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

Review: Food-induced mucosal alterations visualized using endomicroscopy

Confocal laser endomicroscopy (CLE) is a novel technique allowing real time in vivo microscopy during standard endoscopy. Recently, acute mucosal alterations after food administration visualized by CLE have been linked to symptoms in irritable bowel syndrome (IBS). Interestingly, the observed reactions occurred in subjects without demonstrable allergic sensitization to food-this is in line with mechanistic research showing local but not systemic allergic sensitization to foods in an animal model for IBS. Here, European experts conducting CLE with food administration provide a narrative review of the available literature and propose practical guidance on the use of this technique. CLE allows physicians to observe acute mucosal reactions after the application of food to the duodenal mucosa in patients with functional gastrointestinal disorders. Some open-label interventions show a symptomatic benefit when patients exclude the nutrient that triggered an acute mucosal reaction. However, many technical, mechanistic, and clinical questions remain unanswered to date. Technically, the interobserver variability and learning curve requires systematic evaluation and criteria or cutoffs for alterations require validation. Mechanistic studies are needed to enhance our understanding of the mechanisms underlying observed alterations. Finally, rigorous blinded controlled studies are needed to assess a link of these observed alterations with symptom generation. CLE offers a platform allowing scientific insights related to food induced acute mucosal alterations. However, many questions remain unanswered, and more research is warranted to understand the role of acute mucosal alterations visualized upon food administration in IBS pathophysiology and treatment.

Management of Refractory Functional Gastrointestinal Disorders: What Role Should Psychiatrists Have?

Currently, it has been stated that psychiatric and psychological problems are equally paramount aspects of the clinical modulation and manifestation of both the central nervous and digestive systems, which could be used to restore balance. The present narrative review aims to provide an elaborate description of the bio-psycho-social facets of refractory functional gastrointestinal disorders, psychiatrists' role, specific psychiatric approach, and the latest psychiatric and psychological perspectives on practical therapeutic management. In this respect, "psyche," "psychiatry," "psychology," "psychiatrist," "psychotropic," and "refractory functional gastrointestinal disorders" (as the keywords) were searched in relevant English publications from January 1, 1950, to March 1, 2024, in the PubMed, Web of Science, Scopus, EMBASE, Cochrane Library, and Google Scholar databases. Eventually, the narrative technique was adopted to reach a compelling story with a high level of cohesion through material synthesis. The current literature recognizes the brain-gut axis modulation as a therapeutic target for refractory functional gastrointestinal disorders and the bio-psycho-social model as an integrated framework to explain disease pathogenesis. The results also reveal some evidence to affirm the benefits of psychotropic medications and psychological therapies in refractory functional gastrointestinal disorders, even when psychiatric symptoms were absent. It seems that psychiatrists are required to pay higher levels of attention to both the assessment and treatment of patients with refractory functional gastrointestinal disorders, accompanied by educating and training practitioners who take care of these patients.

Network pharmacology integrated with molecular docking and molecular dynamics simulations to explore the mechanism of Shaoyao Gancao Tang in the treatment of asthma and irritable bowel syndrome

BACKGROUND

Numerous studies have demonstrated a correlation between asthma and irritable bowel syndrome (IBS). The Chinese herbal compound Shaoyao Gancao Tang (SYGCT) has been found to have therapeutic effects on both asthma and IBS, but the underlying mechanisms are not yet fully understood. This study aims to explore the key components, key targets, and potential mechanisms of SYGCT in treating asthma with IBS by using network pharmacology, molecular docking techniques and molecular dynamics simulation.

METHODS

The major chemical components and potential target genes of SYGCT were screened by bioinformatics. The key targets of Asthma-IBS comorbidity were identified based on network modules. The intersection of the drug targets and disease targets was identified as the potential targets of SYGCT in treating asthma-IBS. Gene Ontology functional annotation and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were performed to identify the biological processes and signaling pathways involved in these potential targets. A protein-protein interaction network was constructed to identify hub targets, while a drug-compound-target topological network was built to screen key compounds. Molecular docking was used to verify the affinity between the hub targets and key compounds. Molecular dynamics analysis was utilized to assess the binding stability of these interactions.

RESULTS

Network pharmacology analysis revealed that the therapeutic effect of SYGCT on asthma-IBS involved multiple biological processes and signaling pathways. It may exert therapeutic effects primarily through signaling pathways such as IL-17, TNF, and Th17 cell differentiation. The possible targets of SYGCT in the treatment of asthma-IBS could be IL6, TNF, JUN, PTGS2, STAT3, IL1B, CASP3, NFKBIA, IL10, and PPARG. Molecular docking verification showed that the predicted targets had good binding affinity with the compounds, among which PTGS2, CASP3, and PPARG had higher binding energy. Molecular dynamics simulation revealed that PTGS2, CASP3, and PPARG proteins had good stability and high binding strength with the compounds 2-[(3R)-8,8-dimethyl-3,4-dihydro-2H-pyrano[6,5-f]chromen-3-yl]-5-methoxyphenol and shinpterocarpin.

CONCLUSION

SYGCT plays a therapeutic role in asthma and IBS through multiple targets and pathways, providing a theoretical basis for explaining the mechanism and clinical application of SYGCT in treating different diseases with the same treatment in asthma and 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.

Specific probiotics and prebiotics to improve the quality of life of patients with chronic irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a chronic disorder with an important impact on patients' quality of life. Although several data indicate that psychological symptoms are frequently reported by patients with IBS, few therapies have been evaluated regarding these issues.

METHODS

A retrospective observational study was conducted to evaluate the effectiveness of a probiotic-based dietary supplement (Colicron®) in a group of patients with diarrhea-predominant IBS (IBS-D). We included patients treated with Colicron® (1 cps/day for 8 weeks). Primary endpoint was the gastrointestinal symptoms' remission evaluated by Visual Analogue Scale (VAS); secondary endpoint was the impact of the treatment on physical and mental health evaluated by Hospital Anxiety and Depression Score (HADS) and Short Form Health Survey 36 (SF-36). VAS was assessed at week 4 (T4), week 8 (T8) and week 12 (T12), whereas HADS and SF-36 were performed even at the start of the Colicron® treatment (T0).

RESULTS

An improvement of VAS Score was observed at T8 (P<0.001) and T12 (P<0.05) compared to T4. Lower HADS-A (anxiety subdomain) score was obtained at each time point versus T0 (P<0.01), and higher scores of all SF-36 domains were observed during the treatment (0.05

CONCLUSIONS

Colicron® could be useful in improving both gastrointestinal and psychological symptoms in IBS-D patients. Further prospective clinical trials are needed to confirm these preliminary data.

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MESH Headings

• Humans
• Irritable Bowel Syndrome/psychology
• Irritable Bowel Syndrome/therapy
• Irritable Bowel Syndrome/complications
• Quality of Life
• Probiotics/therapeutic use
• Female
• Male
• Retrospective Studies
• Adult
• Middle Aged
• Prebiotics
• Chronic Disease
• Treatment Outcome
• Anxiety/etiology
• Diarrhea
• Depression/etiology
• Dietary Supplements

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Affiliation(s)

Lorenzo Bertani Department of General Surgery and Gastroenterology, Tuscany North West ASL, Hospital of Pontedera, Pontedera, Pisa, Italy -
Linda Balestrini Laboratori Aliveda srl, Crespina Lorenzana, Pisa, Italy
Lucia Chico Laboratori Aliveda srl, Crespina Lorenzana, Pisa, Italy
Giulia Della Scala Laboratori Aliveda srl, Crespina Lorenzana, Pisa, Italy
Francesca Geri Department of General Surgery and Gastroenterology, Tuscany North West ASL, Hospital of Pontedera, Pontedera, Pisa, Italy
Alessandro Tornar Department of General Surgery and Gastroenterology, Tuscany North West ASL, Hospital of Pontedera, Pontedera, Pisa, Italy
Claudio Belcari Department of General Surgery and Gastroenterology, Tuscany North West ASL, Hospital of Pontedera, Pontedera, Pisa, Italy

