Coffee, Alcohol, and Artificial Sweeteners Have Temporal Associations with Gastrointestinal Symptoms.

BACKGROUND: Various dietary strategies for managing irritable bowel syndrome (IBS) target mechanisms such as brain-gut interactions, osmotic actions, microbial gas production, and local immune activity. These pathophysiological mechanisms are diverse, making it unclear which foods trigger IBS symptoms for a substantial proportion of patients. AIM: To identify associations between foods and gastrointestinal symptoms. METHODS: From the mySymptoms smartphone app, we collected anonymized diaries of food intake and symptoms (abdominal pain, diarrhea, bloating, and gas). We selected diaries that were at least 3 weeks long. The diaries were analyzed for food-symptom associations using a proprietary algorithm. As the participants were anonymous, we conducted an app-wide user survey to identify IBS diagnoses according to Rome IV criteria. RESULTS: A total of 9,710 food symptom diaries that met the quality criteria were collected. Of the survey respondents, 70% had IBS according to Rome IV criteria. Generally, strong associations existed for caffeinated coffee (diarrhea, 1-2 h postprandial), alcoholic beverages (multiple symptoms, 4-72 h postprandial), and artificial sweeteners (multiple symptoms, 24-72 h postprandial). Histamine-rich food intake was associated with abdominal pain and diarrhea. Some associations are in line with existing literature, whilst the absence of an enriched FODMAP-symptom association contrasts with current knowledge. CONCLUSIONS: Coffee, alcohol, and artificial sweeteners were associated with GI symptoms in this large IBS-predominant sample. Symptom onset is often within 2 h postprandial, but some foods were associated with a delayed response, possibly an important consideration in implementing dietary recommendations. Clinical trials must test the causality of the demonstrated food-symptom associations.

Food Avoidance and Restriction in Irritable Bowel Syndrome: Relevance for Symptoms, Quality of Life and Nutrient Intake.

BACKGROUND & AIMS: Neither food intake nor the clinical characteristics of irritable bowel syndrome (IBS) patients with severe food avoidance and restriction have been investigated. The aim of our study was to identify those patients and to characterize their symptoms, quality of life, and nutrient intake. METHODS: IBS patients who completed the IBS Quality of Life Instrument (IBS-QOL) at our secondar and tertiary center were included. The 3 questions constituting the food domain were used to identify patients with reported severe food avoidance and restriction. The patients also completed validated questionnaires to assess stool form (Bristol Stool Form), gastrointestinal (GI) symptom severity (z score of IBS Severity Scoring System and Gastrointestinal Symptom Rating Scale-IBS), psychological distress (Hospital Anxiety and Depression Scale), GI-specific anxiety (Visceral Sensitivity Index), and somatic symptom severity (z score of Symptom Checklist-90-Revised and Patient Health Questionnaire-15). A 4-day food diary was used to analyze food intake in 246 patients. RESULTS: We included 955 IBS patients (75 % women; mean age 38.3 ± 13.3 years). In total, 13.2 % of the patients reported severe food avoidance and restriction, and in these patients all aspects of quality of life were lower (P < .01) and psychological, GI, and somatic symptoms were more severe (P < .05). Reported severe food avoidance and restriction was associated with lower total energy intake (P = .002) and lower intake of protein (P = .001) and carbohydrates (P = .005). In a logistic regression analysis, loose stools were found to be independently associated with reported severe food avoidance and restriction (R2 = 0.062). CONCLUSIONS: IBS patients with severe food avoidance and restriction constitute a subgroup with more severe symptoms overall, reduced quality of life, and reduced intake of nutrients. This needs to be acknowledged in the clinical management of these patients.

Global prevalence and burden of meal-related abdominal pain.

