Irritable Bowel Syndrome: Clinical Manifestations, Dietary Influences, and Management

Food Intolerances, Food Allergies and IBS: Lights and Shadows

This narrative review delves into the intricate relationship between irritable bowel syndrome (IBS) and food intolerances. IBS, a chronic functional gastrointestinal disorder, is characterized by symptoms like abdominal pain and altered bowel habits. The prevalence of IBS has increased globally, especially among young adults. Food and dietary habits play a crucial role in IBS management. About 85-90% of IBS patients report symptom exacerbation linked to specific food consumption, highlighting the strong connection between food intolerances and IBS. Food intolerances often exhibit a dose-dependent pattern, posing a challenge in identifying trigger foods. This issue is further complicated by the complex nature of gastrointestinal physiology and varying food compositions. This review discusses various dietary patterns and their impact on IBS, including the low-FODMAP diet, gluten-free diet, and Mediterranean diet. It highlights the importance of a personalized approach in dietary management, considering individual symptom variability and dietary history. In conclusion, this review emphasizes the need for accurate diagnosis and holistic management of IBS, considering the complex interplay between dietary factors and gastrointestinal pathophysiology. It underlines the importance of patient education and adherence to treatment plans, acknowledging the challenges posed by the variability in dietary triggers and the psychological impact of dietary restrictions.

Gut Microbiome and Lipidome Signatures in Irritable Bowel Syndrome Patients from a Low-Income, Food-Desert Area: A Pilot Study

Irritable bowel syndrome (IBS) is a common gastroenterological disorder with triggers such as fructose. We showed that our IBS patients suffering from socioeconomic challenges have a significantly high consumption of high-fructose corn syrup (HFCS). Here, we characterize gut microbial dysbiosis and fatty acid changes, with respect to IBS, HFCS consumption, and socioeconomic factors. Fecal samples from IBS patients and healthy controls were subjected to microbiome and lipidome analyses. We assessed phylogenetic diversity and community composition of the microbiomes, and used linear discriminant analysis effect size (LEfSe), analysis of compositions of microbiomes (ANCOM) on highly co-occurring subcommunities (modules), least absolute shrinkage and selection operator (LASSO) on phylogenetic isometric log-ratio transformed (PhILR) taxon abundances to identify differentially abundant taxa. Based on a Procrustes randomization test, the microbiome and lipidome datasets correlated significantly (p = 0.002). Alpha diversity correlated with economic factors (p < 0.001). Multiple subsets of the phylogenetic tree were associated with HFCS consumption (p < 0.001). In IBS patients, relative abundances of potentially beneficial bacteria such as Monoglobaceae, Lachnospiraceae, and Ruminococcaceae were lower (p = 0.007), and Eisenbergiella, associated with inflammatory disorders, was higher. In IBS patients, certain saturated fatty acids were higher and unsaturated fatty acids were lower (p < 0.05). Our study aims first to underscore the influence of HFCS consumption and socioeconomic factors on IBS pathophysiology, and provides new insights that inform patient care.

[Irritable bowel syndrome in the Russian Federation: results of the ROMERUS multicenter observational study]

BACKGROUND

Irritable bowel syndrome (IBS) is one of the most common functional disorders of the gastrointestinal tract. According to Russian guidelines, a standard examination using laboratory and instrumental evaluation methods, including colonoscopy, should be performed to establish the diagnosis of IBS.

AIM

To characterize the Russian population of IBS patients.

MATERIALS AND METHODS

A multicenter observational prospective study ROMERUS was conducted at 35 clinical centers in the Russian Federation. The study included male and female patients aged 18 to 50 with a diagnosis of IBS based on the Rome IV criteria, with no signs of structural gastrointestinal disease. The follow-up duration was 6 months and included three patients' visits to the study site. During the study, data were collected on patients' demographic and clinical characteristics, medical history, and drug therapy. The secondary parameters included the assessment of the proportion of patients with a diagnosis of IBS confirmed by a standard examination among all patients meeting the Rome IV criteria, the evaluation of the change over time of the IBS symptoms, quality of life (QoL), and adherence to therapy. Characterization of the population was performed using descriptive statistics methods. The standard examination results were presented as the percentage of patients with IBS confirmed by the standard examination among all patients meeting the Rome IV criteria, with a two-sided 95% confidence interval.

