Review article: the economic impact of the irritable bowel syndrome

Dorsoventral hippocampus distinctly modulates visceral sensitivity and anxiety behaviors in male IBS-like rats

Accumulating evidences suggest dysfunctions in the hippocampus are associated with chronic pain. Nevertheless, the role of hippocampal circuitry in pain memories and emotional responses is not yet fully understood. In this study, we utilized a comprehensive approach that combined electromyography (EMG), photochemical genetic techniques, and anxiety-related behavioral paradigms to investigate the involvement of dorsal hippocampus (DH) and ventral hippocampus (VH) in visceral sensitivity and anxiety behaviors in male rats. Our results demonstrated that IBS-like rats exhibited comorbid visceral hypersensitivity and anxiety, along with the number of activated neurons in the VH was higher than that in the DH. Manipulation of glutamatergic neurons in the hippocampus was identified as a crucial mechanism underlying the mediation of both visceral sensitivity and anxiety behaviors. Specifically, optogenetic activation of the DH induced both visceral hypersensitivity and anxiety, while activation of the VH induced anxiety but did not affect visceral sensitivity. Conversely, chemogenetic inhibition of the DH reduced both visceral hypersensitivity and anxiety, whereas inhibition of the VH alleviated anxiety but did not alleviate visceral hypersensitivity in IBS-like rats. Our study highlights the important role of early life stress in inducing visceral hypersensitivity and anxiety, and further elucidates the distinct functional contributions of the DH and VH to these behavioral changes. These findings provide a theoretical basis for the diagnosis and treatment of IBS, and suggest that targeting specific hippocampal neuron subtypes may represent a promising therapeutic approach.

Shared decision-making improving efficacy in diarrhoea-dominant irritable bowel syndrome in Chinese outpatient setting: protocol of a prospective, randomised controlled trial

INTRODUCTION

Diarrhoea-dominant irritable bowel syndrome (IBS-D) is a disorder with multiple pathogenesis; many people with IBS-D may have psychosocial issues which can make assessment and treatment more difficult. Routine treatment procedure might not always achieve the desired outcome. Therefore, patients may not be satisfied with the conventional experience and would like to be more involved in clinical decision-making. A shared decision-making (SDM) model, that requires patient participation, has been demonstrated to have a powerful effect on the diagnosis and treatment of other diseases, which improves patients' compliance, satisfaction, thus refining the clinical outcome. However, there is no corresponding evidence in IBS-D. Herein, we hope to verify the effect of SDM through clinical studies, and we anticipate that SDM can improve the therapeutic effect in patients with IBS-D.

METHODS

The study is a prospective, randomised, single-centre trial. 166 IBS-D outpatients who attend Peking Union Medical College Hospital will be allocated into routine treatment group and SDM group. The primary endpoint is the severity of bowel symptoms, measured by the IBS symptom severity scale. Secondary endpoints include impact of disease and quality of life, negative psychology and the evaluation of diagnosis and treatment process.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the research ethics committee of Peking Union Medical College Hospital (I-23PJ470). This protocol has been approved by Chinese Clinical Trial Register (ChiCTR2300073681) in July 2023. The results of this trial will be published in an open-access way and disseminated among gastrointestinal physicians.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Register (ChiCTR2300073681).

Different therapies of Chinese herbal medicine for diarrhea-predominant irritable bowel syndrome: A network meta-analysis of double-blinded, placebo-controlled trials

ETHNOPHARMACOLOGICAL RELEVANCE

Shuganjianpi Therapy (SGJP), Jianpi Therapy (JP), Shugan Therapy (SG), Jianpiwenshen Therapy (JPWS), and Shuganjianpiwenshen Therapy (SGJPWS), consisting of formulas from Chinese herbal medicine (CHM), have been tremendously applied to irritable bowel syndrome (IBS). However, it remains uncertain when exploring the preferable option among different CHM therapies for diarrhea-predominant irritable bowel syndrome (IBS-D).

AIM OF THE STUDY

To compare and rank the efficacy and safety of different CHM therapies for IBS-D.

MATERIALS AND METHODS

We searched randomized, double-blinded, placebo-controlled trials through mainstream databases from their inception to October 31, 2022. Eligible randomized controlled trials (RCTs) applied one of the CHM therapies as the experimental group and placebo as the control group. Two authors independently extracted data into a form and evaluated the quality of the retrieved articles by the Cochrane Risk of Bias Tool. At least one of the following outcomes was assessed: Serotonin, Neuropeptide Y (NPY), Incidence of Adverse Events (AE), and Irritable Bowel Syndrome-Severity Scoring System (IBS-SSS) with its subscales of Severity of Abdominal Pain (SAP), Frequency of Abdominal Pain (FAP), Severity of Abdominal Distension (SAD), Dissatisfaction with Bowel Habits (DBH), and Interference with Quality of Life (IQOL). A Bayesian network meta-analysis on a random-effect model was conducted using R 4.2.2 software.

RESULTS

1367 records were retrieved from databases in an initial search. Fourteen studies involving six interventions with 2248 participants were identified. Provided pairwise comparisons, the surface under the cumulative ranking curve (SUCRA) ranking, and cluster analysis, JPWS was the best option for ameliorating clinical symptoms simultaneously, which included IBS-SSS, SAP, FAP, SAD, DBH, and IQOL. As for AE, JPWS contributed to fewer adverse events than others as well. In respect of serum indicators, we noticed the dominance of SGJP in regulating both serotonin and NPY.

CONCLUSIONS

JPWS and SGJP were the most prominent CHM therapies for IBS-D in terms of clinical symptoms, including abdominal pain, distension, bowel habits, and improvement of quality of life. The effect of JP and SG for IBS-D required further investigation. As a potential candidate, SGJP may well treat IBS-D by mediating dysmotility, visceral hypersensitivity, and the gut-brain axis with an increase of NPY and a reduction of serotonin. For safety, JPWS was ideal for the fewest adverse events in the treatment of IBS-D. On account of a small sample size and possible geographical publication bias, more double-blinded and placebo-controlled trials with larger samples worldwide would be necessary for strengthening current evidence.

The effect of eye movement desensitization and reprocessing (EMDR) on abdominal pain in patients with irritable bowel syndrome (IBS): a study protocol for a randomized controlled trial (EMDR4IBS)

BACKGROUND

Irritable bowel syndrome (IBS) is a highly prevalent disorder for which treatment options such as medication, diets, and hypnotherapy either have shown limited effect or relieve symptoms in only a limited subset of patients. Abdominal pain is the key criterion for the diagnosis and is deemed the most distressing IBS symptom, and the most disruptive of everyday life. A growing body of research demonstrates the effect of Eye Movement Desensitization and Reprocessing (EMDR) on chronic pain. EMDR is known as a safe and successful treatment for disorders in which unresolved traumatic memories play a role in the cause or maintenance of symptoms. In IBS, activated memories may increase pain through pain flashbacks and the stress generated by unresolved memories. The aim of this study is to ascertain whether applying EMDR to traumatic memories including pain memories will reduce abdominal pain in IBS patients.

METHODS

This study is a randomized controlled trial which will be conducted at a city hospital in the Netherlands. Adult patients with considerable IBS pain (pain intensity at least 60/100 during at least 5/10 days) will be randomly assigned to either EMDR therapy or the wait list. We aim to include 34 participants. The EMDR condition comprises seven sessions, around 90 min in length delivered weekly, the first of which is a case conceptualization session. All participants will be assessed at baseline, post-treatment, and at 3 months follow-up. The primary outcome measure is pain intensity on a Likert scale which is self-reported daily during a 2-week period. Secondary outcomes include similar daily ratings on other IBS symptoms and reported hindrance of valued activities, and also standardized questionnaires on IBS symptoms and Quality of Life. Data will be analyzed by a Linear Mixed Effects Model for repeated measures.

DISCUSSION

The results are expected to gain insight into the effectiveness of EMDR treatment on abdominal pain in IBS. As there are very few effective treatment options for IBS-related abdominal pain, this study could have important implications for clinical practice.

TRIAL REGISTRATION

Human ethics committee MEC-U NL71740.100.20. International Clinical Trial Registry Platform: NL8894. Prospectively registered on 28 January 2020.

The Potential Use of Artificial Intelligence in Irritable Bowel Syndrome Management

Irritable bowel syndrome (IBS) has a global prevalence of around 4.1% and is associated with a low quality of life and increased healthcare costs. Current guidelines recommend that IBS is diagnosed using the symptom-based Rome IV criteria. Despite this, when patients seek medical attention, they are usually over-investigated. This issue might be resolved by novel technologies in medicine, such as the use of Artificial Intelligence (AI). In this context, this paper aims to review AI applications in IBS. AI in colonoscopy proved to be useful in organic lesion detection and diagnosis and in objectively assessing the quality of the procedure. Only a recently published study talked about the potential of AI-colonoscopy in IBS. AI was also used to study biofilm characteristics in the large bowel and establish a potential relationship with IBS. Moreover, an AI algorithm was developed in order to correlate specific bowel sounds with IBS. In addition to that, AI-based smartphone applications have been developed to facilitate the monitoring of IBS symptoms. From a therapeutic standpoint, an AI system was created to recommend specific diets based on an individual's microbiota. In conclusion, future IBS diagnosis and treatment may benefit from AI.