BACKGROUND: Patients with disorders of gut-brain interaction (DGBI) report meal intake to be associated with symptoms. DGBI patients with meal-related symptoms may have more severe symptoms overall and worse health outcomes, but this subgroup has not been well characterized. We aimed to describe the global prevalence of meal-related abdominal pain and characterize this subgroup. METHODS: The data analyzed originated from the Internet survey component of the population-based Rome Foundation Global Epidemiology Study, completed in 26 countries (n = 54,127). Adult subjects were asked whether they had abdominal pain and how often this was meal-related. Respondents were categorized into "no," "occasional," and "frequent" meal-related abdominal pain groups based on 0%, 10-40%, and ≥50% of the pain episodes being meal-related, respectively. DGBI diagnoses, frequency of other GI symptoms, psychological distress, non-GI somatic symptoms, quality of life, and healthcare utilization were compared between groups. Mixed linear and ordinal regression was used to assess independent associations between psychological distress, non-GI somatic symptoms, quality of life, other GI symptoms, and meal-related abdominal pain. RESULTS: Overall, 51.9% of the respondents reported abdominal pain in the last 3 months, and 11.0% belonged to the group with frequent meal-related abdominal pain, which included more females and younger subjects. DGBI diagnoses were more common in subjects with frequent meal-related abdominal pain, and the frequency of several GI symptoms was associated with having more frequent meal-related abdominal pain. Having meal-related abdominal pain more frequently was also associated with more severe psychological distress, non-GI somatic symptoms, and a poorer quality of life. The group with frequent meal-related abdominal pain also more often consulted a doctor for bowel problems compared to the other groups of meal-related abdominal pain. CONCLUSION: Reporting frequent meal-related abdominal pain is common across the globe and associated with other GI and non-GI somatic symptoms, psychological distress, healthcare utilization, and a poorer quality of life. Individuals who frequently experience meal-related abdominal pain also more frequently fulfill the diagnostic criteria for DGBI. Assessing meal-related symptoms in all DGBI patients could be of major importance to improve and individualize symptom management.

Online Education Is Non-Inferior to Group Education for Irritable Bowel Syndrome: A Randomized Trial and Patient Preference Trial.

BACKGROUND & AIMS: Structured education can reduce symptoms in patients with irritable bowel syndrome (IBS), but the availability of such interventions is limited and online formats could facilitate their dissemination. We compared the effectiveness of Internet-delivered vs face-to-face education in patients with IBS, hypothesizing that the online format would not be inferior. METHODS: We conducted 2 trials of Internet-delivered vs face-to-face group education (3 weeks) at a gastroenterology outpatient clinic in Sweden. In the first trial, 141 patients with IBS were assigned randomly (1:1) to either Internet-delivered or face-to-face education, from August 2016 through June 2017. In the second trial, 155 patients with IBS were allowed to choose whether to receive education via the Internet or face to face, from August 2017 through September 2018. Patients completed questionnaires before, during, and after education. The primary outcome measure was the irritable bowel syndrome severity scoring system, which measures IBS severity on a scale from 0 to 500, based on abdominal pain, bloating, dissatisfaction with bowel habits, and interference with life. The primary test of noninferiority adhered to the intent-to-treat principle and concerned the difference in change up to 6 months after education, tested using the 1-sided CI for the time by group interaction in a linear mixed model fitted on data from the randomized controlled trial. A secondary per-protocol analysis used data from all treatment completers in both trials. The noninferiority margin was 40 points on the irritable bowel syndrome severity scoring system. RESULTS: In the primary analysis, patients who received face-to-face education had an average reduction in irritable bowel syndrome severity score that was 12.2 points more than that of patients who received Internet education (1-sided 95% CI upper bound, 38.4). In the per-protocol analysis, patients who received face-to-face education reduced their average irritable bowel syndrome severity score by 14.7 points more than patients who received Internet education (95% CI upper bound, 35.5). Face-to-face education had significantly higher credibility and produced a significantly larger increase in self-rated knowledge, although most patients preferred Internet-delivered education. Between-group effects on secondary symptoms were small. CONCLUSIONS: Based on the comparison of Internet-delivered vs face-to-face education for IBS, the upper bound of the CI for the difference in change up to 6 months after education was within the noninferiority margin of 40 points. We therefore conclude that Internet-delivered education is noninferior to face-to-face education. Future research should focus on increasing within-group effects. ClinicalTrials.gov no: NCT03466281.

Multivariate modelling of faecal bacterial profiles of patients with IBS predicts responsiveness to a diet low in FODMAPs.

