Acacia fiber or probiotic supplements to relieve gastrointestinal complaints in patients with constipation-predominant IBS: a 4-week randomized double-blinded placebo-controlled intervention trial.

PURPOSE: To date, no adequate treatment for irritable bowel syndrome with predominant constipation complaints (IBS-C) is available. Fibers with prebiotic properties and probiotic compounds have shown promise in relieving IBS-C-related complaints. We aimed to determine the effects of a 4-week intervention with either an Acacia fiber (AF) with prebiotic properties or a probiotic Bifidobacterium Lactis (BLa80) supplement, compared to a control supplement, on stool pattern, IBS symptoms and Quality of Life (QoL), in IBS-C individuals. METHODS: A parallel, double-blind, randomized controlled trial involving 180 subjects meeting the ROME IV criteria for IBS-C was conducted. Following a 4-week observation period, subjects received either AF (10 g), Probiotic BLa80 (4 g; 2 × 1011 CFU/g) or a maltodextrin placebo (10 g) daily for 4 weeks. Subjects reported daily information on stool pattern and gastrointestinal complaints. Before and after each 4-week period, questionnaires on symptom severity, constipation symptoms, anxiety and depression and QoL were completed. Stool mass was measured for 5-days before and after the intervention. RESULTS: Stool frequency significantly improved in the AF and Probiotic BLa80 groups compared to placebo (P < 0.001, P = 0.02, respectively). Probiotic BLa80 showed a significant reduction in IBS symptom severity (P = 0.03), for AF a trend towards decreased constipation symptoms (PAC-SYM, P = 0.10) was observed. No significant changes in stool consistency, stool mass or QoL measures were observed between the AF and Probiotic BLa80 compared to placebo. CONCLUSION: Daily dietary supplementation with Acacia fiber and probiotic supplements might help IBS-C patients by relieving IBS-related complaints compared to a placebo supplement. REGISTRATION NUMBER OF CLINICAL TRIAL: The trial is registered at ClinicalTrials.gov: NCT04798417: Study Details | Nutrition to Relieve IBS Constipation | ClinicalTrials.gov.

Three-year follow-up of sacral nerve stimulation for patients with diarrhoea-predominant and mixed irritable bowel syndrome.

AIM: Our unit has recently shown that sacral nerve stimulation (SNS) has a significantly positive short-term effect on selected patients with diarrhoea-predominant or mixed irritable bowel syndrome (IBS). The aim of the present prospective study was to evaluate the medium-term efficacy of SNS for IBS to establish whether SNS could have a future role in the treatment of IBS. METHOD: Patients with IBS who had previously been implanted with a permanent neurostimulator as part of a randomized, controlled, crossover study, were assessed for medium-term follow-up. The primary end-point was change in the IBS-specific symptom score (Gastrointestinal Symptom Rating Scale-Irritable Bowel Syndrome version questionnaire) from baseline to 3-year follow-up. The secondary end-point was a change in the IBS-specific quality of life score (Irritable Bowel Syndrome-Impact Scale questionnaire) from baseline to 3-year follow-up. RESULTS: Of 26 patients, 20 were eligible for 3-year follow-up. The median IBS-specific symptom score was significantly lower at 3-year follow-up (30, range 13-71) than at baseline (62, 45-80) (P = 0.0001). The effect was observed in all symptom clusters within the score. Also, the median IBS-specific quality of life score was significantly improved at 3-year follow-up (52, 26-169) compared with baseline (135, 82-180, P = 0.0002). The effect was observed in all domains of the score. As per the protocol, 75% of patients were judged therapeutic successes. Seventy per cent of patients had a more than 50% reduction in daily IBS symptoms. CONCLUSION: At medium-term follow-up, SNS continues to be an effective treatment for highly selected patients with diarrhoea-predominant or mixed IBS.

