A survey about irritable bowel syndrome in South Korea: prevalence and observable organic abnormalities in IBS patients

Characterization of the mucosal microbiota in patients with nodular lymphoid hyperplasia with concurrent irritable bowel syndrome compared to healthy controls

BACKGROUND

Nodular lymphoid hyperplasia (NLH) is known as a lymphoproliferative lesion in which multiple small nodules appear on the intestinal wall. It has been documented that patients who struggle with irritable bowel syndrome (IBS) are at greater risk of developing NLH. Here, we aimed to investigate the previously reported pathogens and the abundance of a selection of mucosal microbiota in IBS + NLH patients compared to IBS, and healthy controls.

METHODS AND RESULTS

Terminal ileum biopsies were collected from 37 IBS + NLH, 37 IBS, and 29 healthy controls. Bacterial culture and PCR was performed to detect the presence of pathogens in biopsies. A qPCR assay was applied to assess the abundance of a selection of bacterial taxa. Totally, five bacterial isolates including two enteropathogenic and one enteroaggregative Escherichia coli (EPEC, EAEC), one enterotoxigenic Staphylococcus aureus (SEA), and one Yersinia enterocolitica strains were detected among the IBS + NLH cases. The relative abundance of Bacteroidetes and Streptococcus spp. in IBS + NLH patients was significantly less than IBS and healthy controls. Firmicutes, Pseudomonas spp., Haemophilus spp., and Campylobacter spp. were notably more abundant in IBS + NLH than in IBS patients. The abundance of Verrucomicrobia was higher in NLH + IBS than in healthy controls. Actinobacteria was also significantly more abundant among NLH + IBS patients than the controls.

CONCLUSION

Our results demonstrated that mucosal microbiota composition in NLH + IBS patients slightly differs from that of IBS patients and healthy controls. Further research using large-scale cohorts are needed to enhance current understanding of the contribution of the mucosal microbiota to NLH pathogenesis with concurrent IBS.

Effect of Oral Intake of Lactiplantibacillus plantarum APsulloc 331261 (GTB1TM) on Diarrhea-Predominant Irritable Bowel Syndrome: A Randomized, Double-Blind, Placebo-Controlled Study

Irritable bowel syndrome (IBS) causes intestinal discomfort, gut dysfunction, and poor quality of life. This randomized, double-blind placebo-controlled trial evaluated the efficacy of Lactiplantibacillus (Lp., formerly Lactobacillus) plantarum APsulloc 331261 (GTB1^TM) from green tea leaves in participants with diarrhea-predominant irritable bowel syndrome (IBS-D). Twenty-seven participants meeting the Rome IV diagnostic criteria were randomized for GTB1 or placebo ingestion for four weeks and follow-up for two weeks. The efficacy endpoints included adequate global relief of symptoms, assessment of intestinal discomfort symptom severity and frequency, stool frequency, satisfaction, and fecal microbiome abundance. Of all participants, 94.4% and 62.5% reported global relief of symptoms in the GTB1 and placebo groups, respectively, with significant differences (p = 0.037). GTB1 significantly reduced the severity and frequency of abdominal pain, bloating, and feeling of incomplete evacuation. The frequencies of diarrhea were decreased −45.89% and −26.76% in the GTB1 and placebo groups, respectively (p = 0.045). Hence, GTB1 ingestion improved IBS-D patient quality of life. After four weeks treatment, the relative abundance of Lactobacillus was higher in the GTB1 than in the placebo group (p = 0.010). Our results showed that GTB1 enhanced intestinal discomfort symptoms, defecation consistency, quality of life, beneficial microbiota, and overall intestinal health.

The relationship between mucosal inflammatory cells, specific symptoms, and psychological functioning in youth with irritable bowel syndrome

Both mucosal inflammation and psychologic dysfunction have been implicated in irritable bowel syndrome (IBS). While some relationships between inflammation (mast cells and eosinophils) and depression have been reported in adults with IBS, relationships between inflammation and psychologic function have not been studied in children and adolescents. The aims of the current study were to: (1) assess densities of colonic mast cells, eosinophils, and TH17 cells in youth with IBS; and, (2) explore relationships between these cells and specific IBS symptoms and psychologic functioning. Utilizing previously obtained biopsies from the descending and rectosigmoid colons, densities were determined for mast cells, eosinophils, and TH17 cells, respectively, in 37 youth with IBS and 10 controls. In IBS patients, densities were assessed in relation to specific IBS symptoms and in relation to self-report anxiety and depression scores. In both the descending and rectosigmoid colons, densities of mast cells, eosinophils, and TH17 cells were higher in IBS patients as compared to controls. In IBS patients, rectosigmoid mast cell density was higher in those reporting pain relief with defecation. Also, in IBS patients, rectosigmoid eosinophilia was associated with higher anxiety scores and eosinophil density correlated with depression scores. In the descending colon, eosinophil and mast cell densities both correlated with depression scores. In conclusion, mucosal inflammation (mast cells and eosinophils) is associated with pain relief with defecation and with anxiety and depression in youth with IBS.

Increased Colonic Epithelial Permeability and Mucosal Eosinophilia in Ulcerative Colitis in Remission Compared With Irritable Bowel Syndrome and Health

BACKGROUND

Barrier dysfunction is recognized as a pathogenic factor in ulcerative colitis (UC) and irritable bowel syndrome (IBS), but it is unclear to what extent the factors related to barrier dysfunction are disease-specific. The aim of this study was to compare these aspects in UC patients in remission, IBS patients, and healthy controls (HCs).