OBJECTIVE: The effects of dietary interventions on gut bacteria are ambiguous. Following a previous intervention study, we aimed to determine how differing diets impact gut bacteria and if bacterial profiles predict intervention response. DESIGN: Sixty-seven patients with IBS were randomised to traditional IBS (n=34) or low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) (n=33) diets for 4 weeks. Food intake was recorded for 4 days during screening and intervention. Faecal samples and IBS Symptom Severity Score (IBS-SSS) reports were collected before (baseline) and after intervention. A faecal microbiota dysbiosis test (GA-map Dysbiosis Test) evaluated bacterial composition. Per protocol analysis was performed on 61 patients from whom microbiome data were available. RESULTS: Responders (reduced IBS-SSS by ≥50) to low FODMAP, but not traditional, dietary intervention were discriminated from non-responders before and after intervention based on faecal bacterial profiles. Bacterial abundance tended to be higher in non-responders to a low FODMAP diet compared with responders before and after intervention. A low FODMAP intervention was associated with an increase in Dysbiosis Index (DI) scores in 42% of patients; while decreased DI scores were recorded in 33% of patients following a traditional IBS diet. Non-responders to a low FODMAP diet, but not a traditional IBS diet had higher DI scores than responders at baseline. Finally, while a traditional IBS diet was not associated with significant reduction of investigated bacteria, a low FODMAP diet was associated with reduced Bifidobacterium and Actinobacteria in patients, correlating with lactose consumption. CONCLUSIONS: A low FODMAP, but not a traditional IBS diet may have significant impact on faecal bacteria. Responsiveness to a low FODMAP diet intervention may be predicted by faecal bacterial profiles. TRIAL REGISTRATION NUMBER: NCT02107625.

Identification of an Intestinal Microbiota Signature Associated With Severity of Irritable Bowel Syndrome.

BACKGROUND & AIMS: We have limited knowledge about the association between the composition of the intestinal microbiota and clinical features of irritable bowel syndrome (IBS). We collected information on the fecal and mucosa-associated microbiota of patients with IBS and evaluated whether these were associated with symptoms. METHODS: We collected fecal and mucosal samples from adult patients who met the Rome III criteria for IBS at a secondary/tertiary care outpatient clinics in Sweden, as well as from healthy subjects. The exploratory set comprised 149 subjects (110 with IBS and 39 healthy subjects); 232 fecal samples and 59 mucosal biopsy samples were collected and analyzed by 16S ribosomal RNA targeted pyrosequencing. The validation set comprised 46 subjects (29 with IBS and 17 healthy subjects); 46 fecal samples, but no mucosal samples, were collected and analyzed. For each subject, we measured exhaled H2 and CH4, oro-anal transit time, and the severity of psychological and gastrointestinal symptoms. Fecal methanogens were measured by quantitative polymerase chain reaction. Numerical ecology analyses and a machine learning procedure were used to analyze the data. RESULTS: Fecal microbiota showed covariation with mucosal adherent microbiota. By using classic approaches, we found no differences in fecal microbiota abundance or composition between patients with IBS vs healthy patients. A machine learning procedure, a computational statistical technique, allowed us to reduce the 16S ribosomal RNA data complexity into a microbial signature for severe IBS, consisting of 90 bacterial operational taxonomic units. We confirmed the robustness of the intestinal microbial signature for severe IBS in the validation set. The signature was able to discriminate between patients with severe symptoms, patients with mild/moderate symptoms, and healthy subjects. By using this intestinal microbiota signature, we found IBS symptom severity to be associated negatively with microbial richness, exhaled CH4, presence of methanogens, and enterotypes enriched with Clostridiales or Prevotella species. This microbiota signature could not be explained by differences in diet or use of medications. CONCLUSIONS: In analyzing fecal and mucosal microbiota from patients with IBS and healthy individuals, we identified an intestinal microbiota profile that is associated with the severity of IBS symptoms. TRIAL REGISTRATION NUMBER: NCT01252550.

Depression and Somatization Are Associated With Increased Postprandial Symptoms in Patients With Irritable Bowel Syndrome.

BACKGROUND & AIMS: Patients with irritable bowel syndrome (IBS) have increased postprandial symptom responses and more psychosocial morbidities than healthy individuals. However, the relationship between psychosocial status and postprandial symptom responses in patients with IBS is unclear. We investigated this relationship in a prospective study of patients with IBS. METHODS: A total of 193 IBS patients, diagnosed according to Rome II (n = 126) or Rome III (n = 67) criteria, consumed a standard breakfast (540 kcal: 36% fat, 15% proteins, 49% carbohydrates, and 8.9 g fiber). They completed visual analogue scales assessing the severity of 5 gastrointestinal symptoms (abdominal pain, bloating, nausea, gas, and fullness) before breakfast and every 30 minutes, up to 240 minutes after eating. All patients completed validated self-report questionnaires for their current levels of anxiety and depression; patients diagnosed based on Rome II criteria also completed a somatization questionnaire. The relationship between these variables and the course of gastrointestinal symptom scores over time was analyzed using linear mixed models, controlling for comorbid functional dyspepsia. RESULTS: We observed a main effect of anxiety levels on fullness and bloating (P < .04), and of depression levels on abdominal pain (P = .007), reflecting a general upward shift of the entire symptom curve. Depression-by-time interactions were seen for nausea and gas (P < .03). Somatization levels had a main effect on all 5 symptoms (P < .0001), independent of anxiety and depression. We observed somatization-by-time interaction effects for bloating (P = .005), and nausea (P = .02), and a nonsignificant trend was found for pain (P = .054), reflecting a steeper early postprandial increase in symptoms among subjects with higher levels of somatization. CONCLUSIONS: Based on a prospective study of patients with IBS, psychosocial morbidities are associated with increased levels of gastrointestinal symptoms in general. Depression and somatization levels are associated specifically with increased postprandial symptoms.