Nutritional Interventions in Adult Patients With Irritable Bowel Syndrome: An Umbrella Review of Systematic Reviews and Meta-analyses of Randomized Clinical Trials.

CONTEXT: There is still debate regarding the effect of nutritional interventions in improving irritable bowel syndrome (IBS) symptoms. OBJECTIVES: The aim was to examine the evidence certainty and validity of all existing meta-analyses of intervention trials on nutritional interventions in patients with IBS. DATA SOURCES: Scopus, PubMed, and Web of Science were reviewed until June 2023. DATA EXTRACTION: Meta-analyses assessing the impacts of nutritional interventions in adults with IBS were entered. Effect sizes of nutritional interventions were recalculated by applying a random-effects model. GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) was implemented to determine evidence certainty. RESULTS: A total of 175 trials in 58 meta-analyses were entered describing the effects of 11 nutritional interventions on IBS-related outcomes. Nutritional interventions had beneficial effects on some IBS-related outcomes. For instance, soluble fiber, peppermint oil, and aloe vera improved IBS symptoms, and vitamin D3 and curcumin improved IBS symptom severity. Tongxieyaofang improved abdominal pain severity and stool frequency. Nevertheless, these outcomes have mainly shown small effects and low to very low evidence certainty. With regard to abdominal pain after probiotic supplementation (relative risk [RR]: 4.04; 95% confidence interval [CI]: 2.36, 6.92; GRADE = moderate) and IBS symptoms after a low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet (RR: 1.48; 95% CI: 1.14, 1.93; GRADE = moderate), there was evidence that probiotics and a low-FODMAP diet can confer clinical and favorable effects. CONCLUSION: The current review does not support nutritional interventions for improving IBS symptoms. With regard to probiotics and a low-FODMAP diet, considering limitations like short-term study duration, there was an influential clinical impact. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42023429991.

Fecal bacteria and short-chain fatty acids in irritable bowel syndrome: Relations to subtype.

BACKGROUND: The relationship between gut microbiota and irritable bowel syndrome (IBS) subtype is unclear. We aimed to explore whether differences in fecal bacteria composition and short-chain fatty acid (SCFA) levels were associated with subtypes and symptoms of IBS. METHODS: All participants delivered fecal samples and self-reports on IBS Symptom Severity Score (IBS-SSS), Bristol Stool Scale (BSS), and Gastrointestinal Symptom Rating Scale (GSRS). Fecal bacteria composition was assessed by the GA-map® Dysbiosis Test based on 16S rRNA sequences of bacterial species/groups. SCFAs were analyzed by vacuum distillation followed by gas chromatography. KEY RESULTS: Sixty patients with IBS were included (mean age 38 years, 46 [77%] females): Twenty-one patients were classified as IBS-D (diarrhea), 31 IBS-M (mixed diarrhea and constipation), and eight IBS-C (constipation). Forty-two healthy controls (HCs) (mean age 35 years, 27 [64%] females) were included. Patients had a significantly higher relative frequency of dysbiosis, lower levels of Actinobacteria, and higher levels of Bacilli than HCs. Eight bacterial markers were significantly different across IBS subgroups and HCs, and 13 bacterial markers were weakly correlated with IBS symptoms. Clostridia and Veillonella spp. had a weak negative correlation with constipation scores (GSRS) and a weak positive correlation with loose stools (BSS). Diarrhea scores (GSRS) and looser stool (BSS) were weakly correlated with levels of total SCFAs, acetic and butyric acid. Levels of total SCFAs and acetic acid were weakly correlated with symptom severity (IBS-SSS). CONCLUSIONS & INFERENCES: Patients with IBS had a different fecal bacteria composition compared to HCs, and alterations of SCFAs may contribute to the subtype.

Fecal Microbiota Transplantation for Patients With Irritable Bowel Syndrome: A Meta-Analysis of Randomized Controlled Trials.