METHODS

Colonic biopsies were collected from 13 patients with UC in remission, 15 patients with IBS-mixed, and 15 HCs. Ulcerative colitis patients had recently been treated for relapse, and biopsies were taken from earlier inflamed areas. Biopsies were mounted in Ussing chambers for measurements of intestinal paracellular permeability to 51chromium (Cr)-ethylenediaminetetraacetic acid (EDTA). In addition, biopsies were analyzed for mast cells and eosinophils by histological procedures, and plasma tumor necrosis factor (TNF)-α was assessed by ELISA.

RESULTS

Ussing chamber experiments revealed an increased 51Cr-EDTA permeability in UC and IBS (P < 0.05). The 51Cr-EDTA permeability was higher in UC compared with IBS (P < 0.005). There were increased numbers of mucosal mast cells and eosinophils in UC and IBS and more eosinophils in UC compared with IBS (P < 0.05). Also, increased extracellular granule content was found in UC compared with HCs (P < 0.05). The 51Cr-EDTA permeability correlated significantly with eosinophils in all groups. Plasma TNF-α concentration was higher in UC compared with IBS and HCs (P < 0.0005).

CONCLUSIONS

Results indicate a more permeable intestinal epithelium in inactive UC and IBS compared with HCs. Ulcerative colitis patients, even during remission, demonstrate a leakier barrier compared with IBS. Both eosinophil numbers and activation state might be involved in the increased barrier function seen in UC patients in remission.

The Association between Helicobacter pylori Infection and Irritable Bowel Syndrome: A Meta-Analysis

The association of Helicobacter pylori (H. pylori) infection with functional dyspepsia has been well studied. However, the data on the relationship between H. pylori infection and irritable bowel syndrome (IBS) are conflicting. This study aims to elucidate the association between H. pylori infection and IBS. PubMed, Cochrane Library, CINAHL and SCOPUS databases were searched to identify eligible English articles published up to December 2019. Cross-sectional studies, case–control studies and cohort studies reporting both prevalence of H. pylori infection and IBS were selected for the detailed review. The pooled odds ratio (ORs) and their 95% confidence interval (CI) were calculated. A total of 7269 individuals in four cross-sectional studies and six case-control studies were included. The prevalence of H. pylori infection ranged from 12.8% to 73.4% in the control group, and 9.7% to 72.1% in the IBS group. The combined OR for H. pylori infection was 1.10 (95% CI: 0.93–1.29, I²: 37.5%). In a subgroup analysis of IBS defined according to Rome criteria, the OR for H. pylori infection was 1.10 (95% CI: 0.93–1.30, I² = 31.7%). In this meta-analysis, H. pylori infection was not significantly associated with IBS. Well-designed studies are needed to identify the relationship between H. pylori infection and IBS.

Mast cells are increased in the small intestinal mucosa of patients with irritable bowel syndrome: A systematic review and meta-analysis

BACKGROUND

Colonic mast cells have been proposed to be related to the pathophysiology of irritable bowel syndrome (IBS). Whether mast cell counts are altered in the small intestine, a less-explored region in patients with IBS is not completely clear.

METHODS

PubMed and EMBASE were searched for case-control studies on mast cell count/density in the small intestine of patients with IBS vs controls through February 2019. Mast cell counts were separately analyzed in the duodenum, jejunum, and ileum. Data were pooled using the standardized mean difference (SMD) method. When zero was not within the 95% confidence interval (CI), the SMD was considered significant.

KEY RESULTS

Data from 344 patients with IBS and 229 healthy controls from three studies in the duodenum, six in the jejunum, and five in the ileum were pooled in this meta-analysis. The number of mast cells was significantly higher in the ileum (SMD: 1.78 [95% CI: 0.89, 2.66]) of patients with IBS. Mast cell counts were not significantly different in the duodenum (SMD: 0.81 [-0.06, 1.67]) or the jejunum (SMD: 0.58 [-0.03, 1.19]) of patients with IBS vs healthy controls.

CONCLUSIONS AND INFERENCES

Mast cells are increased in the small intestine of IBS vs controls, mainly in the ileum. Future studies should address whether such findings are IBS subtype or gender-dependent. Methodological variations, single-center bias, and the limited number of studies included in this meta-analysis may affect the final results.

Current insights into the innate immune system dysfunction in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional bowel disorder associated with abdominal pain and alterations in bowel habits. The presence of IBS greatly impairs patients' quality of life and imposes a high economic burden on the community; thus, there is intense pressure to reveal its elusive pathogenesis. Many etiological mechanisms have been implicated, but the pathophysiology of the syndrome remains unclear. As a result, novel drug development has been slow and no pharmacological intervention is universally accepted. A growing evidence implicates the role of low-grade inflammation and innate immune system dysfunction, although contradictory results have frequently been presented. Mast cells (MC), eosinophils and other key immune cells together with their mediators seem to play an important role, at least in subgroups of IBS patients. Cytokine imbalance in the systematic circulation and in the intestinal mucosa may also characterize IBS presentation. Toll-like receptors and their emerging role in pathogen recognition have also been highlighted recently, as dysregulation has been reported to occur in patients with IBS. This review summarizes the current knowledge regarding the involvement of any immunological alteration in the development of IBS. There is substantial evidence to support innate immune system dysfunction in several IBS phenotypes, but additional studies are required to better clarify the underlying pathogenetic pathways. IBS heterogeneity could potentially be attributed to multiple causes that lead to different disease phenotypes, thus explaining the variability found between study results.