RESULTS

The study included 1004 patients with a diagnosis of IBS according to the Rome IV criteria, with 790 (78.7%) patients included in the final analysis. The mean age of patients was 34.0±7.5 years; they were predominantly female (70.4%), Caucasian (99.4%), married (55.1%), urban residents (97.5%) with higher education (64.5%) and a permanent position (74.9%). Patients enrolled in the study have low physical activity and lack a healthy diet. The smoking rate was 26.3%. IBS symptoms with predominant constipation (IBS-C) were observed in 28.1% of patients; 28.9% had IBS with predominant diarrhea (IBS-D), 11.9% had mixed-type IBS, and 31.1% had non-classified IBS. The main IBS symptoms were pain (99.7%), abdominal distension (71.1%), and fullness (36.8%). Biliary tract dysfunction (18.9%) and gastritis (17.2%) were the most frequently reported comorbidities. Prior to enrollment, 28% of patients received drug therapy. The most commonly prescribed drug during the study was mebeverine (54.1%). At 6 months of follow-up, there was a significant reduction of abdominal pain, bloating, and distention, and a twofold reduction in the incidence of constipation and diarrhea in the subgroups of patients with IBS-C and IBS-D, respectively. The overall QoL score measured by the IBS-QoL questionnaire increased from 83.0 to 95.2 points (p<0.05) during the study. In the overall assessment of their condition, 69.6% of patients noted no symptoms and 25.3% reported marked improvement, 35% were asymptomatic according to the physician's overall assessment of the patient's condition, and 51.8% showed significant improvement.

CONCLUSION

IBS patients in the Russian Federation were characterized. The diagnosis of IBS, established following the Rome IV criteria, is confirmed by the results of a standard examination in 96.3% of patients. The Rome IV criteria for the IBS diagnosis make it possible to establish a diagnosis with a probability of 94.7%. For 6 months of follow-up, there was a clinical improvement with a decrease in the severity of symptoms and a QoL improvement.

Post-Infectious Irritable Bowel Syndrome after an Epidemic of Gastroenteritis in South of Iran

Background: Irritable bowel syndrome (IBS) is a chronic disabling condition without a well-defined etiology. Infectious gastroenteritis (IGE) has been linked to this syndrome. There are few data from Iran on this association. Methods: In August 2018, an epidemic of IGE caused by Escherichia coli occurred in a village in the west of Shiraz in southern Iran. One year after this epidemic, the occurrence of IBS was surveyed in those who suffered from IGE based on Rome IV criteria in that village. Results: Of 179 patients included in the present study, 17 patients (9.5%) had post-infectious (PI)-IBS. There was no difference in age, sex, antibiotic use, hematochezia, duration of infectious diarrhea, fever, and weight loss at the time of IGE between those with and without PI-IBS. Conclusion: PI-IBS is common after IGE, but no risk factor for its development was found in this study.

Turmeric for Treatment of Irritable Bowel Syndrome: A Systematic Review of Population-Based Evidence

BACKGROUND

Irritable bowel syndrome (IBS) is a highly prevalent disorder of the gut interaction characterized by abdominal discomfort and pain associated with altered bowel habits in the absence of structural abnormalities. In spite of IBS' high prevalence and disease burden across the globe, no explanations have been given as to its underlying pathophysiology. As for the treatment of IBS, there is no specific medication, and the most beneficial treatment is usually supportive therapy. Recent animal and human studies have demonstrated the therapeutic potential of curcumin or turmeric in the treatment of IBS.

METHODS

We systematically reviewed all available evidence supporting curcumin and turmeric's therapeutic potential in relieving IBS symptoms in the present study. For this purpose, a database search was performed using curcumin, turmeric, and IBS and all their equivalents as of the search terms in Web of Science, Pub-Med, Scopus, Ovid, Embase, and Google Scholar from1990 up to Feb 2021. The investigation was then limited to clinical trials, and then nine articles were collected for data analysis.

RESULTS

The findings of the included literature showed that curcumin and turmeric alone or in combination with other medications could improve the severity of IBS as well as the quality of life among people who suffer from IBS symptoms.

CONCLUSION

Overall, medications containing curcumin and turmeric extract due to these compounds' anti-inflammatory effects may improve IBS symptoms, particularly abdominal pain and life quality.

Non-alcoholic fatty liver disease in irritable bowel syndrome: More than a coincidence?

