in this pain. The Central Sensitization Inventory, a validated self-reported questionnaire of central sensitization symptoms, may identify individuals with endometriosis who have more pain after surgery due to pain sensitization.

OBJECTIVE

To examine whether greater baseline Central Sensitization Inventory scores are associated with postsurgical pain outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, longitudinal cohort study performed at a tertiary center for endometriosis and pelvic pain in British Columbia, Canada, included all patients aged 18 to 50 years with diagnosed or suspected endometriosis and a baseline visit between January 1, 2018, and December 31, 2019, who underwent surgery after the baseline visit. Individuals who were menopausal, had a prior hysterectomy, or were missing data for outcomes or measures were excluded. Data analysis was performed from July 2021 to June 2022.

MAIN OUTCOMES AND MEASURES

The primary outcome was chronic pelvic pain at follow-up measured on a scale of 0 to 10, with 0 to 3 indicating no pain or mild pain, 4 to 6 indicating moderate pain, and 7 to 10 indicating severe pain. Secondary outcomes were deep dyspareunia, dysmenorrhea, dyschezia, and back pain at follow-up. The main variable of interest was baseline Central Sensitization Inventory score (measured from 0 to 100, consisting of 25 self-reported questions rated from 0 to 4 [never, rarely, sometimes, often, and always, respectively]).

RESULTS

A total of 239 patients (mean [SD] age, 34 [7] years; 189 [79.1%] White [11 (5.8%) identified as White mixed with another ethnicity], 1 [0.4%] Black or African American, 29 [12.1%] Asian, 2 [0.8%] Native Hawaiian or Pacific Islander, 16 [6.7%] other, and 2 [0.8%] mixed race or ethnicity) with follow-up data at more than 4 months after surgery were included in this study (71.0% follow-up rate). The mean (SD) baseline Central Sensitization Inventory score was 43.8 (18.2), and the mean (SD) follow-up was 16.1 (6.1) months. Higher baseline Central Sensitization Inventory scores were significantly associated with higher chronic pelvic pain (odds ratio [OR], 1.02; 95% CI, 1.00-1.03; P = .02), deep dyspareunia (OR, 1.03; 95% CI, 1.01-1.04; P = .004), dyschezia (OR, 1.03; 95% CI, 1.01-1.04; P < .001), and back pain (OR, 1.02; 95% CI, 1.00-1.03; P = .02) at follow-up, when controlling for baseline pain scores. The Central Sensitization Inventory scores themselves decreased slightly from baseline to follow-up (mean [SD] score, 43.8 [18.2] vs 41.7 [18.9]; P = .05); however, individuals with high baseline Central Sensitization Inventory scores still had high scores at follow-up.

CONCLUSIONS AND RELEVANCE

In this cohort study of 239 patients with endometriosis, higher Central Sensitization Inventory scores at baseline were associated with worse pain outcomes after endometriosis surgery, when controlling for baseline pain scores. The Central Sensitization Inventory could be used to counsel patients with endometriosis on their expected outcomes after surgery.

Associations between postprandial symptoms, hydrogen and methane production, and transit time in irritable bowel syndrome

BACKGROUND

Abnormal oroanal transit time (OATT) and visceral hypersensitivity are key pathophysiological factors in irritable bowel syndrome (IBS). The lactulose nutrient challenge test (LNCT) has been developed to assess the postprandial symptoms and gut microbial fermentation. We aimed to investigate associations between OATT, rectal sensitivity, and LNCT in IBS patients.

METHODS

We included 263 IBS patients from two study cohorts, where the link between pathophysiology and symptoms was investigated. During the LNCT, severity of postprandial symptoms was graded, and breath hydrogen/methane concentrations were measured after ingestion of a combined lactulose nutrient drink every 15 min for 4 h. The patients underwent rectal sensitivity (rectal barostat) and OATT (radiopaque markers) investigations. Comorbid conditions (functional dyspepsia, anxiety, depression, and somatization) were assessed with questionnaires.

KEY RESULTS

After controlling for comorbid conditions, rectal sensitivity was associated with abdominal pain (p < 0.05), and more rapid OATT was associated with higher severity of abdominal discomfort, rumbling, nausea, and urgency (p < 0.05 for all) both pre- and post-prandially. Postprandial nausea, urgency, and abdominal pain changed differently over time depending on OATT (p < 0.05 for all). OATT, but not rectal sensitivity, was associated with hydrogen and methane concentrations (p = 0.002 for both). Trajectories over time of postprandial symptoms and exhaled hydrogen/methane concentrations were correlated with different correlations depending on OATT.

CONCLUSION AND INFERENCES

This study highlights the importance of oroanal transit and hydrogen and methane production in the pathophysiology of IBS and increases our understanding of pathophysiological factors involved in postprandial symptom generation. Treatments targeting oroanal transit and hydrogen and methane production may improve specific postprandial symptoms.

Diagnostic yield of colonoscopy for organic disease in irritable bowel syndrome and its risk factors: A meta-analysis

BACKGROUND

Colonoscopy is commonly performed in patients with irritable bowel syndrome (IBS) to rule out organic disease. We performed a meta-analysis to assess the prevalence of organic disease detected at colonoscopy in IBS and its potential risk factors.

METHODS

Medline, Embase, and Web of Science were searched through January 2022. Observational studies that reported diagnostic yield of colonoscopy for organic disease including colorectal cancer (CRC), inflammatory bowel disease (IBD), or microscopic colitis (MC) in adult IBS patients were eligible. Pooled prevalence and risk difference (RD) with 95% confidence intervals (CIs) were calculated.

RESULTS

Of 2490 citations identified, 12 studies were eligible containing 28,630 patients with IBS undergoing colonoscopy. Pooled prevalence of CRC, IBD, and MC in IBS was 0.78%, 4.48%, and 2.35%, respectively. No difference in the yield for CRC, IBD, and MC was seen between IBS and non-IBS patients. CRC was rare in IBS patients without alarm symptoms or younger than 40 years (<0.1%). Pooled Prevalence of CRC (2.47% vs. 0.11%; RD 2.57%, 95% CI 0.37%-4.78%) and IBD (8.86% vs. 4.25%; RD 10.75%, 95% CI 4.81%-16.68%) was significantly higher in IBS patients with alarm symptoms compared with those without. IBD and MC were more likely to be detected at colonoscopy in IBS-D compared with IBS-C. The prevalence of CRC and MC was higher in IBS patients with older age than younger age.

CONCLUSION

We provide the first pooled estimate of yield of colonoscopy in IBS and its risk factors, which may be used to inform clinical decision and support guidelines.