Prevalence of Organic Colonic Lesions by Colonoscopy in Patients Fulfilling ROME IV Criteria of Irritable Bowel Syndrome

INTRODUCTION

Irritable bowel syndrome occurs as recurrent abdominal pain that is related to defecation and associated with change in frequency and/or form of stool. Few Patients with IBS may have organic lesions detectable at colonoscopy.

METHODS

A cross sectional study was carried out in 140 consecutive patients of IBS fulfilling the ROME IV criteria. The study was conducted in Gastroenterology unit, Department of Medicine, Bir hospital, Kathmandu from July 2016 to September 2017. All patients underwent full colonoscopy along with biopsy from sigmoid colon and any visibly abnormal areas.

RESULTS

The average age of patients was 37.5 years with 76 (52.8%) males. Forty-two (30%) had IBS-D, 36 (26%) had IBS-C, 31 (22%) had IBS-M and 31 (22%) had IBS-U. Dyspepsia was seen in 16 (11.4%) and fear of TB/Malignancy/IBD was seen in 27 (19.2%). Organic lesions were seen in 39 (27.85%) patients. Nonspecific colitis was seen in 10 (7.1%) followed by ileal erosions in 7 (5%), polyps in 8 (5.7%), hemorrhoids in 6 (4.2%) and diverticula in 3 (2.1%). Only one (0.71%) patient had microscopic colitis and one (0.71%) had malignant lesion seen at histopathological examination. Females with IBS-D had more organic findings than males (P=0.03, RR=4.13, 95% CI=1.21-15.71).

CONCLUSIONS

The prevalence of organic lesions in patients with IBS fulfilling ROME IV criteria is 27%. Dyspepsia is the most common comorbidity and fear of TB/malignancy/IBD is the most common reason for seeking health care. Females with IBS-D have a higher risk of detecting organic lesions by colonoscopy and histopathology examination.

Changes of excitatory and inhibitory neurotransmitters in the colon of rats underwent to the wrap partial restraint stress

BACKGROUND

Animal models proposed to reproduce some of the human irritable bowel syndrome (IBS) symptoms are based on the hypothesis that psychosocial stressors play a pivotal role in the IBS etio-pathology. We investigated the wrap restraint stress (WRS) model with the aim to analyze the morphological changes of the entire colonic wall of these animals that showed some of the human IBS symptoms such as visceral hypersensitivity.

METHODS

Male Wistar rats were used and WRS was maintained for 2 h. Abdominal contractions (AC) were recorded in the colon-rectum by balloon distension. Fecal pellets were quantitated. Colonic specimens were examined by routine histology, immunohistochemistry and western blot.

KEY RESULTS

WRS animals were characterized by: (i) increase in AC number and fecal pellets mean weight; (ii) clusters of mononucleated cells, increase in eosinophilic granulocytes and mast cells in the mucosa; (iii) increase in CGRP-immunoreactive (IR) nerve fibers in the lamina propria; (iv) decrease in myenteric NK1r-IR and nNOS-IR neurons and in submucous nNOS-IR neurons; (v) decrease in SP-IR nerve fibers in the muscle wall; (vi) reduction in S100β-IR glia in the entire colonic wall; (vii) increase in CRF1r-IR myenteric neurons; (viii) no change in ChAT-IR neurons, smooth muscle cells and interstitial cells of Cajal.

CONCLUSIONS AND INFERENCES

The present results support the consistency of the WRS as a potential model where part of the human IBS signs and symptoms are reproduced. The changes in glial cells and in excitatory and inhibitory neurotransmitters might represent the substrate for the dysmotility and hypersensitivity.

Systematic review with meta-analysis: diagnostic overlap of microscopic colitis and functional bowel disorders

BACKGROUND

Microscopic colitis shares certain common clinical manifestations with functional bowel disorders, especially diarrhoea-dominant irritable bowel syndrome (IBS) and functional diarrhoea. However, the exact relationship between microscopic colitis and functional bowel disorders has not been systematically assessed.

AIM

To conduct a systematic review and meta-analysis on the diagnostic overlap between functional bowel disorders and microscopic colitis.

METHODS

We searched MEDLINE, EMBASE and SCOPUS databases, as well as the abstract books of the major gastroenterology meetings, to investigate the prevalence of microscopic colitis among patients with functional bowel disorders (considering all subtypes of both disorders) and vice versa. Data were pooled with a random-effects model.

RESULTS

Of 227 references identified, data were collected from 26 studies and a total of 5,099 adult patients. The pooled prevalence any type of functional bowel disorders in patients who present diagnostic criteria of microscopic colitis was 39.1% (95% CI: 22.8-56.6%; I² : 97%) and was higher for lymphocytic colitis than for collagenous colitis (40.7% vs. 28.4%, respectively; P = 0.58). The prevalence of microscopic colitis in functional bowel disorders patients was 7% (95% CI: 3.6-11.4%), reaching 9.8% (95% CI: 4.4-17.1%; I² : 95%) in patients exhibiting diarrhoea-dominant IBS, nonsignificantly higher than microscopic colitis rates among patients with constipation-dominant IBS (1.3%) or mixed-dominant IBS (1.9%).