Update in diagnosis and management of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by a lack of structural or biochemical abnormalities. The current diagnosis of IBS is based on the Rome IV criteria, and it is recommended to approach IBS patients using a multidimensional clinical profile (MDCP). The pathophysiology of IBS is multifactorial and involves motility disorders, genetic factors, immune responses, visceral hypersensitivity, brain-gut dysregulation, and altered intestinal microbiota. The management of IBS includes both nonpharmacologic and pharmacologic therapies. Nonpharmacologic therapy options include physical activity, low fermentable oligosaccharides, disaccharides, monosaccharides, and polyol diet, as well as cognitive behavioral therapy. Pharmacologic therapy options include probiotics, antidepressants, antispasmodics, and new agents. In clinical practice, a multidisciplinary strategy, including nonpharmacologic or/and pharmacologic treatment for IBS, is emphasized. Therefore, clinicians should carefully consider the underlying pathophysiology before selecting an appropriate therapeutic option for the treatment of IBS. In other words, individualized treatment plans are necessary for managing IBS.

Burden of anxiety and depression among hospitalized patients with irritable bowel syndrome: a nationwide analysis

BACKGROUND AND AIM

Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder that affects patients both physically and mentally. Our study aimed to investigate the burden of psychiatric disorders in IBS patients.

METHODS

We conducted a retrospective analysis of the National inpatient sample (NIS) from 2016 to 2019. We recruited patients admitted with a diagnosis of IBS and determined the prevalence of anxiety, depression, and suicide attempt/ideation.

RESULTS

We found a total of 1,256,325 hospitalizations with a diagnosis of IBS. Among them, 478,515 (38.1%) had anxiety and 344,165 (27.4%) had depression. The prevalence of psychiatric disorders including anxiety (38.1% vs. 15.1%), depression (38.1% vs. 15.1%), bipolar disorder (5.22% vs. 2.38%), suicidal attempt/Ideation (3.22% vs. 2.38%), and eating disorder (0.32% vs. 0.08%) was significantly higher in IBS patient population when compared to general adult population (p < 0.001). Patients with IBS had greater odds of anxiety (AOR 2.88, 95% CI 2.85-2.91, P < 0.001), depression (AOR 2.16, 95% CI 2.14-2.19, P < 0.001) and suicidal attempt/ideation (AOR 1.94, 95% CI 1.88-2.00, P < 0.001) in comparison to general population. IBS subtypes including diarrhea-predominant, constipation-predominant and mixed type were independently associated with increased odds of anxiety, depression, and suicide attempt/ideation. Patients with IBS and a co-diagnosis of anxiety or depression had increased mean length of hospital stay by 0.48 (95% CI 0.43-0.52, P < 0.001) and 0.52 (95% CI 0.06-0.97, P < 0.03) days, respectively.

CONCLUSION

The presence of IBS is associated with an increased associated prevalence of psychiatric disorders such as anxiety, depression, and suicide attempt/ideation.

Impact of Sleep Disturbance on Fatigue, Nausea, and Pain: Mediating Role of Depressive Symptoms Among Youth With Disorders of Gut-Brain Interaction

OBJECTIVES

A high degree of sleep disturbance is reported among youth with disorders of gut-brain interaction (DGBIs). Given that sleep quality impacts a range of pediatric health outcomes including somatic sensations (eg, pain) and depressive mood occurs relatively frequently among youth with DGBIs, there is a dire need to disentangle the unique contributions of sleep and depressive mood on the somatic sensations experienced by youth with DGBIs. We aimed to examine whether depressive mood mediates the relations among sleep disturbance and pain intensity, nausea, and fatigue among youth with DGBIs.

METHODS

One hundred eighteen patients aged 8-17 years ( Mage = 14.05, SD = 2.88; 70.34% female), 83.05% White/non-Hispanic recruited at a pediatric neurogastroenterology clinic completed measures of sleep disturbance, nausea, fatigue, pain intensity, and depressive mood. Three mediation models examined the effect of sleep disturbance on nausea, fatigue, and pain, with depressive mood as a mediator.

RESULTS

Participants reported moderate sleep disturbance. Depressive mood partially mediated the significant, respective relations between greater sleep disturbance and more severe nausea and fatigue. Sleep disturbance was significantly associated with higher pain intensity; however, depressive mood was not a significant mediator of this relation.

CONCLUSIONS

Sleep quality is a major concern among youth with DGBIs. Low sleep quality may worsen nausea and fatigue via co-occurring increases in depressive mood symptoms. In contrast, sleep disturbance may directly increase pain, regardless of youths' depressive mood symptoms. Future research should explore these relations through prospective studies leveraging a combination of subjective and objective assessment approaches.

Optimizing educational methods for the low FODMAP diet in disorders of gut-brain interaction: A feasibility randomized controlled trial

BACKGROUND

A diet low in fermentable oligo-saccharides, di-saccharides, mono-saccharides and polyols (low FODMAP diet) is complex and clinical effectiveness is achieved with dietitian-led education, although dietitian availability in clinical practice varies. This study aimed to assess the feasibility of undertaking a trial to investigate the clinical and cost-effectiveness of different education delivery methods of the low FODMAP diet in patients with disorders of gut-brain interaction (DGBI).

METHODS

In this feasibility randomized controlled trial, patients with DGBI requiring the low FODMAP diet were randomized to receive one of the following education delivery methods: booklet, app, or dietitian. Recruitment and retention rates, acceptability, symptoms, stool output, quality of life, and dietary intake were assessed.

KEY RESULTS

Fifty-one patients were randomized with a recruitment rate of 2.4 patients/month and retention of 48 of 51 (94%). Nobody in the booklet group strongly agreed that this education delivery method enabled them to self-manage symptoms without further support, compared to 7 of 14 (50%) in the dietitian group (p = 0.013). More patients reported adequate relief of symptoms in the dietitian group (12, 80%) compared with the booklet group (7, 39%; p = 0.026), but not when compared to the app group (10, 63%, p > 0.05). There was a greater decrease in the IBS-SSS score in the dietitian group (mean -153, SD 90) compared with the booklet group (mean -90, SD 56; p = 0.043), but not when compared with the app group (mean -120, SD 62; p = 0.595).

CONCLUSIONS & INFERENCES

Booklets were the least acceptable education delivery methods. Dietitian-led consultations led to high levels of clinical effectiveness, followed by the app, while the dietitian was superior to booklets alone. However, an adequately powered clinical trial is needed to confirm clinical effectiveness of these education delivery methods.

Outcome-Specific Efficacy of Different Probiotic Strains and Mixtures in Irritable Bowel Syndrome: A Systematic Review and Network Meta-Analysis

Irritable bowel syndrome (IBS) is a common gastrointestinal disease. The efficacy of different probiotics in treating IBS remains controversial. This network meta-analysis aimed to compare and rank the outcome-specific efficacy of different probiotic strains or combinations in adults with IBS. We searched the literature up to June 2023. Randomized controlled trials (RCTs) that evaluated the efficacy of probiotics in IBS were included. A frequentist framework was used to perform this study. In total, 9253 participants from 81 RCTs were included in the study. Four probiotic strains and five mixtures were significantly superior to placebo in improving IBS Symptom Severity Scale, among which Lactobacillus acidophilus DDS-1 ranked first (surface under the cumulative ranking, SUCRA, 92.9%). A mixture containing five probiotics (SUCRA, 100%) ranked first in improving the IBS-Quality of life. Bacillus coagulans MTCC 5856 (SUCRA, 96.9%) and Bacillus coagulans Unique IS2 (SUCRA, 92.6%) were among the most effective probiotics for improving abdominal pain. Three probiotic strains and two mixtures were effective in alleviating abdominal bloating. Four probiotic strains and a mixture were significantly superior to placebo in reducing the bowel movement frequency in diarrhea-predominant IBS (IBS-D). Bacillus coagulans MTCC 5856 (SUCRA, 99.6%) and Saccharomyces cerevisiae CNCM I-3856 (SUCRA, 89.7%) were among the most effective probiotics for improving the Bristol stool form scale of IBS-D. Only some probiotics are effective for particular outcomes in IBS patients. This study provided the first ranking of outcome-specific efficacy of different probiotic strains and combinations in IBS. Further studies are needed to confirm these results.

Irritable bowel syndrome and mental health comorbidity - approach to multidisciplinary management

Irritable bowel syndrome (IBS) affects 5-10% of the global population. Up to one-third of people with IBS also experience anxiety or depression. Gastrointestinal and psychological symptoms both drive health-care use in people with IBS, but psychological comorbidity seems to be more important for long-term quality of life. An integrated care approach that addresses gastrointestinal symptoms with nutrition and brain-gut behaviour therapies is considered the gold standard. However, best practice for the treatment of individuals with IBS who have a comorbid psychological condition is unclear. Given the rising prevalence of mental health disorders, discussion of the challenges of implementing therapy for people with IBS and anxiety and depression is critical. In this Review, we draw upon our expertise in gastroenterology, nutrition science and psychology to highlight common challenges that arise when managing patients with IBS and co-occurring anxiety and depression, and provide recommendations for tailoring clinical assessment and treatment. We provide best practice recommendations, including dietary and behavioural interventions that could be applied by non-specialists and clinicians working outside an integrated care model.

The Socioeconomic Impact of Irritable Bowel Syndrome: An Analysis of Direct and Indirect Health Care Costs

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) is associated with substantial costs to society. Extensive data on direct costs (health care consumption) and indirect costs (health-related productivity loss) are lacking. Hence, we examined the socioeconomic costs of IBS and assessed which patient characteristics are associated with higher costs.

METHODS

Cross-sectional data from 3 Rome-defined Dutch IBS patient cohorts (n = 419) were collected. Bootstrapped mean direct and indirect costs were evaluated per patient with IBS using validated questionnaires (ie, medical cost questionnaire and productivity cost questionnaire, respectively). Multivariable regression analyses were performed to identify variables associated with higher costs.

