Diarrhea-predominant irritable bowel syndrome: Diagnosis, etiology, and new treatment considerations

Cimifugin improves intestinal barrier dysfunction by upregulating SIRT1 to regulate the NRF2/HO-1 signaling pathway

Irritable bowel syndrome (IBS) is a prevalent gastrointestinal dysfunction. Cimifugin is an active component of Radix saposhnikoviae which is effective for maintaining intestinal barrier integrity and intestinal function. This study aimed to investigate the treatment efficacy of Cimifugin on intestinal barrier dysfunction and to unveil the relevant mechanism through network pharmacology and experimental verification as well as molecular docking. Through SuperPred and Pubchem databases, the targets of Cimifugin were obtained. The disease targets were screened using Disgenet and GEO databases. With STRING database and Cytoscape software, the analysis of PPI network was performed. In DAVID database, the hub genes of Cimifugin were analyzed using GO and Pathway enrichment analyses. To validate the binding of Cimifugin with core targets, molecular docking was performed. The in vitro cellular model of intestinal barrier was established via the induction of Caco2 cells with LPS. TEER was used to detect epithelial barrier function and permeability was measured using FITC-dextran (FD4). Western blotting was used to measure the expressions of SIRT1, tight junction proteins, and NRF2/HO-1 signaling pathway-related proteins. The fluorescence intensity of ZO-1, Occludin, and Claudin-1 was detected using immunofluorescence staining. ELISA was used to detect the expression levels of inflammatory cytokines. Through the integration of all targets of IBS and Cimifugin, 94 frequent drug-disease-related targets were identified. These targets were enriched in some signaling pathways, like cellular responses to stress, cellular responses to stimuli, and VEGFA-VEGFR2. Ten hub genes including PTGS2, ANPRP, TGFB1, ACACA, SIRT1, NEF2L2, APEX1, IL6, AKT1, and HSP90AB1 were obtained. Cimifugin showed strong affinity with four key genes, including AKT1, SIRT1, IL6, and NFE2L2 (NRF2), which were obtained through the intersection of hug genes with cellular responses to stimuli. In vitro experiments showed that Cimifugin ameliorated LPS-induced intestinal barrier injury in Caco2 cells via upregulating SIRT1 to modulate NRF2/HO-1 signaling pathway. Cimifugin could alleviate intestinal barrier dysfunction in IBS by upregulating SIRT1 to regulate the NRF2/HO-1 signaling pathway.

Functional yogurt: a comprehensive review of its nutritional composition and health benefits

Functional yogurt, renowned for its enhanced nutritional profile and potential health benefits, has emerged as a promising functional food. This review meticulously examines the nutritional composition of functional yogurt, highlighting its enriched content of probiotics, prebiotics, synbiotics, antioxidants, vitamins, minerals, proteins, and other bioactive compounds, which contribute to its health-promoting properties. Functional yogurt has positively affected digestive health, immune function, metabolic health, and mental well-being. It benefits digestive health by alleviating diarrhoeal symptoms, constipation, colon cancer, irritable bowel syndrome (IBS), Helicobacter pylori infection, and digestive-related allergies. Moreover, the immune-boosting properties of functional yogurt play a pivotal role in reducing the risk of infections and inflammation. In addition, functional yogurt has the potential to improve metabolic health, leading to decreased cholesterol levels and enhanced blood sugar regulation. Emerging research also suggests functional yogurt may positively influence mood, behavior, and cognitive function. Functional yogurt is a valuable addition to the human diet, holding significant implications for public health. In addition to its numerous health benefits, functional yogurt also faces limitations, such as the stability of functional compounds, sensory alterations, potential digestive discomfort, and inconsistent efficacy across populations, highlighting the need for further research and optimization.

The Role of Diet in the Management of Irritable Bowel Syndrome: A Comprehensive Review

Irritable bowel syndrome (IBS) is a highly prevalent gastrointestinal disorder that has a significant impact on the general population. The suboptimal medical treatments available for IBS contribute to its large economic burden. The pathophysiology of IBS is complex, and treatments often focus on managing specific symptoms. Many individuals with IBS associate their symptoms with specific food intake, leading to increased scientific research on the role of diet in managing IBS. Dietary management has become a crucial aspect of IBS treatment, with initial recommendations focusing on adopting a healthy eating pattern and lifestyle. This comprehensive review aims to synthesise the current literature on the impact of diet on IBS, exploring various dietary approaches to managing IBS, including the low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet, gluten-free diet, Mediterranean diet, and tritordeum-based diet. It presents evidence from both experimental and observational studies and summarises the underlying dietary triggers in IBS, including gut microbiota dysbiosis, visceral hypersensitivity, and immune activation. In addition, it explores the efficacy and limitations of the key diet and lifestyle recommendations provided by dietary guidelines and scientific literature, highlighting the importance of individualised dietary strategies tailored to the unique needs of different types of IBS patients. By elucidating the complex interplay between diet and IBS pathophysiology, this review provides valuable insights into optimising dietary management approaches for improving symptom control and enhancing the quality of life for individuals with IBS.