CONCLUSIONS

There is a significant overlap of symptoms between microscopic colitis and functional bowel disorders, especially in diarrhoeal subtypes. The high proportion of microscopic colitis among diarrhoea-dominant functional syndromes should serve as a call for more active diagnosis in selected patients.

Lactobacillus rhamnosus GG supernatant upregulates serotonin transporter expression in intestinal epithelial cells and mice intestinal tissues

BACKGROUND

The role that probiotics play in relieving irritable bowel syndrome (IBS) has been demonstrated; however, the mechanism by which IBS is affected remains unclear. In this study, serotonin transporter (SERT) mRNA and serotonin transporter protein (SERT-P) levels in HT-29, Caco-2 cells, and mice intestinal tissues were examined after treatment with Lactobacillus rhamnosus GG supernatant (LGG-s).

METHODS

HT-29 and Caco-2 cells were treated with different concentrations of LGG-s for 12 and 24 h and C57BL/6 mice received supplements of different concentrations for 4 weeks. SERT mRNA and SERT-P levels were detected by real-time PCR and Western blotting.

KEY RESULTS

SERT mRNA and SERT-P levels in HT-29 and Caco-2 cells were higher than those in the control 24 h after treatment. Undiluted LGG-s upregulated SERT mRNA levels by 9.4-fold in the first week, which dropped in the second week. The double-diluted LGG-s upregulated SERT mRNA by 2.07-fold in the first week; levels dropped to 1.75-fold within the second week and under base expression levels by the third week, while they again climbed to 1.56-fold in the fourth week. The triple-diluted LGG-s could not upregulate SERT mRNA expression until the end of the fourth week. The SERT-P levels in the double-diluted LGG-s group were higher than that in the control but fluctuated with time. SERT-P levels in the triple-diluted LGG-s were higher than that in the control in the last 2 weeks and increased with time.

CONCLUSIONS & INFERENCES

LGG-s can upregulate SERT mRNA and SERT-P levels in intestinal epithelial cells and mice intestinal tissues.

Therapeutic strategies for functional dyspepsia and irritable bowel syndrome based on pathophysiology

Functional gastrointestinal disorders (FGIDs) are common and distressing. They are so named because a defined pathophysiology in terms of structural or biochemical pathways is lacking. Traditionally FGIDs have been conceptualized as brain-gut disorders, with subgroups of patients demonstrating visceral hypersensitivity and motility abnormalities as well as psychological distress. However, it is becoming apparent that there are certain structural or biochemical gut alterations among subsets with the common FGIDs, most notably functional dyspepsia (FD) and irritable bowel syndrome (IBS). For example, a sodium channel mutation has been identified in IBS that may account for 2 % of cases, and subtle intestinal inflammation has been observed in both IBS and FD. Other research has implicated early life events and stress, autoimmune disorders and atopy and infections, the gut microbiome and disordered mucosal immune activation in patients with IBS or FD. Understanding the origin of symptoms in FGIDs will allow therapy to be targeted at the pathophysiological changes, not at merely alleviating symptoms, and holds hope for eventual cure in some cases. For example, there are promising developments in manipulating the microbiome through diet, prebiotics and antibiotics in IBS, and testing and treating patients for Helicobacter pylori infection remains a mainstay of therapy in patients with dyspepsia and this infection. Locally acting drugs such as linaclotide have been an advance in treating the symptoms of constipation-predominant IBS, but do not alter the natural history of the disease. A role for a holistic approach to patients with FGIDs is warranted, as brain-to-gut and gut-to-brain pathways appear to be activated.

Irritable bowel syndrome: Emerging paradigm in pathophysiology

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders, characterized by abdominal pain, bloating, and changes in bowel habits. These symptoms cannot be explained by structural abnormalities and there is no specific laboratory test or biomarker for IBS. Therefore, IBS is classified as a functional disorder with diagnosis dependent on the history taking about manifested symptoms and careful physical examination. Although a great deal of research has been carried out in this area, the pathophysiology of IBS is complex and not completely understood. Multiple factors are thought to contribute to the symptoms in IBS patients; altered gastrointestinal motility, visceral hypersensitivity, and the brain-gut interaction are important classical concepts in IBS pathophysiology. New areas of research in this arena include inflammation, postinfectious low-grade inflammation, genetic and immunologic factors, an altered microbiota, dietary factors, and enteroendocrine cells. These emerging studies have not shown consistent results, provoking controversy in the IBS field. However, certain lines of evidence suggest that these mechanisms are important at least a subset of IBS patients, confirming that IBS symptoms cannot be explained by a single etiological mechanism. Therefore, it is important to keep in mind that IBS requires a more holistic approach to determining effective treatment and understanding the underlying mechanisms.

Pathogenesis of irritable bowel syndrome--review regarding associated infection and immune activation

There is increasing evidence regarding the role of immune activation in the etiology of irritable bowel syndrome (IBS), which has been mainly been shown in studies investigating mechanisms of postinfectious IBS (PI-IBS). Exposure to intestinal infection induces persistent low-grade systemic and mucosal inflammation, which is characterized by an altered population of circulating cells, mucosal infiltration of immune cells and increased production of various cytokines in IBS patients. Recent studies have also indicated an increased innate immune response in these patients by evaluating expression and activation of Toll-like receptors (TLRs). These findings suggest that immune activation may play a crucial role in the pathogenesis of IBS. In addition, psychological stress has been reported to be one of the factors that induces immune activation. However, it remains unknown whether immune activation in IBS patients is largely dependent on infectious gastroenteritis and/or psychological stress. Additional studies are necessary to understand the precise mechanism of immune activation and its relationship to the development of IBS.