Diet low in FODMAPs reduces symptoms of irritable bowel syndrome as well as traditional dietary advice: a randomized controlled trial.

BACKGROUND & AIMS: A diet with reduced content of fermentable short-chain carbohydrates (fermentable oligo-, di-, monosaccharides, and polyols [FODMAPs]) has been reported to be effective in the treatment of patients with irritable bowel syndrome (IBS). However, there is no evidence of its superiority to traditional dietary advice for these patients. We compared the effects of a diet low in FODMAPs with traditional dietary advice in a randomized controlled trial of patients with IBS. METHODS: We performed a multi-center, parallel, single-blind study of 75 patients who met Rome III criteria for IBS and were enrolled at gastroenterology outpatient clinics in Sweden. Subjects were randomly assigned to groups that ate specific diets for 4 weeks-a diet low in FODMAPs (n = 38) or a diet frequently recommended for patients with IBS (ie, a regular meal pattern; avoidance of large meals; and reduced intake of fat, insoluble fibers, caffeine, and gas-producing foods, such as beans, cabbage, and onions), with greater emphasis on how and when to eat rather than on what foods to ingest (n = 37). Symptom severity was assessed using the IBS Symptom Severity Scale, and patients completed a 4-day food diary before and at the end of the intervention. RESULTS: A total of 67 patients completed the dietary intervention (33 completed the diet low in FODMAPs, 34 completed the traditional IBS diet). The severity of IBS symptoms was reduced in both groups during the intervention (P < .0001 in both groups before vs at the end of the 4-week diet), without a significant difference between the groups (P = .62). At the end of the 4-week diet period, 19 patients (50%) in the low-FODMAP group had reductions in IBS severity scores ≥50 compared with baseline vs 17 patients (46%) in the traditional IBS diet group (P = .72). Food diaries demonstrated good adherence to the dietary advice. CONCLUSIONS: A diet low in FODMAPs reduces IBS symptoms as well as traditional IBS dietary advice. Combining elements from these 2 strategies might further reduce symptoms of IBS. ClinicalTrials.gov ID NCT02107625.

A small particle size diet reduces upper gastrointestinal symptoms in patients with diabetic gastroparesis: a randomized controlled trial.

OBJECTIVES: Gastroparesis is a well-known complication to diabetes mellitus (DM). Dietary advice is considered to be of importance to reduce gastrointestinal (GI) symptoms in patients with diabetic gastroparesis, but no randomized controlled trials exist. Our aim was to compare GI symptoms in insulin treated DM subjects with gastroparesis eating a diet with small particle size ("intervention diet") with the recommended diet for DM ("control diet"). METHODS: 56 subjects with insulin treated DM and gastroparesis were randomized to the intervention diet or the control diet. The patients received dietary advice by a dietitian at 7 occasions during 20 weeks. GI symptom severity, nutrient intake and glycemic control were measured before and after the intervention. RESULTS: A significantly greater reduction of the severity of the key gastroparetic symptoms-nausea/vomiting (P=0.01), postprandial fullness (P=0.02) and bloating (P=0.006)-were seen in patients who received the intervention diet compared with the control diet, and this was also true for regurgitation/heartburn (P=0.02), but not for abdominal pain. Anxiety was reduced after the intervention diet, but not after the control diet, whereas no effect on depression or quality of life was noted in any of the groups. A higher fat intake in the intervention group was noted, but otherwise no differences in body weight, HbA1c or nutrient intake were seen. CONCLUSIONS: A small particle diet improves the key symptoms of gastroparesis in patients with diabetes mellitus. (ClinicalTrials.gov NCT01557296).

Development of celiac-safe foods: prevention of transglutaminase 2 (TG2) deamidation of gluten in healthy non-celiac volunteers.