Network pharmacology and molecular docking reveal the immunomodulatory mechanism of rhubarb peony decoction for the treatment of ulcerative colitis and irritable bowel syndrome

Background: Ulcerative colitis (UC) and irritable bowel syndrome (IBS) share various similarities in clinical symptoms, pathogenesis, and treatment. UC concurrent IBS tends toward more severe symptoms and worse prognosis, and promising feasible therapies for the overlapping symptoms remains a challenge. Rhubarb peony decoction (RPD) is a well-known traditional Chinese medicine that has been widely applied in treating UC. RPD may exert extensive therapeutic effects on both IBS and UC. However, the common mechanism of its treatment remains unclear. We aimed to assess the potential pharmacological mechanism of RPD in the treatment of overlapping IBS and UC. Methods: The active components and targets of RPD were retrieved from ETCM, TCMSP, BATMAN-TCM, and TCM databases. The disease targets were screened by searching the DrugBank, OMIM, TTD, and PharmGKB databases. PPI network analysis was performed and visualized via the STRING platform and Cytoscape software. GO and KEGG enrichment analyses of the hub genes of RPD were predicted to elucidate the potential molecular mechanism. Subsequently, molecular docking was carried out to verify the combination of active compounds with core targets. Results: By integrating all targets of RPD and disease, a total of 31 bioactive ingredients were identified including quercetin, kaempferol, aloe-emodin, beta-sitosterol, and (+)-catechin, etc. JUN, TP53, MAPK1, RELA, MYC, and ESR1 were explored as potential therapeutic targets among 126 common drug-disease-related targets. They were enriched in the AGE-RAGE signaling pathway in diabetic complications, as well as the NF-kappa B signaling pathway and MAPK signaling pathway. Additionally, some active ingredients were identified as candidates for binding to the hub targets via molecular docking, further suggesting their anti-inflammatory and antioxidative properties. Conclusion: RPD may exert the overall treatment effect for UC and IBS overlap syndrome via the biological mechanism of "multi-ingredients, multi-targets, and multi-pathways" on inflammation, oxidative stress, immune, oncogenicity, and gut microbiota dysbiosis.

Mechanistic insights of Cucumis melo L. seeds for gastrointestinal muscle spasms through calcium signaling pathway-related gene regulation networks in WGCNA and in vitro, in vivo studies

BACKGROUND

In addition to the nutritional benefits of Cucumis melo L., herbalists in Pakistan and India employ seeds to treat various ailments. This study aimed to determine the regulatory role of C. melo seeds in calcium-mediated smooth muscle contraction.

METHODS

We identified and quantified the phytochemicals of C. melo with LC ESI-MS/MS and HPLC, then conducted in vitro and in vivo tests to confirm the involvement in smooth muscle relaxation. Then, diarrhea-predominant irritable bowel syndrome gene datasets from NCBI GEO were acquired, DEGs and WGCNA followed by functional enrichment analysis. Next, molecular docking of key genes was performed.

RESULTS

The quantification of C. melo seeds revealed concentrations of rutin, kaempferol, and quercetin were 702.38 μg/g, 686.29 μg/g, and 658.41 μg/g, respectively. In vitro experiments revealed that C. melo seeds had a dose-dependent relaxant effect for potassium chloride (80 mM)-induced spastic contraction and exhibited calcium antagonistic response in calcium dose-response curves. In in vivo studies, Cm.EtOH exhibited antidiarrheal, antiperistaltic, and antisecretory effects. The functional enrichment of WGCNA and DEGs IBS-associated pathogenic genes, including those involved in calcium-mediated signaling, MAPK cascade, and inflammatory responses. MAPK1 and PIK3CG were identified as key genes with greater binding affinity with rutin, quercitrin, and kaempferol in molecular docking.

CONCLUSIONS

The bronchodilator and antidiarrheal effects of C. melo were produced by altering the regulatory genes of calcium-mediated smooth contraction.

The association between dietary total antioxidant capacity and odds and severity of irritable bowel syndrome among Iranian adults: a cross-sectional study

Background

Little evidence is available in terms of the role of dietary antioxidants in the management of irritable bowel syndrome (IBS) disease. This study aimed to examine the association between dietary total antioxidant capacity (dTAC) and odds of IBS and its severity.

Methods

This cross-sectional study was conducted on 3,362 Iranian adults who were referred to health centers in Isfahan province, Iran. Participants' dietary intakes were collected using a semi-quantitative validated food frequency questionnaire (DS-FFQ). The dTAC was measured by the ferric-reducing antioxidant power (FRAP) method. Multivariable binary or ordinal logistic regression analyses were performed to estimate any associations between dTAC and odds of IBS, IBS severity, and IBS subtypes.