RESULTS

Quarterly mean total costs per patient were €2.156 (95% confidence interval (CI), €1793-€2541 [$2444]), consisting of €802 (95% CI, €625-€1010 [$909]) direct costs and €1.354 (95% CI, €1072-€1670 [$1535]) indirect costs. Direct costs consisted primarily of health care professional consultations, with costs related to gastrointestinal clinic visits accounting for 6% and costs related to mental health care visits for 20%. Higher direct costs were significantly associated with older age (P = .007), unemployment (P = .001), IBS subtypes other than constipation (P = .033), lower disease-specific quality of life (P = .027), and more severe depressive symptoms (P = .001). Indirect costs consisted of absenteeism (45%), presenteeism (42%), and productivity loss related to unpaid labor (13%) and were significantly associated with the male sex (P = .014) and more severe depressive symptoms (P = .047).

CONCLUSIONS

Productivity loss is the main contributor to the socioeconomic burden of IBS. Direct costs were not predominantly related to gastrointestinal care, but rather to mental health care. Awareness of the nature of costs and contributing patient factors should lead to significant socioeconomic benefits for society.

Efficacy of probiotics, prebiotics and synbiotics in irritable bowel syndrome: a systematic review and meta-analysis of randomized, double-blind, placebo-controlled trials

Introduction. Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that affects the quality of life of numerous people worldwide.Gap statement. The therapeutic role of gut microbiota modulation in IBS remains controversial.Aim. We aimed to assess the efficacy of probiotics, prebiotics or synbiotics in patients with IBS.Methodology. We searched MEDLINE and EMBASE up to 1 August 2023, to identify the randomized, double-blind, placebo-controlled trials investigating the effectiveness of probiotics, prebiotics or synbiotics among patients with IBS. Pooled analyses of the effects of probiotics in relieving IBS symptoms were calculated using a random-effects model. Further subgroup analyses were performed by different genera, doses and duration of treatment.Results. Our final analysis included 52 trials involving 6289 IBS patients. Probiotics significantly increased the overall response rate (RR:1.64; P<0.00001), subjective relief rate (RR:1.50; P=0.0002) and abdominal pain relief rate (RR:1.69; P<0.00001). As for specific genera, mixed probiotics (RR:1.41; P=0.0001), Bifidobacterium (RR:1.76; P<0.00001), Lactobacillus (RR:1.97; P=0.0004) and Saccharomyces (RR:1.31; P=0.0004) markedly relieved IBS symptoms. Mixed probiotics (RR:1.31; P=0.005), Lactobacillus (RR:2.22; P=0.04) and Bifidobacterium (RR:1.62; P<0.0001) elevated patients' subjective relief rate. Besides, probiotics effectively relieved the abdominal pain in IBS patients (RR:1.69; P<0.00001). Probiotics appeared to show a remarkable beneficial role at a dose of 109 c.f.u./day or above (RR:1.662; P<0.0001) and started to work at 4 weeks (RR 1.72; P<0.00001). Efficacy of prebiotics and synbiotics in IBS remained uncertain, due to the deficiency of available RCTs.Conclusions. Probiotics have a therapeutic role in IBS. However, the effect of different probiotics varies. The minimal effective dose of probiotics may be 109 c.f.u./day. With appropriate probiotic formula, the therapeutic effect can occur at 4 weeks. These data provide a basis for further research on the optimal probiotic therapy in IBS.

Antispasmodic Effect of Valeriana pilosa Root Essential Oil and Potential Mechanisms of Action: Ex Vivo and In Silico Studies

Infusions of Valeriana pilosa are commonly used in Peruvian folk medicine for treating gastrointestinal disorders. This study aimed to investigate the spasmolytic and antispasmodic effects of Valeriana pilosa essential oil (VPEO) on rat ileum. The basal tone of ileal sections decreased in response to accumulative concentrations of VPEO. Moreover, ileal sections precontracted with acetylcholine (ACh), potassium chloride (KCl), or barium chloride (BaCl2) were relaxed in response to VPEO by a mechanism that depended on atropine, hyoscine butylbromide, solifenacin, and verapamil, but not glibenclamide. The results showed that VPEO produced a relaxant effect by inhibiting muscarinic receptors and blocking calcium channels, with no apparent effect on the opening of potassium channels. In addition, molecular docking was employed to evaluate VPEO constituents that could inhibit intestinal contractile activity. The study showed that α-cubebene, β-patchoulene, β-bourbonene, β-caryophyllene, α-guaiene, γ-muurolene, valencene, eremophyllene, and δ-cadinene displayed the highest docking scores on muscarinic acetylcholine receptors and voltage-gated calcium channels, which may antagonize M2 and/or M3 muscarinic acetylcholine receptors and block voltage-gated calcium channels. In summary, VPEO has both spasmolytic and antispasmodic effects. It may block muscarinic receptors and calcium channels, thus providing a scientific basis for its traditional use for gastrointestinal disorders.

Dietary fibre definition revisited - The case of low molecular weight carbohydrates

Low molecular weight (LMW) non-digestible carbohydrates (namely, oligosaccharides and inulin) are accepted as dietary fibre in many countries worldwide. The inclusion of oligosaccharides as dietary fibre was made optional within the Codex Alimentarius definition in 2009, which has caused great controversy. Inulin is accepted as dietary fibre by default, due to being a non-digestible carbohydrate polymer. Oligosaccharides and inulin occur naturally in numerous foods and are frequently incorporated into commonly consumed food products for a variety of purposes, such as to increase dietary fibre content. LMW non-digestible carbohydrates, due to their rapid fermentation in the proximal colon, may cause deleterious effects in individuals with functional bowel disorders (FBDs) and, as such, are excluded on the low FODMAP (fermentable oligosaccharides, disaccharides, and polyols) diet and similar protocols. Their addition to food products as dietary fibre allows the use of associated nutrition/health claims, causing a paradox for those with FBDs, which is further complicated by lack of clarity on food labelling. Therefore, this review aimed to discuss whether the inclusion of LMW non-digestible carbohydrates within the Codex definition of dietary fibre is warranted. This review provides justification for the exclusion of oligosaccharides and inulin from the Codex definition of dietary fibre. LMW non-digestible carbohydrates could, instead, be placed in their own category as prebiotics, recognised for their specific functional properties, or considered food additives, whereby they are not promoted for being beneficial for health. This would preserve the concept of dietary fibre being a universally beneficial dietary component for all individuals.

Prevalence and description of disorders of gut-brain interaction in Spain according to the results of the Rome Foundation Global Epidemiology Study

BACKGROUND

Data for Spain from the Rome Foundation Global Epidemiology Study on the disorders of gut-brain interaction (DGBI) were used to assess the national and regional prevalence of all 22 DGBI, the percentage of respondents meeting diagnostic criteria for at least one DGBI, and the impact on burden of disease in our country.

METHODS

Data were collected through an anonymous, nationwide, and secure Internet survey with multiple built-in quality-assurance techniques that included the Rome IV diagnostic questionnaire and an in-depth supplemental questionnaire.

KEY RESULTS

The survey was completed by 2072 adult Spanish participants (50.2% female) with a mean age of 45.67 ± 15.44 years with a good representative national distribution. 43.6% (41.5%-45.8%) met diagnostic criteria for at least one DGBI, with 8.2% for any esophageal disorder, 12.1% for any gastroduodenal disorder, 30.1% for any bowel disorder, and 11.5% for any anorectal disorder. Functional constipation was the most prevalent DGBI in Spain (12.8%). We found that proctalgia fugax (9.3%), unspecified bowel disorders (10.8%), and functional dysphagia (5.6%) showed unexplained high rates in our country. DGBI rates were higher for women. Having any DGBI was negatively associated with psychosocial variables (including quality of life, somatization, and concern about digestive problems), and associated with increased healthcare utilization.

CONCLUSIONS & INFERENCES

We provide the first comprehensive data on the prevalence and burden of all DGBI in Spain using the Rome IV criteria. The enormous burden of DGBI in Spain highlights the need for specialized training and future research.

Assessment of Self-Reported Executive Function in Patients with Irritable Bowel Syndrome Using a Machine-Learning Framework

Introduction: Irritable bowel syndrome (IBS) is characterized as a disorder of the gut-brain interaction (DGBI). Here, we explored the presence of problems related to executive function (EF) in patients with IBS and tested the relative importance of cognitive features involved in EF. Methods: A total of 44 patients with IBS and 22 healthy controls (HCs) completed the Behavior Rating Inventory of Executive Function (BRIEF-A), used to identify nine EF features. The PyCaret 3.0 machine-learning library in Python was used to explore the data, generate a robust model to classify patients with IBS versus HCs and identify the relative importance of the EF features in this model. The robustness of the model was evaluated by training the model on a subset of data and testing it on the unseen, hold-out dataset. Results: The explorative analysis showed that patients with IBS reported significantly more severe EF problems than the HC group on measures of working memory function, initiation, cognitive flexibility and emotional control. Impairment at a level in need of clinical attention was found in up to 40% on some of these scales. When the nine EF features were used as input to a collection of different binary classifiers, the Extreme Gradient Boosting algorithm (XGBoost) showed superior performance. The working memory subscale was consistently selected with the strongest importance in this model, followed by planning and emotional control. The goodness of the machine-learning model was confirmed in an unseen dataset by correctly classifying 85% of the IBS patients. Conclusions: The results showed the presence of EF-related problems in patients with IBS, with a substantial impact of problems related to working memory function. These results suggest that EF should be part of an assessment procedure when a patient presents other symptoms of IBS and that working memory function should be considered a target when treating patients with the disorder. Further studies should include measures of EF as part of the symptom cluster characterizing patients with IBS and other DGBIs.

