Palmitoylethanolamide and polydatin in pediatric irritable bowel syndrome: A multicentric randomized controlled trial

OBJECTIVE

This study aimed to evaluate the efficacy and safety of co-micronized palmitoylethanolamide (PEA)/polydatin (PD) in the treatment of abdominal pain symptoms in pediatric patients with irritable bowel syndrome (IBS).

METHODS

This was a multicenter trial conducted at three Italian pediatric gastroenterology centers, employing a double-blind, placebo-controlled, parallel-arm design. Participants were ages 10 to 17 y and met Rome IV criteria for pediatric IBS. They were randomly allocated to receive either co-micronized PEA/PD or placebo, administered three times daily in a 1:1 ratio, over a 12-wk period. The study assessed baseline severity using the IBS-Severity Scoring System (IBS-SSS) at enrollment and after 4, 8, and 12 wk of treatment. Abdominal pain frequency was assessed on a scale from 1 to 7 d/wk, while stool consistency was classified using the Bristol Stool Scale (BSS) to categorize various IBS subtypes. The primary outcome was the percentage of patients who achieved complete remission, defined as IBS-SSS score <75 points after 12 wk of therapy.

RESULTS

The study involved 70 children with IBS. Of the participants, 34 received co-micronized PEA/PD, and 36 received a placebo. As compared with the placebo group, the co-micronized therapy group had significantly more patients achieving complete remission after 12 wk (P = 0.015), with particular benefit in the IBS-diarrhea subtype (P = 0.01). The treatment group also experienced a significant reduction in abdominal pain intensity and frequency compared with the placebo group. No adverse events were recorded during the study period.

CONCLUSIONS

Co-micronized PEA/PD is a safe and effective treatment to treat abdominal pain symptoms in pediatric IBS.

Microbiota modulation in disorders of gut-brain interaction

Disorders of gut-brain interaction (DGBI) are common chronic conditions characterized by persistent and recurring gastrointestinal symptoms triggered by several pathophysiological factors, including an altered gut microbiota. The most common DGBI are irritable bowel syndrome (IBS), functional constipation (FC) and functional dyspepsia (FD). Recently, a deep understanding of the role of the gut microbiota in these diseases was possible due to multi-omics methods capable to provide a comprehensive assessment. Most of the therapies recommended for these patients, can modulate the gut microbiota such as diet, prebiotics, probiotics and non-absorbable antibiotics, which were shown to be safe and effective. Since patients complain symptoms after food ingestion, diet represents the first line therapeutic approach. Avoiding dietary fat and fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, and increasing the number of soluble fibers represent the therapeutic choices for FD, IBS and FC respectively. Probiotics, as a category, have been employed with good results in all the abovementioned DGBI. Rifaximin has been shown to be useful in the context of bowel related disorders, although a recent trial showed positive results for FD. Fecal microbiota transplantation has been tested for IBS and FC with promising results. In this review, we will briefly summarize the current understanding on dysbiosis and discuss microbiota modulation strategies to treat patients with DGBI.

Italian guidelines for the management of irritable bowel syndrome in children and adolescents : Joint Consensus from the Italian Societies of: Gastroenterology, Hepatology and Pediatric Nutrition (SIGENP), Pediatrics (SIP), Gastroenterology and Endoscopy (SIGE) and Neurogastroenterology and Motility (SINGEM)

The irritable bowel syndrome (IBS) is a functional gastrointestinal disorder (FGID), whose prevalence has widely increased in pediatric population during the past two decades. The exact pathophysiological mechanism underlying IBS is still uncertain, thus resulting in challenging diagnosis and management. Experts from 4 Italian Societies participated in a Delphi consensus, searching medical literature and voting process on 22 statements on both diagnosis and management of IBS in children. Recommendations and levels of evidence were evaluated according to the grading of recommendations, assessment, development, and evaluation (GRADE) criteria. Consensus was reached for all statements. These guidelines suggest a positive diagnostic strategy within a symptom-based approach, comprehensive of psychological comorbidities assessment, alarm signs and symptoms' exclusion, testing for celiac disease and, under specific circumstances, fecal calprotectin and C-reactive protein. Consensus also suggests to rule out constipation in case of therapeutic failure. Conversely, routine stool testing for enteric pathogens, testing for food allergy/intolerance or small intestinal bacterial overgrowth are not recommended. Colonoscopy is recommended only in patients with alarm features. Regarding treatment, the consensus strongly suggests a dietary approach, psychologically directed therapies and, in specific conditions, gut-brain neuromodulators, under specialist supervision. Conditional recommendation was provided for both probiotics and specific fibers supplementation. Polyethylene glycol achieved consensus recommendation for specific subtypes of IBS. Secretagogues and 5-HT4 agonists are not recommended in children with IBS-C. Certain complementary alternative therapies, antispasmodics and, in specific IBS subtypes, loperamide and rifaximin could be considered.

Journal of Clinical Gastroenterology Lectureship Dubai 2022 : Management of Irritable Bowel Syndrome With Diarrhea

Irritable bowel syndrome (IBS) with diarrhea (IBS-D) affects ~1% of the general population and is characterized by abdominal pain associated with diarrhea. IBS-D symptoms significantly impact the quality of life of patients. Major uncertainties remain regarding the optimal management of these patients. Several therapies have been investigated over the years for the treatment of IBS-D. In the initial management, commonly prescribed approaches with an effect on global IBS symptoms include a low Fermentable Oligo-, Di-, Mono-Saccharides and Polyols diet and probiotics, while antispasmodics are used for targeting abdominal pain and loperamide for diarrhea only. Additional therapeutic options for the relief of global IBS symptoms include rifaximin, 5-HT 3 antagonists, gut-directed psychological therapies, and eluxadoline, while tricyclic antidepressants can target abdominal pain and bile acid sequestrants diarrhea. Promising evidence exists for the use of mesalazine and fecal microbiota transplantation in IBS-D, although further evidence is needed for definitive conclusions regarding their efficacy.

The Role of the FODMAP Diet in IBS

The low FODMAP (fermentable oligosaccharide, disaccharide, monosaccharide, and polyol) diet is a beneficial therapeutic approach for patients with irritable bowel syndrome (IBS). However, how the low FODMAP diet works is still not completely understood. These mechanisms encompass not only traditionally known factors such as luminal distension induced by gas and water but also recent evidence on the role of FOMAPs in the modulation of visceral hypersensitivity, increases in intestinal permeability, the induction of microbiota changes, and the production of short-chain fatty acids (SCFAs), as well as metabolomics and alterations in motility. Although most of the supporting evidence is of low quality, recent trials have confirmed its effectiveness, even though the majority of the evidence pertains only to the restriction phase and its effectiveness in relieving abdominal bloating and pain. This review examines potential pathophysiological mechanisms and provides an overview of the existing evidence on the effectiveness of the low FODMAP diet across various IBS subtypes. Key considerations for its use include the challenges and disadvantages associated with its practical implementation, including the need for professional guidance, variations in individual responses, concerns related to microbiota, nutritional deficiencies, the development of constipation, the necessity of excluding an eating disorder before commencing the diet, and the scarcity of long-term data. Despite its recognized efficacy in symptom management, acknowledging these limitations becomes imperative for a nuanced comprehension of the role of a low FODMAP diet in managing IBS. By investigating its potential mechanisms and evidence across IBS subtypes and addressing emerging modulations alongside limitations, this review aims to serve as a valuable resource for healthcare practitioners, researchers, and patients navigating the intricate landscape of IBS.

Collinsella aerofaciens as a predictive marker of response to probiotic treatment in non-constipated irritable bowel syndrome

Probiotics are exploited for adjuvant treatment in IBS, but reliable guidance for selecting the appropriate probiotic to adopt for different forms of IBS is lacking. We aimed to identify markers for recognizing non-constipated (NC) IBS patients that may show significant clinical improvements upon treatment with the probiotic strain Lacticaseibacillus paracasei DG (LDG). To this purpose, we performed a post-hoc analysis of samples collected during a multicenter, double-blind, parallel-group, placebo-controlled trial in which NC-IBS patients were randomized to receive at least 24 billion CFU LDG or placebo capsules b.i.d. for 12 weeks. The primary clinical endpoint was the composite response based on improved abdominal pain and fecal type. The fecal microbiome and serum markers of intestinal (PV1 and zonulin), liver, and kidney functions were investigated. We found that responders (R) in the probiotic arm (25%) differed from non-responders (NR) based on the abundance of 18 bacterial taxa, including the families Coriobacteriaceae, Dorea spp. and Collinsella aerofaciens, which were overrepresented in R patients. These taxa also distinguished R (but not NR) patients from healthy controls. Probiotic intervention significantly reduced the abundance of these bacteria in R, but not in NR. Analogous results emerged for C. aerofaciens from the analysis of data from a previous trial on IBS with the same probiotic. Finally, C. aerofaciens was positively correlated with the plasmalemmal vesicle associated protein-1 (PV-1) and the markers of liver function. In conclusion, LDG is effective on NC-IBS patients with NC-IBS with a greater abundance of potential pathobionts. Among these, C. aerofaciens has emerged as a potential predictor of probiotic efficacy.