Results

The average age and BMI of the participants and dTAC score were 36.3 ± 7.87 year, 24.9 ± 3.82 kg/m2. The prevalence of IBS, IBS with constipation (IBS-C), IBS with diarrhoea (IBS-D), mixed IBS (IBS-M), and un-subtyped IBS (IBS-U) were 22.2, 7.5, 4.6, 3.8, and 6.2%, respectively. In crude and adjusted models, the results did not show any significant association between dTAC and odds of IBS among whole and gender-age stratified populations. Being in the third compared with the first tertile of dTAC was not also significantly associated with odds of IBS severity. Besides, there were no significant associations between dTAC and odds of IBS-C, IBS-D, IBS-M, and IBS-U.

Conclusion

This study indicates that dTAC may not be associated with the odds of IBS and its severity even after stratification for gender and body mass index.

The association between dietary acid load and odds and severity of irritable bowel syndrome in adults

No study has been conducted to investigate the association between dietary acid load and irritable bowel syndrome (IBS). So, this cross-sectional study was performed to investigate the association between dietary acid load and odds of IBS, its severity, and IBS subtypes. A sample of 3362 Iranian subjects was selected from health centers in Isfahan province. A validated semi-quantitative food frequency questionnaire (DS-FFQ) was applied to estimate dietary intakes. The dietary acid load was measured using net endogenous acid production (NEAP), dietary acid load (DAL), and potential renal acid load (PRAL) scores. In crude models, the highest compared with the lowest category of the PRAL score was significantly associated with increased odds of IBS severity in participants with BMI ≥ 25 (kg/m²) (OR = 1.54; 95% CI = (1.03-2.32). Also, the results indicated a significant positive association between the PARL and odds of mixed subtype of IBS (OR = 1.74; 95% CI = (1.11-2.74); P trend = 0.02). In propensity score-adjusted model with potential confounders, only a positive association was found between PRAL and odds of mixed subtype of IBS (OR = 1.78; 95% CI = (1.05-3.00); P trend = 0.03). The DAL and NEAP scores tended to show non-significant similar findings. This study indicates that dietary acid load might be associated with odds of mixed type of IBS. However, further research is warranted to infer these findings.

Identification of putative transcriptomic biomarkers in irritable bowel syndrome (IBS): Differential gene expression and regulation of TPH1 and SERT by vitamin D

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders and affects approximately 4% of the global population. The diagnosis of IBS can be made based on symptoms using the validated Rome criteria and ruling out commonly occurring organic diseases. Although biomarkers exist for "IBS mimickers" such as celiac disease and inflammatory bowel disease (IBD), no such test exists for IBS. DNA microarrays of colonic tissue have been used to identify disease-associated variants in other gastrointestinal (GI) disorders. In this study, our objective was to identify biomarkers and unique gene expression patterns that may define the pathological state of IBS. Mucosal tissue samples were collected from the sigmoid colon of 29 participants (11 IBS and 18 healthy controls). DNA microarray analysis was used to assess gene expression profiling. Extraction and purification of RNA were then performed and used to synthesize cDNA. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) was employed to identify differentially expressed genes in patients diagnosed with IBS compared to healthy, non-IBS patient-derived cDNA. Additional testing probed vitamin D-mediated regulation of select genes associated with serotonergic metabolism. DNA microarray analyses led to the identification of 858 differentially expressed genes that may characterize the IBS pathological state. After screening a series of genes using a combination of gene ontological analysis and RT-qPCR, this spectrum of potential IBS biomarkers was narrowed to 23 genes, some of which are regulated by vitamin D. Seven putative IBS biomarkers, including genes involved in serotonin metabolism, were identified. This work further supports the hypothesis that IBS pathophysiology is evident within the human transcriptome and that vitamin D modulates differential expression of genes in IBS patients. This suggests that IBS pathophysiology may also involve vitamin D deficiency and/or an irregularity in serotonin metabolism.

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

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

Efficacy and safety of Qinghua Zhixie Decoction against diarrhea-predominate irritable bowel syndrome: A protocol for a randomized controlled trial

BACKGROUND

Diarrhea-predominant irritable bowel syndrome (D-IBS) is the main subtypes of irritable bowel syndrome (IBS). In recent years, more than half of IBS patients have received complementary and alternative medicine. Traditional Chinese herbal formula is widely used in Asia, and clinical studies have also found that Chinese herbal formula could significantly improve abdominal pain and diarrhea. We plan to carry out a randomized, controlled, double blind, clinical studies to observe the clinical efficacy of Qinghua Zhixie decoction in the treatment of D-IBS.

METHODS

Four hundred sixty-four participants will be randomly assigned to the treatment group and control group. Patients in both groups would take medications and stimulations simultaneously. The outcomes of IBS symptom severity score, quality of life, psychological states, and recurrence rate will be recorded. Statistics will be analyzed with the SPSS 22.0.