Cellular and molecular basis of intestinal barrier dysfunction in the irritable bowel syndrome

The etiopathogenesis of the irritable bowel syndrome (IBS), one of the most prevalent gastrointestinal disorders, is not well known. The most accepted hypothesis is that IBS is the result of the disturbance of the 'brain-gut axis.' Although the pathophysiological mechanisms of intestinal dysfunction are complex and not completely understood, stress, infections, gut flora, and altered immune response are thought to play a role in IBS development. The intestinal barrier, composed of a single-cell layer, forms a physical barrier that separates the intestinal lumen from the internal milieu. The loss of integrity of this barrier is related with mucosal immune activation and intestinal dysfunction in IBS. The number of mast cells and T lymphocytes is increased in the intestinal mucosa of certain IBS patients, and the mediators released by these cells could compromise the epithelial barrier function and alter nerve signaling within the enteric nervous system. The association of clinical symptoms to structural and functional abnormalities of the mucosal barrier in IBS patients highlights the importance of understanding the physiological role of the gut barrier in the pathogenesis of this disorder. This review summarizes the clinical and experimental evidences indicating the cellular and molecular mechanisms of IBS symptomatology, and its relevance for future translational research.

Serotonin transporter gene promoter region polymorphisms and serotonin transporter expression in the colonic mucosa of irritable bowel syndrome patients

BACKGROUND

The role of serotonin transporter (SERT) gene polymorphism in irritable bowel syndrome (IBS) has been demonstrated. However, the expression of SERT mRNA and proteins in the colonic mucosa with different 5-HTT gene-linked polymorphic region (5-HTTLPR) genotypes remains unknown. We examined SERT mRNA and protein levels in colon biopsies from patients with different 5-HTTLPR genotypes and evaluated the links between the polymorphism and the expression levels.

METHODS

Two hundred and fifty-four patients with IBS and 120 healthy subjects were studied. DNA samples were extracted from peripheral blood and genotyped by polymerase chain reaction (PCR). SERT mRNA and protein levels were evaluated by quantitative real time PCR and western blotting. The promoter efficiency of the serotonin transporter promoter (SERT-P) was evaluated with luciferase reporter system.

KEY RESULTS

The frequency of the L/L genotype in C-IBS group was significantly higher than that in the control and D-IBS. However, the S/S genotype in D-IBS was significantly higher than that in C-IBS. The transcriptional efficiency of the L/L genotype was significantly higher than that in the L/S and S/S genotype. Patients with the L/L genotype demonstrated increased production of the SERT protein when compared with L/S and S/S patients. The l variant increased SERT promoter activity by 2.43-fold when compared with the s variant.

CONCLUSIONS & INFERENCES

Polymorphism in the promoter region of the SERT gene can influence the expression of SERT mRNA and the levels of the SERT protein in the colonic mucosa, thereby playing a key role in motility-related symptoms of IBS patients.

Are Food Constituents Relevant to the Irritable Bowel Syndrome in Young Adults? - A Rome III Based Prevalence Study of the Korean Medical Students

Background/Aims

Irritable bowel syndrome (IBS) is prevalent in general population. This study investigates the prevalence of IBS in medical college students in Korea as well as the influence of dietary habits and nutritional intake on IBS.

Methods

This study is a cross-sectional study of 319 students (239 males and 80 females, age 22.3 ± 2.5 years) from the 6 grade levels of the Medical College in Korea. All students filled out a self-reported questionnaire for ROME III criteria. They also completed a questionnaire to validate dietary habits and food frequency in Korean.

Results

The overall prevalence of IBS was 29.2% without correlation to age, body mass index and grade level in Medical School. However, the prevalence was significantly higher in females than males (33/80 vs 60/239, P = 0.007). There were no significant differences between the IBS-group and the non-IBS group in aspect of nutrition. Not only the diet habits, but also the daily nutritional intake, and even the breakdown into the 12 micronutrients, yielded no significant differences between the 2 groups.

Conclusions

Twenty-nine percent of the medical college students have IBS with a greater prevalence in females. The dietary habits and nutritional intake of the students might not be associated with IBS.

Post-infectious irritable bowel syndrome: the past, the present and the future

BACKGROUND

Irritable bowel syndrome (IBS), once thought to be a psychosomatic disease, is being considered to be more organic. Post-infectious IBS (PI-IBS), defined as acute onset IBS (by Rome criteria) after gastrointestinal infection in an individual without prior IBS with two or more of the followings: fever, vomiting, diarrhea, a positive stool culture. The recent and old literature of PI-IBS will be reviewed. Future directions for research will be presented.

METHODS

Literature on PI-IBS was reviewed by electronic search and cross references of these papers.