The role of microbiota and its modulation in colonic diverticular disease

BACKGROUND

Diverticular disease (DD) is a common condition in Western countries. The role of microbiota in the pathogenesis of DD and its related symptoms has been frequently postulated since most complications of this disease are bacteria-driven and most therapies rely on microbiota modulation. Preliminary data showed fecal microbial imbalance in patients with DD, particularly when symptomatic, with an increase of pro-inflammatory and potentially pathogenetic bacteria. In addition, bacterial metabolic markers can mirror specific pathways of the disease and may be even used for monitoring treatment effects. All treatments currently suggested for DD can affect microbiota structure and metabolome compositions.

PURPOSE

Sparse evidence is available linking gut microbiota perturbations, diverticular disease pathophysiology, and symptom development. We aimed to summarize the available knowledge on gut microbiota evaluation in diverticular disease, with a focus on symptomatic uncomplicated DD, and the relative treatment strategies.

Fecal short-chain fatty acids in non-constipated irritable bowel syndrome: a potential clinically relevant stratification factor based on catabotyping analysis

The gut microbiota is believed to be a critical factor in the pathogenesis of IBS, and its metabolic byproducts, such as short-chain fatty acids (SCFAs), are known to influence gut function and host health. Despite this, the precise role of SCFAs in IBS remains a topic of debate. In this study, we examined the bacterial community structure by 16S rRNA gene profiling and SCFA levels by UPLC-MS/MS in fecal samples from healthy controls (HC; n = 100) and non-constipated patients (IBS-D and IBS-M; NC-IBS; n = 240) enrolled in 19 hospitals in Italy. Our findings suggest a significant difference between the fecal microbiomes of NC-IBS patients and HC subjects, with HC exhibiting higher intra-sample biodiversity. Furthermore, we were able to classify non-constipated patients into two distinct subgroups based on their fecal SCFA levels (fecal catabotype "high" and "low"), each characterized by unique taxonomic bacterial signatures. Our results suggest that the fecal catabotype with higher SCFA levels may represent a distinct clinical phenotype of IBS that could have implications for its diagnosis and treatment. This study provides a new perspective on the intricate relationship between the gut microbiome and bowel symptoms in IBS, underscoring the importance of personalized strategies for its management.

Current and Novel Therapies for Eosinophilic Gastrointestinal Diseases

Eosinophilic gastrointestinal diseases (EGIDs) are an emerging group of pathological entities characterized by an eosinophil-predominant infiltration of different tracts of the gut in the absence of secondary causes of eosinophilia. According to the specific tract of the gut involved, EGIDs can be classified into eosinophilic esophagitis (EoE), eosinophilic gastritis (EoG), eosinophilic enteritis (EoN), and eosinophilic colitis (EoC). The epidemiology of EGIDs is evolving rapidly. EoE, once considered a rare disease, now has an incidence and prevalence of 7.7 new cases per 100,000 inhabitants per years and 34.4 cases per 100,000 inhabitants per year, respectively. Fewer data are available regarding non-EoE EGIDs, whose prevalence are estimated to range between 2.1 and 17.6 in 100,000 individuals, depending on age, sex, and ethnicity. Diagnosis requires the presence of suggestive symptoms, endoscopic biopsies showing abnormal values of eosinophils infiltrating the gut, and exclusion of secondary causes of eosinophilia. EoE typically presents with dysphagia and episodes of food bolus impactions, while EoG, EoN, and EoC may all present with abdominal pain and diarrhea, with or without other non-specific symptoms. In addition, although different EGIDs are currently classified as different entities, there may be overlap between different diseases in the same patient. Despite EGIDs being relatively novel pathological entities, the research on possible treatments is rapidly growing. In this regard, several randomized controlled trials are currently ongoing to investigate novel molecules, including ad-hoc steroid formulations, immunosuppressants, and mostly monoclonal antibodies that target the specific molecular mediators of EGIDs. This narrative review provides an up-to-date overview of available and investigational drugs for different EGIDs.

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.

Meta-analysis: Post-COVID-19 functional dyspepsia and irritable bowel syndrome

INTRODUCTION

The burden of post-COVID-19 functional dyspepsia (FD) and irritable bowel syndrome (IBS) remains unclear. The aim of this meta-analysis was to estimate the rate of post-COVID-19 FD and IBS.

METHODS

MEDLINE, Scopus and Embase were searched through 17 December 2022. Studies reporting the incidence of FD and/or IBS in COVID-19 survivors and controls (without COVID-19), when available, according to the Rome criteria, were included. Estimated incidence with 95% confidence intervals (CI) was pooled. The odds ratio (OR) with 95% confidence intervals (CI) was pooled; heterogeneity was expressed as I² .

RESULTS

Ten studies met the inclusion criteria and were included in the analysis. Overall, four studies including 1199 COVID-19 patients were considered for FD. Post-COVID-19 FD was reported by 72 patients (4%, 95% CI: 3%-5% and I² 0%). The pooled OR for FD development (three studies) in post-COVID-19 patients compared to controls was 8.07 (95% CI: 0.84-77.87, p = 0.071 and I²  = 67.9%). Overall, 10 studies including 2763 COVID-19 patients were considered for IBS. Post-COVID-19 IBS was reported by 195 patients (12%, 95% CI: 8%-16%, I² 95.6% and Egger's p = 0.002 test). The pooled OR for IBS development (four studies) in COVID-19 patients compared to controls was 6.27 (95% CI: 0.88-44.76, p = 0.067 and I²  = 81.4%); considering only studies with a prospective COVID-19 cohort (three studies), the pooled OR was 12.92 (95% CI: 3.58-46.60, p < 0.001 and I²  = 0%).

CONCLUSIONS

COVID-19 survivors were found to be at risk for IBS development compared to controls. No definitive data are available for FD.

Role of inflammation in pediatric irritable bowel syndrome

BACKGROUND

IBS affects a large number of children throughout the world and is thought to be the result of disturbed neuroimmune function along with the brain-gut axis. Although the underlying pathophysiologic mechanisms are not clear, the role of low-grade inflammation and mucosal immune activation in IBS symptom generation has become evident also in subsets of pediatric patients. Animal models provided meaningful insight in the causal relationship between abnormal mucosal immune activation and changes in gastrointestinal (GI) sensory-motor function. Likewise, the development of long-standing GI symptoms fulfilling the current criteria for functional GI disorders after infection gastroenteritis and in patients with IBD or celiac disease in remission further supports this hypothesis. Immune activation, its impact on gut sensory-motor function, and potential implications for symptom generation emerged in both children and adults with IBS.

PURPOSE

The aim of this review is to summarize the main evidence on the presence of low-grade inflammation and immune activation in children with IBS, its possible role in symptom generation, and its potential implication for new therapeutic strategies.

Chronic constipation: from pathophysiology to management

Chronic constipation (CC) is one of the most common conditions found in gastrointestinal clinical practice and defined by the presence of fewer than 3 bowel movements per week and/or more than one fourth of bowel movements with Bristol stool form types 1 or 2. CC affects people regardless of race, age, or sex, although it is most common in women and in elderly. It is associated with relevant disease burden, including significant impairment of patients' quality of life. In the absence of alarm features, patients should receive a symptom-based diagnosis. Treatment options include lifestyle and general measures, bulking agents, in particular dietary fiber supplementation. Osmotic laxatives are currently considered the first-line gold-standard pharmacological treatment of CC together with stimulant laxatives which are often used as a rescue therapy. When necessary, prokinetic agents and/or intestinal secretagogues can be used. Biofeedback may be indicated in patients with functional defecation disorders. In this review, we will briefly summarize the current understanding on epidemiology, classification, pathophysiology and clinical evaluation of CC and discuss in depth the pharmacological and not pharmacological management of patients with this disorder.