Irritable bowel syndrome (IBS) and non-alcoholic fatty liver disease (NAFLD) are amongst the most common gastrointestinal and liver conditions encountered in primary and secondary care. Recently, there has been interest in the apparent co-incidence of NAFLD in patients with IBS mainly driven by improved understanding of their shared risk factors and pathophysiology. In this paper we summarize the shared risk factors which include; overlapping nutritional and dietary factors as well as shared putative mechanisms of pathophysiology. These include changes in the gut microbiome, gut permeability, immunity, small bowel bacterial overgrowth and bile acid metabolism. This paper describes how these shared risk factors and etiological factors may have practical clinical implications for these highly prevalent conditions. It also highlights some of the limitations of current epidemiological data relating to estimates of the overlapping prevalence of the two conditions which have resulted in inconsistent results and, therefore the need for further research. Early recognition and management of the overlap could potentially have impacts on treatment outcomes, compliance and morbidity of both conditions. Patients with known IBS who have abnormal liver function tests or significant risk factors for NAFLD should be investigated appropriately for this possibility. Similarly, IBS should be considered in patients with NAFLD and symptoms of abdominal pain associated with defecation, an altered bowel habit and bloating.

Gwakhyangjeonggi-san for irritable bowel syndrome: A protocol for systematic review and meta-analysis

BACKGROUND

Irritable bowel syndrome (IBS) is a chronic functional bowel disorder characterized by abdominal pain or discomfort, stool irregularities, and bloating. Owing to its atypical symptoms and various mechanisms, there is no standard treatment for IBS. Gwakhyangjeonggi-san (GJS), a traditional Korean herbal medicine, has been used to treat lower intestinal abnormalities in Asia. We will systematically review randomized controlled trials (RCTs) to evaluate the efficacy and safety of GJS as a complementary treatment for IBS.

METHODS AND ANALYSIS

Four English databases, namely, Medline (via PubMed), EMBASE, the Cochrane Central Register of Controlled Trials, and the Allied and Complementary Medicine Database, will be searched for entries up to May, 2021. Additional databases will include 5 Korean databases, 1 Chinese database, and 1 Japanese database. RCTs and quasi-RCTs will be searched for to assess the effectiveness and safety of GJS. The primary outcome measure will be the overall efficacy rate, and the secondary outcome will include data such as global symptom scores, IBS Quality of Life measurements, and adverse events. Data analysis will be performed using Review Manager Version 5.3, and the risk of bias will be assessed using the Cochrane Collaboration's risk-of-bias tool. The quality of the results will be evaluated using the Grading of Recommendations Assessment, Development, and Evaluation approach.

CONCLUSION

This systematic review will provide evidence for the efficacy and safety of GJS for IBS.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/V93JN (https://osf.io/v93jn).

Positive Correlation between nNOS and Stress-Activated Bowel Motility Is Confirmed by In Vivo HiBiT System

Neuronal nitric oxide synthase (nNOS) has various roles as a neurotransmitter. However, studies to date have produced insufficient data to fully support the correlation between nNOS and bowel motility. This study aimed to investigate the correlation between nNOS expression and gastrointestinal (GI) tract motility using a stress-induced neonatal maternal separation (NMS) mouse model. In this study, we generated a genetically modified mouse with the HiBiT sequence knock-in into the nNOS gene using CRISPR/Cas9 for analyzing accurate nNOS expression. nNOS expression was measured in the stomach, small intestine, large intestine, adrenal gland, and hypothalamus tissues after establishing the NMS model. The NMS model exhibited a significant increase in nNOS expression in large intestine, adrenal gland, and hypothalamus. Moreover, a significant positive correlation was observed between whole gastrointestinal transit time and the expression level of nNOS. We reasoned that NMS induced chronic stress and consequent nNOS activation in the hypothalamic-pituitary-adrenal (HPA) axis, and led to an excessive increase in intestinal motility in the lower GI tract. These results demonstrated that HiBiT is a sensitive and valuable tool for analyzing in vivo gene activation, and nNOS could be a biomarker of the HPA axis-linked lower intestinal tract dysfunction.

Function of intestinal barrier protected by regulating the miR-199a-3p in ulcerative colitis: Modulation of IL-23/IL-17A axis

Ulcerative colitis is a chronic inflammatory bowel disorder, which is having higher mortality rate. The present report evaluates the protective effect of miR-199a-3p oligomer for the treatment of Ulcerative colitis (UC). Ulcerative colitis was induced by administration of dextran sulfate sodium [DSS (3%)] with drinking water for the duration of one week in mice and miR-199a-3p oligomer was treated for the same duration. Effect of miR-199a-3p oligomer was determined by estimating the body weight, blood stool and length of colon in UC mice. Inflammatory cytokines, oxidative stress parameters and Treg/Th17 ratio was determined in the serum, intestinal and spleen tissue of UC mice. mRNA expression of TGFβ, Foxp3, RORγt and STAT3 was estimated in the intestinal tissue of UC mice. Moreover, permeability of intestine was determined by estimating the expression of FITC-dextran in the serum and expression of junction protein in the tissue of UC mice. The data of the study suggest that treatment with miR-199a-3p oligomer ameliorates the altered condition in ulcerative colitis mice. There was reduction in the level of cytokines and parameters of oxidative stress in the intestine of miR-199a-3p oligomer than UC group. Moreover, intestinal permeability was enhanced in miR-199a-3p oligomer treated UC mice. The level of Th17 in the serum and mRNA expression of TGFβ, Foxp3, RORγt and STAT3 was attenuated in miR-199a-3p oligomer treated UC mice. In conclusion, the data of the study suggest that treatment with miR-199a-3p oligomer ameliorates intestinal barrier in ulcerative colitis by down regulating the IL-17A/IL-23 axis.

