El consumo de dos kiwis diarios podría mejorar el hábito intestinal en personas con estreñimiento crónico / Daily consumption of two kiwifruits could improve bowel habits in people with chronic constipation

A partir del caso de una paciente con síndrome de intestino irritable a predominio de estreñimiento cuyos síntomas mejoraron con el consumo regular de kiwi, el médico de familia se planteó la pregunta de si el kiwi podría mejorar los síntomas asociados a constipación crónica en comparación con el tratamiento habitual. Tras realizar una búsqueda de estudios que analizaran los efectos del consumo de kiwi sobre el hábito intestinal, fueron seleccionados tres artículos que permiten concluir que el consumo de esta fruta tiene una eficacia superior al placebo y comparable al psyllium y las pasas de ciruela para mejorar los síntomas de personas con estreñimiento crónico. (AU)

Based on the case of a patient with constipation-predominant irritable bowel syndrome whose symptoms improved with regular consumption of kiwi, the family doctor wondered if kiwi could improve symptoms associated with chronic constipation compared to usual treatment. After conducting a search for studies that analyzed the effects of kiwi consumption on intestinal habit, three articles were selected that allow us to conclude that the consumption of this fruit has an efficacy superior to placebo and comparable to psyllium and plum raisins to improve the symptoms of people with chronic constipation. (AU)

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

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

Lactose Malabsorption and Presumed Related Disorders: A Review of Current Evidence.

BACKGROUND: Lactose malabsorption (LM) is a frequent clinical problem associated with several digestive and extra-digestive diseases. The aim of this manuscript was to clarify the real clinical impact of LM on these disorders. METHODS: A literature search for digestive and extra-digestive disorders related to LM was carried out using PubMed, Medline and Cochrane. RESULTS: A transient lactase deficiency is present in celiac disease (CD) on a normal diet. The persistence of symptoms in CD on a gluten-free diet may be instead, in part, attributed to a primary LM. Similar circumstances are present in inflammatory bowel diseases (IBD), in which LM can be responsible for a part of persistent symptoms in IBD on clinical remission. LM and irritable bowel syndrome (IBS) are instead independent conditions. On the other hand, a lactose-restricted diet may be useful for some IBS patients. A reduced lactose intake can lead to low bone mass and limited risk of fragility fractures. Finally, the absorption of levothyroxine could be conditioned by LM. CONCLUSIONS: LM can be responsible for persistent symptoms in CD and IBD. The association with IBS seems to be casual. Bone mass and levothyroxine absorption can be affected by LM.

The Ketogenic Diet Improves Gut-Brain Axis in a Rat Model of Irritable Bowel Syndrome: Impact on 5-HT and BDNF Systems.

Altered gut-brain communication can contribute to intestinal dysfunctions in the intestinal bowel syndrome. The neuroprotective high-fat, adequate-protein, low-carbohydrate ketogenic diet (KD) modulates the levels of different neurotransmitters and neurotrophins. The aim was to evaluate the effects of KD on levels of 5-HT, the receptors 5-HT3B and 5-HT4, the 5-HT transporter SERT, the neurotrophin BDNF, and its receptor TrkB in the colon and brain of a rat model of irritable bowel syndrome (IBS). Samples from Wistar rats exposed to maternal deprivation as newborns and then fed with a standard diet (IBS-Std) or KD (IBS-KD) for ten weeks were analyzed. As controls, unexposed rats (Ctrl-Std and Ctrl-KD) were studied. IBS-Std rats had a disordered enteric serotoninergic signaling shown by increased mucosal 5-HT content and reduced SERT, 5-HT3B, and 5-HT4 levels compared to controls. In the brain, these animals showed up-regulation of the BDNF receptor TrkB as a counteracting response to the stress-induced reduction of the neurotrophin. KD showed a dual effect in improving the altered 5-HT and BDNF systems. It down-regulated the increased mucosal 5-HT without affecting transporter and receptor levels. KD improved brain BDNF levels and established negative feedback, leading to a compensatory downregulation of TrkB to maintain a physiological steady state.

Predictors of Symptom-Specific Treatment Response to Dietary Interventions in Irritable Bowel Syndrome.