Italian guidelines for the management of irritable bowel syndrome: Joint Consensus from the Italian Societies of: Gastroenterology and Endoscopy (SIGE), Neurogastroenterology and Motility (SINGEM), Hospital Gastroenterologists and Endoscopists (AIGO), Digestive Endoscopy (SIED), General Medicine (SIMG), Gastroenterology, Hepatology and Pediatric Nutrition (SIGENP) and Pediatrics (SIP)

The irritable bowel syndrome (IBS) is a chronic disorder of gut-brain interaction. IBS is still associated with areas of uncertainties, especially regarding the optimal diagnostic work-up and the more appropriate management. Experts from 7 Italian Societies conducted a Delphi consensus with literature summary and voting process on 27 statements. Recommendations and quality of evidence were evaluated using the grading of recommendations, assessment, development, and evaluation (GRADE) criteria. Consensus was defined as >80% agreement and reached for all statements. In terms of diagnosis, the consensus supports a positive diagnostic strategy with a symptom-based approach, including the psychological comorbidities assessment and the exclusion of alarm symptoms, together with the digital rectal examination, full blood count, C-reactive protein, serology for coeliac disease, and fecal calprotectin assessment. Colonoscopy should be recommended in patients with alarm features. Regarding treatment, the consensus strongly supports a dietary approach for patients with IBS, the use of soluble fiber, secretagogues, tricyclic antidepressants, psychologically directed therapies and, only in specific IBS subtypes, rifaximin. A conditional recommendation was achieved for probiotics, polyethylene glycol, antispasmodics, selective serotonin reuptake inhibitors and, only in specific IBS subtypes, 5-HT3 antagonists, 5-HT4 agonists, bile acid sequestrants.

Post COVID-19 irritable bowel syndrome

OBJECTIVES

The long-term consequences of COVID-19 infection on the gastrointestinal tract remain unclear. Here, we aimed to evaluate the prevalence of gastrointestinal symptoms and post-COVID-19 disorders of gut-brain interaction after hospitalisation for SARS-CoV-2 infection.

DESIGN

GI-COVID-19 is a prospective, multicentre, controlled study. Patients with and without COVID-19 diagnosis were evaluated on hospital admission and after 1, 6 and 12 months post hospitalisation. Gastrointestinal symptoms, anxiety and depression were assessed using validated questionnaires.

RESULTS

The study included 2183 hospitalised patients. The primary analysis included a total of 883 patients (614 patients with COVID-19 and 269 controls) due to the exclusion of patients with pre-existing gastrointestinal symptoms and/or surgery. At enrolment, gastrointestinal symptoms were more frequent among patients with COVID-19 than in the control group (59.3% vs 39.7%, p<0.001). At the 12-month follow-up, constipation and hard stools were significantly more prevalent in controls than in patients with COVID-19 (16% vs 9.6%, p=0.019 and 17.7% vs 10.9%, p=0.011, respectively). Compared with controls, patients with COVID-19 reported higher rates of irritable bowel syndrome (IBS) according to Rome IV criteria: 0.5% versus 3.2%, p=0.045. Factors significantly associated with IBS diagnosis included history of allergies, chronic intake of proton pump inhibitors and presence of dyspnoea. At the 6-month follow-up, the rate of patients with COVID-19 fulfilling the criteria for depression was higher than among controls.

CONCLUSION

Compared with controls, hospitalised patients with COVID-19 had fewer problems of constipation and hard stools at 12 months after acute infection. Patients with COVID-19 had significantly higher rates of IBS than controls.

TRIAL REGISTRATION NUMBER

NCT04691895.

Functional bowel disorders with diarrhoea: Clinical guidelines of the United European Gastroenterology and European Society for Neurogastroenterology and Motility

Irritable bowel syndrome with diarrhoea (IBS‐D) and functional diarrhoea (FDr) are the two major functional bowel disorders characterized by diarrhoea. In spite of their high prevalence, IBS‐D and FDr are associated with major uncertainties, especially regarding their optimal diagnostic work‐up and management. A Delphi consensus was performed with experts from 10 European countries who conducted a literature summary and voting process on 31 statements. Quality of evidence was evaluated using the grading of recommendations, assessment, development, and evaluation criteria. Consensus (defined as >80% agreement) was reached for all the statements. The panel agreed with the potential overlapping of IBS‐D and FDr. In terms of diagnosis, the consensus supports a symptom‐based approach also with the exclusion of alarm symptoms, recommending the evaluation of full blood count, C‐reactive protein, serology for coeliac disease, and faecal calprotectin, and consideration of diagnosing bile acid diarrhoea. Colonoscopy with random biopsies in both the right and left colon is recommended in patients older than 50 years and in presence of alarm features. Regarding treatment, a strong consensus was achieved for the use of a diet low fermentable oligo‐, di‐, monosaccharides and polyols, gut‐directed psychological therapies, rifaximin, loperamide, and eluxadoline. A weak or conditional recommendation was achieved for antispasmodics, probiotics, tryciclic antidepressants, bile acid sequestrants, 5‐hydroxytryptamine‐3 antagonists (i.e. alosetron, ondansetron, or ramosetron). A multinational group of European experts summarized the current state of consensus on the definition, diagnosis, and management of IBS‐D and FDr.

Pathophysiology and Clinical Management of Bile Acid Diarrhea

Bile acid malabsorption (BAM) represents a common cause of chronic diarrhea whose prevalence is under-investigated. We reviewed the evidence available regarding the pathophysiology and clinical management of bile acid diarrhea (BAD). BAD results from dysregulation of the enterohepatic recirculation of bile acids. It has been estimated that 25–33% of patients with functional diarrhea and irritable bowel syndrome with diarrhea have BAM. Currently, the selenium homotaurocholic acid test is the gold standard for BAD diagnosis and severity assessment. However, it is an expensive method and not widely available. The validation of the utility in the clinical practice of several other serum markers, such as 7α-hydroxy-4-cholesten-3-one (C4) and the fibroblast growth factor 19 (FGF19) is ongoing. The first-line treatment of patients with BAD is bile acid sequestrants. Patients that are refractory to first-line therapy should undergo further diagnostics to confirm the diagnosis and to treat the underlying cause of BAD. An early and correct diagnosis of BAD would improve patient’s quality of life, avoiding additional diagnostic tests that burden health care systems. Considering the limited availability and tolerability of specific medications for BAD treatment, future research is awaited to identify other therapeutic approaches, such as gut microbiota modulating therapies.

Gut microbiota signatures and modulation in irritable bowel syndrome

Irritable bowel syndrome (IBS) affects approximately one tenth of the general population and is characterized by abdominal pain associated with abnormalities in bowel habits. Visceral hypersensitivity, abnormal intestinal motor function, mucosal immune activation, and increased intestinal permeability concur to its pathophysiology. Psychological factors can influence symptom perception at the central nervous system level. In addition, recent evidence suggests that dysbiosis may be a key pathophysiological factor in patients with IBS. Increasing understanding of the pathophysiological mechanisms translates into new and more effective therapeutic approaches. Indeed, in line with this evidence, IBS therapies nowadays include agents able to modulate gut microbiota function and composition, such as diet, prebiotics, probiotics, and antibiotics. In addition, in the last decade, an increasing interest in fecal microbiota transplantation has been paid. An in-depth understanding of the intestinal microenvironment through accurate faucal microbiota and metabolite analysis may provide valuable insights into the pathophysiology of IBS, finally shaping new tailored IBS therapies.

Inflammatory and Microbiota-Related Regulation of the Intestinal Epithelial Barrier

The intestinal epithelial barrier (IEB) is one of the largest interfaces between the environment and the internal milieu of the body. It is essential to limit the passage of harmful antigens and microorganisms and, on the other side, to assure the absorption of nutrients and water. The maintenance of this delicate equilibrium is tightly regulated as it is essential for human homeostasis. Luminal solutes and ions can pass across the IEB via two main routes: the transcellular pathway or the paracellular pathway. Tight junctions (TJs) are a multi-protein complex responsible for the regulation of paracellular permeability. TJs control the passage of antigens through the IEB and have a key role in maintaining barrier integrity. Several factors, including cytokines, gut microbiota, and dietary components are known to regulate intestinal TJs. Gut microbiota participates in several human functions including the modulation of epithelial cells and immune system through the release of several metabolites, such as short-chain fatty acids (SCFAs). Mediators released by immune cells can induce epithelial cell damage and TJs dysfunction. The subsequent disruption of the IEB allows the passage of antigens into the mucosa leading to further inflammation. Growing evidence indicates that dysbiosis, immune activation, and IEB dysfunction have a role in several diseases, including irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and gluten-related conditions. Here we summarize the interplay between the IEB and gut microbiota and mucosal immune system and their involvement in IBS, IBD, and gluten-related disorders.