CONCLUSIONS

The findings of the study will identify the safety and efficacy of Qinghua Zhixie decoction in the treatment of D-IBS.

TRIAL REGISTRATION OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/C8MHW.

Therapeutic Effects of Berberine Hydrochloride on Stress-Induced Diarrhea-Predominant Irritable Bowel Syndrome Rats by Inhibiting Neurotransmission in Colonic Smooth Muscle

The etiology of diarrhea-predominant irritable bowel syndrome (IBS-D) is complicated and closely related to neurotransmission in the gastrointestinal (GI) tract. Developing new strategies for treating this disease is a major challenge for IBS-D research. Berberine hydrochloride (BBH), the derivative of berberine, is a herbal constituent used to treat IBS. Previous studies have shown that BBH has potential anti-inflammatory, antibacterial, analgesic, and antidiarrheal effects and a wide range of biological activities, especially in regulating the release of some neurotransmitters. A modified IBS-D rat model induced by chronic restraint stress was used in all experiments to study the effects of BBH on the GI tract. This study measured the abdominal withdrawal reflex (AWR) response to graded colorectal distention (CRD; 20, 40, 60, and 80 mmHg) and observed the fecal areas of stress-induced IBS-D model. Experiments were conducted using organ bath techniques, which were performed in vitro using strips of colonic longitudinal smooth muscle. Inhibitory and excitatory neurotransmitter agents were added to each organ bath to observe contractile responses on the strips and the treatment effect exerted by BBH. The IBS-D rat model was successfully induced by chronic restraint stress, which resulted in an increased defecation frequency and visceral hypersensitivity similar to that of humans. BBH could reduce 4-h fecal areas and AWR response to CRD in IBS-D. The stress-induced IBS-D model showed upregulated colonic mRNA expression levels of 5-hydroxytryptamine-3A receptor and downregulated expression levels of neuronal nitric oxide synthase. Meanwhile, BBH could reverse this outcome. The responses of substances that regulate the contraction induced by related neurotransmission in the longitudinal smooth muscle of IBS-D colon (including the agonist of acetylcholine, carbachol; NOS inhibitor, L-NAME; and P2Y₁ receptor antagonist, MRS2500) can be inhibited by BBH. In summary, BBH promotes defecation frequency and visceral hypersensitivity in IBS-D and exerts inhibitory effects on contractile responses in colonic longitudinal smooth muscle. Thus, BBH may represent a new therapeutic approach for treating IBS-D.

Diarrhea Predominant-Irritable Bowel Syndrome (IBS-D): Effects of Different Nutritional Patterns on Intestinal Dysbiosis and Symptoms

Irritable Bowel Syndrome (IBS) is a chronic functional gastrointestinal disorder characterized by abdominal pain associated with defecation or a change in bowel habits. Gut microbiota, which acts as a real organ with well-defined functions, is in a mutualistic relationship with the host, harvesting additional energy and nutrients from the diet and protecting the host from pathogens; specific alterations in its composition seem to play a crucial role in IBS pathophysiology. It is well known that diet can significantly modulate the intestinal microbiota profile but it is less known how different nutritional approach effective in IBS patients, such as the low-FODMAP diet, could be responsible of intestinal microbiota changes, thus influencing the presence of gastrointestinal (GI) symptoms. The aim of this review was to explore the effects of different nutritional protocols (e.g., traditional nutritional advice, low-FODMAP diet, gluten-free diet, etc.) on IBS-D symptoms and on intestinal microbiota variations in both IBS-D patients and healthy subjects. To date, an ideal nutritional protocol does not exist for IBS-D patients but it seems crucial to consider the effect of the different nutritional approaches on the intestinal microbiota composition to better define an efficient strategy to manage this functional disorder.

Review of Treatment Options for Irritable Bowel Syndrome with Constipation and Chronic Idiopathic Constipation

Irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC) are two common disorders of gut-brain interaction. Affected patients often first present to their primary care providers seeking care for symptoms of constipation, abdominal pain, and bloating, which have a significant impact on their health-related quality of life. These patients often require extensive counseling and reassurance, and knowledge of reliable diagnostic criteria and treatment options is imperative to managing their conditions. Family medicine practitioners, including nurse practitioners and physician assistants, are uniquely qualified to provide a diagnosis and safe, effective management of these disorders. This article reviews the latest evidence and provides practical advice related to diagnosis and management of IBS-C and CIC.

The characteristics of intestinal flora of IBS-D with different syndromes

OBJECTIVE

To study the distribution of fecal microbiota in diarrhea-predominant irritable bowel syndrome (IBS-D) patients of spleen-kidney-yang deficiency and liver depression and spleen deficiency, to make an objective foundation for dialectics of different type of IBS-D. And to provide the clinical doctors an experimental basis for medication by regulating dysbacteriosis.