An evaluation of dietary adequacy among patients with constipation-predominant irritable bowel syndrome in Malaysia

Background/Aims

Substantial proportions of patients with constipation-predominant irritable bowel syndrome (IBS-C) linked their symptoms with particular intake of foods. However, there is lack of current data regarding the intake among IBS-C patients before any dietary interventions. Thus, this study aimed to evaluate the dietary adequacy among IBS-C against the standard recommended nutrient intake (RNI) and healthy controls.

Methods

A retrospective case-control study was conducted involving IBS-C patients and healthy control subjects. A validated 126-food items frequency questionnaire was administered to all the subjects to assess their dietary intake, guided by dietitians. The calculated nutrients intake for IBS-C patients was then compared against the standard RNI and healthy controls.

Results

A total of 306 subjects were recruited, among which 218 were diagnosed with IBS-C and 88 were included as healthy controls. IBS-C patients had significantly lower intake of wholegrain products, fried foods, dairy products, fruits, and vegetables compared to healthy controls. The daily intake of energy, certain macronutrients, and micronutrients among IBS-C patients was significantly lower than the healthy subjects. Less than 5% of IBS-C patients and healthy subjects achieved the standard recommendation for dietary fiber. Also, various vitamin intake (B₁, B₂, B₆, folate, B₁₂, E, K, and potassium) among IBS-C patients did not meet the standard RNI.

Conclusions

Dietary intakes of IBS-C patients did not meet the recommended intake for Malaysian and showed the nutritional inadequacies compared to the control subjects. Our study highlighted the importance of dietary evaluation prior to planning strategies for dietary intervention targeting IBS-C patients.

Global Dietary Patterns and Functional Gastrointestinal Disorders

Functional Gastrointestinal Disorders (FGIDs) are common. In the United States alone, approximately 25 million Americans are estimated to have at least one FGID. Nonpharmacological treatment options include psychological/behavioral approaches, and dietary interventions that can vary across countries. The aim of this review is to evaluate the available evidence for dietary interventions for the treatment of childhood FGIDs amongst various cultures and regions of the world. This review includes clinical trials of dietary therapies for the treatment of FGIDs in children posted on or before 13 July 2020 in PubMed. Overall, the consensus view suggests that the westernization of diets is linked to the development of FGIDs, and diets low in Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols (FODMAPs) may reduce abdominal symptoms. However, more work is needed to confirm these findings.

Synergistic Effect of Berberine-Based Chinese Medicine Assembled Nanostructures on Diarrhea-Predominant Irritable Bowel Syndrome In Vivo

Diarrhea-predominant irritable bowel syndrome (IBS-D) is one common chronic functional disease of the digestive system with limited treatments. The microbiota–gut–brain axis (MGBA) has a central function in the pathogeny of IBS-D, which includes the participation of many various factors, such as brain-gut peptides (BGPs), immune inflammation, and intestinal flora. Inspired by the drug combination in traditional Chinese medicine (TCM), our previous study discovered that berberine (BBR) and baicalin (BA) could form natural self-assemblies as BA-BBR nanoparticles (BA-BBR NPs) and showed synergistic effects against IBS-D. Here, we investigated the synergistic effects of BA-BBR NPs on IBS-D model mice induced by chronic restraint stress plus Senna alexandrina Mill decoction with the influence on MGBA. BA-BBR NPs showed the best therapeutic effect on improving visceral hypersensitivity and diarrhea on IBS-D model mice, compared with BBR, BA, and BA/BBR mixture. Furthermore, BA-BBR NPs significantly (P<0.05) reduced the levels of 5-hydroxytryptamine (5-HT), vasoactive intestinal polypeptide (VIP) and choline acety transferase (CHAT) in colon tissues or of serum from BGPs; it lowered the expressions of the nuclear factor kappa-B (NF-κB) in colon tissues and changed the levels of basophil granulocyte (BASO) and leukomonocyte (LYMPH) in whole blood from immune inflammation; it altered the intestinal flora of Bacteroidia, Deferribacteres, Verrucomicrobia, Candidatus_Saccharibacteria, and Cyanobacteria from intestinal flora. In conclusion, BA-BBR NPs, after forming the natural self-assembly between BBR and BA, promoted the synergistic effect on IBS-D mice than the sum of BBR and BA effects, based to the formation of self-assemblies rather than the simple mixing. It further proved that synergistic effect of BA-BBR NPs on IBS-D mice might be related to BGPs, immune inflammation, and intestinal flora from three important interrelated components of MGBA. This study will provide a novel idea for the interpretation of TCM compatibility theory and provide the basis for BA-BBR NPs as a medicinal plant-derived natural and efficient nanomaterial for clinical use.