Implications of SARS-CoV-2 infection for neurogastroenterology

BACKGROUND

Coronavirus disease 2019 (COVID-19) is associated with gastrointestinal and hepatic manifestation in up to one fifth of patients. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent of COVID-19, infects gastrointestinal epithelial cells expressing angiotensin-converting enzyme 2 (ACE2) receptors triggering a cascade of events leading to mucosal and systemic inflammation. Symptomatic patients display changes in gut microbiota composition and function which may contribute to intestinal barrier dysfunction and immune activation. Evidence suggests that SARS-CoV-2 infection and related mucosal inflammation impact on the function of the enteric nervous system and the activation of sensory fibers conveying information to the central nervous system, which, may at least in part, contribute symptom generation such as vomiting and diarrhea described in COVID-19. Liver and pancreas dysfunctions have also been described as non-respiratory complications of COVID-19 and add further emphasis to the common view of SARS-CoV-2 infection as a systemic disease with multiorgan involvement.

PURPOSE

The aim of this review was to highlight the current knowledge on the pathophysiology of gastrointestinal SARS-CoV-2 infection, including the crosstalk with the gut microbiota, the fecal-oral route of virus transmission, and the potential interaction of the virus with the enteric nervous system. We also review the current available data on gastrointestinal and liver manifestations, management, and outcomes of patients with COVID-19.

Distinguishing features between patients with acute diverticulitis and diverticular bleeding: Results from the REMAD registry

BACKGROUND

Pathogenesis of acute diverticulitis and diverticular bleeding remains poorly defined, and few data compare directly risk factors for these complications.

AIMS

to assess differences in clinical features, lifestyles factors and concurrent drug use in patients with acute diverticulitis and those with diverticular bleeding.

METHODS

Data were obtained from the REMAD Registry, an ongoing 5-year prospective, observational, multicenter, cohort study conducted on 1,217 patients. Patient- and clinical- related factors were compared among patients with uncomplicated diverticular disease, patients with previous acute diverticulitis, and patients with previous diverticular bleeding.

RESULTS

Age was significantly lower (OR 0.48, 95% CI: 0.34-0.67) and family history of diverticular disease was significantly higher (OR 1.60, 95% CI: 1.11-2.31) in patients with previous diverticulitis than in patients with uncomplicated diverticular disease, respectively. Chronic obstructive pulmonary disease was significantly higher in patients with previous diverticular bleeding as compared with both uncomplicated diverticular disease (OR 8.37, 95% CI: 2.60-27.0) and diverticulitis (OR 4.23, 95% CI: 1.11-16.1).

CONCLUSION

This ancillary study from a nationwide Registry showed that some distinctive features identify patients with acute diverticulitis and diverticular bleeding. These information might improve the assessment of risk factors for diverticular complications.

Non-Celiac Gluten Sensitivity in the Context of Functional Gastrointestinal Disorders

Gluten-free diets are increasingly chosen in the Western world, even in the absence of a diagnosis of celiac disease. Around 10% of people worldwide self-report gluten-related complaints, including intestinal and extra-intestinal symptoms. In most cases, these subjects would be labeled as patients suffering from irritable bowel syndrome (IBS) who place themselves on a gluten-free diet even in the absence of celiac disease. In some instances, patients report a clear benefit by avoiding gluten from their diet and/or symptom worsening upon gluten reintroduction. This clinical entity has been termed non-celiac gluten sensitivity (NCGS). The symptoms referred by these patients are both intestinal and extra-intestinal, suggesting that similarly to functional gastrointestinal disorders, NCGS is a disorder of gut-brain interaction. It remains unclear if gluten is the only wheat component involved in NCGS. The mechanisms underlying symptom generation in NCGS remain to be fully clarified, although in the past few years, the research has significantly moved forward with new data linking NCGS to changes in gut motility, permeability and innate immunity. The diagnosis is largely based on the self-reported reaction to gluten by the patient, as there are no available biomarkers, and confirmatory double-blind challenge protocols are unfeasible in daily clinical practice. Some studies suggest that a small proportion of patients with IBS have an intolerance to gluten. However, the benefits of gluten-free or low-gluten diets in non-celiac disease-related conditions are limited, and the long-term consequences of this practice may include nutritional and gut microbiota unbalance. Here, we summarize the role of gluten in the clinical features, pathophysiology, and management of NCGS and disorders of gut-brain interaction.

Serum zonulin and its diagnostic performance in non-coeliac gluten sensitivity

OBJECTIVE

Non-coeliac gluten sensitivity (NCGS) is characterised by intestinal and extraintestinal symptoms related to the ingestion of gluten-containing foods, in the absence of coeliac disease (CD) and wheat allergy. No biomarkers are available to diagnose NCGS and the gold standard double-blind placebo-controlled gluten challenge is clinically impractical. The aim of our work was to investigate the role of serum zonulin as a diagnostic biomarker of NCGS and to develop a diagnostic algorithm.

DESIGN

In a multicentre study, we enrolled 86 patients with either self-reported or double-blind confirmed NCGS, 59 patients with diarrhoea-predominant IBS (IBS-D), 15 patients with CD and 25 asymptomatic controls (AC). Zonulin serum levels were assessed and the associated diagnostic power calculated. Clinical and symptomatic data were recorded. The effect of diet on zonulin levels was evaluated in a subgroup of patients with NCGS.

RESULTS

Compared with ACs, the NCGS, irrespective of modality of diagnosis, and patients with CD had significantly increased levels of zonulin, as did both NCGS and patients with CD compared with participants with IBS-D. Self-reported NCGS showed increased zonulin levels compared with double-blind confirmed and not-confirmed NCGS. Six-month wheat avoidance significantly reduced zonulin levels only in HLA-DQ2/8-positive participants with NCGS. The diagnostic accuracy of zonulin levels in distinguishing NCGS from IBS-D was 81%. After exclusion of CD, a diagnostic algorithm combining zonulin levels, symptoms and gender improved the accuracy to 89%.

CONCLUSION

Zonulin can be considered a diagnostic biomarker in NCGS and combined with demographic and clinical data differentiates NCGS from IBS-D with high accuracy. Wheat withdrawal was associated with a reduction in zonulin levels only in NCGS carrying HLA genotype.

µ-opioid receptor, β-endorphin, and cannabinoid receptor-2 are increased in the colonic mucosa of irritable bowel syndrome patients

BACKGROUND AND AIMS

The gut immune, cannabinoid, and opioid systems constitute an integrated network contributing to visceral sensation and pain modulation. We aimed to assess the expression of the µ-opioid receptor (MOR), its ligand β-endorphin (β-END), and cannabinoid receptor-2 (CB2 ) in patients with irritable bowel syndrome (IBS) and asymptomatic controls (AC) and their correlation with sex and symptom perception.

METHODS

Mucosal biopsies were obtained from the left colon of 31 IBS patients (45% women) with predominant constipation (IBS-C, 9) or diarrhea (IBS-D, 10) or with mixed bowel habits (IBS-M, 12) and 32 AC (44% women) and processed for qRT-PCR, Western blotting, and immunohistochemistry.

KEY RESULTS

µ-opioid receptor and CB2 mRNA and protein expression and β-END protein levels were increased in patients with IBS compared to AC (all Ps=0.021). A significant sex by IBS interaction was found in relation to CB2 mRNA expression (P = .003) with women showing a markedly higher expression to men (P = .035). In contrast, in AC, men had higher expression than women (P = .033). β-END, MOR, and CB2 immunoreactivities (IR) were localized to CD4+T cells including EMR-1+ eosinophils and CD31+ T cells but not to mast cells.

CONCLUSIONS

The increased expression of MOR, β-END, and CB2 in the mucosa of IBS patients, where they are localized to immune cells, suggests that opioid and cannabinoid systems play an immune-related compensatory role in visceral pain in IBS patients. Further work is necessary to support this hypothesis.

Nerve fiber overgrowth in patients with symptomatic diverticular disease

BACKGROUND

Colonic diverticulosis is a common condition in industrialized countries. Up to 25% of patients with diverticula develop symptoms, a condition termed symptomatic uncomplicated diverticular disease (SUDD). The aim of the present study was to characterize neuroimmune interactions and nerve fiber plasticity in the colonic mucosa of patients with diverticula.

METHODS

Controls, patients with diverticulosis and with SUDD were enrolled in the study. Mucosal biopsies were obtained close to diverticula (diverticular region) and in a normal mucosa (distant site), corresponding to sigmoid and descending colon in the controls. Quantitative immunohistochemistry was used to assess mast cells, T cells, macrophages, nerve fibers, and neuronal outgrowth (growth-associated protein 43, GAP43+fibers).