METHODS

We collected feces from the control group, spleen-kidney-yang deficiency IBS-D group, and liver-depression and spleen-deficiency IBS-D group. After the extraction of fecal DNA, global DNA was isolated from every sample, and 16S ribosomal RNA was sequenced, and then we analyzed the results for bacteria such as Alpha diversity, community composition, LEfSe, and partial least squares discriminant analysis.

RESULTS

We compared the changes among the fecal bacteria in the intestine of the IBS-D patients and healthy controls and found the specificity of spleen-kidney-yang deficiency syndrome and liver-depression and spleen-deficiency syndrome. The control group has the highest flora diversity (control group > liver-depression and spleen-deficiency > spleen-kidney-yang deficiency group). The control group, spleen-kidney-yang deficiency group, and liver-depression and spleen-deficiency group are different in phylum (Actinobacteria, Fusobacteria), class (Actinobacteria, Fusobacteria), order (Enterobacteriales, Bifidobacteriales, Fusobacteriales), and family (Bifidobacteriaceae, Ruminococcaceae, Enterobacteriaceae, Acidaminococcaceae, Veillonellaceae, Fusobacteriaceae). Bifidobacteriaceae and Ruminococcaceae in the control group, Enterobacteriales, Fusobacteriales, Acidaminococcaceae, and Phascolarctobacterium in the spleen-kidney-yang deficiency group, and streptococcus are the specific bacteria in the liver-depression and spleen-deficiency group. Intestinal flora disturbance is closely related to IBS-D.

CONCLUSIONS

There is a correlation between traditional Chinese medicine syndrome type and intestinal flora. The control group, the spleen-kidney-yang deficiency group, and the liver-depression and spleen-deficiency group have specific bacteria.

Food Additives, Gut Microbiota, and Irritable Bowel Syndrome: A Hidden Track

The interactions between diet, gut microbiota, and irritable bowel syndrome (IBS) have many complex mechanisms that are not fully understood. Food additives are one component of the modern human diet that deserves attention from science and government policies. This review aims at identifying the current knowledge about the impact of food additives on gut microbiota and their potential role in the development of IBS. To date, few data on the effect of food additives on gut microbiota in IBS patients are available. However, exposure to food additives could induce the dysbiosis and dysregulation of gut homeostasis with an alteration of the gut barrier and activation of the immune response. These microbial changes could exacerbate the gut symptoms associated with IBS, such as visceral pain, low-grade inflammation, and changes in bowel habits. Some additives (polyols) are excluded in the low fermentable oligo-, di- and monosaccharide, and polyol (FODMAP), diets for IBS patients. Even if most studies have been performed in animals, and human studies are required, many artificial sweeteners, emulsifiers, and food colorants could represent a potential hidden driver of IBS, through gut microbiota alterations. Consequently, food additives should be preventively avoided in the diet as well as dietary supplements for patients with IBS.

An update on efficacy and safety considerations for the latest drugs used to treat irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome (IBS), globally affecting 11.2% of the population and imposing a direct annual cost of $1.7bn-$10bn in the US, is one of the today's major therapeutic challenges. Therefore, there is urgent need to address this issue through reviewing the tolerability and efficacy of available medications.

AREAS COVERED

Over the past decade, related experiments were cited through Clinicaltrials.gov, PubMed, WHO ICTRP, and Cochrane library. Pharmacological parameters of approved medications available in the USFDA, EMA, TGA and PMDA were also stated.

EXPERT OPINION

Anti-spasmodics are used as the first-line treatment in pain-predominant IBS and IBS-D, among which calcium channel blockers and neurokinin-type 2 receptor antagonists seem to replace anti-cholinergic drugs. As second-line treatments, rifaximin is considered to be the best for IBS-D though it has lower efficacy than alosetron and eluxadoline. For IBS-C, linaclotide is the most effective and the safest second-line therapy, following laxatives/fibers, which may be replaced by tenapanor, in the future. When moderate to severe IBS is associated with severe pain or comorbid psychological disorders, gut-brain neuromodulators could also be prescribed. Regarding all this, there is still a paramount need to conduct careful clinical studies on efficacy, safety and cost-effectiveness of current approved and non-approved treatments.

Effects of vitamin D3 supplementation on clinical symptoms, quality of life, serum serotonin (5-hydroxytryptamine), 5-hydroxy-indole acetic acid, and ratio of 5-HIAA/5-HT in patients with diarrhea-predominant irritable bowel syndrome: A randomized clinical trial