Potential neuro-immune therapeutic targets in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder characterized by recurring abdominal pain and disturbed bowel habits. The aetiology of IBS is unknown but there is evidence that genetic, environmental and immunological factors together contribute to the development of the disease. Current treatment of IBS includes lifestyle and dietary interventions, laxatives or antimotility drugs, probiotics, antispasmodics and antidepressant medication. The gut-brain axis comprises the central nervous system, the hypothalamic pituitary axis, the autonomic nervous system and the enteric nervous system. Within the intestinal mucosa there are close connections between immune cells and nerve fibres of the enteric nervous system, and signalling between, for example, mast cells and nerves has shown to be of great importance during GI disorders such as IBS. Communication between the gut and the brain is most importantly routed via the vagus nerve, where signals are transmitted by neuropeptides. It is evident that IBS is a disease of a gut-brain axis dysregulation, involving altered signalling between immune cells and neurotransmitters. In this review, we analyse the most novel and distinct neuro-immune interactions within the IBS mucosa in association with already existing and potential therapeutic targets.

5-Aminosalicylic acid for treatment of irritable bowel syndrome: A protocol for a systematic review and meta-analysis

BACKGROUND

The global prevalence of irritable bowel syndrome (IBS) is estimated to be as high as 15%, and it is estimated that IBS has a prevalence of approximately 10% to 20% in Western countries. Some trials showed mesalazine (5-aminosalicylic acid [5-ASA]) might be effective for IBS, but the results still need to be confirmed. Hence, this meta-analysis is designed to assess the efficacy and safety of mesalazine for IBS in adults and children.

METHODS

We conducted a comprehensive database search for randomized trials of mesalazine for IBS in PubMed, EMBASE, and the Cochrane Library. The search strategy was performed from inception to December 31, 2019, without restrictions on publication status and language. The reference lists of the included articles were also checked to identify additional studies for potential inclusion. Two reviewers will independently review all literature for inclusion and assess their risk of bias. Two reviewers will independently extract data from eligible studies based on a pre-designed standardized form. Any disagreements will be resolved by consensus. Stata SE 15.0 software will be used for data synthesis.

RESULTS

This is the first meta-analysis focusing on mesalazine for the treatment of IBS. We predict it will provide high-quality synthesis on existing evidence for IBS and a relatively comprehensive reference for clinical practice and development of clinical guidelines for IBS.

CONCLUSION

This protocol outlined the significance and methodological details of a systematic review of mesalazine for IBS. This ongoing meta-analysis will provide high-quality synthesis on existing evidence for IBS.

REGISTRATION

The meta-analysis has been prospectively registered in PROSPERO (CRD42019147860).

Targeting the gut microbiota for the treatment of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder that affects an estimated 11% of people across the world. IBS patients are one of the largest subgroups seen in gastroenterology clinics, exhibit a lesser quality of life, and take greater use of the healthcare system. The exact etiology of IBS remains uncertain. Alterations in the gut microbiome may characterize apotential mechanism in the pathogenesis of IBS. This hypothesis is paralleled by rodent models in which manipulation of the gut microbiota leads to disturbed physiological functions along the brain-gut axis. Recent research in IBS treatments has redirected its focus towards gu microbiome based therapeutics. In this review, we discuss potential roles of enteric bacteria in the pathogenesis of IBS and its comorbidities. We then explore the manipulation of the enteric microbiota by prebiotics, probiotics, antibiotics, dietary changes, and fecal microbiota transfer. We also discuss the positive and negative effects of these therapeutics on IBS symptoms.