KEY RESULTS

No difference emerged in mast cells and T cells among the three groups. Macrophages were increased in patients with SUDD and diverticulosis as compared to controls. Nerve fibers were enhanced in patients with SUDD and diverticulosis in comparison with controls in the diverticular region. GAP43+ fibers were increased only in patients with SUDD as compared to controls and to patients with diverticulosis in the diverticular region. In patients with SUDD, GAP43 density was increased in the diverticular region compared to distant site. Macrophages close to GAP43+ fibers were increased in the diverticular region of patients with SUDD. Significant correlations were found between GAP43+ fibers and immune cells.

CONCLUSIONS AND INFERENCES

Patients with diverticula are characterized by increased macrophage counts, while nerve fiber sprouting is increased only in the diverticular region of patients with SUDD suggesting a role in symptom generation.

Italian nationwide survey of pharmacologic treatments in diverticular disease: Results from the REMAD registry

BACKGROUND

Although diverticular disease is a common condition, its effective treatment is challenging in clinical practice.

OBJECTIVE

The objective of this article is to assess pharmacological management in different clinical settings of diverticular disease and factors associated with treatment using the Italian registry Registro Malattia Diverticolare (REMAD).

METHODS

At study enrolment, patients were categorised into subgroups: diverticulosis, symptomatic uncomplicated diverticular disease and previous diverticulitis. We registered demographic, clinical and lifestyle factors, quality of life and the use of treatments for diverticular disease in the last year. Logistic regression analysis assessed the association between clinical factors and treatment consumption.

RESULTS

A total of 500 of the 1206 individuals included had had at least one treatment for diverticular disease in the last year: 23.6% (166/702) of patients with diverticulosis, 55.9% (165/295) of patients with symptomatic diverticular disease, and 80.9% (169/209) of patients with previous diverticulitis (p < 0.001). In multivariate analysis, the following factors were significantly associated with treatment use: female gender, family history of colonic diverticula, organic digestive comorbidity and impaired physical quality of life components.

CONCLUSION

Individuals with diverticular disease take medications based on the different clinical settings of disease. We identified different features associated with treatment use in the distinct clinical entities of diverticular disease.ClinicalTrial.gov Identifier: NCT03325829.

Is gastroparesis a gastric disease?

BACKGROUND

Gastroparesis is a digestive syndrome characterized by delayed gastric emptying (GE) and by symptoms that are suggestive of gastroduodenal motor disorders. There are three grades of gastroparesis of increasing severity: (a) mild gastroparesis; (b) compensated gastroparesis; and (c) gastric failure. GE abnormalities are partially related to symptom type and severity, and other mechanisms may be involved.

AIM

To investigate enteric dysmotility (ED) in patients with suspected gastroparesis.

METHODS

Patients with symptoms suggestive of gastroparesis were consecutively included in the study and underwent a ¹³ C-octanoic acid GE breath test and small bowel manometry (SBM). Clinical features were recorded using predefined, validated questionnaires at entry.

KEY RESULTS

The study enrolled 88 patients (71 women; mean age: 37.8 ± 14.3 years). Gastric emptying was delayed in 25 patients (28.4%), and 70 patients (79.5%) presented small bowel motor abnormalities including bursts, abnormal activity fronts, inability to respond to meal ingestion, and hypocontractility. Gastric emptying was delayed in 24 of the 70 patients with ED (34.3% vs 5.5% of patients with normal SBM). Enteric dysmotility was detected in 24 of 25 patients (96%) with delayed GE. Patients with and without delayed GE showed similar moderate/severe gastroparesis manifestations, but patients with ED significantly more often had moderate/severe gastroparesis manifestations than patients with normal SBM (grade 1:14% vs 39%, grade 2:62% vs 56%, grade 3:24% vs 5%, respectively).

CONCLUSIONS AND INFERENCES

Enteric dysmotility was more frequent than delayed GE in patients with symptoms suggestive of gastroparesis. Gastroparesis severity was associated with small bowel motor abnormalities but not with delayed GE.

Probiotics in irritable bowel syndrome: Where are we?

We have only recently begun to understand how alterations of the intestinal microbial ecosystem lead to the disruption of host-microbial interactions and are associated with diseases, including functional gastrointestinal disorders such as irritable bowel syndrome (IBS). Although we are still far from understanding the human microbiome, gut microbiota is already a therapeutic target. Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit to the host and may represent a therapeutic option for diseases characterized by dysbiosis such as IBS. Meta-analyses suggest that probiotics provide a therapeutic gain over placebo on global symptoms with a high safety profile in IBS patients. However, the mechanisms by which they provide benefit in IBS remain virtually unknown. In this issue of Neurogastroenterology and Motility, BIO-25, a multispecies probiotic, did not significantly modify the composition of the fecal microbiota, but interestingly, patients with specific basal features of the intestinal microbial ecosystem improved with treatment. Based on these data, it is tantalizing to speculate that microbiota composition serves as a predictor of the response to probiotic intervention. This mini-review addresses unresolved issues related to mechanisms through which probiotics may exert their beneficial effects, the biological, as well as clinical predictors of favorable outcomes in IBS and finally considers possible new directions for future studies.

Recent advances in understanding non-celiac gluten sensitivity

Non-celiac gluten sensitivity (NCGS) is a condition characterized by intestinal and extra-intestinal symptoms related to the ingestion of gluten-containing foods in the absence of celiac disease and wheat allergy. The diagnosis is cumbersome and currently confirmed only by gluten withdrawal and double-blind placebo challenge protocols. There is great overlap in symptoms between NCGS and other functional gastrointestinal disorders, making a differential diagnosis difficult. The pathophysiology of NCGS is largely unclear, and there are contrasting data on the trigger of this condition. This review will highlight the state-of-the-art knowledge on NCGS and the key open questions.

Fecal Clostridiales distribution and short-chain fatty acids reflect bowel habits in irritable bowel syndrome

Irritable bowel syndrome (IBS), a common functional gastrointestinal disorder, is classified according to bowel habits as IBS with constipation (IBS-C), with diarrhea (IBS-D), with alternating constipation and diarrhea (IBS-M), and unsubtyped (IBS-U). The mechanisms leading to the different IBS forms are mostly unknown. This study aims to evaluate whether specific fecal bacterial taxa and/or short-chain fatty acids (SCFAs) can be used to distinguish IBS subtypes and are relevant for explaining the clinical differences between IBS subcategories. We characterized five fecal samples collected at 4-weeks intervals from 40 IBS patients by 16S rRNA gene profiling and SCFA quantification. Finally, we investigated the potential correlations in IBS subtypes between the fecal microbial signatures and host physiological and clinical parameters. We found significant differences in the distribution of Clostridiales OTUs among IBS subtypes and reduced levels of SCFAs in IBS-C compared to IBS-U and IBS-D patients. Correlation analyses showed that the diverse representation of Clostridiales OTUs between IBS subtypes was associated with altered levels of SCFAs; furthermore, the same OTUs and SCFAs were associated with the fecal cytokine levels and stool consistency. Our results suggest that intestinal Clostridiales and SCFAs might serve as potential mechanistic biomarkers of IBS subtypes and represent therapeutic targets.

Pre- and probiotic overview

The dynamic relationship between gut microbiota and its human host is also known as a trophic association that might range from commensalism, where only the microbe enjoys a positive effect from the relationship, to intestinal symbiosis where both host and microbe benefit from their interaction. In the last years, we have started to understand how alterations of the gut microbiota composition leading to the disruption of host-microbial interactions are associated and/or predispose individuals to disease conditions ranging from inflammatory bowel diseases to allergy and functional gastrointestinal disorders, such as irritable bowel syndrome. While we await important insights in this field, the microbiota is already a therapeutic target. Based on the actual definitions, prebiotics are defined as substrates that are selectively utilized by host microorganisms conferring a health benefit, while probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Although their health promoting activities encompasses numerous effects, including immunostimulation, competitive exclusion of pathogens, and gut barrier enhancement, the exact mechanism of action by which these compounds exert their beneficial actions in humans is only partially known. In this review, we highlight the current insights into the clinical applications of prebiotics and probiotics in gastroenterology.

Demographic and clinical features distinguish subgroups of diverticular disease patients: Results from an Italian nationwide registry

BACKGROUND

Clinical features and lifestyle factors associated with diverticulosis compared to diverticular disease (DD), either symptomatic uncomplicated diverticular disease (SUDD) or in patients who have had previous diverticulitis (PD), are unclear.

OBJECTIVE

The objective of this article is to compare cross-sectionally demographic and clinical features and quality of life (QoL) in diverticulosis, SUDD and PD patients.