(1) Background: Predictors of dietary treatment response in irritable bowel syndrome (IBS) remain understudied. We aimed to investigate predictors of symptom improvement during the low FODMAP and the traditional IBS diet for four weeks. (2) Methods: Baseline measures included faecal Dysbiosis Index, food diaries with daily energy and FODMAP intake, non-gastrointestinal (GI) somatic symptoms, GI-specific anxiety, and psychological distress. Outcomes were bloating, constipation, diarrhea, and pain symptom scores treated as continuous variables in linear mixed models. (3) Results: We included 33 and 34 patients on the low FODMAP and traditional IBS diet, respectively. Less severe dysbiosis and higher energy intake predicted better pain response to both diets. Less severe dysbiosis also predicted better constipation response to both diets. More severe psychological distress predicted worse bloating response to both diets. For the different outcomes, several differential predictors were identified, indicating that baseline factors could predict better improvement in one treatment arm, but worse improvement in the other treatment arm. (4) Conclusions: Psychological, nutritional, and microbial factors predict symptom improvement when following the low FODMAP and traditional IBS diet. Findings may help individualize dietary treatment in IBS.

Narrative review: Risk of eating disorders and nutritional deficiencies with dietary therapies for irritable bowel syndrome.

BACKGROUND AND AIMS: Dietary treatments are growing in popularity as interventions for chronic digestive conditions. Patients with irritable bowel syndrome (IBS) often change their eating behaviors to mitigate symptoms. This can occur under the direction of their physician, a dietitian, or be self-directed. Poorly implemented and monitored diet treatments occur frequently with considerable risks for negative consequences. We aim to review the literature related to dietary treatments and risks associated with nutritional deficiencies and disordered eating. METHODS: Searches were conducted from June to December 2020 on PubMed, MEDLINE, EMBASE, DARE and the Cochrane Database of Systematic Reviews using relevant keywords based on the Patient, Intervention, Comparator and Outcome (PICO) format. Studies included both adult and pediatric populations. Results are synthesized into a narrative review. RESULTS: While dietary approaches are efficacious in many research studies, their translation to clinical practice has been less clear. Patients with IBS are at risk for nutritional deficiencies, disordered eating, increased anxiety, and decreases in quality of life in both adult and pediatric groups. CONCLUSIONS: Physicians prescribing dietary treatment for IBS should be aware of nutritional and psychological risks and implement mitigation measures. These include using a combination of brief, validated questionnaires and clinical history, and collaboration with registered dietitians and/or psychologists. Recommendations for clinical decisions are provided.

Efficacy of a low FODMAP diet in irritable bowel syndrome: systematic review and network meta-analysis.

OBJECTIVE: A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) is recommended for irritable bowel syndrome (IBS), if general lifestyle and dietary advice fails. However, although the impact of a low FODMAP diet on individual IBS symptoms has been examined in some randomised controlled trials (RCTs), there has been no recent systematic assessment, and individual trials have studied numerous alternative or control interventions, meaning the best comparator is unclear. We performed a network meta-analysis addressing these uncertainties. DESIGN: We searched the medical literature through to 2 April 2021 to identify RCTs of a low FODMAP diet in IBS. Efficacy was judged using dichotomous assessment of improvement in global IBS symptoms or improvement in individual IBS symptoms, including abdominal pain, abdominal bloating or distension, and bowel habit. Data were pooled using a random effects model, with efficacy reported as pooled relative risks (RRs) with 95% CIs, and interventions ranked according to their P-score. RESULTS: We identified 13 eligible RCTs (944 patients). Based on failure to achieve an improvement in global IBS symptoms, a low FODMAP diet ranked first vs habitual diet (RR of symptoms not improving=0.67; 95% CI 0.48 to 0.91, P-score=0.99), and was superior to all other interventions. Low FODMAP diet ranked first for abdominal pain severity, abdominal bloating or distension severity and bowel habit, although for the latter it was not superior to any other intervention. A low FODMAP diet was superior to British Dietetic Association (BDA)/National Institute for Health and Care Excellence (NICE) dietary advice for abdominal bloating or distension (RR=0.72; 95% CI 0.55 to 0.94). BDA/NICE dietary advice was not superior to any other intervention in any analysis. CONCLUSION: In a network analysis, low FODMAP diet ranked first for all endpoints studied. However, most trials were based in secondary or tertiary care and did not study effects of FODMAP reintroduction and personalisation on symptoms.

Fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs), but not gluten, elicit modest symptoms of irritable bowel syndrome: a double-blind, placebo-controlled, randomized three-way crossover trial.