Low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet in children

Irritable bowel syndrome (IBS) is a lifelong condition with a high prevalence among children and adults. As the diet is a frequent factor that triggers the symptoms, it has been assumed that by avoiding the consumption of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP), the symptoms might be improved. Therefore, in the past decade, low FODMAP diet has been intensively investigated in the management of IBS. The capacity of FODMAPs to trigger the symptoms in patients with IBS was related to the stimulation of mechanoreceptors in the small and large intestine. This stimulation appears as a response to a combination of increased luminal water (the osmotic effect) and the release of gases (carbon dioxide and hydrogen) due to the fermentation of oligosaccharides and malabsorption of fructose, lactose and polyols. Numerous studies have been published regarding the efficacy of a low FODMAP diet compared to a traditional diet in releasing the IBS symptoms in adults, but there are only a few studies in the juvenile population. The aim of this review is to analyze the current data on both low FODMAP diet in children with IBS and the effects on their nutritional status and physiological development, given the fact that it is a restrictive diet.

Impact of occupational stress on irritable bowel syndrome pathophysiology and potential management in active duty noncombat Greek military personnel: a multicenter prospective survey

INTRODUCTION

Irritable bowel syndrome (IBS) is one of the gut-brain axis interaction disorders. It has global distribution with varying prevalence and particular financial and psychological consequences. IBS has been associated with stress and anxiety, conditions that are usually prevalent in the army. There are scarce data investigating the impact of IBS on noncombat active duty military without reports of Greek military or stress in the occupational environment.

MATERIALS AND METHODS

The main exclusion criteria in our noncombat military multicenter prospective survey were gastrointestinal pathologies, malignancies, hematochezia, recent infections and antibiotics prescription, and pregnancy. Questionnaires included a synthesis of baseline information, lifestyle, and diet, psychological and stress-investigating scales and the IBS diagnosis checklist. Hospital Anxiety and Depression Scale and Rome IV criteria were utilized.

RESULTS

Among 1605 participants included finally, the prevalence of IBS was 8% and 131 cases were identified. Women were more vulnerable to IBS, although male sex was prevalent at a ratio of 3.5 : 1 (male:female) in the entire sample. The mean age of all participants was 23.85 years; most of the IBS patients were older than thirty. Abnormal anxiety scores and high levels of occupational stress were related to an IBS diagnosis.

DISCUSSION

This prospective multicenter survey showed, for the first time, the potential impact of occupational stress on IBS in active duty noncombat Greek Military personnel. The diagnosis of IBS by questionnaire is a quick, affordable way that can upgrade, by its management, the quality of life and relieve from the military burden. Our results are comparable with previous studies, although large-scale epidemiological studies are required for the confirmation of a possible causative relationship.

Painful neurotrophins and their role in visceral pain

Beyond their well-known role in embryonic development of the central and peripheral nervous system, neurotrophins, particularly nerve growth factor and brain-derived neurotrophic factor, exert an essential role in pain production and sensitization. This has mainly been studied within the framework of somatic pain, and even antibodies (tanezumab and fasinumab) have recently been developed for their use in chronic somatic painful conditions, such as osteoarthritis or low back pain. However, data suggest that neurotrophins also exert an important role in the occurrence of visceral pain and visceral sensitization. Visceral pain is a distressing symptom that prompts many consultations and is typically encountered in both 'organic' (generally inflammatory) and 'functional' (displaying no obvious structural changes in routine clinical evaluations) disorders of the gut, such as inflammatory bowel disease and irritable bowel syndrome, respectively. The present review provides a summary of neurotrophins as a molecular family and their role in pain in general and addresses recent investigations of the involvement of nerve growth factor and brain-derived neurotrophic factor in visceral pain, particularly that associated with inflammatory bowel disease and irritable bowel syndrome.

Irritable Bowel Syndrome: What Treatments Really Work

Irritable bowel syndrome (IBS) is present in patients with symptoms of chronic abdominal pain and altered bowel habits but no identifiable organic etiology. Rome IV classification groups patients based on predominant stool pattern. Low-FODMAP diets have been helpful in providing symptom relief, as have cognitive behavioral and mind-body techniques that help patients manage symptoms. Targeted symptomatic relief for the patient's predominant symptoms provides relief in addition to effective older medications that are inexpensive and reliable. Newer treatments for IBS-D, such as eluxadoline, and IBS-C, with linaclotide, lubiprostone, plecanatide, also can provide durable relief.

Celiac disease in Iranian irritable bowel syndrome patients; a systematic review and meta-analysis

AIM

The present study was conducted to evaluate the prevalence, clinical symptoms and pathological findings of celiac disease (CD) in irritable bowel syndrome (IBS) patients in Iran.

BACKGROUND

Several studies show high prevalence of CD in IBS patients, but the results are contradictory.

METHODS

The present study was conducted based on MOOSE protocol and results were reported according to PRISMA guideline. The search was done using international online databases (Scopus, PubMed, Science Direct, Cochrane Library, Embase, and Web of Science), national databases and Google Scholar search engine.