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A Review of Pharmacologic and Non-Pharmacologic Therapies in the Management of Irritable Bowel Syndrome: Current Recommendations and Evidence

Irritable bowel syndrome (IBS) is a highly prevalent and debilitating disorder of gut-brain interaction (DGBI) affecting millions globally. It imposes a significant burden on healthcare systems and is a leading cause of workplace absenteeism. IBS is classified into several subtypes based on predominant presenting symptoms, including IBS with constipation (IBS-C) and IBS with diarrhea (IBS-D), with each requiring targeted approaches to treatment. Some treatments, such as psychotherapy, dietary intervention, and medications like tricyclic antidepressants, are nonspecific and recommended for managing IBS symptoms across all subtypes. In contrast, therapies like secretagogues for IBS-C and eluxadoline or rifaximin for IBS-D are subtype-specific. However, many IBS treatments carry conditional recommendations and are based on low-certainty evidence, emphasizing the need for further research to expand the available treatment options. This review compares the latest IBS management guidelines from the American Gastroenterological Association (AGA), American College of Gastroenterology (ACG), British Society of Gastroenterology (BSG), and European Society for Neurogastroenterology and Motility (ESNM). Pharmacologic and non-pharmacologic therapies, including established and emerging interventions, will be explored to provide a comprehensive guide to management.

Polysaccharides of natural products alleviate antibiotic-associated diarrhea by regulating gut microbiota: a review

Antibiotic-associated diarrhea (AAD) is diarrhea caused by disturbances in intestinal microbiota and metabolism following inappropriate use of antibiotics. With the over-reliance on antibiotics, the incidence of AAD is increasing worldwide. Recently, the role of probiotics and prebiotic preparations in the prevention and treatment of AAD has received increasing attention. Various prebiotics can not only reduce the incidence of AAD, but also effectively shorten the course of the disease and alleviate the symptoms. Notably, many polysaccharides derived from plants and fungi are a class of biologically active and rich prebiotics with great potential to alleviate AAD. Therefore, this review aims to summarize the latest research on natural product polysaccharides to alleviate antibiotic-associated diarrhea by modulating the gut microbiota. It provides a theoretical basis for exploring the mechanism of natural product modulation of gut microbiota to alleviate AAD, and provides a reference for further development of active prebiotics.

Pharmacological potential of natural medicine Astragali Radix in treating intestinal diseases

Due to changes in diet and lifestyle, the prevalence of intestinal diseases has been increasing annually. Current treatment methods exhibit several limitations, including adverse reactions and drug resistance, necessitating the development of new, safe, and effective therapies. Astragali Radix, a natural medicine utilized for over two millennia, offers unique advantages in treating intestinal ailments due to its multi-component and multi-target properties. This study aims to review the effective components of Astragali Radix that provide intestinal protection and to explore its pharmacological effects and molecular mechanisms across various intestinal diseases. This will provide a comprehensive foundation for using Astragali Radix in treating intestinal diseases and serve as a reference for future research directions. The active components of Astragali Radix with protective effects on the intestines include astragaloside (AS)-IV, AS-III, AS-II, astragalus polysaccharide (APS), cycloastagenol, calycosin, formononetin, and ononin. Astragali Radix and its active components primarily address intestinal diseases such as colorectal cancer (CRC), inflammatory bowel disease (IBD), and enterocolitis through mechanisms including anti-inflammatory actions, antioxidative stress responses, anti-proliferation and invasion activities, regulation of programmed cell death, immunoregulation, restoration of the intestinal epithelial barrier, and modulation of the intestinal microbiota and its metabolites. Consequently, Astragali Radix demonstrates significant intestinal protective activity and represents a promising natural treatment for intestinal diseases. However, the pharmacological actions and mechanisms of some active components in Astragali Radix remain unexplored. Moreover, further comprehensive toxicological and clinical studies are required to ascertain its safety and clinical effectiveness.

Impact of Enteric Nervous Cells on Irritable Bowel Syndrome: Potential Treatment Options

Irritable bowel syndrome (IBS) is a condition that significantly impacts the lifestyle, health, and habits of numerous individuals worldwide. Its diagnosis and classification are based on the Rome criteria, updated periodically to reflect new research findings in this field. IBS can be classified into different types based on symptoms, each with distinct treatment approaches and some differences in their pathophysiology. The exact pathological background of IBS remains unclear, with many aspects still unknown. Recent research developments suggest that disorders in the brain-gut-microbiota axis are key contributors to the symptoms and severity of IBS. The central nervous system (CNS) interacts bidirectionally with intestinal processes within the lumen and the intestinal wall, with the autonomic nervous system, particularly the vagus nerve, playing an important role. However, the enteric nervous system (ENS) is also crucial in the pathophysiological pathway of IBS. The apeline-corticotropin-releasing factor (CRF)-toll-like receptor 4 (TLR4) signaling route via enteric glia and serotonin production in enteroendocrine cells at the enteric barrier are among the most well-understood new findings that affect IBS through the ENS. Additionally, the microbiota regulates neuronal signals, modifying enteric function by altering the number of enteric bacteria and other mechanisms. Given the limited therapeutic options currently available, it is essential to identify new treatment targets, with the brain-gut axis, particularly the enteric nervous system, being a promising focus. This study aims to delineate the molecular mechanisms that induce IBS and to suggest potential targets for future research and treatment of this potentially debilitating disease.

A Synbiotic Combining Chitin-Glucan and Lactobacillus acidophilus NCFM Induces a Colonic Molecular Signature Soothing Intestinal Pain and Inflammation in an Animal Model of IBS

Chitin-glucan (CG) is a new generation of prebiotic. Lactobacillus acidophilus NCFM® (NCFM) is a probiotic with the ability to decrease abdominal pain. We evaluate the functional and molecular gastrointestinal responses to a synbiotic administration combining CG and NCFM in a rat model of long-lasting colon hypersensitivity. The intracolonic pressure was assessed during the 9-week experiment in animals receiving CG in association or not with NCFM and compared to that in Lacticaseibacillus paracasei Lpc-37®-treated animals and control rats receiving tap water. The effects of the synbiotic were evaluated using the Wallace score, the quantification of colon myeloperoxidase (MPO) and the master genes driving analgesia and inflammation. CG 1.5 alone and NCFM 109 colony forming units (CFU) alone similarly decreased the visceral pain sensitivity. Lpc-37 had no significant effect. The best profile of pain perception inhibition was obtained with the combination of CG 1.5 g and NCFM 109 CFU, confirming a synbiotic property. This synbiotic treatment significantly reduced macroscopic colonic lesions and MPO concentrations, and induced master genes involved in analgesia (CB1, CB2, MOR, PPARα), with a downregulation of inflammatory cytokines (IL-1β, TNFα) and an induction of IL-10 and PPARγ. In conclusion, CG 1.5 g + NCFM 109 CFU significantly decreased visceral pain perception and intestinal inflammation through the regulation of master genes.

Clinical presentation of celiac disease in adult patients: current real-life experience

BACKGROUND AND AIMS

The clinical presentation of celiac disease (CD) has changed over time with more patients presenting with non-classical symptoms, extra-intestinal manifestations (EIM) or no symptoms. We aimed to investigate the main symptoms/signs leading to the diagnosis of CD in adult patients. As secondary end-point, we evaluated the outcome of gastrointestinal (GI) symptoms following gluten-free diet (GFD).

METHODS

All consecutive CD adult patients referring to our University Hospital from September 2022 to February 2024 were included. Clinical data were retrospectively evaluated.