BACKGROUND: Irritable bowel syndrome (IBS) has been associated with diets rich in fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs), and gluten. Most previous studies have been single-blind and have focused on the elimination of FODMAPs or provocation with single FODMAPs. The effect of gluten is unclear, large trials isolating the effect of gluten from that of FODMAPs are needed. OBJECTIVES: The aims of this study were to ensure high intakes of a wide range of FODMAPs, gluten, or placebo, and to evaluate the effects on IBS symptoms using the IBS-severity scoring system (IBS-SSS). METHODS: The study was carried out with a double-blind, placebo-controlled, randomized 3-way crossover design in a clinical facility in Uppsala from September 2018 to June 2019. In all, 110 participants fulfilling the IBS Rome IV criteria, with moderate to severe IBS, were randomly assigned; 103 (90 female, 13 male) completed the trial. Throughout, IBS participants maintained a diet with minimal FODMAP content and no gluten. Participants were block-randomly assigned to 1-wk interventions with FODMAPs (50 g/d), gluten (17.3 g/d), or placebo, separated by 1-wk washout. All participants who completed ≥1 intervention were included in the intention-to-treat analysis. RESULTS: In participants with IBS (n = 103), FODMAPs caused higher IBS-SSS scores (mean 240 [95% CI: 222, 257]) than placebo (198 [180, 215]; P = 0.00056) or gluten (208 [190, 226]; P = 0.013); no differences were found between the placebo and gluten groups (P = 1.0). There were large interindividual differences in IBS-SSS scores associated with treatment. No adverse events were reported. CONCLUSION: In participants with IBS, FODMAPs had a modest effect on typical IBS symptoms, whereas gluten had no effect. The large interindividual differences in responses to the interventions warrant further detailed studies to identify possible underlying causes and enable individual prediction of responses. This trial was registered at www.clinicaltrials.gov as NCT03653689.

Diarrhea-Predominant and Constipation-Predominant Irritable Bowel Syndrome: Current Prescription Drug Treatment Options.

Irritable bowel syndrome (IBS) is a heterogenous disease with a variety of therapeutic options, including eight prescription drugs approved for use in IBS in the USA. Choosing among the myriad treatment options requires attention to patient preferences both on clinical outcomes and costs associated with treatment. We performed a narrative review of the literature to summarize these important determinants of treatment choice including: labeled indications; clinical profiles of efficacy, safety, and tolerability of prescription drugs; and cost-effectiveness for diarrhea-predominant IBS drugs (IBS-D: alosetron, eluxadoline, and rifaximin) and constipation-predominant IBS drugs (IBS-C: linaclotide, lubiprostone, plecanatide, tegaserod, and tenapanor). We then review the standard model of shared decision-making aimed at guiding an informed, patient-centered discussion to integrate comparative clinical and cost outcomes toward choosing an IBS treatment in practice.

Association between Self-Reported Gluten Avoidance and Irritable Bowel Syndrome: Findings of the NutriNet-Santé Study.

Self-management of irritable bowel syndrome (IBS) is increasingly focusing on exclusion diets. In particular; patients are showing a significant interest in the gluten-free diet for the treatment of IBS. However; the lack of scientific evidence prevents the establishment of clear dietary guidelines and attention is needed as dietary restriction can lead to potentially adverse effects. This cross-sectional study aims to explore the practice of gluten avoidance in participants identified with IBS in a large cohort of non-celiac French adults. The population included 15,103 participants of the NutriNet-Santé study who completed a functional gastrointestinal disorder questionnaire based on the Rome III criteria to identify IBS in 2013 and a food avoidance questionnaire in 2016. Data on diet and anthropometric and sociodemographic characteristics were collected. Multivariate logistic regression models were used to compare the avoidance of gluten between IBS and non-IBS participants. Participants were mainly women (73.4%) and the mean age in this population was 55.8 ± 13.2 years. Among these individuals, 804 (5.4%) participants were identified as IBS cases. Among them, the prevalence of gluten avoidance was estimated at 14.8%, of which 3.0% reported total avoidance; versus 8.8% and 1.6% in non-IBS participants. After adjustments; gluten avoidance was higher in IBS participants compared to their non-IBS counterparts: (OR = 1.86; 95%CI = 1.21, 2.85) for total and (OR = 1.71; 95%CI = 1.36, 2.14) for partial avoidance. Participants identified with IBS were more associated with gluten avoidance than non-IBS participants. Further studies are needed to explore the long-term consequences of dietary interventions and to provide consistent dietary guidance connected to patient perception.

Changes in serum and urinary metabolomic profile after a dietary intervention in patients with irritable bowel syndrome.