Fecal microbiota transplantation for the treatment of irritable bowel syndrome: A systematic review and meta-analysis

BACKGROUND

Irritable bowel syndrome (IBS) is the most prevalent gastrointestinal disorder in developed countries and reduces patients’ quality of life, hinders their ability to work, and increases health care costs. A growing number of trials have demonstrated an aberrant gut microbiota composition in IBS, also known as ‘gut dysbiosis’. Fecal microbiota transplantation (FMT) has been suggested as a treatment for IBS.

AIM

To assess the efficacy and safety of FMT for the treatment of IBS.

METHODS

We searched Cochrane Central, MEDLINE, EMBASE and Web of Science up to 24 October 2022 for randomised controlled trials (RCTs) investigating the effectiveness of FMT compared to placebo (including autologous FMT) in treating IBS. The primary outcome was the number of patients with improvements of symptoms measured using a validated, global IBS symptoms score. Secondary outcomes were changes in quality-of-life scores, non-serious and serious adverse events. Risk ratios (RR) and corresponding 95%CI were calculated for dichotomous outcomes, as were the mean differences (MD) and 95%CI for continuous outcomes. The Cochrane risk of bias tool was used to assess the quality of the trials. GRADE criteria were used to assess the overall quality of the evidence.

RESULTS

Eight RCTs (484 participants) were included in the review. FMT resulted in no significant benefit in IBS symptoms three months after treatment compared to placebo (RR 1.19, 95%CI: 0.68-2.10). Adverse events were reported in 97 participants in the FMT group and in 45 participants in the placebo group (RR 1.17, 95%CI: 0.63-2.15). One serious adverse event occurred in the FMT group and two in the placebo group (RR 0.42, 95%CI: 0.07-2.60). Endoscopic FMT delivery resulted in a significant improvement in symptoms, while capsules did not. FMT did not improve the quality of life of IBS patients but, instead, appeared to reduce it, albeit non significantly (MD -6.30, 95%CI: -13.39-0.79). The overall quality of the evidence was low due to moderate-high inconsistency, the small number of patients in the studies, and imprecision.

CONCLUSION

We found insufficient evidence to support or refute the use of FMT for IBS. Larger trials are needed.

Eluxadoline-Loaded Eudragit Nanoparticles for Irritable Bowel Syndrome with Diarrhea: Formulation, Optimization Using Box-Behnken Design, and Anti-Diarrheal Activity

Eluxadoline (ELD), a recently approved drug, exhibits potential therapeutic effects in the management and treatment of IBS-D. However, its applications have been limited due to poor aqueous solubility, leading to a low dissolution rate and oral bioavailability. The current study's goals are to prepare ELD-loaded eudragit (EG) nanoparticles (ENPs) and to investigate the anti-diarrheal activity on rats. The prepared ELD-loaded EG-NPs (ENP1-ENP14) were optimized with the help of Box-Behnken Design Expert software. The developed formulation (ENP2) was optimized based on the particle size (286 ± 3.67 nm), PDI (0.263 ± 0.01), and zeta potential (31.8 ± 3.18 mV). The optimized formulation (ENP2) exhibited a sustained release behavior with maximum drug release and followed the Higuchi model. The chronic restraint stress (CRS) was successfully used to develop the IBS-D rat model, which led to increased defecation frequency. The in vivo studies revealed a significant reduction in defecation frequency and disease activity index by ENP2 compared with pure ELD. Thus, the results demonstrated that the developed eudragit-based polymeric nanoparticles can act as a potential approach for the effective delivery of eluxadoline through oral administration for irritable bowel syndrome diarrhea treatment.

Exploration of associations among dietary tryptophan, microbiome composition and function, and symptom severity in irritable bowel syndrome

BACKGROUND

Imbalance of the tryptophan (TRP) pathway may influence symptoms among patients with irritable bowel syndrome (IBS). This study explored relationships among different components that contribute to TRP metabolism (dietary intake, stool metabolite levels, predicted microbiome metabolic capability) in females with IBS and healthy controls (HCs). Within the IBS group, we also investigated relationships between TRP metabolic determinants, Bifidobacterium abundance, and symptoms of IBS.

METHODS

Participants with IBS (Rome III) and HCs completed a 28-day diary of gastrointestinal symptoms and a 3-day food record for TRP intake. They provided a stool sample for shotgun metagenomics, 16 S rRNA analyses, and quantitative measurement of TRP by mass spectrometry.

RESULTS

Our cohort included 115 females, 69 with IBS and 46 HCs, with a mean age of 28.5 years (SD 7.4). TRP intake (p = 0.71) and stool TRP level (p = 0.27) did not differ between IBS and HC. Bifidobacterium abundance was lower in the IBS group than in HCs (p = 0.004). Predicted TRP metabolism gene content was higher in IBS than HCs (FDR-corrected q = 0.006), whereas predicted biosynthesis gene content was lower (q = 0.045). Within the IBS group, there was no association between symptom severity and TRP intake or stool TRP, but there was a significant interaction between Bifidobacterium abundance and TRP intake (q = 0.029) in predicting stool character.

CONCLUSIONS

Dietary TRP intake, microbiome composition, and differences in TRP metabolism constitute a complex interplay of factors that could modulate IBS symptom severity.

Health care utilizations and costs of Campylobacter enteritis in Germany: A claims data analysis

OBJECTIVE

The number of reported cases of Campylobacter enteritis (CE) remains on a high level in many parts of the world. The aim of this study was to analyze the health care utilizations and direct and indirect costs of CE and sequelae of patients insured by a large health insurance with 26 million members in Germany.

METHODS

Claims data of insurants with at least one CE diagnosis in 2017 (n = 13,150) were provided, of which 9,945 were included in the analysis of health care utilizations and costs. If medical services were not diagnosis-linked, CE-associated costs were estimated in comparison to up to three healthy controls per CE patient. Indirect costs were calculated by multiplying the work incapacities by the average labor costs. Total costs of CE in Germany were extrapolated by including all officially reported CE cases in 2017 using Monte Carlo simulations.

RESULTS

Insurants showed a lower rate of 56 CE diagnoses per 100,000 than German surveillance data for 2017, but with a similar age, gender and regional distribution. Of those CE cases, 6.3% developed post-infectious reactive arthritis, Guillain-Barré syndrome (GBS), inflammatory bowel disease (IBD) and/or irritable bowel syndrome (IBS). Health care utilizations differed depending on CE severity, age and gender. Average CE-specific costs per patient receiving outpatient care were € 524 (95% CI 495-560) over a 12-month period, whereas costs per hospitalized CE case amounted to € 2,830 (2,769-2,905). The analyzed partial costs of sequelae ranged between € 221 (IBS) and € 22,721 (GBS) per patient per 12 months. Total costs of CE and sequelae extrapolated to Germany 2017 ranged between € 74.25 and € 95.19 million, of which 10-30% were due to sequelae.

CONCLUSION

CE is associated with a substantial economic burden in Germany, also due to care-intensive long-lasting sequelae. However, uncertainties remain as to the causal relationship of IBD and IBS after CE.

Experiencing multiple concurrent functional gastrointestinal disorders is associated with greater symptom severity and worse quality of life in chronic constipation and defecation disorders

BACKGROUND

Recent community-based studies have demonstrated that experiencing multiple concurrent functional gastrointestinal disorders (FGIDs) is associated with increased somatization, worse quality of life (QoL), and greater health care utilization. However, the presence of multiple overlapping FGIDs is unstudied specifically in chronic constipation and functional defecation disorders (FDD). We investigated the prevalence and impact of additional nonconstipation FGIDs on constipation severity, anorectal physiology, anxiety and depression, and QoL, in patients with chronic constipation and FDD.

METHODS

One-hundred and forty-six consecutive patients with functional constipation or irritable bowel syndrome (IBS-C/IBS-M) presenting to a tertiary referral Neurogastroenterology Clinic were studied. In addition, 90/146 (62%) qualified for FDD due to abnormal defecatory physiology. Patients underwent comprehensive baseline assessment comprising anorectal physiology, Bristol Stool Chart, Rome questionnaire, Knowles-Eccersley-Scott-Symptom (KESS) constipation score, Hospital Anxiety, and Depression Scale, and modified 36-Item Short Form Health Survey (SF-36) for QoL. Additional FGIDs were diagnosed using Rome III criteria.

KEY RESULTS

Additional nonconstipation FGIDs occurred in 85% of patients, with a mean of 2.1 (SD 1.6) additional FGIDs. Patients with four or more additional FGIDs experienced greater constipation severity compared to those with no additional FGIDs (p = 0.004). Comorbid FGIDs were associated with worse SF-36 scores for physical functioning (p < 0.001), role-physical (p = 0.005), bodily pain (p < 0.001), vitality (p = 0.008), social functioning (p = 0.004), and mental health index (p = 0.031).

CONCLUSIONS AND INFERENCES

Functional gastrointestinal disorders comorbidity is highly prevalent in chronic constipation and defecatory disorders, and this is associated with greater symptom severity and worse QoL. Multimodal treatments targeting comorbid FGIDs may lead to superior outcomes.

Sex- and gender-related differences in the prevalence and burden of disorders of gut-brain interaction in Poland

BACKGROUND

The aim of the study was to assess sex- and gender-related differences in the epidemiology and impact of disorders of gut-brain interaction (DGBI) in Poland.

METHODS

Data used for the current analysis were derived from the Polish population sample of 2057 subjects (1030 F, 1027 M) collected via the Internet survey that included the Rome IV diagnostic questionnaire and 80 supplementary questions.