RESULTS

134 patients, 104 females/30 males, median age at diagnosis 35 years, were included. 79 patients reported GI symptoms (i.e., diarrhea, abdominal bloating, dyspepsia) as the main symptom leading to CD diagnosis. In 40 patients, the leading symptom/sign was an EIM (i.e., iron deficiency anemia, infertility/miscarriages, dermatitis, osteoporosis, elevated transaminase levels). Fifteen patients were asymptomatic, being diagnosed because of a positive family history or concomitant autoimmune hypothyroidism. Of the 79 patients reporting GI symptoms, 20 did not experience complete resolution with the GFD. Among the 17 patients who reported a strict adherence to GFD (vs 1 patient with low-adherence, 2 non-compliant), lactose intolerance and irritable bowel syndrome overlap were diagnosed in 2 and 15 patients, respectively.

CONCLUSION

GI manifestations remain the main symptoms at presentation of CD, however clinicians should be aware of the EIM of CD and the association with other autoimmune disorders. In non-responsive CD patients, an overlap with functional disorders might be considered.

Managing bile acid diarrhea: aspects of contention

INTRODUCTION

Bile acid diarrhea is a common cause of bowel symptoms and often goes unrecognized or misdiagnosed. Many aspects of management remain contentious.

AREAS COVERED

The primary, idiopathic condition should be suspected in people with functional diarrhea or diarrhea-predominant irritable bowel syndrome. Secondary causes include ileal resection, inflammation, and post-cholecystectomy. Diagnostic tests vary globally, being unavailable in many countries, and further refinement of testing strategy is needed. Management is usually long-term symptom control, rather than reversal of the causative factors, which are still being defined. Bile acid sequestrants remain the main drugs used. They are relatively inexpensive, and better-quality data is now available for colesevelam. However, optimal use, including timing and formulation, needs clarification. The GLP-1 receptor agonist, liraglutide, is also effective, although mechanisms of action and whether this effect is common to other class members is unclear. They are more expensive, and availability varies. FXR agonists can also be effective but require further validation. The role of dietary factors in symptom development is a major patient concern, needing more formal studies.

EXPERT OPINION

To build on recent findings, bile acid diarrhea needs further investment into causes, diagnosis and therapy to guide present and future patient care.

Evidence-Based Clinical Guidelines for Chronic Diarrhea 2023

The Japan Gastroenterological Association (JGA) published the first version of clinical guidelines for chronic diarrhea 2023. These guidelines describe the definition, classification, diagnostic criteria, diagnostic testing methods, epidemiology, pathophysiology, and treatment of chronic diarrhea, and provide flowcharts for the diagnosis and treatment of chronic diarrhea based on the latest evidence. Treatment for chronic diarrhea begins by distinguishing secondary chronic constipation with a clear etiology, such as drug-induced diarrhea, food-induced diarrhea, systemic disease-associated diarrhea, infection-associated diarrhea, organic disease-associated diarrhea, and bile acid diarrhea. The first line of treatment for chronic diarrhea in the narrow sense, defined in these guidelines as functional diarrhea in routine medical care, is lifestyle modification and dietary therapy. The first medicines to be considered for oral treatment are probiotics for regulating the gut microbiome and anti-diarrheals. Other medications, such as 5HT3 receptor antagonists, anticholinergics, Kampo medicine, psychotherapy, antibiotics, bulking agents, adrenergic agonists, and somatostatin analogs, lack sufficient evidence for their use, highlighting a challenge for future research. This Clinical Guidelines for Chronic Diarrhea 2023, which provides the best clinical strategies for treating chronic diarrhea in Japan, will also be useful for medical treatment worldwide.

Insights into Probiotic Prescription among Gastroenterologists and Other Healthcare Professionals: Evidence from an Italian Survey

Background: Probiotics, which are live microorganisms that provide health benefits, have been extensively studied for their various clinical applications. However, despite their potential, high-quality data supporting their use in several gastrointestinal diseases are often lacking, and prescription behaviors can widely differ. This study aimed to assess different behaviors in probiotics knowledge and prescriptions among Italian gastroenterologists and healthcare professionals (HPs). Methods: A web-based electronic survey was distributed to all participants at the National Meeting of the Italian Young Gastroenterologist and Endoscopist Association (AGGEI) held in 2023. The survey investigated probiotic prescription practices for several gastrointestinal conditions, such as acute diarrhea, irritable bowel syndrome, inflammatory bowel disease, and diverticular disease. Results: Among 200 participants, 142 completed the survey, of whom 59 were gastroenterologists and 83 were HPs (surgeons, nutrition biologists, and other physicians). Significant differences were observed in the prescription of probiotics for the treatment of acute diarrhea and H. pylori. Both groups prescribed probiotics in monthly cycles for patients with IBS, although the majority prescribed multistrain formulations. Gastroenterologists were more likely to prescribe cyclic courses for IBS, while HPs tended to continue therapy by changing the probiotic strain in case of inefficacy. For ulcerative colitis, gastroenterologists prescribed probiotics more but for shorter durations. In Crohn's disease, gastroenterologists prescribed probiotics less and were less likely to prescribe multistrain formulations. Regarding SUDD, gastroenterologists tended to prescribe probiotics less frequently, although without a significant difference, with similar rates of preference for multistrain formulations. Conclusions: This survey highlights heterogeneous behaviors in probiotic prescription between gastroenterologists and HPs, with gastroenterologists more aligned with guidelines and available scientific evidence. Hence, enhancing probiotic education among healthcare professionals and gastroenterologists is crucial. Further studies are needed to better understand probiotics' role in gastrointestinal disorders through large-scale randomized controlled trials.

Lactiplantibacillus plantarum P9 for chronic diarrhea in young adults: a large double-blind, randomized, placebo-controlled trial

Current treatments for chronic diarrhea have limited efficacy and several side effects. Probiotics have the potential to alleviate symptoms of diarrhea. This randomized, double-blind, placebo-controlled trial evaluates the effects of administering the probiotic Lactiplantibacillus plantarum P9 (P9) strain in young adults with chronic diarrhea (Clinical Trial Registration Number: ChiCTR2000038410). The intervention period lasts for 28 days, followed by a 14-day post-intervention period. Participants are randomized into the P9 (n = 93) and placebo (n = 96) groups, with 170 individuals completing the double-blind intervention phase (n = 85 per group). The primary endpoint is the diarrhea symptom severity score. Both intention-to-treat (n = 189) and per-protocol (n = 170) analyses reveal a modest yet statistically significant reduction in diarrhea severity compared to the placebo group (20.0%, P = 0.050; 21.4%, P = 0.048, respectively). In conclusion, the results of this study support the use of probiotics in managing chronic diarrhea in young adults. However, the lack of blood parameter assessment and the short intervention period represent limitations of this study.

Microscopic Colitis and Celiac Disease: Sharing More than a Diagnostic Overlap

Microscopic colitis (MC) is an emergent group of chronic inflammatory diseases of the colon, and celiac disease (CD) is a chronic gluten-induced immune-mediated enteropathy affecting the small bowel. We performed a narrative review to provide an overview regarding the relationship between both disorders, analyzing the most recent studies published at the epidemiological, clinical and pathophysiological levels. In fact, MC and CD are concomitantly prevalent in approximately 6% of the cases, mainly in the subset of refractory patients. Thus, physicians should screen refractory patients with CD against MC and vice versa. Both disorders share more than a simple epidemiological association, being multifactorial diseases involving innate and adaptive immune responses to known or unknown luminal factors based on a rather common genetic ground. Moreover, autoimmunity is a shared characteristic between the patients with MC and those with CD, with autoimmunity in the latter being quite well-established. Furthermore, CD and MC share some common clinical symptoms and risk factors and overlap with other gastrointestinal diseases, but some differences exist between both disorders. More studies are therefore needed to better understand the complex mechanisms involving the common pathogenetic ground contributing to the CD and MC epidemiological association.