RESULTS

The pooled prevalence of CD in 2,367 Iranian IBS patients was estimated to be 6.13% (95%CI: 4.11-9.05). The prevalence of CD in men and women with IBS was 4.28% (95% CI: 2.45-7.37) and 7.19% (95% CI: 4.51-11.28), respectively. The serological prevalence of anti tTG-IgA (11 studies with 2901 IBS patients) and AGA-IgG (4 studies with 936 IBS patients) was estimated to be 5.35% (95%CI: 3.60-7.89) and 6.35% (95%CI: 2.05-18.03), respectively. The clinical symptoms of CD among IBS patients included predominant diarrhea (47.87% [95%CI: 22.46-74.43]), predominant constipation (17.34% [95%CI: 9.17-30.35]), and alternative diarrhea and constipation (27.84% [95%CI: 11.57-53.23]). According to pathological findings based on marsh classification, the prevalence of CD at stages 1, 2 and 3 were 30.89% (95%CI: 13.25-56.68), 36.56% (95%CI: 21.74-54.45) and 52.87% (95%CI: 14.48-88.13), respectively.

CONCLUSION

In the present meta-analysis, we observed a high prevalence for CD among Iranian IBS patients, which is higher than global estimates. Examination of all IBS patients in terms of CD seems to be necessary, but cost-effectiveness should be considered.

ChREBP deficiency leads to diarrhea-predominant irritable bowel syndrome

OBJECTIVE

Fructose malabsorption is a common digestive disorder in which absorption of fructose in the small intestine is impaired. An abnormality of the main intestinal fructose transporter proteins has been proposed as a cause for fructose malabsorption. However the underlying molecular mechanism for this remains unclear. In this study, we investigated whether carbohydrate response element-binding protein (ChREBP) plays a role in intestinal fructose absorption through the regulation of genes involved in fructose transport and metabolism and ion transport.

METHODS

Wild type (WT) and Chrebp knockout (KO) mice (6 or 8 weeks old) were fed a control diet (55% starch, 15% maltodextrin 10) or high-fructose diet (HFrD, 60% fructose, 10% starch) for 3-12 days. Body weight and food intake were measured, signs of fructose malabsorption were monitored, and the expression of genes involved in fructose transport/metabolism and ion transport was evaluated. Furthermore, transient transfection and chromatin immunoprecipitation were performed to show the direct interaction between ChREBP and carbohydrate response elements in the promoter of Slc2A5, which encodes the fructose transporter GLUT5.

RESULTS

Chrebp KO mice fed the control diet maintained a constant body weight, whereas those fed a HFrD showed significant weight loss within 3-5 days. In addition, Chrebp KO mice fed the HFrD exhibited a markedly distended cecum and proximal colon containing both fluid and gas, suggesting incomplete fructose absorption. Fructose-induced increases of genes involved in fructose transport (GLUT5), fructose metabolism (fructokinase, aldolase B, triokinase, and lactate dehydrogenase), and gluconeogenesis (glucose-6-phosphatase and fructose-1,6-bisphosphatase) were observed in the intestine of WT but not of Chrebp KO mice. Moreover the Na⁺/H⁺ exchanger NHE3, which is involved in Na⁺ and water absorption in the intestine, was significantly decreased in HFrD-fed Chrebp KO mice. Consistent with this finding, the high-fructose diet-fed Chrebp KO mice developed severe diarrhea. Results of chromatin immunoprecipitation assays showed a direct interaction of ChREBP with the Glut5 promoter, but not the Nhe3 promoter, in the small intestine. Ectopic co-expression of ChREBP and its heterodimer partner Max-like protein X activated the Glut5 promoter in Caco-2BBE cells.

CONCLUSIONS

ChREBP plays a key role in the dietary fructose transport as well as conversion into lactate and glucose through direct transcriptional control of genes involved in fructose transport, fructolysis, and gluconeogenesis. Moreover, ablation of Chrebp results in a severe diarrhea in mice fed a high-fructose diet, which is associated with the insufficient induction of GLUT5 in the intestine.