Background: Gut microbiota has been identified as an imbalance in patients with irritable bowel syndrome (IBS). Fecal microbiota transplantation (FMT) is a novel method to restore microbiota and treat IBS patients. Objective: To conduct a meta-analysis and estimate the efficacy and safety of FMT for the treatment of IBS patients with subgroup analyses to explore the most effective way of FMT for IBS. Methods: All eligible studies were searched from PubMed, Embase, Web of Science, and the Cochrane Library through multiple search strategies. Data were extracted from studies comprising the following criteria: double-blind, randomized controlled trials (RCTs) that compared the efficacy of FMT with placebo for adult patients (≥18 years old) with IBS. A meta-analysis was performed to evaluate the summary relative risk (RR) and 95% confidence intervals (CIs). Results: A total of seven RCTs comprising 489 subjects were eligible for this meta-analysis. Pooled data showed no significant improvement of global IBS symptoms in patients with FMT compared with placebo (RR = 1.34; 95% CI 0.75-2.41, p = 0.32). A significant heterogeneity was observed among the studies (I 2 = 83%, p < 0.00001). There was no significant evidence of funnel plot asymmetry (Egger's test, p = 0.719; Begg's test, p = 1.000), indicating no existence of publication bias. Subgroup analyses revealed that FMT operated by invasive routes, including gastroscope, colonoscope, and nasojejunal tube, significantly improved global IBS symptoms (RR = 1.96; 95% CI 1.23-3.11, p = 0.004) with heterogeneity (I 2 = 57%, p = 0.06) and an NNT of 3 (95% CI 2-14). However, FMT delivered via oral capsules showed a negative impact on patients with IBS (RR = 0.56; 95% CI 0.33-0.96, p = 0.03) with a low heterogeneity (I 2 = 39%, p = 0.2) and an NNH of 3 (95% CI 2-37). Conclusion: The current evidence from RCTs with all routes of FMT does not show significant global improvement in patients with IBS. However, FMT operated by invasive routes significantly improved global IBS symptoms.

Irritable bowel syndrome in women: Association between decreased insular subregion volumes and gastrointestinal symptoms.

OBJECTIVE: Irritable bowel syndrome (IBS) is a chronic pain disorder characterized by disturbed interactions between the gut and the brain with depression as a common comorbidity. In both IBS and depression, structural brain alterations of the insular cortices, key structures for pain processing and interoception, have been demonstrated but the specificity of these findings remains unclear. We compared the gray matter volume (GMV) of insular cortex (IC) subregions in IBS women and healthy controls (HC) and examined relations to gastrointestinal (GI) symptoms and glutamate + glutamine (Glx) concentrations. We further analyzed GMV of IC subregions in women with major depression (MDD) compared to HC and addressed possible differences between depression, IBS, IBS with depression and HC. DESIGN: Women with IBS (n = 75), MDD (n = 41) and their respective HC (n = 39 and n = 43) underwent structural brain MRI. IC subregion volumes were estimated using statistical parametric mapping software. General linear model approaches were applied to IC volumetric data and FDR-corrected partial correlation analyses assessed relations between GMV, GI symptoms and Glx concentrations. RESULTS: IBS patients had significantly smaller IC subregions than HC in both hemispheres but there was no significant difference between MDD compared with IBS and HC for any insular subregion. In IBS, the dorsal anterior insular volumes were negatively correlated with symptoms of nausea and pain, and the left ventral subregion showed a positive correlation with straining to defecate, while the posterior subregion volumes showed no relation to symptoms. In the anterior insula, concentration of Glx showed positive correlations with GMV bilaterally in HC and with GMV of the right anterior insula in IBS. CONCLUSION: As the interoceptive cortex, the insula shows substantial and disease-specific structural differences in patients with chronic interoceptive visceral pain. Particularly changes in the anterior proportions might be related to chronic exposure to or enhanced salience towards adverse interoceptive visceral signals and could be linked to biochemical changes, calling for further multimodal and longitudinal work.