Identification and management of gastrointestinal manifestations of hereditary transthyretin amyloidosis: Recommendations from an Italian group of experts

Gastrointestinal manifestations are common across all hereditary transthyretin amyloidosis (ATTRv) genotypes. However, they are poorly specific, and their recognition as part of ATTRv is difficult, resulting in misdiagnosis with more common conditions. Moreover, delays in diagnosis occur because of fragmented knowledge, a shortage of centers of excellence and specialists dedicated to ATTRv management, and the scarce involvement of gastroenterologists in multidisciplinary teams. A group of Italian gastroenterologists with experience in the management of ATTRv took part in a project aimed at assessing the awareness of ATTRv among the community of Italian gastroenterologists through an online survey and providing education about practical aspects of ATTRv management. Survey results reported low participation, and very few patients with ATTRv were cared for by gastroenterologists. This highlights the need for greater attention to rare diseases in gastroenterology and emphasizes increasing awareness of ATTRv and diagnostic suspicion. Based on the experts' recommendations, a diagnosis of ATTRv should be suspected when at least one of the 'red flags' is detected. Subsequently, it is suggested to promptly ask for genetic testing and exclude a serum and urinary monoclonal protein, even before the detection of amyloid in biopsy samples, particularly in non-endemic areas.

Celiac Disease-Related Conditions: Who to Test?

Celiac disease (CeD) is a chronic immune-mediated condition triggered by gluten consumption in genetically predisposed individuals. Approximately 1% of the general population is affected by the disorder. Disease presentation is heterogeneous and, despite growing awareness among physicians and the public, it continues to be underestimated. The most effective strategy for identifying undiagnosed CeD is proactive case finding through serologic testing in high-risk groups. We reviewed the most recent evidence on the association between CeD and more than 20 conditions. In light of this review, CeD screening is recommended in individuals with (1) autoimmune disease and accompanying symptoms suggestive of CeD; (2) diseases that may mimic CeD (eg, irritable bowel syndrome [IBS], inflammatory bowel disease [IBD], and microscopic colitis); and (3) among patients with conditions with a high CeD prevalence: first-degree relatives, idiopathic pancreatitis, unexplained liver enzyme abnormalities, autoimmune hepatitis, primary biliary cholangitis, hyposplenism or functional asplenia with severe bacterial infection, type 1 diabetes mellitus, Hashimoto's thyroiditis and Graves' disease, Sjögren's syndrome, dermatitis herpetiformis, recurrent aphthous syndrome and enamel defects, unexplained ataxia, peripheral neuropathy, delayed menarche or premature menopause, Down syndrome, Turner syndrome, Williams syndrome, chronic fatigue syndrome, IgA nephropathy, and IgA deficiency. CeD serology should be the initial step in the screening process. However, for patients with any of the aforementioned disorders who are undergoing upper endoscopy, biopsies should be performed to rule out CeD.

Efficacy and tolerability of chitin-glucan combined with simethicone (GASTRAP® DIRECT) in irritable bowel syndrome: A prospective, open-label, multicenter study

BACKGROUND

Irritable bowel syndrome (IBS), defined according to the Rome IV diagnostic criteria, is a chronic functional gastrointestinal disorder characterized by recurrent abdominal pain related to altered bowel habits. First-line recommended treatments are limited to combining drugs targeting predominant symptoms, particularly pain (antispasmodics), constipation (laxatives), and diarrhea (loperamide), yielding only a limited therapeutic gain. GASTRAP® DIRECT is a class IIa medical formulation composed of a combination of chitin-glucan and simethicone indicated for the symptomatic treatment of gas-related gastrointestinal disorders by combining different mechanisms of action.

AIM

To evaluate the efficacy, tolerability, and safety of 4-week GASTRAP® DIRECT treatment in patients with IBS.

METHODS

In this prospective, multicenter, open-label trial, 120 patients with IBS received three sticks of GASTRAP® DIRECT (1.5 g/d of chitin-glucan and 0.75 mg/d of simethicone) per day for 4 weeks. The primary endpoint was the responder rate, defined as the number of patients whose abdominal pain score decreased by ≥ 30% from baseline to week (W) 4. The analysis was performed using the per-protocol set. Cardinal symptoms, impact of global symptoms on daily life, change in stool consistency, and improvement in defecatory disorders were evaluated.

RESULTS

Overall, 100 patients were evaluated. At W4, 67% (95%CI: 57-75) showed improvement in abdominal pain (score: 5.8 ± 2.4 vs 2.9 ± 2.0, P < 0.0001). Similar improvements were observed for bloating [8.0 ± 1.7 vs 4.7 ± 2.9, P < 0.0001; 60% (95%CI: 50-70) responders], abdominal distension [7.2 ± 2.1 vs 4.4 ± 3.1, P < 0.0001; 53% (95%CI: 43-63) responders], and impact of global symptoms on daily life [7.1 ± 2.0 vs 4.6 ± 2.9, P < 0.0001; 54% (95%CI: 44-64) responders]. Stool consistency improved in most patients (90% and 57% for patients with liquid and hard stools, respectively). Overall, 42% of patients with defecatory disorders reported very much/considerable improvements by W2. No severe adverse event occurred, and tolerability was rated "good" or "very good" by 93% of patients.

CONCLUSION

GASTRAP® DIRECT is safe and well tolerated, alleviating IBS symptoms rapidly in 2 weeks. This open-label study suggests that the combination of chitin-glucan and simethicone could be beneficial in patients with IBS.

Utilization of the microbiome in personalized medicine

Inter-individual human variability, driven by various genetic and environmental factors, complicates the ability to develop effective population-based early disease detection, treatment and prognostic assessment. The microbiome, consisting of diverse microorganism communities including viruses, bacteria, fungi and eukaryotes colonizing human body surfaces, has recently been identified as a contributor to inter-individual variation, through its person-specific signatures. As such, the microbiome may modulate disease manifestations, even among individuals with similar genetic disease susceptibility risks. Information stored within microbiomes may therefore enable early detection and prognostic assessment of disease in at-risk populations, whereas microbiome modulation may constitute an effective and safe treatment tailored to the individual. In this Review, we explore recent advances in the application of microbiome data in precision medicine across a growing number of human diseases. We also discuss the challenges, limitations and prospects of analysing microbiome data for personalized patient care.

Chitin-glucan improves important pathophysiological features of irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is one of the most frequent and debilitating conditions leading to gastroenterological referrals. However, recommended treatments remain limited, yielding only limited therapeutic gains. Chitin-glucan (CG) is a novel dietary prebiotic classically used in humans at a dosage of 1.5-3.0 g/d and is considered a safe food ingredient by the European Food Safety Authority. To provide an alternative approach to managing patients with IBS, we performed preclinical molecular, cellular, and animal studies to evaluate the role of chitin-glucan in the main pathophysiological mechanisms involved in IBS.

AIM

To evaluate the roles of CG in visceral analgesia, intestinal inflammation, barrier function, and to develop computational molecular models.

METHODS

Visceral pain was recorded through colorectal distension (CRD) in a model of long-lasting colon hypersensitivity induced by an intra-rectal administration of TNBS [15 milligrams (mg)/kilogram (kg)] in 33 Sprague-Dawley rats. Intracolonic pressure was regularly assessed during the 9 wk-experiment (weeks 0, 3, 5, and 7) in animals receiving CG (n = 14) at a human equivalent dose (HED) of 1.5 g/d or 3.0 g/d and compared to negative control (tap water, n = 11) and positive control (phloroglucinol at 1.5 g/d HED, n = 8) groups. The anti-inflammatory effect of CG was evaluated using clinical and histological scores in 30 C57bl6 male mice with colitis induced by dextran sodium sulfate (DSS) administered in their drinking water during 14 d. HT-29 cells under basal conditions and after stimulation with lipopolysaccharide (LPS) were treated with CG to evaluate changes in pathways related to analgesia (µ-opioid receptor (MOR), cannabinoid receptor 2 (CB2), peroxisome proliferator-activated receptor alpha, inflammation [interleukin (IL)-10, IL-1b, and IL-8] and barrier function [mucin 2-5AC, claudin-2, zonula occludens (ZO)-1, ZO-2] using the real-time PCR method. Molecular modelling of CG, LPS, lipoteichoic acid (LTA), and phospholipomannan (PLM) was developed, and the ability of CG to chelate microbial pathogenic lipids was evaluated by docking and molecular dynamics simulations. Data were expressed as the mean ± SEM.