In celiac disease, intestinal transglutaminase (TG2) produces immunogenic peptides by deamidation of gluten proteins. These products drive the celiac immune response. We have previously identified an interaction between gliadin and a food additive, E304i, which prevents gliadin processing (both deamidation and transamidation) by TG2, in vitro. In this study, we investigated if E304i could prevent TG2 processing of gluten in flours and if the effect was evident after simulated gastrointestinal digestion. We also confirmed the outcome in vivo in a human cross-over intervention study in healthy non-celiac participants. TG2 transamidation experiments (in vitro) of digested wheat and rye flours supplemented with E304i at 30 mg/g indicated full prevention of TG2 processing. In the intervention study, participant serum levels of deamidated gliadin peptides (dGDPs) increased after the intake of reference wheat rolls (80 g per day for a week; 41% ± 4% compared to washout), while the intake of the intervention E304i/zinc sulfate wheat rolls generated a modest response (80 g per day for a week; 8 ± 10% of control). The difference between the groups (32.8 ± 15.6%) was significant (p = 0.00003, n = 9), confirming that E304i /zinc addition to wheat rolls prevented TG2 deamidation of gluten. In conclusion, this study shows that E304i /zinc addition to wheat rolls prevents TG2 deamidation of gluten in non-celiac participants. Clinical trial registration: clinicaltrials.gov, identifier (NCT06005376).

A low FODMAP diet plus traditional dietary advice versus a low-carbohydrate diet versus pharmacological treatment in irritable bowel syndrome (CARIBS): a single-centre, single-blind, randomised controlled trial.

BACKGROUND: Dietary advice and medical treatments are recommended to patients with irritable bowel syndrome (IBS). Studies have not yet compared the efficacy of dietary treatment with pharmacological treatment targeting the predominant IBS symptom. We therefore aimed to compare the effects of two restrictive dietary treatment options versus optimised medical treatment in people with IBS. METHODS: This single-centre, single-blind, randomised controlled trial was conducted in a specialised outpatient clinic at the Sahlgrenska University Hospital, Gothenburg, Sweden. Participants (aged ≥18 years) with moderate-to-severe IBS (Rome IV; IBS Severity Scoring System [IBS-SSS] ≥175) and no other serious diseases or food allergies were randomly assigned (1:1:1) by web-based randomisation to receive a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) plus traditional IBS dietary advice recommended by the UK National Institute for Health and Care Excellence (hereafter the LFTD diet), a fibre-optimised diet low in total carbohydrates and high in protein and fat (hereafter the low-carbohydrate diet), or optimised medical treatment based on predominant IBS symptom. Participants were masked to the names of the diets, but the pharmacological treatment was open-label. The intervention lasted 4 weeks, after which time participants in the dietary interventions were unmasked to their diets and encouraged to continue during 6 months' follow-up, participants in the LFTD group were instructed on how to reintroduce FODMAPs, and participants receiving pharmacological treatment were offered diet counselling and to continue with their medication. The primary endpoint was the proportion of participants who responded to the 4-week intervention, defined as a reduction of 50 or more in IBS-SSS relative to baseline, and was analysed per modified intention-to-treat (ie, all participants who started the intervention). Safety was analysed in the modified intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT02970591, and is complete. FINDINGS: Between Jan 24, 2017, and Sept 2, 2021, 1104 participants were assessed for eligibility and 304 were randomly assigned. Ten participants did not receive their intervention after randomisation and thus 294 participants were included in the modified intention-to-treat population (96 assigned to the LFTD diet, 97 to the low-carbohydrate diet, and 101 to optimised medical treatment). 241 (82%) of 294 participants were women and 53 (18%) were men and the mean age was 38 (SD 13). After 4 weeks, 73 (76%) of 96 participants in the LFTD diet group, 69 (71%) of 97 participants in the low-carbohydrate diet group, and 59 (58%) of 101 participants in the optimised medical treatment group had a reduction of 50 or more in IBS-SSS compared with baseline, with a significant difference between the groups (p=0·023). 91 (95%) of 96 participants completed 4 weeks in the LFTD group, 92 (95%) of 97 completed 4 weeks in the low-carbohydrate group, and 91 (90%) of 101 completed 4 weeks in the optimised medical treatment group. Two individuals in each of the intervention groups stated that adverse events were the reason for discontinuing the 4-week intervention. Five (5%) of 91 participants in the optimised medical treatment group stopped treatment prematurely due to side-effects. No serious adverse events or treatment-related deaths occurred. INTERPRETATION: Two 4-week dietary interventions and optimised medical treatment reduced the severity of IBS symptoms, with a larger effect size in the diet groups. Dietary interventions might be considered as an initial treatment for patients with IBS. Research is needed to enable personalised treatment strategies. FUNDING: The Healthcare Board Region Västra Götaland, the Swedish Research Council, the Swedish Research Council for Health, Working Life and Welfare, AFA Insurance, grants from the Swedish state, the Wilhelm and Martina Lundgren Science Foundation, Skandia, the Dietary Science Foundation, and the Nanna Swartz Foundation.