Vitamin D deficiency, common in the population with irritable bowel syndrome (IBS), can induce the main factors that lead to IBS clinical symptoms, such as depression, anxiety, and inflammation. Serotonin (5-HT) plays an important role in the pathophysiology of IBS, and its production and secretion are increased from the lumen due to stress and inflammation. The aim of this study was to evaluate the effect of vitamin D3 supplementation on the pathogenesis of diarrhea-predominant IBS (IBS-D). Seventy-four IBS-D patients (age: 18-65 y) participated in a randomized, double-blind, placebo-controlled trial study from February 2017 to May 2018, at Rasoul-e-Akram Hospital, Tehran, Iran. Subjects were allocated into two groups receiving 50,000 IU/week of vitamin D3 or placebo for 9 weeks. IBS severity score system (IBS-SSS), IBS-quality of life questionnaire (QoL), hospital anxiety and depression Scale (HADs), visceral sensitivity index (VSI) and serum 25(OH) vitamin D3, serotonin, 5-hydroxy-indole acetic acid and ratio of 5-HIAA/5-HT were evaluated before and after the interventions. Symptoms severity, QoL, HADs-depression, and VSI score improved significantly in the vitamin D group as compared to the placebo group (P-values: <0.001, 0.049, 0.023, and 0.008; respectively). There were no significant differences in abdominal bloating, HADs-anxiety, serum 5-HT, 5-HIAA, and 5-HIAA/5-HT between the two groups at the end of the study. Based on our results, we recommend serum vitamin D be evaluated in the process of treatment of these patients to ameliorate symptoms and quality life of IBS-D patients with vitamin D deficiency and/or insufficiency.

CSTI-300 (SMP-100); a Novel 5-HT3 Receptor Partial Agonist with Potential to Treat Patients with Irritable Bowel Syndrome or Carcinoid Syndrome

The 5-hydroxytryptamine (5-HT) (serotonin) 5-HT3 receptor represents a clinical target for antagonists to deliver symptomatic relief to patients with diarrhea-predominant irritable bowel syndrome (IBS-d) or carcinoid syndrome. Unfortunately, this pharmacological strategy can present side effects (e.g., severe constipation). The present study investigates the potential of a novel 5-HT3 receptor partial agonist, CSTI-300, to treat patients with IBS-d and other conditions associated with discomfort from colonic distension, with a predicted reduced side-effect profile. The in vitro and in vivo preclinical pharmacology of the drug CSTI-300 was investigated to explore the potential to treat patients with IBS-d. CSTI-300 displayed selective high affinity for the human and rat 5-HT3 receptor (Ki approximately 2.0 nM) and acted as a partial agonist (approximately 30%-50% intrinsic efficacy) in vitro. In an in vivo model of IBS-d, the rat colon distension model, CSTI-300 displayed dose-dependent efficacy. In addition, oral administration of CSTI-300 to dogs that achieved plasma levels of the drug exceeding the Ki value for the 5-HT3 receptor failed to either evoke emesis or alter the state of feces. Pharmacokinetics for CSTI-300 in rat and dog identified high levels of oral availability with t 1/2 range of 1.6-4.4 hours. The preclinical pharmacology of the lead candidate drug, CSTI-300, supports the potential of this novel drug to offer symptomatic relief to patients with irritable bowel syndrome and carcinoid syndrome with a rationale for a reduced "on-target" side-effect profile relative to 5-HT3 receptor antagonists, such as alosetron. SIGNIFICANCE STATEMENT: There is a lack of effective current treatment for diarrhea-predominant irritable bowel syndrome and carcinoid syndrome, and in both conditions, overactivity of the 5-hydroxytryptamine (5-HT) 5-HT3 receptor is thought to be implicated in the pathophysiology. Because 5-HT3 receptor blockade with antagonists results in significant side effects, we present evidence that treatment with a suitable 5-HT3 receptor partial agonist will alleviate some symptoms associated with these conditions yet, without fully inhibiting the receptor, predict a less pronounced side-effect profile associated with this therapeutic strategy.

Vitamin D3 Supplementation in Diarrhea-Predominant Irritable Bowel Syndrome Patients: The Effects on Symptoms Improvement, Serum Corticotropin-Releasing Hormone, and Interleukin-6 - A Randomized Clinical Trial

OBJECTIVES

This study aimed to evaluate whether vitamin D deficiency is associated with the severity of symptoms of irritable bowel syndrome (IBS) patients. Stress and gut inflammation can increase the serum level of corticotropin-releasing hormone (CRH) and interleukin-6 (IL-6), leading to a change in bowel movements. The aim of this study was to evaluate the anti-inflammatory and psychological effects of vitamin D3 supplementation on the symptom improvement of patients with a diarrhea-predominant form of IBS (IBS-D).

METHODS

Eighty-eight IBS-D patients (age: 18-65 years) based on Rome IV criteria who suffered from vitamin D deficiency and/or insufficiency were enrolled in this randomized, placebo-controlled trial from February 2017 to May 2018 at Rasoul-e-Akram Hospital, Tehran, Iran. Participants were randomly divided into two groups. The intervention group received 50,000 IU vitamin D3 weekly and the control group received a placebo for 9 weeks. All patients received Mebeverine 135 mg twice a day besides supplementation. The IBS Severity Score System (IBS-SSS), serum 25(OH) vitamin D3, CRH, and IL-6 were measured before and after interventions.