RESULTS

Daily CG orally-administered to rats or mice was well tolerated without including diarrhea, visceral hypersensitivity, or inflammation, as evaluated at histological and molecular levels. In a model of CRD, CG at a dosage of 3 g/d HED significantly decreased visceral pain perception by 14% after 2 wk of administration (P < 0.01) and reduced inflammation intensity by 50%, resulting in complete regeneration of the colonic mucosa in mice with DSS-induced colitis. To better reproduce the characteristics of visceral pain in patients with IBS, we then measured the therapeutic impact of CG in rats with TNBS-induced inflammation to long-lasting visceral hypersensitivity. CG at a dosage of 1.5 g/d HED decreased visceral pain perception by 20% five weeks after colitis induction (P < 0.01). When the CG dosage was increased to 3.0 g/d HED, this analgesic effect surpassed that of the spasmolytic agent phloroglucinol, manifesting more rapidly within 3 wk and leading to a 50% inhibition of pain perception (P < 0.0001). The underlying molecular mechanisms contributing to these analgesic and anti-inflammatory effects of CG involved, at least in part, a significant induction of MOR, CB2 receptor, and IL-10, as well as a significant decrease in pro-inflammatory cytokines IL-1b and IL-8. CG also significantly upregulated barrier-related genes including muc5AC, claudin-2, and ZO-2. Molecular modelling of CG revealed a new property of the molecule as a chelator of microbial pathogenic lipids, sequestering gram-negative LPS and gram-positive LTA bacterial toxins, as well as PLM in fungi at the lowesr energy conformations.

CONCLUSION

CG decreased visceral perception and intestinal inflammation through master gene regulation and direct binding of microbial products, suggesting that CG may constitute a new therapeutic strategy for patients with IBS or IBS-like symptoms.

Short-Chain Fatty Acids and Human Health: From Metabolic Pathways to Current Therapeutic Implications

The gastrointestinal tract is home to trillions of diverse microorganisms collectively known as the gut microbiota, which play a pivotal role in breaking down undigested foods, such as dietary fibers. Through the fermentation of these food components, short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate are produced, offering numerous health benefits to the host. The production and absorption of these SCFAs occur through various mechanisms within the human intestine, contingent upon the types of dietary fibers reaching the gut and the specific microorganisms engaged in fermentation. Medical literature extensively documents the supplementation of SCFAs, particularly butyrate, in the treatment of gastrointestinal, metabolic, cardiovascular, and gut-brain-related disorders. This review seeks to provide an overview of the dynamics involved in the production and absorption of acetate, propionate, and butyrate within the human gut. Additionally, it will focus on the pivotal roles these SCFAs play in promoting gastrointestinal and metabolic health, as well as their current therapeutic implications.

[Bile Acid Diarrhea]

Diarrhea is a very common gastrointestinal symptom, and the presence of higher concentrations of bile acid in the colon leads to bile acid diarrhea (BAD). In BAD patients, a portion of bile from the small intestine that is normally controlled by enterohepatic circulation is present at a high concentration in the lumen of the large intestine, resulting in increased motility and secretion of the large intestine. The prevalence of BAD is estimated to be 1-2% of the general population, and it comprises one-third of the instances of diarrhea-predominant irritable bowel syndrome. The clinical symptoms of BAD include chronic diarrhea, increased frequency of defecation, urgency to defecate, fecal incontinence, and cramping abdominal pain. The pathophysiology of BAD has not yet been fully elucidated. However, recent studies have reported increased intestinal permeability, shortened intestinal transit time, and changes in the intestinal microbial community to be the possible causes of BAD. Although fecal and serum bile acid tests are widely used for diagnosis, new test methods that are non-invasive, inexpensive, and have high sensitivity and specificity are needed at various institutions to facilitate the diagnosis. The selenium homo-tauro-cholic acid (SeHCAT) test is the gold standard for BAD diagnosis and severity assessment. The validation of several other serum markers, such as 7-hydroxy-4-cholesten-3-one (serum 7αC4) and the fibroblast growth factor 19 (FGF19) for use in clinical practice is ongoing. Although bile acid sequestrants are the mainstay of treatment, the development of drugs that are more effective and have better compliance is required. Farnesoid X receptor (FXR) agonists are showing promising results.

Efficacy of a Low-FODMAP Diet for Coeliac Patients with Persistent IBS-like Symptoms despite a Gluten-Free Diet: A Systematic Review

Background: Persistent symptoms in coeliac disease (CD) can be due to not only poor gluten-free diet (GFD) adherence and complications of CD, but also functional gastrointestinal disorders such as irritable bowel syndrome (IBS). Although the role of a low fermentable oligo-, di-, and monosaccharides and polyols (FODMAP) diet is well-established in IBS, little data are available on its role in coeliac patients with persistent IBS-like symptoms despite a GFD. Methods: We systematically reviewed the literature in accordance with the PRISMA guidelines for studies evaluating the role of FODMAPs and/or a low-FODMAP diet in coeliac patients with persistent symptoms. PubMed and Embase were searched from inception to 16 January 2024 for eligible full-text papers. The study protocol was registered on Open Science Framework. Results: A total of 239 records were identified, and six papers were included. Of these, four were interventional studies comparing a low-FODMAP GFD to a regular GFD for persistent symptoms in 115 total coeliac patients (two randomized controlled trials and two open-label studies). A low-FODMAP GFD for a minimum of 4 weeks was significantly more effective than a regular GFD in reducing symptoms (p < 0.05 in 3/4 studies). Dietary FODMAP content of a conventional GFD was significantly lower than that of non-coeliac patients on a gluten-containing diet (both p < 0.05), especially regarding high-FODMAP grain products. However, coeliac patients consumed more servings of fruits/vegetables high in FODMAP. No relationship between FODMAP intake and persistence of symptoms was reported. Conclusions: A low-FODMAP diet may be beneficial for uncomplicated celiac patients with persistent IBS-like symptoms despite strict adherence to a GFD.

Diagnosing and managing irritable bowel syndrome with predominant diarrhoea in clinical practice: online survey among gastroenterologists and general practitioners

Introduction

Irritable bowel syndrome (IBS) represents the most common disorder of gut-brain interaction encountered in clinical practice. The Rome IV criteria define the disorder. Over the years, many guidelines proposed guidance during the diagnostic and therapeutic approach of patients with presumed IBS.

Aim

This study investigates the management of IBS with predominant diarrhoea (IBS-D) by Belgian gastroenterologists (GE) and general practitioners (GP) in daily practice.

Methods

An online vignette-based survey was conducted exploring the diagnostic and therapeutic approach of patients suffering from IBS with predominant diarrhoea (IBS-D) in primary and secondary care.

Results

64 GE and 31 GP completed the survey. Abdominal pain and discomfort led to an IBS diagnosis in 88% and 84% of cases, respectively. The diagnosis rate dropped to 58.3% with diarrhoea as main presentation and 26.8% for patients aged 65. Additional tests were ordered by 89.5% of physicians, including biochemistry (77.9%), stool culture and parasites (59.3%), iFOBT (60.5%), breath testing (17.4%), imaging (12.8%), and endoscopy (9.3%). Upon normal results, 57% of physicians did not order further investigations. Both GP and GE preferred spasmolytics (64.3%) and dietary interventions (23.9%) as first-line treatment for IBS. Second-line treatment options included referral to a specialist or colleague (19.4%), dietary intervention (22.6%), neuromodulators (19.4%), and spasmolytics (14.5%). No GP initiated neuromodulators.