RESULTS

Interest in studies on PI-IBS, which was described five to six decades ago, re-surfaced recently. 3.6 to 32% patients with acute gastroenteritis develop PI-IBS during 3-12 month follow-up. PI-IBS is commonly diarrhea predominant. Factors implicated in development include nature of pathogens, duration and severity of diarrhea, younger age, female gender and psychological co-morbidities like anxiety and depression. The pathogenesis of PI-IBS is largely related to continuing gut inflammation due to inability of the host to contain the inflammatory reaction, altered gut microbiota, increased intestinal permeability, muscle hyper-contractility and visceral hypersensitivity. There could be an overlap between PI-IBS and post-infectious malabsorption syndrome (PI-MAS), popularly known as tropical sprue.

CONCLUSIONS

Development of IBS in a subset of patients with acute gastroenteritis is uncontested. This is expected to open a paradigm shift in understanding the pathogenesis of IBS. Future studies should address the issue of overlap of PI-IBS and PI-MAS. Exploring the molecular mechanisms of pathogenesis of PI-IBS may help to design preventive and therapeutic strategies.

The current prevalence of irritable bowel syndrome in Asia

Irritable bowel syndrome (IBS) has been one of the commonly presented gastrointestinal disorders. It is of interest how commonly it presents in the society. Western studies indicated that most population-based IBS prevalences range 10%-15%. It is believed that IBS is prevalent in both East and West countries without a significant prevalence difference. Most recently, the Asia IBS prevalence has a higher trend in the affluent cities compared to South Asia. Since many Asia IBS prevalence studies have been published in the recent decade, we could compare the IBS prevalence data divided by various criteria in looking whether they were also comparable to this of West community. Summarized together, most Asia community IBS prevalences based on various criteria are usually within the range 1%-10% and are apparently lower than these of selected populations. Within the same population, the prevalence orders are first higher based on Manning criteria, then followed by Rome I criteria and finally reported in Rome II criteria. Overall, the median value of Asia IBS prevalences defined by various criteria ranges 6.5%-10.1%. With regard to gender difference, female predominance is usually found but not uniquely existed. For the IBS subtypes, the proportions of diarrhea predominant-IBS distribute widely from 0.8% to 74.0%, while constipation predominant-IBS proportion ranges 12%-77%. In conclusions, current Asia IBS prevalence is at least equal to the Western countries. Female predominant prevalence in Asia is common but not uniquely existed, while the proportions of IBS subtypes are too variable to find a rule.

Systematic review and meta-analysis of Saccharomyces boulardii in adult patients

This article reviews the evidence for efficacy and safety of Saccharomyces boulardii (S. boulardii) for various disease indications in adults based on the peer-reviewed, randomized clinical trials and pre-clinical studies from the published medical literature (Medline, Clinical Trial websites and meeting abstracts) between 1976 and 2009. For meta-analysis, only randomized, blinded controlled trials unrestricted by language were included. Pre-clinical studies, volunteer studies and uncontrolled studies were excluded from the review of efficacy and meta-analysis, but included in the systematic review. Of 31 randomized, placebo-controlled treatment arms in 27 trials (encompassing 5029 study patients), S. boulardii was found to be significantly efficacious and safe in 84% of those treatment arms. A meta-analysis found a significant therapeutic efficacy for S. boulardii in the prevention of antibiotic-associated diarrhea (AAD) (RR = 0.47, 95% CI: 0.35-0.63, P < 0.001). In adults, S. boulardii can be strongly recommended for the prevention of AAD and the traveler's diarrhea. Randomized trials also support the use of this yeast probiotic for prevention of enteral nutrition-related diarrhea and reduction of Helicobacter pylori treatment-related symptoms. S. boulardii shows promise for the prevention of C. difficile disease recurrences; treatment of irritable bowel syndrome, acute adult diarrhea, Crohn's disease, giardiasis, human immunodeficiency virus-related diarrhea; but more supporting evidence is recommended for these indications. The use of S. boulardii as a therapeutic probiotic is evidence-based for both efficacy and safety for several types of diarrhea.

The Differences in Prevalence and Sociodemographic Characteristics of Irritable Bowel Syndrome According to Rome II and Rome III

BACKGROUND/AIMS

Irritable bowel syndrome (IBS) is one of the most frequently observed disorders by primary care and practitioners. The aim of this study was to estimate the prevalence of IBS using the Rome II and III criteria in the general Korean population and also to compare sociodemographic differences between subjects diagnosed by these criteria.

METHODS

Telephone interview surveys were performed with a total of 1,009 individuals in Korea, 15 years of age or older. The questionnaire, based on the Rome II and III criteria, was validated.

RESULTS

Among the 1,009 subjects, the prevalence of IBS was 8.0% under the Rome II criteria (81 subjects; 6.4%, male; 9.6%, female), and 9.0% (91 subjects; 7.0%, male; 11.0%, female) under the Rome III criteria. The accordance rate of Rome II and III was 73.5%. Both groups showed highest frequency in the age of 30s (13.9% vs. 15.3% respectively). Female subjects showed a higher prevalence than male subjects under Rome III (91 subjects; 11.0% in female, 7.0% in male; p < 0.05), but not under Rome II criteria. Many patients older than 50 years were added when analyzed under the Rome III criteria, but not under the Rome II criteria (p = 0.017).

CONCLUSIONS

The Rome III criteria were less restrictive and showed good agreement with the Rome II criteria. The prevalence of IBS was increased in young women.