Self-reported food-related gastrointestinal symptoms in IBS are common and associated with more severe symptoms and reduced quality of life.

OBJECTIVES: Despite the fact that food and diet are central issues, that concern patients with irritable bowel syndrome (IBS), the current understanding about the association between the intake of certain foods/food groups and the gastrointestinal (GI) symptom pattern, psychological symptoms, and quality of life is poor. The aim of this study was to determine which food groups and specific food items IBS patients report causing GI symptoms, and to investigate the association with GI and psychological symptoms and quality of life. METHODS: We included 197 IBS patients (mean age 35 (18-72) years; 142 female subjects) who completed a food questionnaire in which they specified symptoms from 56 different food items or food groups relevant to food intolerance/allergy. The patients also completed questionnaires to assess depression and general anxiety (Hospital Anxiety and Depression), GI-specific anxiety (Visceral Sensitivity Index), IBS symptoms (IBS-Severity Scoring System), somatic symptoms (Patient Health Questionnaire-15), and quality of life (Irritable Bowel Syndrome Quality of Life Questionnaire). RESULTS: In all, 84% of the studied population reported symptoms related to at least one of the food items surveyed. Symptoms related to intake of food items with incompletely absorbed carbohydrates were noted in 138 (70%) patients; the most common were dairy products (49%), beans/lentils (36%), apple (28%), flour (24%), and plum (23%). Of these, 58% experienced GI symptoms from foods rich in biogenic amines, such as wine/beer (31%), salami (22%), and cheese (20%). Histamine-releasing foods, such as milk (43%), wine/beer (31%), and pork (21%), were also considered causes of symptoms in IBS patients. GI symptoms were also frequently reported after intake of fried and fatty foods (52%). With increasing IBS symptom severity, patients reported more food items responsible for their GI symptoms (P=0.004), and this was also found in patients with more severe somatic symptoms (P<0.0001). Women tended to report more food items causing symptoms than men (P=0.06). A high number of food items causing GI symptoms was also associated with reduced quality of life and this was significant for the following domains: sleep (r=-0.25; P=0.001), energy (r=-0.21; P=0.005), food (r=-0.29; P<0.001), social functioning (r=-0.23; P=0.001), and physical status (r=-0.16; P<0.05). However, the number of food items reported to provoke GI symptoms was unrelated to body mass index, age, IBS subtype, anxiety, depression, or GI-specific anxiety. CONCLUSIONS: The majority of IBS patients believe that certain food items are important triggers of their GI symptoms. This is especially true for foods containing carbohydrates and fat, and also may be relevant for histamine-releasing food items and foods rich in biogenic amines. Self-reported food intolerance is associated with high symptom burden and reduced quality of life.

Meditation over medication for irritable bowel syndrome? On exercise and alternative treatments for irritable bowel syndrome.

Complimentary alternative treatment regimens are widely used in irritable bowel syndrome (IBS), but the evidence supporting their use varies. For psychological treatment options, such as cognitive behavioral therapy, mindfulness, gut-directed hypnotherapy, and psychodynamic therapy, the evidence supporting their use in IBS patients is strong, but the availability limits their use in clinical practice. Dietary interventions are commonly included in the management of IBS patients, but these are primarily based on studies assessing physiological function in relation to dietary components, and to a lesser degree upon research examining the role of dietary components in the therapeutic management of IBS. Several probiotic products improve a range of symptoms in IBS patients. Physical activity is of benefit for health in general and recent data implicates its usefulness also for IBS patients. Acupuncture does not seem to have an effect beyond placebo in IBS. A beneficial effect of some herbal treatments has been reported.

The Role of Carbohydrates in Irritable Bowel Syndrome: Protocol for a Randomized Controlled Trial Comparing Three Different Treatment Options.