METHODS

The REMAD Registry is a prospective, observational, multicentre, cohort study. Patients were categorised according to: diverticulosis; SUDD (recurrent abdominal symptoms attributed to diverticula in absence of overt inflammation) and PD (≥1 previous diverticulitis).

RESULTS

A total of 1217 patients (57.9% diverticulosis, 24.7% SUDD and 17.4% PD) were included. Compared to diverticulosis, female gender was associated to SUDD (OR 1.94; 95% CI: 1.43-2.62) and PD (OR 1.79; 95% CI: 1.24-2.56); age ≤ 60 years was associated to PD (OR 2.10; 95% CI: 1.42-3.08 vs diverticulosis, OR 1.57; 95% CI: 1.01-2.45 vs SUDD). PD patients showed an association with past bleeding (OR 29.29; 95% CI: 8.17-104.98 vs diverticulosis, OR 16.84; 95% CI: 3.77-75.25 vs SUDD). Compared to diverticulosis, family history for diverticula was associated to PD (OR 1.88; 95% CI: 1.27-2.78). Patients with diverticulosis showed higher QoL scores, both physical (p = 0.0001 and 0.0257) and mental (p < 0.0001 and 0.0038), in comparison to SUDD and PD.

CONCLUSION

Family history for diverticula and history of bleeding distinguish diverticulosis from DD. These clinical features should be kept in mind in the management of DD.

Escherichia coli Nissle 1917 restores epithelial permeability alterations induced by irritable bowel syndrome mediators

BACKGROUND

Intestinal permeability is altered in a subgroup of irritable bowel syndrome (IBS) patients and may contribute to symptom development. The aim of this study was to evaluate the in vitro effect of the probiotic Escherichia coli Nissle 1917 (EcN) on Caco-2 permeability alterations induced by mediators released by IBS mucosal biopsies compared to asymptomatic controls (AC).

METHODS

Caco-2 cells were used as an in vitro model of intestinal permeability. Seven AC and 28 well-phenotyped IBS (9 IBS-D, 8 IBS-C, and 11 IBS-M) patients were enrolled. Mucosal mediators spontaneously released (SUP) by IBS and AC biopsies were collected. Two concentrations of EcN (108 and 106 ) were applied to Caco-2 with or without SUP or SLIGRL (a protease-activated receptor-2 activating peptide), tumor necrosis factor-α, and interferon-γ. Paracellular permeability was assessed by evaluating the flow of sulfonic-acid conjugated to fluorescein through Caco-2 monolayer.

KEY RESULTS

EcN 108 significantly reinforced Caco-2 monolayer compared to cells incubated with medium alone. IBS SUP induced a significant increase in paracellular permeability compared to AC SUP, independently of IBS bowel habit. EcN 108 induced a significant recovery of permeability rate compared to IBS SUP. Permeability increase induced by IBS SUP significantly correlated with severity and frequency of abdominal pain and abdominal distension. The co-incubation of EcN and IBS SUP abolished the above significant correlations.

CONCLUSIONS AND INFERENCES

EcN reinforces the integrity of Caco-2 monolayer and reverts the increase of permeability induced by mediators released by IBS biopsies. Future studies should investigate EcN therapeutic potentials in IBS.

Effect of Lactobacillus paracasei CNCM I-1572 on symptoms, gut microbiota, short chain fatty acids, and immune activation in patients with irritable bowel syndrome: A pilot randomized clinical trial

BACKGROUND

Evidence suggests a role of intestinal microbiota-host interactions in the pathophysiology and symptoms of irritable bowel syndrome (IBS).

OBJECTIVE

The objective of this article is to assess the effects of Lactobacillus paracasei CNCM I-1572 on clinical and gut microbiota-related factors in IBS.

METHODS

We conducted a multicenter, randomized, double-blind, cross-over, 18-week, placebo-controlled, pilot trial assessing the effect of Lactobacillus paracasei CNCM I-1572 on symptoms, gut microbiota composition, fecal short chain fatty acid (SCFA), immunoglobulin A, and cytokines in IBS. The intestinal microbial ecosystem was characterized by 16S rRNA gene profiling.

RESULTS

Forty IBS patients were enrolled from five Italian centers. Lactobacillus paracasei CNCM I-1572 did not significantly improve IBS symptoms, including primary efficacy variables worst abdominal pain/discomfort and IBS degree of relief. Interestingly, Lactobacillus paracasei CNCM I-1572 induced a significant reduction in genus Ruminococcus, dominated by taxa related to Ruminococcus bromii and Ruminococcus callidus, a significant increase in the SCFAs acetate and butyrate, and a significant reduction in the pro-inflammatory cytokine interleukin-15.

CONCLUSIONS

This pilot study shows that Lactobacillus paracasei CNCM I-1572 is able to modulate gut microbiota structure/function and reduce immune activation in IBS. As no statistically significant effect on IBS-symptoms was found, further studies are necessary to determine the role of this probiotic in IBS. The study was registered at ClinicalTrials.gov registry under identifier NCT02371499.

Allergic Proctocolitis Is a Risk Factor for Functional Gastrointestinal Disorders in Children

OBJECTIVE

To test the hypothesis that allergic proctocolitis, a cause of self-limiting rectal bleeding in infants, can predispose to the development of functional gastrointestinal disorders (FGIDs) later in childhood.

STUDY DESIGN

We studied a cohort of 80 consecutive patients diagnosed with allergic proctocolitis. Their sibling or matched children presenting to the same hospital for minor trauma served as controls. Parents of the patients with allergic proctocolitis and controls participated in a telephone interview every 12 months until the child was at least 4 years old. At that time, they were asked to complete the parental Questionnaire on Pediatric Gastrointestinal Symptoms, Rome III version.

RESULTS

Sixteen of the 160 subjects (10.0%) included in the study met the Rome III criteria for FGIDs. Among the 80 patients with allergic proctocolitis, 12 (15.0%) reported FGIDs, compared with 4 of 80 (5.0%) controls (P = .035). After adjustment for age and sex, the OR for FGIDs in allergic proctocolitis group was 4.39 (95% CI, 1.03-18.68). FGIDs were significantly associated with iron deficiency anemia, duration of hematochezia, and younger age at presentation. In a multivariate analysis, only the duration of hematochezia was significantly associated with the development of FGIDs (OR, 3.14; 95% CI,1.72-5.74).

CONCLUSIONS

We have identified allergic proctocolitis as a new risk factor for the development of FGIDs in children. Our data suggest that not only infection, but also a transient early-life allergic inflammatory trigger may induce persistent digestive symptoms, supporting the existence of "postinflammatory" FGIDs.

Colonic immune cells in irritable bowel syndrome: A systematic review and meta-analysis

BACKGROUND & AIMS

Increases in mucosal immune cells have frequently been observed in irritable bowel syndrome (IBS) patients. However, this finding is not completely consistent between studies, possibly due to a combination of methodological variability, population differences and small sample sizes. We performed a meta-analysis of case-control studies that compared immune cell counts in colonic biopsies of IBS patients and controls.

METHODS

PubMed and Embase were searched in February 2017. Results were pooled using standardized mean difference (SMD) and were considered significant when zero was not within the 95% confidence interval (CI). Heterogeneity was assessed based on I² statistics where I²  ≤ 50% and I²  > 50% indicated fixed and random effect models, respectively.

KEY RESULTS

Twenty-two studies on 706 IBS patients and 401 controls were included. Mast cells were increased in the rectosigmoid (SMD: 0.38 [95% CI: 0.06-0.71]; P = .02) and descending colon (SMD: 1.69 [95% CI: 0.65-2.73]; P = .001) of IBS patients. Increased mast cells were observed in both constipation (IBS-C) and diarrhea predominant IBS (IBS-D). CD3⁺ T cells were increased in the rectosigmoid (SMD: 0.53 [95% CI: 0.21-0.85]; P = .001) and the descending colon of the IBS patients (SMD: 0.79, 95% CI [0.28-1.30]; P = .002). This was possibly in relation to higher CD4⁺ T cells in IBS (SMD: 0.33 [95% CI: 0.01-0.65]; P = .04) as there were no differences in CD8⁺ T cells.

CONCLUSIONS & INFERENCES

Mast cells and CD3⁺ T cells are increased in colonic biopsies of patients with IBS vs non-inflamed controls. These changes are segmental and sometimes IBS-subtype dependent. The diagnostic value of the quantification of colonic mucosal cells in IBS requires further investigation.