The Food-Specific Serum IgG Reactivity in Major Depressive Disorder Patients, Irritable Bowel Syndrome Patients and Healthy Controls

There is an increasing amount of evidence which links the pathogenesis of irritable bowel syndrome (IBS) with food IgG hyperreactivity. Some authors have suggested that food IgG hyperreactivity could be also involved in the pathophysiology of major depressive disorder (MDD). The aim of this study was to compare levels of serum IgG against 39 selected food antigens between three groups of participants: patients with MDD (MDD group), patients with IBS (IBS group) and healthy controls (HC group). The study included 65 participants (22 in the MDD group, 22 in the IBS group and 21 in the HC group). Serum IgG levels were examined using enzyme-linked immunosorbent assay (ELISA). Medical records, clinical data and laboratory results were collected for the analysis. IgG food hyperreactivity (interpreted as an average of levels of IgG antibodies above 7.5 µg/mL) was detected in 28 (43%) participants, including 14 (64%) from the MDD group, ten (46%) from the IBS group and four (19%) from the HC group. We found differences between extreme IgG levels in MDD versus HC groups and in IBS versus HC groups. Patients with MDD had significantly higher serum levels of total IgG antibodies and IgG against celery, garlic and gluten compared with healthy controls. The MDD group also had higher serum IgG levels against gluten compared with the IBS group. Our results suggest dissimilarity in immune responses against food proteins between the examined groups, with the highest immunoreactivity in the MDD group. Further studies are needed to repeat and confirm these results in bigger cohorts and also examine clinical utility of IgG-based elimination diet in patients with MDD and IBS.

Radar plots: A novel modality for displaying disparate data on the efficacy of eluxadoline for the treatment of irritable bowel syndrome with diarrhea

BACKGROUND

Patients with irritable bowel syndrome with diarrhea (IBS-D) experience a range of abdominal and bowel symptoms; successful management requires alleviation of this constellation of symptoms. Eluxadoline, a locally active mixed μ- and κ-opioid receptor agonist and δ-opioid receptor antagonist, is approved for the treatment of IBS-D in adults based on the results of 2 Phase 3 studies. Radar plots can facilitate comprehensive, visual evaluation of diverse but interrelated efficacy endpoints.

METHODS

Two double-blind, placebo-controlled, Phase 3 trials (IBS-3001 and IBS-3002) randomized patients meeting Rome III criteria for IBS-D to twice-daily eluxadoline 75 or 100 mg or placebo. Radar plots were prepared showing pooled Weeks 1-26 response rates for the primary efficacy composite endpoint (simultaneous improvement in abdominal pain and stool consistency), stool consistency, abdominal pain, urgency-free days, and adequate relief, and change from baseline to Week 26 in IBS-D global symptom score, abdominal discomfort, abdominal pain, abdominal bloating, and daily number of bowel movements.

KEY RESULTS

The studies enrolled 2428 patients. Eluxadoline increased Weeks 1-26 responder proportions vs placebo for the composite endpoint, stool consistency, abdominal pain, urgency-free days, and adequate relief. Changes from baseline to Week 26 in IBS-D global symptom score, abdominal discomfort, abdominal pain, abdominal bloating, and number of bowel movements were greater with eluxadoline vs placebo.

CONCLUSIONS AND INFERENCES

Data presentation in radar plot format facilitates interpretation across multiple domains, demonstrating that eluxadoline treatment led to improvements vs placebo across 13 endpoints representing the range of symptoms experienced by patients with IBS-D.

Layperson's knowledge and perceptions of irritable bowel syndrome as potential barriers to care

AIMS

The aim of this study was to describe the layperson's knowledge and perceptions regarding the aetiology, pathogenesis, prevalence, medical evaluation, diagnosis and treatment of irritable bowel syndrome.

BACKGROUND

Diagnosis acceptance and adherence to treatment is influenced by the views of the patient's social networks. Little is known how these networks influence those with irritable bowel syndrome.

DESIGN

Cross-sectional study of two-hundred four laypersons, ages 18-80 years without an irritable bowel syndrome diagnosis.

METHODS

Data were collected May 2016-March 2017. Laypersons without a diagnosis of IBS self-reported their knowledge and perceptions about IBS.

RESULTS/FINDINGS

Participants were able to identify many symptoms associated with irritable bowel syndrome however held misconceptions regarding the development of irritable bowel syndrome as noted by the endorsement of genetics, environment and diet or alcohol/smoking behaviours as specific causes. Further misconceptions held included the belief that irritable bowel syndrome was associated with an increased risk for the development of colon cancer and inflammatory bowel disease. Contrary to current guidelines, many thought a gastroenterologist was the only person appropriate to diagnose irritable bowel syndrome and objective testing, such as colonoscopy, was necessary to establish a diagnosis.

CONCLUSION

Laypersons have an understanding of the symptoms associated with IBS; however, hold numerous misconceptions regarding the aetiology, role of the healthcare provider, necessary testing and risks associated with irritable bowel syndrome. These misconceptions are inconsistent with current guidelines and practices. Establishing partnerships and educating social networks in addition to patients may enhance outcomes for those with IBS.