Pathogenesis of IBS: role of inflammation, immunity and neuroimmune interactions

IBS is one of the most common functional gastrointestinal disorders worldwide and is thought to be the result of disturbed neural function along the brain-gut axis. The mechanisms behind this disturbance are not clear, but important roles for low-grade inflammation and immunological alterations in the development of symptoms compatible with IBS have become evident. The development of long-standing gastrointestinal symptoms after infectious gastroenteritis and patients with IBD in remission frequently having functional gastrointestinal symptoms support this hypothesis. An increased innate immune activity in the intestinal mucosa and in blood is found in subpopulations of patients with IBS. Mast cells and monocytes seem to be particularly important. In addition, studies have demonstrated that IBS may be associated with an activated adaptive immune response. Increased epithelial barrier permeability and an abnormal gut flora might lead to increased activation of the intestinal immune system. Functional and anatomical evidence for abnormal neuroimmune interactions has been found in patients with IBS. The link between immune alterations and severity of gastrointestinal symptoms and the positive effect of anti-inflammatory treatments in IBS further highlight the relevance of neuroimmune interactions in this condition.

Socioeconomic status moderates the association between John Henryism and NEO PI-R personality domains

OBJECTIVE

To investigate associations between John Henryism (JH) and NEO Personality Inventory-Revised (PI-R) personality domains. JH-a strong behavioral predisposition to engage in high-effort coping with difficult psychosocial and economic stressors-has been associated with poor health, particularly among persons in lower socioeconomic (SES) groups. Unfavorable personality profiles have also been frequently linked to poor health; however, no studies have yet examined what global personality traits characterize JH.

METHODS

Hypotheses were examined, using data from a sample of 233 community volunteers (mean age, 33 years; 61% black and 39% white) recruited specifically to represent the full range of the SES gradient. Personality (NEO PI-R) and active coping (12-item JH scale) measures and covariates were derived from baseline interviews.

RESULTS

In a multiple regression analysis, independent of SES, JH was positively associated with Conscientiousness (C) (p < .001) and Extraversion (E) (p < .001), whereas the combination of low JH and high SES was associated with Neuroticism (N) (p = .02) When examining associations between JH and combinations of NEO PI-R domains called "styles," high JH was most strongly associated with a high E/high C "Go-Getters" style of activity, whereas low JH was associated with the low E/high Openness (O) "Introspectors" style. In facet level data, the most robust associations with JH were found for five C and five E facets.

CONCLUSIONS

High JH was associated with higher scores on C and E, but the combination of low JH and high SES was associated with higher scores on N.

Bugs and irritable bowel syndrome: The good, the bad and the ugly

Recently, there has been strong interest in the therapeutic potential of probiotics for irritable bowel syndrome (IBS). At the same time, there is a rapidly growing body of evidence to support an etiological role for gastrointestinal infection and the associated immune activation in the development of post-infectious IBS. In a more controversial area, small intestinal bacterial overgrowth has been associated with a subset of patients with IBS; the issue of whether it is appropriate to treat a subset of IBS patients with antibiotics and probiotics is currently a matter for debate. Thus, it appears that the gastrointestinal microbial flora may exert beneficial effects for symptoms of IBS under some circumstances, while in other situations gut microbes could give rise to symptoms of IBS. How do we make sense of the apparently diverse roles that 'bugs' may play in IBS? To address this question, we have conducted an in-depth review, attempting where possible to draw lessons from Asian studies.

[Irritable bowel syndrome: epidemiology/economic burden]

The prevalence of irritable bowel syndrome (IBS) is high wherever it is assessed. The definition is still controversial, but the IBS patient's characteristics are quite similar in industrialized countries. The lack of a definite biological marker results in the prescription of many complementary examinations. The diagnosis of IBS remains an elimination diagnosis, despite the publication of the Rome criteria, which has attempted to advance toward a positive diagnosis. Abdominal pain or discomfort are the main symptoms and are the major reasons for consulting. The quality of life is impaired in IBS and is clearly correlated with symptom severity. All these points at least partially explain the economic burden of IBS on health care resources. The cost of IBS is difficult to assess because of its different components: the direct costs such as the number of medical consultations, drug consumption, and the number and quality of complementary investigations are easier to evaluate than the indirect costs such as work absenteeism or altered presenteeism, which can have a major impact on the cost of IBS.

Epidemiology of irritable bowel syndrome in Asia: something old, something new, something borrowed

In this review we have unearthed epidemiological data that; support the 'old' concept of irritable bowel syndrome (IBS) as a disorder of civilization, build a 'new' symptom profile of IBS for Asia, and persuade us against the use of 'borrowed' Western diagnostic criteria and illness models by Asian societies. In the 1960s, IBS was described as a disorder of civilization. Early studies from Asia suggested a prevalence of IBS below 5%. Recent studies from Asia suggest a trend for the more affluent city states like Singapore and Tokyo, to have higher prevalence of 8.6% and 9.8%, respectively, while India had the lowest prevalence of 4.2%. Furthermore, there was a trend among the better educated and more affluent strata of society in several urban Chinese populations for a higher prevalence of IBS, as well as a trend for a higher consultation rate. Across Chinese and Indian predominant populations, a majority of patients with IBS criteria report upper abdominal symptoms such as epigastric pain relieved by defecation, bloating and dyspepsia. Bloating and incomplete evacuation appear to be more important determinants of consultation behavior, than psychological factors. The failure of the Rome criteria to recognize the relationship to meals, may have led to a substantial misclassification of IBS as dyspepsia. The relevance of the Western model of psychological disturbance as a determinant of consultation behavior is questionable because of the accessibility and acceptability of medical consultation for gastrointestinal complaints in many Asian communities.