BACKGROUND: Although it is widely acknowledged that food intake can worsen symptoms in patients with irritable bowel syndrome (IBS), there is a lack of efficient treatments that can apply to all patients and subtypes of IBS. As IBS can manifest in different ways, it is likely that the most successful treatment option will differ among patients; therefore, this large, randomized controlled trial comparing 3 different treatment options for patients with IBS is highly warranted. OBJECTIVE: This study aims to conduct a randomized controlled trial to evaluate the effectiveness of 3 different treatment options for patients with IBS. METHODS: A total of 300 patients with IBS will be randomized (1:1:1) to receive one of the following three treatment options: a diet with low total carbohydrate content; a diet combining low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols and traditional dietary advice in IBS; and optimized medical treatment. The study will comprise a 10-day screening period, 28 days of intervention, and a 6-month follow-up for patients receiving dietary treatment. Questionnaires assessing both gastrointestinal and extraintestinal symptoms will be used as end points, as well as metabolomics, microbiota profiling, and immunological markers. Furthermore, qualitative methods will be used to evaluate the patients' experiences regarding diet treatments. RESULTS: Recruitment for this study began in January 2017. By May 2021, of the proposed 300 participants, 270 (90%) had been randomized, and 244 (81.3%) participants had finished the 4-week intervention. The study is still in progress, and the results are expected to be published in 2022. CONCLUSIONS: By collecting a wide range of data before, during, and after treatment in a large group of patients with IBS and diverse bowel habits, we will gain new insights into the predictors of response to treatment. That information can, in the future, be used to personalize treatment for the patient, based on the individual's phenotype and IBS symptoms. In addition, the long-term effects of 2 different dietary treatments will be evaluated regarding their impact on gut microbiota and clinical laboratory tests and to ensure that they are safe, effective, and applicable for patients with IBS. TRIAL REGISTRATION: ClinicalTrials.gov NCT02970591; https://clinicaltrials.gov/ct2/show/NCT02970591. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/31413.

Low FODMAP diet reduces gastrointestinal symptoms in irritable bowel syndrome and clinical response could be predicted by symptom severity: A randomized crossover trial.

BACKGROUND & AIMS: Fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) can provoke symptoms in patients with irritable bowel syndrome (IBS). We aimed to compare the effects of diets with low vs. moderate FODMAP content on gastrointestinal (GI) symptoms and bowel habits, and to identify possible predictors of clinical response to a low FODMAP diet and FODMAP sensitivity in IBS. METHODS: Adult participants with IBS (Rome IV criteria, n = 29) were included and adhered to two 7-day diet periods, with either low (4 g/day) or moderate (23 g/day) amounts of FODMAPs, in this randomized, double-blind, crossover study. The periods were separated by a wash-out period (≥14 days). IBS-Severity Scoring System (IBS-SSS) and a stool diary (Bristol Stool Form) were completed before and after the diet periods. At baseline, severity of GI symptoms and gut microbial fermentation were assessed (every 15 min, 4 h) during the Lactulose Nutrient Challenge Test (LNCT). Clinical response and FODMAP sensitivity were defined by reduction after low FODMAP period, and increase after moderate FODMAP period in IBS-SSS (≥50 points), respectively. RESULTS: Severity of GI symptoms (P = 0.04), stool consistency (P = 0.01), and stool frequency (P = 0.01) differed between the interventions, with reduced overall GI symptom severity, abdominal pain intensity and frequency, bowel habits dissatisfaction, and daily life interference (P < 0.05 for all), as well as more firm (P = 0.03) and less frequent (P < 0.01) stools after low FODMAP intervention, but not after moderate FODMAP intervention. A third (34%) responded clinically to the low FODMAP diet, and the response could be predicted by higher IBS-SSS at baseline (P = 0.02). Although modest associations between FODMAP sensitivity (22%) and GI symptoms during LNCT were observed, no independent predictors could be identified. CONCLUSIONS: A diet low in FODMAPs reduces GI symptoms and affects bowel habits in IBS, compared with a moderate FODMAP diet. Assessment of IBS severity before the intervention may be used to predict clinical response to a low FODMAP diet. Trial registry (http://www. CLINICALTRIALS: gov): Registered under Clinical Trial number NCT05182593.

Randomised controlled trial: effects of gluten-free diet on symptoms and the gut microenvironment in irritable bowel syndrome.