Gut microbiota, metabolome and immune signatures in patients with uncomplicated diverticular disease

OBJECTIVE

The engagement of the gut microbiota in the development of symptoms and complications of diverticular disease has been frequently hypothesised. Our aim was to explore colonic immunocytes, gut microbiota and the metabolome in patients with diverticular disease in a descriptive, cross-sectional, pilot study.

DESIGN

Following colonoscopy with biopsy and questionnaire phenotyping, patients were classified into diverticulosis or symptomatic uncomplicated diverticular disease; asymptomatic subjects served as controls. Mucosal immunocytes, in the diverticular region and in unaffected sites, were quantified with immunohistochemistry. Mucosa and faecal microbiota were analysed by the phylogenetic platform high taxonomic fingerprint (HTF)-Microbi.Array, while the metabolome was assessed by ¹H nuclear magnetic resonance.

RESULTS

Compared with controls, patients with diverticula, regardless of symptoms, had a >70% increase in colonic macrophages. Their faecal microbiota showed depletion of Clostridium cluster IV. Clostridium cluster IX, Fusobacterium and Lactobacillaceae were reduced in symptomatic versus asymptomatic patients. A negative correlation was found between macrophages and mucosal Clostridium cluster IV and Akkermansia. Urinary and faecal metabolome changes in diverticular disease involved the hippurate and kynurenine pathways. Six urinary molecules allowed to discriminate diverticular disease and control groups with >95% accuracy.

CONCLUSIONS

Patients with colonic diverticular disease show depletion of microbiota members with anti-inflammatory activity associated with mucosal macrophage infiltration. Metabolome profiles were linked to inflammatory pathways and gut neuromotor dysfunction and showed the ability to discriminate diverticular subgroups and controls. These data pave the way for further large-scale studies specifically aimed at identifying microbiota signatures with a potential diagnostic value in patients with diverticular disease.

Randomised clinical trial: the analgesic properties of dietary supplementation with palmitoylethanolamide and polydatin in irritable bowel syndrome

BACKGROUND

Intestinal immune activation is involved in irritable bowel syndrome (IBS) pathophysiology. While most dietary approaches in IBS involve food avoidance, there are fewer indications on food supplementation. Palmithoylethanolamide, structurally related to the endocannabinoid anandamide, and polydatin are dietary compounds which act synergistically to reduce mast cell activation.

AIM

To assess the effect on mast cell count and the efficacy of palmithoylethanolamide/polydatin in patients with IBS.

METHODS

We conducted a pilot, 12-week, randomised, double-blind, placebo-controlled, multicentre study assessing the effect of palmithoylethanolamide/polydatin 200 mg/20 mg or placebo b.d. on low-grade immune activation, endocannabinoid system and symptoms in IBS patients. Biopsy samples, obtained at screening visit and at the end of the study, were analysed by immunohistochemistry, enzyme-linked immunoassay, liquid chromatography and Western blot.

RESULTS

A total of 54 patients with IBS and 12 healthy controls were enrolled from five European centres. Compared with controls, IBS patients showed higher mucosal mast cell counts (3.2 ± 1.3 vs. 5.3 ± 2.7%, P = 0.013), reduced fatty acid amide oleoylethanolamide (12.7 ± 9.8 vs. 45.8 ± 55.6 pmol/mg, P = 0.002) and increased expression of cannabinoid receptor 2 (0.7 ± 0.1 vs. 1.0 ± 0.8, P = 0.012). The treatment did not significantly modify IBS biological profile, including mast cell count. Compared with placebo, palmithoylethanolamide/polydatin markedly improved abdominal pain severity (P < 0.05).

CONCLUSIONS

The marked effect of the dietary supplement palmithoylethanolamide/polydatin on abdominal pain in patients with IBS suggests that this is a promising natural approach for pain management in this condition. Further studies are now required to elucidate the mechanism of action of palmithoylethanolamide/polydatin in IBS. ClinicalTrials.gov number, NCT01370720.

Supernatants of irritable bowel syndrome mucosal biopsies impair human colonic smooth muscle contractility

BACKGROUND

Changes in intestinal motility are likely to contribute to irritable bowel syndrome (IBS) pathophysiology. The aim of the study was to investigate the effects of IBS mucosal supernatants on human colonic muscle contractility.

METHODS

Supernatants were obtained from biopsies of 18 IBS patients-nine with constipation (IBS-C) and nine with diarrhea-predominant IBS (IBS-D)-and nine asymptomatic subjects, used as controls. Colonic circular smooth muscle strips or isolated cells (SMC) were exposed to control or IBS supernatants. Spontaneous phasic contractions on strips and morphofunctional parameters on cells were evaluated in basal conditions and in response to acetylcholine (Ach). Incubation with IBS supernatants was also conducted in the presence of antagonists and inhibitors (namely histamine, protease and prostaglandin antagonists, nuclear factor-kappa B inhibitor, catalase, NADPH oxidase inhibitor, and the cAMP- and/or cGMP-cyclase inhibitors).

KEY RESULTS

Exposure to IBS-C and IBS-D supernatants induced a significant reduction in basal tone and Ach-elicited contraction of muscle strips and a significant shortening and impairment of Ach contraction of SMCs. The NADPH oxidase inhibitor prevented the effect of supernatants, while the protease antagonist only IBS-C effect. No effect was observed with the other antagonists and inhibitors. Dilution of IBS-D supernatants partially restored the effects only on SMCs, whereas dilution of IBS-C supernatants significantly reverted the effects on muscle strips and Ach-elicited response on SMC.

CONCLUSIONS & INFERENCES

Supernatants from mucosal biopsies of IBS patients reduce colonic contractility. The observed impairment was concentration dependent, likely occurring through intracellular oxidative stress damage, involving different neuromotor mechanisms depending on the IBS subtype.

Diagnostic challenges of symptomatic uncomplicated diverticular disease

Colonic diverticulosis is a common condition in Western industrialized countries occurring in up to 65% of people over the age of 60 years. Only a minority of these subjects (about 10-25%) experience symptoms, fulfilling Rome III Diagnostic Criteria for irritable bowel syndrome (IBS) diagnosis (IBS-like symptoms) in 10% to 66% of cases. Symptomatic uncomplicated diverticular disease (SUDD) is a syndrome characterized by recurrent abdominal symptoms attributed to diverticula in the absence of macroscopically evident alterations other than the presence of diverticula. Due to the different peak of incidence, the overlap between SUDD and IBS is predominantly present in middle-aged or older patients. In these cases, it is very complex to establish if the symptoms are related to the presence of diverticula or due to an overlapping IBS. In fact, the link between gastrointestinal symptoms and diverticula is unclear, and the mechanism by which diverticula may induce the development of IBS-like symptoms remains to be elucidated. Currently, the etiology and pathophysiology of SUDD, particularly when IBS-like symptoms are present, are not completely understood, and thus these two entities remain a diagnostic challenge not only for the general practitioner but also for the gastroenterologist. Although many issues remain open and unresolved, some minimize the importance of a distinction of these two entities as dietary and pharmacological management may be largely overlapping.

Treatment of Diverticular Disease With Aminosalicylates: The Evidence

Colonic diverticulosis is an increasingly common condition in Western industrialized countries. About 20% of patients develop symptoms, including abdominal pain, bloating, changes in bowel habits, and, eventually, diverticulitis or other complications. The management of symptomatic uncomplicated diverticular disease (SUDD) and the prevention of acute diverticulitis remains a challenge for the clinician. The rationale for the use of aminosalicylates, such as mesalazine, is based on the assumption of low-grade inflammation in SUDD and symptoms generation, whereas an overt inflammation may induce diverticulitis in patients with diverticular disease. Clinical scenarios in which the efficacy and safety of mesalazine have been studied include SUDD, prevention of diverticulitis, and of recurrent diverticulitis. Data from uncontrolled studies suggest a benefit of mesalazine on patients with SUDD, whereas data from randomized controlled trials showed some evidence of improvement of symptoms, although contrasting results are reported. The largest study so far published on the efficacy of mesalamine in the prevention of recurrence of diverticulitis showed that mesalamine was not superior to placebo. At this time, the role of mesalazine in the prevention of acute diverticulitis remains to be defined with many issues open and unresolved.

Esophageal Inlet Patch: An Under-Recognized Cause of Symptoms in Children

OBJECTIVES

To determine the incidence of inlet patch (IP) and to assess the clinical and pathological features, role of the diagnostic workup in treatment decision making, efficacy of medical and endoscopic therapy, and natural history in a pediatric population.