RESULTS

Seventy-four patients completed the study. The severity of IBS symptoms (p < 0.01) and IL-6 (p = 0.02) decreased significantly in the intervention group as compared to the control group, but there was no significant difference in the serum level of CRH. Also, in the treatment group, IBS-SSS and IL-6 were significantly reduced at the end of the study from baseline (p < 0.01 and p < 0.03, respectively).

CONCLUSION

Our findings indicate that vitamin D3 supplementation can modulate the serum level of CRH and IL-6 and can improve symptoms in IBS-D patients. Vitamin D3 supplementation should be considered in IBS-D patients who suffer from vitamin D deficiency and/or insufficiency.

Metabolomics analysis revealed metabolic changes in patients with diarrhea-predominant irritable bowel syndrome and metabolic responses to a synbiotic yogurt intervention

PURPOSE

Irritable bowel syndrome is a gastrointestinal disorder which can influence human metabolism. It has been demonstrated that probiotics are beneficial in controlling IBS. Thus, the main objective of the present study was to determine metabolic changes in response to diarrhea predominant irritable bowel syndrome (IBS-D) and to investigate the metabolic effects of a synbiotic intervention on serum, urine, and stool samples from IBS-D patients and healthy controls using proton nuclear magnetic resonance (1HNMR).

METHODS

A 1HNMR-based metabolomics study was conducted on urine and serum metabolites from 16 healthy and eight IBS-D participants at baseline and after 4 weeks of a synbiotic yogurt intervention.

RESULTS

At the baseline, serum acetoacetate, myo-inositol, and sarcosine concentrations were higher and threonine and methionine concentrations were lower in the IBS-D cohort than the control group. Moreover, Indoxyl-sulfate concentration of urine was lower and dimethylamine and taurine were higher in the IBS-D group. After intervention, serum concentration of ketone bodies decreased, choline, phenylalanine, and branched-chain amino acids increased in IBS-D group. Metabolomics analysis indicated a shift in one-carbon metabolism. Thus, the level of serum homocysteine was determined and found to be higher in the IBS-D cohort at baseline, and then decreased after the intervention.

CONCLUSION

IBS causes a shift in one-carbon metabolism and these changes can be reversed by a synbiotic intervention. An increase in the number of fecal Lactobacilli and an improvement in the health status of IBS-D patients were also observed in response to intervention.

Dysbiosis of the Gut Microbiome: A Concept Analysis

Background:Gut microbes influence the development several chronic conditions marking them as targets for holistic care, prevention strategies, and potential treatments. Microbiome studies are relatively new to health research and present unfamiliar terms to clinicians and researchers. "Dysbiosis" often refers to an alteration in the gut microbiome, but conceptual clarification is rarely provided. Purpose: The purpose of this study is to refine a conceptual definition of dysbiosis based on a review of nursing literature. Method: A Rodgerian approach to concept analysis was used. CINAHL, PubMed, and Web of Science were queried using "dysbiosis" through December 2018. Each article was analyzed with regard to the antecedents, attributes, and consequences of dysbiosis. Essential elements were tabulated and compared across studies to determine recurring themes and notable outliers. Findings: Analysis revealed several important antecedences, attributes, and consequences of dysbiosis. The findings also elucidated notable gaps and highlighted the co-evolving nature of the proposed definition with advances in microbiome research. Conclusion: This article adds a proposed definition of dysbiosis, offering a contribution of conceptual clarity upon which to enhance dialogue and build research. The definition emphasizes risk factors and consequences of dysbiosis as implications for holistic nursing practice.

Bile acids and FXR in functional gastrointestinal disorders

Functional gastrointestinal disorders (FGIDs), such as irritable bowel syndrome (IBS) and chronic constipation (CC), are commonly diagnosed conditions in clinical practice which create a substantial global burden. Since the farnesoid X receptor (FXR) and bile acids (BAs) are responsible for maintaining homeostasis in the GI tract, any disturbances in the expression of FXR or the composition of BAs may contribute to the development of the GI symptoms. Alterations in the mechanism of action of FXR directly affect the BAs pool and account for increased intestinal permeability and changes in abundance and diversity of gut microbiota leading to intestinal dysmotility. Current review focuses on the correlation between the FXR, BAs and the composition of gut microbiota and its influence on the occurrence of GI symptoms in FGIDs.