Conclusion

In Belgium, abdominal pain or discomfort are equivalent cardinal symptoms when diagnosing IBS. During the further diagnostic and therapeutic approach most physicians order only limited additional non-invasive testing. Spasmolytics and dietary interventions are favoured in first-line. Upon failure, only GE prescribe neuromodulators, while GP opt for referral. These findings are consistent with the general principles and recommendations outlined in the recently published Belgian guideline for IBS.

New paradigm of oral rehydration in patients affected by irritable bowel syndrome with chronic diarrhea

Irritable bowel syndrome with diarrhea is a very frequent clinical condition characterized by disabling intestinal symptoms. This disease presents with daily abdominal pain for at least 3 months related to defecation and associated with a change in the frequency of bowel movements and the shape of the stool. International surveys about this disease report a global prevalence of about 1.5%. A new amino acid based electrolyte solution has recently been commercialized for oral rehydration in diarrhea. It is composed of water, electrolytes, and five selected amino acids that function as sodium co-transporters without containing glucose. In recent years, some studies explored the effectiveness of the amino acid based electrolyte beverage in oncologic patients with gastrointestinal mucositis, reporting good results. Recently, a prospective study to evaluate the clinical impact of the amino acid based medical beverage was conducted in patients with diarrhea predominant irritable bowel syndrome. The research was based on a real-life methodology minimizing the disruption of the routine care. One hundred patients suffering from irritable bowel syndrome with diarrhea drank a solution based on selected amino acids twice a day for 2 wk. Each enrolled patient completed the study and showed a significant response rate with regard to stool consistency and pain reduction. Based on this data, we can hypothesize that the amino acid based oral rehydration solution could be a valid tool in the treatment of patients affected by irritable bowel syndrome with diarrhea. It is certainly necessary to plan high-quality clinical trials comparing glucose based oral solutions and amino acid based solutions in patients with persisting diarrhea. Probably in the near future all oral rehydration solutions will contain amino acids.

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.

[Efficacy of navel application of Jianpiwenyang Gel for chronic diarrhea of spleen and stomach weakness type: a randomized controlled trial and analysis of the mechanism]

OBJECTIVE

To investigate the efficacy of Jianpiwenyang Gel (SSWYG) for treating chronic diarrhea and explore its therapeutic mechanism.

METHODS

Eighty patients with chronic diarrhea of spleen and stomach weakness type were randomized into two groups for interventions with lifestyle adjustment and treatment with bifid triple viable capsules (control group, n=40) or naval application with SSWYG (treatment group, n=40) for one week, after which symptoms of chronic diarrhea were evaluated. The Chinese medicine system pharmacology analysis platform (TCMSP), GeneCards, NCBI, OMIM database and GEO database (GSE14841) were used to obtain the active ingredients and target proteins of SSWYG and chronic diarrhea-related targets. The key targets were obtained by topological analysis for Gene Ontology (GO) and KEGG analyses. The affinity and binding characteristics of SSWYG for specific targets were verified by molecular docking using AutoDock software.

RESULTS

In both groups, gastrointestinal symptom rating scale (GSRS), Bristol Scale and TCM syndrome scores significantly improved after the treatments (P < 0.05), and better effects were observed in the treatment group (P < 0.05). Sixtyeight targets of SSWYG in treating chronic diarrhea were obtained, and 33 most probable ones were screened out by topological analysis. GO and KEGG analyses identified several chronic diarrhea-related pathways including the TNF and IL-17 pathways. Molecular docking study showed good affinity of the core components of SSWYG for the key targets CASP3, JNK, IL1B, IL6, and AKT1. JUN and CASP3 had the lowest binding energy and the highest stable binding energy with multiple major active ingredients of SSWYG.

CONCLUSION

SSWYG can significantly improve clinical symptoms of chronic diarrhea possibly by regulating the TNF and IL-17 as well as other pathways via CASP3 and JUN, suggesting a complex therapeutic mechanism of SSWYG involving multiple ingredients and targets and coordinated regulation of multiple pathways.

Efficacy and safety of peppermint oil for the treatment in Japanese patients with irritable bowel syndrome: a prospective, open-label, and single-arm study

BACKGROUND

In Europe, an herbal medicine containing peppermint oil is widely used in patients with irritable bowel syndrome (IBS). In Japan, however, no clinical evidence for peppermint oil in IBS has been established, and it has not been approved as a drug for IBS. Accordingly, we conducted a clinical study to confirm the efficacy and safety of peppermint oil (ZO-Y60) in Japanese patients with IBS.

METHODS

The study was a multi-center, open-label, single-arm, phase 3 trial in Japanese outpatients with IBS aged 17-60 years and diagnosed according to the Rome III criteria. The subjects were treated with an oral capsule of ZO-Y60 three times a day before meals, for four weeks. The efficacy of ZO-Y60 was evaluated using the patient's global assessment (PtGA), IBS symptom severity score, stool frequency score, stool form score, and physician's global assessment (PGA). The safety of ZO-Y60 was also assessed.

RESULTS

Sixty-nine subjects were treated with ZO-Y60. During the four-week administration of ZO-Y60, the improvement rate of the PtGA was 71.6% (48/67) in week 2 and 85.1% (57/67) in week 4. It was also suggested that ZO-Y60 is effective against any type of IBS (IBS with constipation, IBS with diarrhea, and mixed/unsubtyped IBS). The improvement rate of the PGA was 73.1% (49/67) in week 2 and 85.1% (57/67) in week 4, also confirming the efficacy of ZO-Y60. Adverse events were observed in 14 subjects (20.3%), however, none of these adverse events were categorized as serious.

CONCLUSION

The efficacy of treatment was confirmed, subjective symptoms were improved, as was observed in previous clinical studies of ZO-Y60 conducted outside of Japan. All adverse reactions were previously known and were non-serious. These findings suggest that peppermint oil may be effective in the Japanese population and that it has an acceptable safety profile.

TRIAL REGISTRATION

JAPIC Clinical Trials Information number: JapicCTI-121727 https://jrct.niph.go.jp/en-latest-detail/jRCT1080221685 . Registration date: 2012-01-10.

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.

Nutrition and Disorders of Gut-Brain Interaction

BACKGROUND

Disorders of gut-brain interaction (DGBIs) have a complex pathophysiology that is often characterized by a relationship between food ingestion and triggering of symptoms. Understanding of the underlying mechanisms and the role of nutrients as a therapeutic target are rapidly evolving.

AIMS AND METHODS

We performed a narrative review of the literature using the following keywords, their acronyms, and their associations: nutrients, disorders of gut-brain interaction; functional dyspepsia; malabsorption; irritable bowel syndrome; diarrhea; constipation.

RESULTS

Functional dyspepsia displayed a significant correlation between volume, fat and/or wheat abundance, chemical composition of ingested food and symptoms of early satiety, fullness and weight loss. Carbohydrate malabsorption is related to enzyme deficiency throughout the GI tract. Food composition and richness in soluble vs. non-soluble fibers is related to constipation and diarrhea. The elimination of fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) has a significant and non-unidirectional impact on irritable bowel syndrome (IBS) symptoms.

CONCLUSIONS

Food volume, nutritive and chemical composition, and its malabsorption are associated with symptom generation in DGBIs. Further multicenter, randomized-controlled clinical trials are needed to clarify the underlying pathophysiology.