KEY RESULTS

The overall prevalence of DGBI in Poland was 46.0% (51.7% in women and 40.3% in men, p < 0.001). Comparing women versus men, esophageal disorders were observed in 6.3% vs. 6.0%, respectively (p > 0.05), gastroduodenal disorders in 14.0% vs. 7.8% (p < 0.001), bowel disorders in 44.3% vs. 33.9% (p < 0.001), and anorectal disorders in 9.9% vs. 7.7% (p > 0.05). The six most common DGBI included functional constipation 14.2%, functional dyspepsia 8.3%, proctalgia fugax 6.6%, functional bloating 4.8%, functional diarrhea 4.5%, and irritable bowel syndrome (IBS) 4.4%. All these disorders, except for functional diarrhea, were more common in women. The DGBI overlap was significantly higher in women than in men (16.7% vs. 11.2%, p < 0.001). A higher number of overlapping DGBI correlated positively with IBS severity, higher level of somatization, anxiety and depression, poorer quality of life (QoL), and increased healthcare utilization.

CONCLUSIONS AND INFERENCES

This is the first comprehensive report on significant sex/gender-related differences in the prevalence and burden of DGBI in Poland. The revealed differences between women and men with DGBI in the clinical profile, psychosocial variables, and healthcare utilization may have important diagnostic and therapeutic implications.

The Cost-Effectiveness of a Dance and Yoga Intervention for Girls with Functional Abdominal Pain Disorders

BACKGROUND

Functional abdominal pain disorders (FAPDs) affect children worldwide, being more prevalent among girls. The individual and societal burdens of the disease are substantial, and evidence-based interventions are needed. Non-pharmacological treatments have generally produced promising results, with dance and yoga specifically having potential as an effective treatment option. Beside efficacy, the cost-effectiveness of interventions is important when prioritizing and allocating public resources.

OBJECTIVE

This study evaluated the cost-effectiveness of an 8-month dance and yoga intervention for girls with functional abdominal pain or irritable bowel syndrome, based on a randomized control trial called 'Just in TIME'.

METHODS

The intervention, performed in Sweden, was studied using a decision analysis tool, i.e., a decision tree within the trial followed by a Markov model with a time horizon of 10 years. The base case considered healthcare costs as well as productivity losses, measuring the effects in gained quality-adjusted life-years (QALYs) and presenting an incremental cost-effectiveness ratio (ICER).

RESULTS

The base case results show that the intervention, compared with current practice, was the dominant strategy from both the 12-month and long-term perspectives. The sensitivity analyses indicated that the long-term, but not the short-term, findings were robust for different assumptions and changes in parameter estimates, resulting in ICERs similar to those of the base case scenario.

CONCLUSIONS

Offering dance and yoga to young girls with FAPDs generates small QALY gains and monetary savings compared with standard healthcare and is likely cost-effective. These findings make a valuable contribution to an area where evidence-based and cost-effective treatment interventions are needed.

CLINICAL TRIALS REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT02920268; Name: Just in TIME-Intervention With Dance and Yoga for Girls With Recurrent Abdominal Pain.

Is Personalized Dietary Therapy Effective for Individuals With Irritable Bowel Syndrome?

Introduction: Adverse reactions to foods and food additives have a critical role in clinical manifestations of irritable bowel syndrome (IBS). Personalized dietary modifications conducted under the supervision of a qualified health practitioner could considerably impact the clinical care and course of the condition. Objective: To investigate the clinical effectiveness of the Lifestyle Eating and Performance (LEAP) program based on the Leukocyte Activation Assay-MRT (LAA-MRT^®) results in improving IBS symptoms and quality of life. Methods: The retrospective study included de-identified client records (n = 146) from private group practices seen by registered dietitians. The eligibility criteria were adults aged > 18 years old with an established diagnosis of IBS. Results: Participants were 46.7 ± 12.6 years old and had a BMI of 26.7 ± 6.1 kg/m²; the majority were female (87.0%) and followed-up by a registered dietitian for 10.1 ± 6.4 weeks. There was a significant reduction post-dietary intervention in overall Global Gastrointestinal Symptom Survey Scores (P < 0.001) and improvement in quality of life (P < 0.001). Conclusion: This study generates real-world evidence of an alternative treatment option for IBS using a personalized dietary approach. A more precise understanding of the effect of food intake reactions is vital for clinical improvements and enhancing health outcomes in IBS.

Strategies for Producing Low FODMAPs Foodstuffs: Challenges and Perspectives

In recent years, there has been a growing interest in a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) as a promising therapeutic approach to reduce the symptoms associated with irritable bowel syndrome (IBS). Hence, the development of low FODMAPs products is an important challenge for the food industry, and among the various foodstuffs associated with the intake of FODMAPs, cereal-based products represent an issue. In fact, even if their content in FODMAPs is limited, their large use in diet can be an important factor in developing IBS symptoms. Several useful approaches have been developed to reduce the FODMAPs content in processed food products. Accurate ingredient selection, the use of enzymes or selected yeasts, and the use of fermentation steps carried out by specific lactic bacteria associated with the use of sourdough represent the technical approaches that have been investigated, alone or in combination, to reduce the FODMAPs content in cereal-based products. This review aims to give an overview of the technological and biotechnological strategies applicable to the formulation of low-FODMAPs products, specifically formulated for consumers affected by IBS. In particular, bread has been the foodstuff mainly investigated throughout the years, but information on other raw or processed products has also been reported. Furthermore, taking into account the required holistic approach for IBS symptoms management, in this review, the use of bioactive compounds that have a positive impact on reducing IBS symptoms as added ingredients in low-FODMAPs products is also discussed.

Identification of irritable bowel syndrome in the Swedish National Patient Register: a validation study

BACKGROUND AND OBJECTIVE

National patient registers are valuable in epidemiological studies. To ensure high-quality data for studies of irritable bowel syndrome (IBS), this study aimed to validate the ICD-10 code for IBS in the Swedish National Patient Register.

METHODS

The positive predictive values (PPV) for IBS defined by the Rome criteria were calculated based on a review of medical records of randomly selected individuals with a first-ever diagnostic listing of IBS in the Swedish National Patient register in the year 2005 (Rome II criteria) or 2010 (Rome III criteria).

KEY RESULTS

340 medical records were reviewed (172 from 2005 and 168 from 2010). The majority of patients were females (74%), and the mean age was 42 years. IBS used in any type of department had a PPV of 76% (95% confidence interval 71-80%), which increased to 80% (76-84%) when we included individuals likely to have IBS but where information about some aspects of the Rome criteria was lacking in the medical record. Two highly specialized gastroenterological departments had the best PPV, 96%, while departments of internal medicine in general had a PPV of 82% (80-95%). The PPV for the IBS subtype was 62% (55-67%). The PPVs were not significantly different comparing the two time periods investigated.

CONCLUSION AND INFERENCES

The validity of a register-based definition of IBS in the Swedish National Patient register is high and can be used to identify patients with IBS in observational research. The data source, i.e., type of hospital and department, influences reliability.

Hypnotherapy and IBS: Implicit, long-term stress memory in the ENS?

The association between irritable bowel syndrome (IBS) and psychiatric and mood disorders may be more fundamental than was previously believed. Prenatal, perinatal, postnatal, and early-age conditions can have a key role in the development of IBS. Subthreshold mental disorders (SMDs) could also be a significant source of countless diverse diseases and may be a cause of IBS development. We hypothesize that stress-induced implicit memories may persist throughout life by epigenetic processes in the enteric nervous system (ENS). These stress-induced implicit memories may play an essential role in the emergence and maintenance of IBS. In recent decades, numerous studies have proven that hypnosis can improve the primary symptoms of IBS and also reduce noncolonic symptoms such as anxiety and depression and improve quality of life and cognitive function. These significant beneficial effects of hypnosis on IBS may be because hypnosis allows access to unconscious brain processes.

Paeoniflorin alleviates inflammatory response in IBS-D mouse model via downregulation of the NLRP3 inflammasome pathway with involvement of miR-29a

Paeoniflorin has been traditionally used to treat pain and immunologic derangement in China. However, its detailed mechanism remains to be illuminated. We investigated the mechanism by which paeoniflorin alleviates the inflammatory response in a mouse model of irritable bowel syndrome with predominant diarrhea (IBS-D). C57BL/6 wild type (WT) and miR-29a knockout (KO) mice were randomly divided into control, model, rifaximin, and paeoniflorin groups (n = 7). IBS-D model was induced by single intracolonic instillation of 0.1 mL trinitro-benzene-sulfonic acid (TNBS, 50 mg/mL) combined with restraint stress for seven consecutive days. The treatment groups received rifaximin (100 mg/kg) and paeoniflorin (50 mg/kg) via intragastric administration for seven days, respectively. The results showed that the fecal water content, fecal pellet output, visceral sensitivity, and histopathological score after paeoniflorin treatment were lower than those of the model group in both WT and miR-29a KO mice (P < 0.05). In both lineage mice, damage was observed in the colon tissues of model group, while paeoniflorin treatment partially ameliorated the tissue damage. Serum levels of DAO, DLA, IL-1β, IL-18, TNF-α, and MPO were decreased after paeoniflorin treatment (P < 0.05), with miR-29a KO mice in a lower level compared with that of WT mice. RT-PCR showed that the relative expression of miR-29a, NF-κB (p65), NLRP3, ASC, caspase-1, IL-1β, and TNF-α was downregulated while NKRF was upregulated after paeoniflorin treatment (P < 0.05). Immunohistochemistry showed that intestinal epithelial protein levels of NLRP3, ASC, and caspase-1 decreased while those of Claudin-1 and ZO-1 increased in the paeoniflorin treatment group (P < 0.05). In general, compared with WT mice, NLRP3 inflammasome pathway targets was in much lower expression level than miR-29a KO mice. In conclusion, paeoniflorin could inhibit abnormal activation of the NLRP3 inflammasome pathway by inhibiting miR-29a in IBS-D, thereby relieving the inflammatory response of the intestinal mucosa and reconstructing the intestinal epithelial barrier.