Neuromuscular electrical stimulation as an adjunctive therapy to drotaverine hydrochloride for treating patients with diarrhea-predominant irritable bowel syndrome: A retrospective study

This retrospective study investigated the effectiveness and safety of neuromuscular electrical stimulation (NMES) as an adjunctive therapy to drotaverine hydrochloride (DHC) in patients with diarrhea-predominant irritable bowel syndrome (BP-IBS).A total of 108 patient cases with BP-IBS were included in this study. Of these, 54 cases were assigned to a treatment group and received NMES and DHC, whereas the other 54 subjects were assigned to a control group and underwent DHC alone. All patients were treated for a total of 4 weeks. Primary outcomes were measured by the visual analog scale (VAS), and average weekly stool frequency. Secondary outcome was measured by the Bristol scale. In addition, adverse events were documented. All outcome measurements were analyzed before and after 4-week treatment.Patients in the treatment group did not show better effectiveness in VAS (P = .14), and average weekly stool frequency (P = .42), as well as the Bristol scale (P = .71), compared with the patients in the control group. Moreover, no significant differences in adverse events were found between 2 groups.The results of this study showed that NMES as an adjunctive therapy to DHC may be not efficacious for patients with BP-IBS after 4-week treatment.

Existing and emerging therapies for managing constipation and diarrhea

Functional bowel disorders (i.e., constipation and diarrhea) are characterized by abdominal pain, bloating, distention, and/or bowel habit abnormalities in the absence of obvious anatomic or physiologic abnormalities on routine diagnostic tests. These symptoms are attributable to gastrointestinal sensorimotor dysfunctions resulting from peripheral and/or central mechanisms. Available drugs target the underlying bowel disturbance (i.e., constipation, diarrhea, or both), supplemented when necessary by management of pain. Osmotic and stimulant laxatives, secretagogues, and serotonin 5-HT4 receptor agonists are approved for treating constipation. Loperamide, anticholinergic agents, rifaximin, bile-acid binding agents, eluxadoline, and clonidine are used to treat diarrhea. Several exciting new compounds, some of which have been evaluated in humans, are currently under development.

Preparation, Evaluation and Bioavailability Studies of Eudragit Coated PLGA Nanoparticles for Sustained Release of Eluxadoline for the Treatment of Irritable Bowel Syndrome

Eluxadoline is a newly approved orally administered drug used for the treatment of Irritable Bowel Syndrome with Diarrhea. It is reported as a poorly water-soluble drug due to which its dissolution rate and oral bioavailability are very poor. In this work, various plain PLGA nanoparticles (NPs) (F1–F4) were prepared and optimized based on particle size, PDI, zeta potential and percent drug entrapment efficiency (EE). The developed plain NPs (F1–F4) showed average particle size ranging from 260.19 to 279.76 nm with smooth surface and EE of 17.83–56.29%. The optimized plain NPs (F3) had particle size of 273.76 ± 7.25 nm with a low PDI value 0.327, zeta potential - 30.63 ± 2.47 mV and % EE of 56.29 ± 2.56%. The optimized F3 NPs was further submitted for enteric coating using Eudragit S100 polymer and evaluated in terms of particles characterization, in vitro release and pharmacokinetic studies in rats. The bioavailability of plain and coated nanaoparticles were enhanced by 6.8- and 18.5-fold, respectively, compared to normal suspension. These results revealed that the developed coated NPs could be used for its oral delivery for an effective treatment of Irritable Bowel Syndrome with Diarrhea.

Rome Criteria and a Diagnostic Approach to Irritable Bowel Syndrome

Functional gastrointestinal disorders (FGIDs) account for at least 40% of all referrals to gastroenterologists. Of the 33 recognized adult FGIDs, irritable bowel syndrome (IBS) is the most prevalent, with a worldwide prevalence estimated at 12%. IBS is an important health care concern as it greatly affects patients' quality of life and imposes a significant economic burden to the health care system. Cardinal symptoms of IBS include abdominal pain and altered bowel habits. The absence of abdominal pain makes the diagnosis of IBS untenable. The diagnosis of IBS can be made by performing a careful review of the patient's symptoms, taking a thoughtful history (e.g., diet, medication, medical, surgical, and psychological history), evaluating the patient for the presence of warning signs (e.g., "red flags" of anemia, hematochezia, unintentional weight loss, or a family history of colorectal cancer or inflammatory bowel disease), performing a guided physical examination, and using the Rome IV criteria. The Rome criteria were developed by a panel of international experts in the field of functional gastrointestinal disorders. Although initially developed to guide researchers, these criteria have undergone several revisions with the intent of making them clinically useful and relevant. This monograph provides a brief overview on the development of the Rome criteria, discusses the utility of the Rome IV criteria, and reviews how the criteria can be applied clinically to diagnose IBS. In addition, a diagnostic strategy for the cost-effective diagnosis of IBS will be reviewed.

▼ Eluxadoline for IBS-D

Irritable bowel syndrome (IBS) is a chronic relapsing gastrointestinal problem characterised by intestinal pain and associated alterations of defecation and/or bowel habit (constipation: IBS-C or diarrhoea: IBS-D).^1,2 Opioid receptors in the gut have a role in gastrointestinal motility, secretion and sensation.³ Τ Eluxadoline (Truberzi-Allergan) is a locally acting, mixed opioid receptor agonist/antagonist licensed for the treatment of IBS-D in adults.⁴ Here, we consider the evidence for eluxadoline and how it fts with current management strategies for IBS-D.