The gut microbiome in disorders of gut-brain interaction

Functional gastrointestinal disorders (FGIDs), chronic disorders characterized by either abdominal pain, altered intestinal motility, or their combination, have a worldwide prevalence of more than 40% and impose a high socioeconomic burden with a significant decline in quality of life. Recently, FGIDs have been reclassified as disorders of gut-brain interaction (DGBI), reflecting the key role of the gut-brain bidirectional communication in these disorders and their impact on psychological comorbidities. Although, during the past decades, the field of DGBIs has advanced significantly, the molecular mechanisms underlying DGBIs pathogenesis and pathophysiology, and the role of the gut microbiome in these processes are not fully understood. This review aims to discuss the latest body of literature on the complex microbiota-gut-brain interactions and their implications in the pathogenesis of DGBIs. A better understanding of the existing communication pathways between the gut microbiome and the brain holds promise in developing effective therapeutic interventions for DGBIs.

Prospective comparison of diagnostic tests for bile acid diarrhoea

BACKGROUND

Bile acid diarrhoea is often missed because gold standard nuclear medicine tauroselcholic [75-Se] acid (SeHCAT) testing has limited availability. Empirical treatment effect has unknown diagnostic performance, whereas plasma 7α-hydroxy-4-cholesten-3-one (C4) is inexpensive but lacks sensitivity.

AIMS

To determine diagnostic characteristics of empirical treatment and explore improvements in diagnostics with potential better availability than SeHCAT.

METHODS

This diagnostic accuracy study was part of a randomised, placebo-controlled trial of colesevelam. Consecutive patients with chronic diarrhoea attending SeHCAT had blood and stool sampled. Key thresholds were C4 > 46 ng/mL and SeHCAT retention ≤10%. A questionnaire recorded patient-reported empirical treatment effect. We analysed receiver operating characteristics and explored machine learning applied logistic regression and decision tree modelling with internal validation.

RESULTS

Ninety-six (38%) of 251 patients had SeHCAT retention ≤10%. The effect of empirical treatment assessed with test results for bile acid studies blinded had 63% (95% confidence interval 44%-79%) sensitivity and 65% (47%-80%) specificity; C4 > 46 ng/mL had 47% (37%-57%) and 92% (87%-96%), respectively. A decision tree combining C4 ≥ 31 ng/mL with ≥1.1 daily watery stools (Bristol type 6 and 7) had 70% (51%-85%) sensitivity and 95% (83%-99%) specificity. The logistic regression model, including C4, the sum of measured stool bile acids and daily watery stools, had 77% (58%-90%) sensitivity and 93% (80%-98%) specificity.

CONCLUSIONS

Diagnosis of bile acid diarrhoea using empirical treatment was inadequate. Exploration suggested considerable improvements in the sensitivity of C4-based testing, offering potential widely available diagnostics. Further validation is warranted.

CLINICALTRIALS

gov: NCT03876717.

Getting the BS out of Irritable Bowel Syndrome with Diarrhea (IBS-D): Let's Make a Diagnosis

PURPOSE OF REVIEW

Irritable bowel syndrome with diarrhea (IBS-D) is diagnosed when chronic symptoms of abdominal pain accompany loose stools, and alarm features, such as fever, anemia, rectal bleeding, and weight loss are absent. This combination of symptoms makes structural disorders, such as inflammatory bowel disease or cancer, unlikely, but does not exclude other conditions that cause these symptoms. The question is whether making a "positive diagnosis" of IBS-D based on symptoms alone and instituting therapy based on that diagnosis still makes sense.

RECENT FINDINGS

Clinical observations suggest that at least two-thirds of cases of IBS-D can be explained by three mechanisms: a) food intolerances (~ 30-40%), b) bile acid diarrhea (~ 20-30%), and c) disturbed microbial flora (~ 15-20%). Other conditions that are less frequent but can cause IBS symptoms or be confused with IBS include: celiac disease, microscopic colitis, mastocytosis/mast cell activation, and drug side-effects. Many cases of IBS-D have a discoverable, underlying cause that can direct therapy more efficiently.

Effectiveness of an amino acid beverage formulation in diarrhea-predominant irritable bowel syndrome: A pragmatic real-world study

BACKGROUND

Amino-acid based medical foods have shown promise in alleviating symptoms of drug induced gastrointestinal side effects; particularly, diarrhea-predominant symptoms. Irritable bowel syndrome (IBS) is a gastrointestinal disorder that affects up to 9% of people globally, with diarrhea predominant IBS (IBS-D) being the most prevalent subtype. Further trials are needed to explore potential added benefits when integrated into standard care for IBS-D.

AIM

To assess the effectiveness of an amino acid-based medical food as an adjunct to standard of care for adults with IBS-D.

METHODS

This is a pragmatic, real world, open label, single arm study comparing a 2-week baseline assessment to a 2-week intervention period. One hundred adults, aged 18 to 65 years, with IBS-D, according to Rome IV criteria, were enrolled after completing a 2-week baseline assessment period and received a 2-week supply of an amino acid based medical food which was consumed at home twice daily on top of their standard of care. The primary outcome was an assessment of tolerability after 2-weeks of consumption, while secondary outcomes included changes in stool consistency (Bristol Stool Form Scale), severity of abdominal pain & discomfort, symptoms of urgency, Global Improvement Survey (GIS), and the IBS severity scoring system (IBS-SSS).

RESULTS

The test product was well-tolerated as each participant successfully completed the full 14-day trial, and there were no instances of dropouts or discontinuation of the study product reported. Forty percent of participants achieved a 50% or more reduction in the number of days with type 6-7 bowel movements (IBS-D stool consistency responders). Fifty-three percent of participants achieved a clinically meaningful reduction of 30% in mean weekly pain scores, and 55% experienced the same for mean weekly discomfort scores (IBS-D pain and discomfort responders). Participants experienced a mean -109.4 (95% confidence interval: -130.1, -88.8) point reduction on the IBS-SSS and 52% experienced a minimally clinically important difference of > 95 points. An IBS-SSS category shift from severe to moderate or mild occurred in 69% of participants. For functional symptoms, 76% of participants reported symptom relief on the GIS.

CONCLUSION

The amino acid-based medical food was well-tolerated, when added to the standard of care, and demonstrated improvements in both overall IBS symptom severity and IBS-D symptoms within just 2 wk.

Myths and Facts about Food Intolerance: A Narrative Review

Most adverse reactions to food are patient self-reported and not based on validated tests but nevertheless lead to dietary restrictions, with patients believing that these restrictions will improve their symptoms and quality of life. We aimed to clarify the myths and reality of common food intolerances, giving clinicians a guide on diagnosing and treating these cases. We performed a narrative review of the latest evidence on the widespread food intolerances reported by our patients, giving indications on the clinical presentations, possible tests, and dietary suggestions, and underlining the myths and reality. While lactose intolerance and hereditary fructose intolerance are based on well-defined mechanisms and have validated diagnostic tests, non-coeliac gluten sensitivity and fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) intolerance are mainly based on patients' reports. Others, like non-hereditary fructose, sorbitol, and histamine intolerance, still need more evidence and often cause unnecessary dietary restrictions. Finally, the main outcome of the present review is that the medical community should work to reduce the spread of unvalidated tests, the leading cause of the problematic management of our patients.