BACKGROUND: Irritable bowel syndrome (IBS) is a multi-faceted gastrointestinal disorder where food intake often triggers symptoms. Metabolomics may provide mechanistical insights to why responses to dietary modifications are diverse. OBJECTIVE: This study aimed to identify metabolite patterns related to dietary intake in patients with IBS, and to identify metabolites driving the separation between responders and non-responders to treatment. METHODS: Participants were randomized to a low fermentable oligo-, di-, monosaccharide and polyol (FODMAP) diet (LFD) or traditional IBS diet (TID) for four weeks. Fasting serum and urine samples pre- and post-intervention were analyzed using 1H nuclear magnetic resonance (NMR) metabolomics. Response to treatment was defined as a reduction in IBS severity scoring system (IBS-SSS) ≥50. RESULTS: Twenty-five individuals in the LFD (13 responders) and 28 in the TID (14 responders) were included in these post hoc analyses. In endpoint samples, significant decreases in polyols and glucose were seen in the LFD. Post-intervention samples revealed that LFD responders had significantly increased levels of 2-hydroxybuturate and decreased levels of glucose and pantothenic acid compared to non-responders. For the TID, only weak multivariate models were identified and a larger diversity in metabolite response compared to the LFD were noted. CONCLUSIONS: In this study, metabolite patterns between individuals who responded well to an LFD compared to non-responders could be distinguished. This provides new hypotheses for mechanistic actions related to response to dietary modifications, but the results need to be validated in larger cohorts. CLINICAL TRIAL REGISTRATION: This trial was registered at www.clinicaltrials.gov, registry number NCT02107625.

High FODMAP diet causes barrier loss via lipopolysaccharide-mediated mast cell activation.

Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) are carbohydrates thought to contribute to the symptoms of IBS. A diet in high in FODMAPs (HFM) induces gastrointestinal symptoms in patients with irritable bowel syndrome (IBS), and a diet low in FODMAPs (LFM) improves symptoms in up to 60% of patients with IBS. However, the mechanism by which FODMAPs affect IBS symptoms is unclear. We showed that mice fed on a HFM diet have mast cell activation and colonic barrier loss. Using mast cell-deficient mice with and without mast cell reconstitution, we showed that HFM-mediated colonic barrier loss is dependent on TLR4-dependent mast cell activation. In in vitro studies, we demonstrated that IBS fecal supernatant stimulates mast cells significantly more compared with fecal supernatant from healthy controls. This effect of IBS fecal supernatant on mast cell stimulation is ameliorated in the absence of the TLR4 receptor and after a LFM diet. We found that a LFM diet improves colonic barrier function and reduces mast cell activation while decreasing fecal LPS levels. Our findings indicate that a HFM diet causes mast cell activation via LPS, which in turn leads to colonic barrier loss, and a LFM diet reverses these pathophysiologic mucosal changes.

Probiotics, Prebiotics, and Synbiotics in the Irritable Bowel Syndrome Treatment: A Review.

Irritable bowel syndrome is not a life-threatening disease, yet it significantly affects the quality of life and contributes to economic loss. It is estimated that even up to 45% of the world's population can suffer from the disease. The first attempts to diagnose irritable bowel syndrome were made at the end of the 19th century; however, establishing appropriate diagnostic criteria and treatment methods is still ongoing. To date, little is known about the etiology of irritable bowel syndrome; however, growing attention is drawn to the intestinal microbiota as a factor in the disease development. For this reason, researchers have conducted many studies on therapies that modulate the microbiota, among which probiotics, prebiotics, and synbiotics are widely studied. To date, most studies have examined probiotics; however, there are also several studies demonstrating the efficacy of prebiotics and synbiotics. The aim of this review was to summarize findings on the usefulness of probiotics, prebiotics, and synbiotics in the treatment of irritable bowel syndrome.

Effect of Low FODMAPs Diet on Irritable Bowel Syndromes: A Systematic Review and Meta-Analysis of Clinical Trials.

We conducted a meta-analysis exploring the effect of a low fermentable oligo-, di-, monosaccharides, and polyols diet (LFD) on the overall symptoms, quality of life, and stool habits of irritable bowel syndrome (IBS) patients. The meta-analysis was performed using a random-effects method. The effect size was presented as weighted standardized mean difference (SMD) and 95% confidence interval (CI). Subgroup analyses were conducted to determine the potential effects of covariates on the outcome. Twenty-two papers were included. The LFD group showed a moderate reduction in symptom severity and a slight improvement in quality of life compared to the control group (SMD, -0.53 and 0.24; 95% CI, -0.68, -0.38 and 0.02, 0.47, respectively). IBS symptom improvement was consistent between subgroups stratified according to proportions of female patients, study durations, IBS subtypes, assessment methods, and control interventions. Three studies regarding stool habits change in IBS-D patients showed a significant decrease in stool frequency (mean differences [MD], -5.56/week; 95% CI, -7.40, -3.72) and a significant improvement in stool consistency (MD, -0.86; 95% CI, -1.52, -0.19) in the LFD group compared to the control group. This is the most updated meta-analysis including studies that adopted diverse control interventions such as dietary interventions, supplementation, habitual diets, and lifestyle changes.