Effect of probiotics on symptoms in korean adults with irritable bowel syndrome

Background/Aims

Irritable bowel syndrome (IBS) is a troublesome disease. Some strains of probiotics reportedly exert remarkable immunomodulatory effects, and so we designed a prospective double-blind randomized placebo-controlled clinical study to assess their effects in Korean adults with IBS.

Methods

IBS patients who met Rome III criteria were randomly assigned to receive composite probiotics or placebo. A total of 20 billion lyophilized bacteria were administered twice daily for 8 weeks. Primary outcome variables were symptom scores consisting of abdominal pain, flatulence, defecation discomfort, and sum of symptom scores. A visual analogue scale was used to quantify the severity. Secondary outcome variables consisted of the quality of life and bowel habits including defecation frequency and stool form.

Results

Thirty-six and 34 patients were randomized to the probiotics and placebo groups, respectively. Intention-to-treat analysis showed significant reductions in pain after 8 weeks of treatment: -31.9 and -17.7 in the probiotics and placebo groups, respectively (p=0.045). The reductions in abdominal pain, defecation discomfort, and sum of scores were more significant in 58 patients with a score of at least 3 on the baseline stool-form scale.

Conclusions

Composite probiotics containing Bifidobacterium bifidum BGN4, Lactobacillus acidophilus AD031, and other species are safe and effective, especially in patients who excrete normal or loose stools.

[Association of lower urinary tract symptoms with irritable bowel syndrome in adult men - an internet-based survey]

BACKGROUND/AIMS

Patients with irritable bowel syndrome (IBS) are more likely to experience certain urinary symptoms. The aims of this study were to investigate the association between lower urinary tract symptoms (LUTS) and IBS, and to determine their impact on the quality of life.

METHODS

E-mails were sent to 23,594 men who were registered at an internet survey company. Subjects were requested to fill out the questionnaires regarding IBS and LUTS assessed by the International Prostate Symptom Score (IPSS).

RESULTS

Among 601 subjects (mean age, 35.5+/-8.4) included in the final analysis, 118 (19.6%) fulfilled the Rome II criteria for the diagnosis of IBS. The total mean IPSS of IBS subjects was 9.6, which was significantly higher than the 7.0 of non-IBS subjects (p<0.01). When IPSS was subcategorized into mild, moderate, and severe symptom categories, the proportions with the moderate and severe symptoms among IBS subjects were 33.9% and 13.6% respectively, which were significantly higher than those of non-IBS subjects; (26.9 and 5.2%) (p<0.01). In multivariate analysis, statistically significant association was found between IBS and moderate to severe LUTS (OR, 1.91; 95% CI, 1.27-2.88). IBS subjects also showed a poorer quality of life score than non-IBS subjects (2.24 vs. 1.65, p< 0.001).

CONCLUSIONS

LUTS in adult men with IBS are more severe and have a more negative impact on the quality of life than in non-IBS subjects.

The challenge of cross-cultural, multi-national research: potential benefits in the functional gastrointestinal disorders

The increasing interest in research in irritable bowel syndrome (IBS) and other functional gastrointestinal disorders (FGIDs), taken together with the growing sophistication of communication technology, makes cross-cultural, multi-national research a feasible endeavour. The aim of this study is to encourage collaborative cross-cultural studies in FGIDs by discussing relevant methodological issues, and by suggesting potential areas in which cross-cultural research can make a significant contribution to the understanding of FGIDs and to patient care. To this end, methodological issues related to cross-cultural research and competences required for its conduct are presented together with a critique of published studies and recommendations for future research in the area. The term 'cross-cultural' research in FGIDs is usually applied to the results of prevalence studies, for example comparative studies of IBS prevalence in different countries and ethnic groups. The validity of these comparisons is impacted negatively by the lack of uniformity in research methods. In addition to prevalence studies, cross-cultural research can make a significant contribution in areas such as molecular biology, genetics, psychosocial factors, symptom presentation, extra-intestinal comorbidity, diagnosis and treatment, determinants of disease severity, healthcare utilization, and health-related quality of life, all issues that can be affected by culture, ethnicity and race. Well-designed and implemented cross-cultural studies can advance our knowledge in many FGID-related areas ranging from epidemiology through psychosocial factors, pathophysiological mechanisms and therapeutics. These studies, conducted by investigators with competence in cross-cultural research methodology, can advance our understanding of the FGIDs and contribute to improved patient care.

Update on irritable bowel syndrome and gender differences

Irritable bowel syndrome (IBS) is a chronic functional GI disorder characterized by abdominal pain associated with alterations in defecation or stool frequency and consistency. In Western industrialized countries, women seek health care services for their symptoms more frequently than men. The cause of IBS is likely multifactorial involving altered motility, visceral hypersensitivity, and dysregulation of the autonomic nervous system. Many patients note that their symptoms are exacerbated by diet and stress, and women frequently report menstrual cycle fluctuations in symptoms. Current approaches to IBS management include behavioral management therapies such as dietary intake changes and stress reduction cognitive restructuring. Drug therapies are targeted at altering pain sensitivity, motility, and secretion. This review provides an overview of the pathogenesis of IBS, factors that contribute to gender differences, and current therapeutic approaches for symptom management.