Modulation of microbiota as a target in the management of patients with irritable bowel syndrome

Irritable  bowel syndrome  (IBS) is one of the  most common  diseases  of the  digestive  tract. IBS negatively  affects  the  quality of life and work ability of patients. It is generally  accepted that  IBS is an important medical  and social problem  associated with high financial  costs  both  on the  part of the  patient  and the  public health  system. The pathophysiology of the  disease involves the participation of many factors (genetic, dietary, psychosocial, infectious) and the mechanisms of their implementation, including  disruption  of interaction along  the  functional  “gut-brain axis”, visceral  hypersensitivity,  changes  in motility, low-grade  inflammation, increased permeability of the epithelial intestinal barrier, modulation of microbiota, changes  in neurohumoral  regulation and  processes of central  processing  of peripheral stimuli. Research  shows  an important role  for gut microbiota  in the development of IBS. Modulation of the intestinal microbiota  through  diet, the use of pre- and probiotics  or fecal microbiota transplantation is considered as a promising target  for disease  therapy. A reduction  in the number of bacteria of the genus  Bifidobacterium is described  as a universal  change  in the microbiota  in IBS, regardless of the clinical course and severity of the disease  and the possibility of using different  strains of Bifidobacterium in treatment regimens  for the disease  is of particular  interest. This article  provides  a review of the literature on modern  approaches to prescribing  probiotics  for IBS. Using our own clinical observations as an example, we demonstrated the effectiveness and safety of prolonged administration of the probiotic strain Bifidobacterium longum 35624®  for up to 12 weeks.

Methods of Determining Irritable Bowel Syndrome and Efficiency of Probiotics in Treatment: A Review

Background

Irritable bowel syndrome (IBS) is a prevalent lifestyle-associated ailment linked to the gut microbiota that significantly influences patients' quality of life. A notable correlation exists between Blastocystis infections and susceptibility to IBS, with infected individuals exhibiting an increased likelihood of developing the condition. Despite promising results from using probiotics to modulate the gut microbiota and manage IBS, the precise mechanisms and potential risks remain unclear.

Objective

This review aims to explore the therapeutic potential of probiotics, particularly Saccharomyces boulardii, in the management of IBS, highlighting the role of the gut microbiota and the gut-brain axis in IBS pathophysiology.

Methods

A comprehensive literature survey was conducted to examine the association between gut microbiota and IBS, the role of probiotics in managing IBS, the mechanisms of their action, and the potential risks associated with their long-term use. Additionally, this study addresses the influence of Blastocystis infections on IBS susceptibility and evaluates various ongoing clinical trials investigating probiotic use for IBS.

Results

S boulardii, a yeast species with probiotic properties, has demonstrated effectiveness in both the treatment and prophylaxis of IBS. Its administration is associated with a decrease in the proinflammatory cytokine interleukin 8 and an increase in the anti-inflammatory cytokine interleukin 10. Probiotics appear to function by inhibiting the growth of pathogenic microorganisms and regulating neurotransmitter activity, influencing the gut-brain axis. However, selecting appropriate probiotic strains and dosing regimens is crucial because of potential adverse effects, such as infections and allergic reactions.

Conclusions

Probiotics, specifically S boulardii, offer a promising avenue for IBS management by modulating gut microbiota. However, further research is necessary to delineate the precise mechanisms of action, optimal strains, dosing regimens for IBS treatment, and potential risks associated with long-term use. A comprehensive approach incorporating probiotics, a low-FODMAP diet, and cognitive-behavioral therapy may provide effective management of IBS symptoms.

Misinterpreting Diarrhea-Predominant Irritable Bowel Syndrome and Functional Diarrhea: Pathophysiological Highlights

Irritable bowel syndrome with predominant diarrhea (IBS-D) and functional diarrhea (FD) are disorders of gut-brain interaction characterized by recurring symptoms which have a serious impact on the patient's quality of life. Their pathophysiology is far from being completely understood. In IBS-D growing evidence suggests that bile acid malabsorption (BAM) could be present in up to 30% of patients. Microscopic colitis (MC) is a well-known cause of watery diarrhea and some patients, at first, can be diagnosed as IBS-D or FD. Both BAM and MC are often responsible for the lack of response to conventional treatments in patients labelled as "refractory". Moreover, because BAM and MC are not mutually exclusive, and can be found in the same patient, they should always be considered in the diagnostic workout when a specific treatment for BAM or MC is unsatisfactory. In the present review the possible shared pathogenetic mechanisms between BAM and MC are discussed highlighting how MC can induce a secondary BAM. Moreover, a brief overview of the current literature regarding the prevalence of their association is provided.

Nutrition Considerations in Patients with Functional Diarrhea

PURPOSE

Functional diarrhea (FD) is a functional gastrointestinal disorder that affects a great percentage of the population and has damaging nutritional and psychological effects. In this review, evidence has been assessed and analyzed to provide nutrition considerations and recommendations for patients with functional diarrhea.

RECENT FINDINGS

The traditional irritable bowel syndrome (IBS) diet, the low FODMAP diet, and general recommendations for diarrhea have been established as interventions for FD. Additionally, nutrition outcomes such as vitamin and mineral deficiencies, hydration levels, and mental health status should be at the forefront of assessment. The importance of medical management of FD and IBS-D is established, with many existing evidence-based recommendations and approved medications available. Nutrition management of FD from a registered dietitian/dietitian nutritionist, from symptom control to dietary advice, is imperative. There are no "one-size-fits-all" approaches to nutrition management of FD, but there is promising literature that can shape personalized nutrition interventions from a registered dietitian.

Fecal Calprotectin for the Diagnosis and Management of Inflammatory Bowel Diseases

Calprotectin is a heterodimeric calcium- and zinc-binding protein mainly derived from the cytoplasm of neutrophils that has direct antimicrobial functions and a role in the regulation of the innate immune response. It can be found in various biological compartments, in particular, the stool, with concentrations related to the level of mucosal inflammation. The measurement of fecal calprotectin has thus been recognized as a useful surrogate marker to distinguish patients with inflammatory bowel disease from those with irritable bowel syndrome. Moreover, it allows the monitoring of intestinal inflammation with a high negative predictive value, making it possible to exclude the diagnosis of inflammatory bowel disease for symptomatic patients. It also shows high sensitivity for the identification of patients requiring additional examinations for diagnosis, such as colonoscopy, and the evaluation of therapeutic responses, providing evidence of relapse or mucosal healing, which can lead to the intensification or reduction of treatment. As calprotectin levels are a measure of mucosal inflammation, high fecal concentrations are also found in other diseases with an inflammatory component, such as infectious enteritis or colorectal cancer. Interpretation of the concentration must therefore always take into account the clinical history and symptoms specific to each patient.

Vitamin D Deficiency (VDD) and Benefits of Supplementation in Veterans with IBS-D

Many veterans deployed to Gulf War areas suffer from persistent chronic diarrhea that is disabling and affects their quality of life. The causes for this condition have eluded investigators until recently and recent literature has shed light on the effect of vitamin D on the brain-gut axis. This study focused on determining clinical causes contributing to diarrhea and assessed whether reversing the identified causes, specifically vitamin D deficiency (VDD), could reduce the incidence of diarrhea in Gulf War veterans (GWVs). All patients completed a workup that included serologies (IBD, celiac), routine laboratory tests (CBC, chemistry panels, TSH, T4, CRP), cultures for enteric pathogens (C diff, bacteria, viruses, small intestinal bacterial overgrowth (SIBO)), and upper and lower endoscopies with histology and a trial of cholestyramine to exclude choleretic diarrhea and rifaximin for dysbiosis. A total of 4221 veterans were screened for chronic diarrhea, yielding 105 GWVs, of which 69 GWVs had irritable bowel syndrome with diarrhea (IBS-D). Paired t-tests demonstrated that all GWVs had VDD (t-11.62, df68 and sig(2-tailed) 0.0001) (defined as a vitamin D level less than 30 ng/mL with normal ranges of 30-100 ng/mL) but no positive serologies, inflammatory markers, abnormal endoscopies, cultures, or histology to explain their persistent diarrhea. There was no correlation with age, BMI, or inflammation. Some zip codes had a higher frequency of GWVs with VDD, but the number of deployments had no impact. Treatment with vitamin D supplementation (3000-5000 units), given in the morning, based on weight, reduced the number of bowel movements per day (p < 0.0001) without causing hypercalcemia. We suggest that VDD is important in the etiology of IBS-D in GWVs and that vitamin D supplementation significantly reduces diarrhea.