Psychological and Gastrointestinal Symptoms of Patients with Irritable Bowel Syndrome Undergoing a Low-FODMAP Diet: The Role of the Intestinal Barrier.

A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (LFD) improves both gastrointestinal (GI) symptoms and the psychological profile of patients with irritable bowel syndrome with diarrhea (IBS-D). The effects of 12 weeks of LFD on GI symptom and psychological profiles in relation to inflammation and the involvement of the intestinal barrier were studied in twenty IBS-D patients. The IBS Severity Scoring System, the Symptom Checklist-90-Revised, the Italian version of the 36-Item Short-Form Health Survey, the IBS-Quality of Life (QoL) questionnaire, and the Psychophysiological questionnaire were administered. The GI barrier function was assessed by sugar absorption test, the serum and fecal zonulin levels, and the serum levels of intestinal fatty-acid binding protein and diamine oxidase. Interleukins (ILs) and lipopolysaccharide (LPS) serum levels were evaluated along with dysbiosis. At the end of LFD, GI symptoms, psychological state (mainly anxiety, somatization, psychoticism, and interpersonal sensitivity), and QoL significantly improved in these patients. Simultaneously, an improvement in small intestinal permeability and intestinal mucosal integrity occurred, while IL-6, Il-10, LPS, and fermentative dysbiosis significantly decreased. The LFD can modify the immune-inflammatory features and enhance intestinal permeability and mucosal integrity, thus determining a concurrent improvement in the clinical and psychological conditions.

Probiotics, Prebiotics, and Synbiotics: Implications and Beneficial Effects against Irritable Bowel Syndrome.

Irritable bowel syndrome (IBS) is still a common functional gastrointestinal disease that presents chronic abdominal symptoms but with a pathophysiology that is not yet fully elucidated. Moreover, the use of the synergistic combination of prebiotics and probiotics, known as synbiotics, for IBS therapy is still in the early stages. Advancements in technology led to determining the important role played by probiotics in IBS, whereas the present paper focuses on the detailed review of the various pathophysiologic mechanisms of action of probiotics, prebiotics, and synbiotics via multidisciplinary domains involving the gastroenterology (microbiota modulation, alteration of gut barrier function, visceral hypersensitivity, and gastrointestinal dysmotility) immunology (intestinal immunological modulation), and neurology (microbiota-gut-brain axis communication and co-morbidities) in mitigating the symptoms of IBS. In addition, this review synthesizes literature about the mechanisms involved in the beneficial effects of prebiotics and synbiotics for patients with IBS, discussing clinical studies testing the efficiency and outcomes of synbiotics used as therapy for IBS.

Long-Term Effect of a Gluten-Free Diet on Diarrhoea- or Bloating-Predominant Functional Bowel Disease: Role of the 'Low-Grade Coeliac Score' and the 'Coeliac Lymphogram' in the Response Rate to the Diet.

1. BACKGROUND: The long-term effect of a gluten-free diet (GFD) on functional bowel disorders (FBDs) has been scarcely studied. The aim was to assess the effect of a GFD on FBD patients, and to assess the role of both the low-grade coeliac score and coeliac lymphogram in the probability of response to a GFD. 2. METHODS: 116 adult patients with either predominant diarrhoea or abdominal bloating, fulfilling Rome IV criteria of FBD, were treated with a GFD. Duodenum biopsies were performed for both pathology studies and intraepithelial lymphocyte subpopulation patterns. Coeliac lymphogram was defined as an increase in TCRγδ+ cells plus a decrease in CD3- cells. A low-grade coeliac score >10 was considered positive. 3. RESULTS: Sustained response to GFD was observed in 72 patients (62%) after a median of 21 months of follow-up, who presented more often with coeliac lymphogram (37.5 vs. 11.4%; p = 0.02) and a score >10 (32 vs. 11.4%; p = 0.027) compared to non-responders. The frequency of low-grade coeliac enteropathy was 19.8%. 4. CONCLUSION: A GFD is effective in the long-term treatment of patients with previously unexplained chronic watery diarrhoea- or bloating-predominant symptoms fulfilling the criteria of FBD. The response rate was much higher in the subgroup of patients defined by the presence of both a positive low-grade coeliac score and coeliac lymphogram.