STUDY DESIGN

Consecutive patients aged <18 years (n = 1000) undergoing esophagogastroduodenoscopy were enrolled prospectively. Biopsy specimens were obtained from IPs and the proximal and distal esophagus, stomach, and duodenum. Multichannel intraluminal impedance and pH monitoring (MII-pH) was performed in all symptomatic patients. Symptomatic patients were treated with proton pump inhibitors for 8 weeks, and IP ablation by argon plasma coagulation (APC) was performed in unresponsive patients.

RESULTS

The endoscopic incidence of IP was 6.3%, with a cumulative missing rate of 5.8%. Thirty-five of the 63 patients (56%) were asymptomatic, 11 (17%) had symptoms clearly related to the underlying digestive disorder, and 17 (27%) had chronic IP-related symptoms. MII-pH was positive in 10 of the 28 symptomatic patients. All 17 patients with IP-related symptoms were unresponsive to proton pump inhibitors and were treated with APC, and all had achieved complete remission by the 3-year follow-up. Patients with underlying disorders were successfully treated with medical therapy, and asymptomatic patients remained symptom-free, with no endoscopic or histological changes seen at the 3-year follow-up.

CONCLUSION

IP is an under-recognized cause of symptoms in children with unexplained esophageal and respiratory symptoms. MII-pH and bioptic sampling are needed to exclude entities mimicking IP symptoms and to direct therapy. APC is safe and effective for treating IP-related symptoms.

Interferon-γ is increased in the gut of patients with irritable bowel syndrome and modulates serotonin metabolism

Mucosal immune activation and altered serotonin metabolism participate in the pathophysiology of irritable bowel syndrome (IBS). However, the reciprocal interplay between these two systems remains unknown. We evaluated the expression and release of interferon (IFN)-γ from the colonic mucosa of patients with IBS and its impact on serotonin reuptake transporter (SERT) gene expression in Caco-2 cells. qPCR was used to evaluate IFN-γ gene expression in colonic mucosal biopsies, whereas IFN-γ protein amount was assessed by ELISA. Colonic T box expressed in T cells (T-bet) and phosphorylated signal transducer and activator of transcription 4 protein amount were evaluated by Western blot. The impact of colonic mucosal mediators on SERT gene expression was evaluated in Caco-2 cells using qPCR. IFN-γ receptor was silenced in Caco-2 cells to determine the effect of IFN-γ released by mucosal biopsies. Compared with asymptomatic controls (ACs), the expression of IFN-γ gene and its transcription factor T-bet were markedly increased in the colonic mucosa of patients with IBS. Compared with ACs, IFN-γ protein tissue levels and its release by mucosal biopsies were significantly increased in IBS. The exposure of Caco-2 cells to IBS supernatants induced a significant decrease in SERT gene expression, independently of IBS subtypes, compared with AC mucosal supernatants. In Caco-2 cells, IFN-γ receptor silencing reversed the reduction of SERT expression evoked by IBS supernatants vs. nonsilenced cell lines. IFN-γ gene, its transcription factor T-bet, IFN-γ protein expression, and its release are increased in the colonic mucosa of patients with IBS and downregulate SERT gene expression in vitro. These results suggest that IFN-γ downregulates SERT expression, hence likely playing a role in altered serotonin metabolism of patients with IBS.

Randomised controlled trial of mesalazine in IBS

OBJECTIVE

Low-grade intestinal inflammation plays a role in the pathophysiology of IBS. In this trial, we aimed at evaluating the efficacy and safety of mesalazine in patients with IBS.

DESIGN

We conducted a phase 3, multicentre, tertiary setting, randomised, double-blind, placebo-controlled trial in patients with Rome III confirmed IBS. Patients were randomly assigned to either mesalazine, 800 mg, or placebo, three times daily for 12 weeks, and were followed for additional 12 weeks. The primary efficacy endpoint was satisfactory relief of abdominal pain/discomfort for at least half of the weeks of the treatment period. The key secondary endpoint was satisfactory relief of overall IBS symptoms. Supportive analyses were also performed classifying as responders patients with a percentage of affirmative answers of at least 75% or >75% of time.

RESULTS

A total of 185 patients with IBS were enrolled from 21 centres. For the primary endpoint, the responder patients were 68.6% in the mesalazine group versus 67.4% in the placebo group (p=0.870; 95% CI -12.8 to 15.1). In explorative analyses, with the 75% rule or >75% rule, the percentage of responders was greater in the mesalazine group with a difference over placebo of 11.6% (p=0.115; 95% CI -2.7% to 26.0%) and 5.9% (p=0.404; 95% CI -7.8% to 19.4%), respectively, although these differences were not significant. For the key secondary endpoint, overall symptoms improved in the mesalazine group and reached a significant difference of 15.1% versus placebo (p=0.032; 95% CI 1.5% to 28.7%) with the >75% rule.

CONCLUSIONS

Mesalazine treatment was not superior than placebo on the study primary endpoint. However, a subgroup of patients with IBS showed a sustained therapy response and benefits from a mesalazine therapy.

TRIAL REGISTRATION NUMBER

ClincialTrials.gov number, NCT00626288.

Nerve fiber outgrowth is increased in the intestinal mucosa of patients with irritable bowel syndrome

BACKGROUND & AIMS

Mediators released by the intestinal mucosa of patients with irritable bowel syndrome (IBS) affect the function of enteric and extrinsic sensory nerves, which can contribute to the development of symptoms. Little is known about the effects of mucosal mediators on intestinal neuroplasticity. We investigated how these mediators affect the phenotypes of colonic mucosa nerve fibers, neuron differentiation, and fiber outgrowth.

METHODS

We analyzed mucosal biopsy samples collected from 101 patients with IBS and 23 asymptomatic healthy individuals (controls). We measured levels of neuronal-specific enolase, growth-associated protein 43, nerve growth factor (NGF), and tyrosine kinase receptor A (NTRK1) by immunohistochemistry and enzyme-linked immunosorbent assay. Primary rat enteric neurons and human SH-SY5Y cells were incubated with supernatants from the mucosal biopsies and analyzed by morphometric and polymerase chain reaction analyses.

RESULTS

Compared with mucosal tissues of controls, mucosa from patients with IBS had a significant increase in the area of lamina propria occupied by neuronal-specific enolase-positive (57.7% increase) and growth-associated protein 43-positive fibers (56.1% increase) and staining density of NGF (89.3% increase) (P < .05 for all). Levels of NGF protein were also increased in tissues from patients with IBS vs controls (18% increase; P = .16) along with levels of NTRK1 (64% increase; P < .05). Mucosal supernatants from tissues of patients with IBS induced higher levels of neuritogenesis in primary culture of enteric neurons, compared with controls, and more NGF-dependent neuronal sprouting in SH-SY5Y cells.

CONCLUSIONS

Nerve fiber density and sprouting, as well as expression of NGF and NTRK1, are significantly increased in mucosal tissues of patients with IBS. Mucosal mediators participate to these neuroplastic changes.

Salmonella gastroenteritis during childhood is a risk factor for irritable bowel syndrome in adulthood

BACKGROUND & AIMS

Acute infectious gastroenteritis increases the risk for irritable bowel syndrome (IBS) and functional dyspepsia (FD). Children are particularly vulnerable to gastroenteritis because of the immaturity of their intestinal barrier, enteric nervous system, and immune response to pathogens. We investigated whether acute gastroenteritis in early life increases the risk of IBS and FD throughout adulthood.

METHODS

In 1994, we identified and monitored a single culture-proven foodborne Salmonella enteritidis outbreak that involved 1811 patients (mostly pediatric) in Bologna, Italy. Clinical data were collected and a prospective, controlled, cohort study was designed. Long-term effects were assessed by mailing a questionnaire to 757 subjects 16 years after the outbreak (when all of the children were adults). We randomly selected a cohort of 250 adults exposed to Salmonella as children, all 127 individuals exposed as adults, and a cohort of nonexposed participants matched for number, age, sex, and area of residence (controls).

RESULTS

Among 198 exposed participants, 64 reported FD (32.3%), compared with 51 of 188 controls (27.1%; P = .268). Among 204 exposed participants, 75 reported having IBS (36.8%) compared with 44 of 189 controls (23.3%; P = .004). The odds ratio for IBS among people exposed to the Salmonella was 1.92 (95% confidence interval: 1.23-2.98). The prevalence of IBS was higher in individuals exposed Salmonella as children than in controls (35.3% vs 20.5%; P = .008), but not in individuals exposed as adults, compared with controls. After multivariate logistic regression, post-infectious IBS was independently associated with anxiety and FD.

CONCLUSIONS

Based on data collected from a single culture-proven foodborne Salmonella enteritidis outbreak in 1994, Salmonella-induced gastroenteritis during childhood (but not adulthood) is a risk factor for IBS.