Chaihu-Guizhi-Ganjiang Decoction is more efficacious in treating irritable bowel syndrome than Dicetel according to metabolomics analysis

BACKGROUND

Chaihu-Guizhi-Ganjiang Decoction (CGGD) is a traditional Chinese medicine (TCM) prescription used to treat viral influenza. There is evidence that CGGD can be used to treat irritable bowel syndrome (IBS) but the potential mechanism of action and metabolites produced upon CGGD treatment remains elusive.

METHODS

Patients with IBS were treated with pinaverium bromide (Dicetel™) and then CGGD after a washout period of 1 week. Both treatments lasted for 30 days. The efficacy and changes of metabolites in plasma after the two treatments were compared. Plasma samples were acquired before and after each treatment, and untargeted metabolics analysis was performed.

RESULTS

Efficacy was measured according to the Rome IV criteria and TCM theory. Our results indicated that CGGD showed significantly better efficacy than Dicetel in the treatment of IBS utilizing each criterion. CGGD exerted greater effects on plasma metabolism than Dicetel. Dicetel treatment led to increased tryptophan metabolism (increased levels of 5-Hydroxyindoleacetaldehyde) and increased protein metabolism (increased levels of L-arginine). CGGD treatment significantly (p < 0.05) increased carnitine metabolism, with elevated levels of L-carnitine and acylcarnitine in plasma. Such changes in these metabolites could exert effects against IBS by improving gastrointestinal motility and suppressing pain, depression, and inflammation.

CONCLUSIONS

CGGD appeared to be more efficacious than Dicetel for treating patients with IBS. The findings provide a sound support for the underlying biomolecular mechanism of CGGD in the prevention and treatment of IBS.

A postbiotic fermented oat gruel may have a beneficial effect on the colonic mucosal barrier in patients with irritable bowel syndrome

BACKGROUND

Impaired intestinal permeability and microbial dysbiosis are important pathophysiological mechanisms underlying irritable bowel syndrome (IBS). ReFerm®, also called Profermin®, is a postbiotic product of oat gruel fermented with Lactobacillus plantarum 299v. In this study, we investigated whether ReFerm® has a beneficial effect on the intestinal epithelial barrier function in patients with IBS.

MATERIALS AND METHODS

Thirty patients with moderate to severe IBS-diarrhoea (IBS-D) or IBS-mixed (IBS-M) were treated with enema containing ReFerm® or placebo. The patients underwent sigmoidoscopy with biopsies obtained from the distal colon at baseline and after 14 days of treatment with ReFerm® or placebo twice daily. The biopsies were mounted in Ussing chambers, and paracellular and transcellular permeabilities were measured for 120 min. In addition, the effects of ReFerm® or placebo on the epithelial barrier were investigated in vitro using Caco-2 cells.

RESULTS

ReFerm® reduced paracellular permeability (p < 0.05) and increased transepithelial resistance (TER) over time (p < 0.01), whereas the placebo had no significant effect in patients. In ReFerm®-treated Caco-2 cells, paracellular and transcellular permeabilities were decreased compared to the control (p < 0.05) and placebo (p < 0.01). TER was increased in Caco-2 ReFerm®-treated cells, and normalised TER was increased in ReFerm®-treated Caco-2 cells compared to control (p < 0.05) and placebo-treated (p < 0.05) cells.

CONCLUSION

ReFerm® significantly reduced paracellular permeability and improved TER in colonic biopsies collected from patients with IBS and in a Caco-2 cell model. Our results offer new insights into the potential benefits of ReFerm® in IBS management. Further studies are needed to identify the molecular mechanisms underlying the barrier-protective properties of ReFerm®.

CLINICAL TRIAL REGISTRATION

[https://clinicaltrials.gov/], identifier [NCT05475314].

Diet or medication in primary care patients with IBS: the DOMINO study - a randomised trial supported by the Belgian Health Care Knowledge Centre (KCE Trials Programme) and the Rome Foundation Research Institute

BACKGROUND

In Europe, IBS is commonly treated with musculotropic spasmolytics (eg, otilonium bromide, OB). In tertiary care, a low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet provides significant improvement. Yet, dietary treatment remains to be explored in primary care. We evaluated the effect of a smartphone FODMAP-lowering diet application versus OB on symptoms in primary care IBS.

METHODS

IBS patients, recruited by primary care physicians, were randomised to 8 weeks of OB (40 mg three times a day) or diet and followed for 24 weeks. We compared IBS Symptom Severity Score and the proportion of responders (improvement ≥50 points) in all patients and the subgroup fulfilling Rome IV criteria (Rome+). We also evaluated treatment efficacy, quality of life, anxiety, depression, somatic symptom severity (Patient Health Questionnaire (PHQ15, PHQ9)) and treatment adherence and analysed predictors of response.

RESULTS

459 primary care IBS patients (41±15 years, 76% female, 70% Rome+) were randomised. The responder rate after 8 weeks was significantly higher with diet compared with OB (71% (155/218) vs 61% (133/217), p=0.03) and more pronounced in Rome+ (77% (118/153) vs 62% (98/158), p=0.004). Patients allocated to diet (199/212) were 94% adherent compared with 73% with OB (148/202) (p<0.001). The significantly higher response rate with diet was already observed after 4 weeks (62% (132/213) vs 51% (110/215), p=0.02) and a high symptom response persisted during follow-up. Predictors of response were female gender (OR=2.08, p=0.04) for diet and PHQ15 (OR=1.10, p=0.02) for OB.

CONCLUSION

In primary care IBS patients, a FODMAP-lowering diet application was superior to a spasmolytic agent in improving IBS symptoms. A FODMAP-lowering diet should be considered the first-line treatment for IBS in primary care.

TRIAL REGISTRATION NUMBER

NCT04270487.

Probiotics therapy for adults with diarrhea-predominant irritable bowel syndrome: a systematic review and meta-analysis of 10 RCTs

PURPOSE

Accumulating evidence showed that probiotics therapy might be effective in treating diarrhea-predominant irritable bowel syndrome (IBS-D). This study aimed to evaluate the effectiveness and safety of probiotics therapy for the treatment of IBS-D.

METHODS

We performed a comprehensive literature search in eight electronic databases, and gray literature from inception to August 4, 2021. Randomized controlled trials (RCTs) of probiotics therapy for the treatment of IBS-D were included and the quality was assessed using the risk of bias tool recommended by the Cochrane Handbook version 5.1.0. RevMan 5.4 software was used to perform the meta-analysis on the outcomes of IBS-D symptoms, abdominal pain, quality of life, and abdominal distension. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of evidence.

RESULTS

Ten RCTs evaluating 943 patients were identified. Only one study had unclear risk of bias, while nine studies had a high risk of bias. The meta-analysis results showed that, compared to the placebo, probiotics therapy significantly decreased the score of IBS-D symptoms (SMD =  - 0.55, 95% CI: [- 0.83, - 0.27], P < 0.05), abdominal pain (SMD =  - 0.43, 95% CI: [- 0.57, - 0.29], P < 0.05), and abdominal distension (SMD =  - 0.45, 95%CI: [- 0.81, - 0.09], P < 0.05). There was no statistical difference in the quality of life. However, all the certainty of evidence was very low.

CONCLUSION

Very low certainty evidence showed that probiotics might be an effective treatment for improving the IBS-D symptoms, abdominal pain, and abdominal distension, in adult IBS-D patients. However, these conclusions should be supported by high-quality evidence.

Treatments targeting the luminal gut microbiota in patients with irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction affecting 4% of the world's population. Patients with IBS experience chronic or recurrent abdominal pain in combination with altered bowel habits (diarrhea and/or constipation), and have reduced quality of life. Despite the high prevalence and substantial burden of IBS, its pathophysiology is incompletely understood and remains to be elucidated. The importance of the gut microenvironment has been highlighted in IBS, as there are signs that the gut microbiota of patients differs from healthy controls. Recent studies have aimed to alter the gut microbiota and thereby, attempted to alleviate gastrointestinal symptoms in IBS patients. We highlighted recent advances in common treatments that are targeting the luminal gut microbiota in IBS.

Diet and irritable bowel syndrome: an update from a UK consensus meeting

There has been a renewed interest in the role of dietary therapies to manage irritable bowel syndrome (IBS), with diet high on the agenda for patients. Currently, interest has focussed on the use of traditional dietary advice (TDA), a gluten-free diet (GFD) and the low FODMAP diet (LFD). A consensus meeting was held to assess the role of these dietary therapies in IBS, in Sheffield, United Kingdom.Evidence for TDA is from case control studies and clinical experience. Randomised controlled trials (RCT) have demonstrated the benefit of soluble fibre in IBS. No studies have assessed TDA in comparison to a habitual or sham diet. There have been a number of RCTs demonstrating the efficacy of a GFD at short-term follow-up, with a lack of long-term outcomes. Whilst gluten may lead to symptom generation in IBS, other components of wheat may also play an important role, with recent interest in the role of fructans, wheat germ agglutinins, as well as alpha amylase trypsin inhibitors. There is good evidence for the use of a LFD at short-term follow-up, with emerging evidence demonstrating its efficacy at long-term follow-up. There is overlap between the LFD and GFD with IBS patients self-initiating gluten or wheat reduction as part of their LFD. Currently, there is a lack of evidence to suggest superiority of one diet over another, although TDA is more acceptable to patients.In view of this evidence, our consensus group recommends that dietary therapies for IBS should be offered by dietitians who first assess dietary triggers and then tailor the intervention according to patient choice. Given the lack of dietetic services, novel approaches such as employing group clinics and online webinars may maximise capacity and accessibility for patients. Further research is also required to assess the comparative efficacy of dietary therapies to other management strategies available to manage IBS.

Aspalathus linearis (Rooibos) and Agmatine May Act Synergistically to Beneficially Modulate Intestinal Tight Junction Integrity and Inflammatory Profile

In order to promote gastrointestinal health, significant increases in the prevalence of gastrointestinal disorders should be paralleled by similar surges in therapeutics research. Nutraceutical interventions may play a significant role in patient management. The current study aimed to determine the potential of Aspalathus linearis (rooibos) to prevent gastrointestinal dysregulation resulting from high-dose trace-amine (TA) exposure. Considering the substantial female bias in functional gastrointestinal disorders, and the suggested phytoestrogenicity of rooibos, the study design allowed for a comparison between the effects of an ethanol extract of green rooibos and 17β-estradiol (E2). High levels of ρ-tyramine (TYR) and agmatine (AGM), but not β-phenethylamine (PEA) or tryptamine (TRP), resulted in prostaglandin E2 (PGE2) hypersecretion, increased tight-junction protein (TJP; occludin and ZO-1) secretion and (dissimilarly) disrupted the TJP cellular distribution profile. Modulating benefits of rooibos and E2 were TA-specific. Rooibos pre-treatment generally reduced IL-8 secretion across all TA conditions and prevented PGE2 hypersecretion after exposure to both TYR and AGM, but was only able to normalise TJP levels and the distribution profile in AGM-exposed cells. In contrast, E2 pre-treatment prevented only TYR-associated PGE2 hypersecretion and TJP dysregulation. Together, the data suggest that the antioxidant and anti-inflammatory effects of rooibos, rather than phytoestrogenicity, affect benefits illustrated for rooibos.

Two microbiota subtypes identified in irritable bowel syndrome with distinct responses to the low FODMAP diet

OBJECTIVE

Reducing FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) can be clinically beneficial in IBS but the mechanism is incompletely understood. We aimed to detect microbial signatures that might predict response to the low FODMAP diet and assess whether microbiota compositional and functional shifts could provide insights into its mode of action.

DESIGN

We used metagenomics to determine high-resolution taxonomic and functional profiles of the stool microbiota from IBS cases and household controls (n=56 pairs) on their usual diet. Clinical response and microbiota changes were studied in 41 pairs after 4 weeks on a low FODMAP diet.

RESULTS

Unsupervised analysis of baseline IBS cases pre-diet identified two distinct microbiota profiles, which we refer to as IBSP (pathogenic-like) and IBSH (health-like) subtypes. IBSP microbiomes were enriched in Firmicutes and genes for amino acid and carbohydrate metabolism, but depleted in Bacteroidetes species. IBSH microbiomes were similar to controls. On the low FODMAP diet, IBSH and control microbiota were unaffected, but the IBSP signature shifted towards a health-associated microbiome with an increase in Bacteroidetes (p=0.009), a decrease in Firmicutes species (p=0.004) and normalisation of primary metabolic genes. The clinical response to the low FODMAP diet was greater in IBSP subjects compared with IBSH (p=0.02).

CONCLUSION

50% of IBS cases manifested a 'pathogenic' gut microbial signature. This shifted towards the healthy profile on the low FODMAP diet; and IBSP cases showed an enhanced clinical responsiveness to the dietary therapy. The effectiveness of FODMAP reduction in IBSP may result from the alterations in gut microbiota and metabolites produced. Microbiota signatures could be useful as biomarkers to guide IBS treatment; and investigating IBSP species and metabolic pathways might yield insights regarding IBS pathogenic mechanisms.

Exploring the Relationship Between Self-Isolation and Distress Among People with Gastrointestinal Disorders During the COVID-19 Pandemic

This study aimed to explore the association between perceived isolation and symptoms of distress in people with GI disorders at the time of the pandemic; and to examine factors which moderate this relationship. This online cross-sectional survey was advertised in May-September 2020 via patient organisations and associated social media. Overall, 831 people (82% female, mean age 49 years) from 27 countries participated. A significant relationship between social isolation and psychological distress was noted (r = .525, p < .001). GI symptoms moderated the association between isolation and distress (B = .047, t = 2.47, p = .015). Interventions targeting these factors may help to reduce distress in people with GI disorders at the time of major stressors such as the COVID-19 pandemic.

Long-Term Outcome of Multidisciplinary Versus Standard Gastroenterologist Care for Functional Gastrointestinal Disorders: A Randomized Trial

BACKGROUND & AIMS

Functional gastrointestinal disorders are common and costly to the healthcare system. In the Multidisciplinary Treatment of Functional Gastrointestinal Disorders study, we demonstrated that multidisciplinary care resulted in superior clinical and cost outcomes, when compared with standard gastroenterologist-only care at end of treatment. In this study we evaluate the longer-term outcomes.

METHODS

In a single-center, pragmatic trial patients with Rome IV criteria-defined functional gastrointestinal disorders were randomized 1:2 to a gastroenterologist-only standard care vs a multidisciplinary clinic comprising gastroenterologists, dietitians, gut hypnotherapists, psychiatrists, and biofeedback physiotherapists. Outcomes in this study were assessed 12 months after the end of treatment. Global symptom improvement was assessed by using a 5-point Likert scale. Symptoms, specific disorder status, psychological state, quality of life, and cost were additional outcomes. A modified intention-to-treat analysis was performed.

RESULTS

Of 188 randomized patients, 143 (46 standard care, 97 multidisciplinary) formed the longer-term modified intention-to-treat analysis. Sixty-two percent of multidisciplinary clinic patients saw allied clinicians. Sixty-five percent (30/46) standard care versus 76% (74/97) multidisciplinary clinic patients achieved global symptom improvement 12 months after end of treatment (P = .17), whereas 20% (9/46) versus 37% (36/97) rated their symptoms as "5/5 much better" (P = .04). A ≥50-point reduction in Irritable Bowel Syndrome Severity Scoring System occurred in 38% versus 66% (P = .02), respectively, for irritable bowel syndrome patients. Anxiety and depression were greater in the standard care than multidisciplinary clinic (12 vs 10, P = .19), and quality of life was lower in standard care than the multidisciplinary clinic (0.75 vs 0.77, P =·.03). An incremental cost-effectivness ratio found that for every additional 3555AUD spent in the multidisciplinary clinic, a further quality-adjusted life year was gained.

CONCLUSIONS

Twelve months after the completion of treatment, integrated multidisciplinary clinical care achieved a greater proportion of patients with improvement of symptoms, psychological state, quality of life, and cost, compared with gastroenterologist-only care.

CLINICAL TRIALS

gov: number NCT03078634.

Factors related to irritable bowel syndrome and differences among subtypes: A cross-sectional study in the UK Biobank

Background: Irritable bowel syndrome (IBS) reduces patients' quality of life and causes great burdens due to its unclear pathogenesis and criteria for diagnosis. This study aimed to explore the differences in prevalence and the influencing factors for IBS and its subtypes. Methods: The UK Biobank surveyed 174,771 adult participants who completed the Digestive Health Questionnaire (DHQ) through emails and websites. DHQ included the Rome III criteria, IBS symptom severity score, and Patient Health Questionnaire 12 Somatic Symptom score. The UK Biobank also asked regarding previous IBS diagnosis, diagnosis for post-infectious IBS (PI-IBS), and environmental exposures and associated conditions (including anxiety or depression, based on treatment sought or offered). Pearson's Chi-squared test or Wilcoxon's rank-sum test was used for potential associations. Binary logic regression based on sex stratification was used to examine associations between selected factors and IBS and its subtypes. Results: This study included 31,918 participants who met the Rome III criteria for IBS. The pooled prevalence of IBS in the UK Biobank was 18.3%, with mixed IBS as the predominant subtype (59.0%), followed by diarrhea-predominant IBS (25.1%), constipation-predominant IBS (14.7%), and untyped IBS (1.1%). IBS was significantly associated with somatization (male: OR = 5.326, 95% CI = 4.863-5.832; female: OR = 4.738, 95% CI = 4.498-4.992) and coeliac disease (male: OR = 4.107, 95% CI = 3.132-5.385; female: OR = 3.783, 95% CI = 3.310-4.323). Differences in antibiotics and mental status were presented among subtypes and sex. Furthermore, 1,787 individuals were diagnosed with PI-IBS in the group of patients with IBS. The prevalence of PI-IBS in IBS was 16.6% in the UK Biobank, and it was characterized by diarrhea, fever, bloody diarrhea, and vomiting. Conclusion: Somatization and coeliac disease are primary risk factors for IBS. Distinguishing differential risk factors is critical for the precise diagnosis and treatment of IBS subtypes, particularly sex-specific differences in mental health status. General practitioners should focus on the treatment according to IBS subtypes.

Modulating the gut microenvironment as a treatment strategy for irritable bowel syndrome: a narrative review

Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction with a complex pathophysiology. Growing evidence suggests that alterations of the gut microenvironment, including microbiota composition and function, may be involved in symptom generation. Therefore, attempts to modulate the gut microenvironment have provided promising results as an indirect approach for IBS management. Antibiotics, probiotics, prebiotics, food and faecal microbiota transplantation are the main strategies for alleviating IBS symptom severity by modulating gut microbiota composition and function (eg. metabolism), gut barrier integrity and immune activity, although with varying efficacy. In this narrative review, we aim to provide an overview of the current approaches targeting the gut microenvironment in order to indirectly manage IBS symptoms.

Irritable bowel syndrome and its associated factors among Jordanian medical students: A cross-sectional study

Very scarce studies investigated the prevalence of irritable bowel syndrome (IBS) and its correlates in the Middle East, particularly in college students. We aimed to investigate the prevalence of IBS and its associated factors among Jordanian medical students. We conducted a cross-sectional study at 2 medical facilities in northern Jordan. We recruited 1135 medical students. Participants completed an anonymous questionnaire addressing sociodemographic, lifestyle, and clinical characteristics. An interview questionnaire was used to diagnose IBS according to the Rome III criteria. Comorbid anxiety and depression were diagnosed by using the Hospital Anxiety and Depression Scale. Of the 1135 completed questionnaires, 1094 (94%) had complete data. The prevalence of IBS in our sample was 30.9%. Binary logistic regression analysis of factors associated with IBS indicated having a family history of IBS as a strong predictor of the disease (odds ratio [OR]: 8.09; 95% confidence interval [CI]: 5.84-11.19). Students in the second and third years of their study had ORs of approximately 4 (95% CI: 2.20-6.54) and 3 (95% CI: 1.70-5.30) for suffering from IBS, respectively, compared with those in the first year (P = .001). Increased anxiety score (OR: 1.88; 95% CI: 1.30-2.71), poor sleep quality (OR: 1.76; 95% CI: 1.13-2.76), female sex (OR: 1.59; 95% CI: 1.14-2.20), and living in a school dormitory (OR: 1.35; 95% CI: 1.00-1.84) were significantly associated with IBS (P < .05). IBS is a highly prevalent disorder among Jordanian medical students, with several factors associated with its occurrence.

Association between irritable bowel syndrome and micronutrients: A systematic review

BACKGROUND AND AIM

Irritable bowel syndrome (IBS) is a highly prevalent disorder of gut brain interaction with a multifactorial etiology. Food trigger avoidance is common among individuals with IBS and exclusion diets are gaining popularity. However, recent guidelines on IBS management cautioned regarding the use of unsupervised dietary therapy with concerns of development of poor eating habits and even nutritional deficiencies. We aimed to review the available literature on the effect of habitual and exclusion diets on micronutrient status as well as the role of micronutrient supplementation in alleviating IBS symptoms.

METHODS

Four electronic databases (PubMed, Embase, Cochrane, Web of Science) were searched for articles that reported micronutrient data in patients with IBS. Serum micronutrient levels and dietary intake of micronutrients in patients with IBS were collected. The extracted data were tabulated and organized by micronutrient type to observe for trends.

RESULTS

Twenty-six articles were included in this systematic review (12 interventional and 14 observational studies). Studies showed that generally IBS subjects had lower levels of vitamin B2, vitamin D, calcium, and iron at baseline compared with non-IBS subjects. Studies also found that exclusion diets were associated with lower intake of micronutrients especially vitamin B1, B2, calcium, iron, and zinc. There was a lack of interventional studies on micronutrients.

CONCLUSION

Irritable bowel syndrome patients are at risk of developing multiple micronutrient deficiencies that may have both localized gastrointestinal as well as systemic effects. Dietary management of IBS patients should include a proper dietitian review to ensure nutritional adequacy where possible.

Quality of life in irritable bowel syndrome: Exploring mediating factors through structural equation modelling

BACKGROUND

Irritable Bowel Syndrome (IBS) negatively influences mental and physical quality of life (QoL), but factors that explain this impact are still unclear. Increasing evidence has associated IBS severity, psychological distress, somatic symptoms, and gastrointestinal (GI)-specific anxiety with QoL in IBS. The aim of this study is to further explore these associations and to analyze potential mediating factors.

METHOD

A total of 1017 IBS patients (69.3% female, mean age 40.6 years) who completed a QoL measure (SF-36) were included in this study. A proportion of these participants (N = 183; 72.7% female, mean age 41.7), who additionally completed psychological distress, somatic symptoms, and GI-specific anxiety measures, was included in the mediation analysis. This analysis was conducted via structural equation modelling to identify factors of importance for generic QoL, using a cross-sectional design.

RESULTS

IBS patients reported lower QoL than what is observed in the general population, in particular regarding role limitations caused by health and emotional functioning, vitality, and social functioning. Female patients scored lower than male patients on most QoL dimensions. The effects of IBS severity on mental and physical QoL were mediated by GI-specific anxiety. In addition to GI-specific anxiety, depressive symptoms were also of importance for mental QoL, and somatic symptom severity for physical QoL.

CONCLUSION

QoL is reduced in patients with IBS and GI-specific anxiety, depressive symptoms, and somatic complaints are particularly important for this outcome. Future trials should test the efficacy of psychological interventions specifically targeting these factors in improving QoL in IBS.

Epidemiology of disorders of Gut-Brain interaction in Israel: Results from the Rome Foundation global epidemiology study

BACKGROUND

Data for Israel from the Rome Foundation Global Epidemiology Study on the disorders of gut-brain interaction (DGBI) were used to assess the national prevalence of all 22 DGBI, the percentage of respondents meeting diagnostic criteria for at least one DGBI, and the impact on burden of disease in Israel.

METHODS

The survey was conducted through the Internet with multiple built-in quality-assurance techniques and included the Rome IV diagnostic questionnaire and an in-depth supplemental questionnaire.

KEY RESULTS

2012 Israeli participants completed the survey nationwide: mean age 44.6 ± 16.4 years, 50% females. The national distribution was very close to the latest Israeli census. 36.4% (95% CI 34.3, 38.4) met diagnostic criteria for at least one DGBI, with 4.4% for any esophageal disorder, 6.5% for any gastroduodenal disorder, 30.8% for any bowel disorder, and 5.3% for any anorectal disorder. The rates were higher for women. Having any DGBI was associated negatively with psychosocial variables (including quality of life, somatization, and concern about digestive problems), and healthcare utilization (including doctor visits, use of medications, and abdominal surgeries).

CONCLUSIONS & INFERENCES

The results of this study provide the first in-depth assessment of the prevalence and burden of Rome IV DGBI in Israel and facilitate comparisons with other countries. As 36.4% of the 2,012 participants met diagnostic criteria for at least one DGBI, and 23.5% of those met criteria for more than one DGBI, the burden of DGBI in Israel is high, indicating a need to focus on research and training for patient care.

Comparing probiotic and drug interventions in irritable bowel syndrome: a meta-analysis of randomised controlled trials

Clinical decisions made by health professionals to recommend either drug or probiotic interventions for irritable bowel syndrome (IBS) should be supported by proper knowledge of the efficacy rates of both types of interventions. In this article, we performed a systematic review and meta-analysis to examine the efficacy of both probiotic- and drug interventions in IBS. Medline was searched between January 2015 - January 2021. Randomised controlled trials (RCT) recruiting participants > 18 years old with IBS and examining the effect of probiotics or drugs were eligible for inclusion. The data of the primary outcome, i.e. the persistence of IBS symptoms (dichotomous symptom data), were pooled to obtain a relative risk (RR), with a 95% confidence interval (CI). Secondary outcomes, abdominal pain- and bloating scores (continuous data), were pooled using a standardised mean difference with a 95% CI. The search identified 269 citations of which 32 RCTs were eligible. Our meta-analysis indicated that both probiotic and drug interventions are able to improve the persistence of IBS symptoms (RR 0.60 [0.51; 0.92] versus 0.87 [0.81; 0.92], respectively) and abdominal pain scores (standardised mean difference (SMD) -0.35 [-0.56; -0.14] versus -0.10 [-0.20; 0.00], respectively). However, determining the overall efficacy of both intervention types is inherently complex and such results should be interpreted with care, due to the large diversity of probiotic- and drug types and doses, which is also complicated by variety in IBS subtypes. Hence, as a first step, more large scale randomised double blind placebo-controlled trials focussing on a specific IBS subtype targeted with specific probiotic strains or specific pharmaceutical modalities should be executed, enabling a more proper comparison between trials.

LMWP (S3-3) from the Larvae of Musca domestica Alleviate D-IBS by Adjusting the Gut Microbiota

Diarrhea-based Irritable Bowel Syndrome (D-IBS) and diarrhea are both associated with ecological imbalance of the gut microbiota. Low Molecular Weight Peptides (LMWP) from the larvae of Musca domestica have been shown to be effective in the treatment of diarrhea and regulation of gut microbiota. Meanwhile, the single polypeptide S3-3 was successfully isolated and identified from LMWP in our previous studies. It remains unclear exactly whether and how LMWP (S3-3) alleviate D-IBS through regulating gut microbiota. We evaluated the gut microbiota and pharmacology to determine the regulation of gut microbiota structure and the alleviating effect on D-IBS through LMWP (S3-3). The rates of loose stools, abdominal withdrawal reflex (AWR) and intestinal tract motility results revealed that LMWP (S3-3) from the larvae of Musca domestica had a regulating effect against diarrhea, visceral hypersensitivity and gastrointestinal (GI) dysfunction in D-IBS model mice. Additionally, 16S rRNA gene sequencing was utilized to examine the gut microbiota, which suggests that LMWP induce structural changes in the gut microbiota and alter the levels of the following gut microbiota: Bacteroidetes, Proteobacteria and Verrucomicrobia. LMWP putatively functioned through regulating 5-HT, SERT, 5-HT2AR, 5-HT3AR and 5-HT4R according to the results of ELISA, qRT-PCR and IHC. The findings of this study will contribute to further understanding how LMWP (S3-3) attenuate the effects of D-IBS on diarrhea, visceral hypersensitivity and GI dysfunction.