BACKGROUND: A gluten-free diet reduces symptoms in some patients with irritable bowel syndrome (IBS) through unclear mechanisms. AIMS: To assess the effects of gluten-free versus gluten-containing diet on symptoms and the gut microenvironment, and to identify predictors of response to the gluten-free diet in IBS METHODS: Twenty patients with IBS and 18 healthy controls (HC) followed a gluten-free diet during two 14-day intervention periods where they sprinkled either gluten (14 g/day) or rice flour powder over their meals. Primary outcomes included effects of the interventions on IBS symptoms (IBS-SSS) and bowel habits. Secondary outcomes included effects of gluten-free diet on faecal microbiota and metabolite profile. RESULTS: IBS symptoms improved during the gluten-free (p = 0.02), but not the gluten-containing period, with no difference between the interventions. IBS patients reported fewer loose stools during the gluten-free intervention (p = 0.01). Patients with IBS and HC presented distinct metabolite profiles based on the effects of the gluten-free diet (p < 0.001). True responders (reduced IBS-SSS by ≥50 solely after gluten-free period) and non-responders were discriminated based on the effects of the gluten-free diet on the microbiota (p < 0.01) and metabolite profiles (p < 0.001). The response to the gluten-free diet could be predicted by the metabolite profile before the intervention (p < 0.001). CONCLUSIONS: A gluten-free diet may influence symptoms in a subset of patients with IBS, with a particular effect on bowel habits. A gluten-free diet seems to impact the gut microenvironment. Responsiveness to the gluten-free diet may be predicted by the metabolite profile. CLINICALTRIALS: gov: NCT03869359.

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.

Effect of heavy exercise on gastrointestinal transit in endurance athletes.

BACKGROUND AND AIMS: Disturbances in transit of the gastrointestinal (GI) tract have been proposed to be involved in the etiology of the GI symptoms in heavy exercise. However, the results are conflicting. In the present study, we investigated the effect of heavy exercise on GI transit in well-trained athletes. METHODS: Fifteen healthy well-trained athletes underwent measurement of gastric emptying, small bowel transit and colonic transit with radiopaque markers during a resting week and during a week with heavy training. GI symptoms, bowel habits, food intake and exercise performed were registered. RESULTS: Small bowel transit was accelerated during the training period compared with the resting period (3.7 (2.6-12.3) h vs. 6.9 (4.2-17.2) h, p = 0.04). Segmental colonic transit in the descending colon was significantly accelerated during exercise compared with rest (0.1 (0-0.4) h vs. 0.4 (0.1-0.7) h, p = 0.03). Gastric emptying did not change during exercise compared with resting (2.4 (0.7-4.6) h vs. 1.8 (0.9-3.3) h, p = 0.16). Stool frequency increased significantly during the week with heavy exercise compared with the week without training (1.5 (1.2-1.8) stools/day vs. 1.3 (1.0-1.7) stools/day, p = 0.02). Stool consistency according to Bristol Stool Form Scale tended to be looser during the training period compared with the resting period (4.2 (3.7-4.5) vs. 3.9 (3.0-4.3), p = 0.08). CONCLUSION: Heavy exercise affects transit in the GI tract, which might be involved in the generation of GI symptoms and altered stool frequency/consistency in endurance athletes.

Gluten and fructan intake and their associations with gastrointestinal symptoms in irritable bowel syndrome: A food diary study.

BACKGROUND & AIMS: Wheat contains several components, including gluten and fructan, that may be associated with gastrointestinal symptoms (GI) in irritable bowel syndrome (IBS). The aims of the study were to determine the average daily intake of gluten, investigate the association of gluten and GI symptoms, as well as the association between fructan and GI symptoms in IBS subjects. METHODS: We assessed dietary intake, including total energy, and calculated average gluten and fructan intake in this 4-day food diary study. The subjects reported GI symptoms using the validated Gastrointestinal Symptom Rating Scale-IBS (GSRS-IBS). RESULTS: In total, 147 IBS subjects (116 females) were included in this study. The median (IQR) intake of gluten was 11.0 (7.5-15.4) (range: 0.6-52.1) g/day, and this intake was significantly higher for males (16.2 (11.5-18.8), g/day) compared with females (10.3 (7.3-13.2), g/day) (P ≤ 0.001). For analyses purposes, the subjects were stratified in tertiles of gluten intake. Median (IQR) overall GI symptom severity (GSRS-IBS) was significantly worse for the subjects with the lowest (52 (45-57)) and intermediate gluten intake (51 (43-58)), compared with the highest gluten intake (45 (37-50), P ≤ 0.05, and P ≤ 0.01 respectively). In addition, caloric intake was significantly lower in subjects with the lowest (1905 ± 446, kcal/day) and intermediate gluten intake (1854 ± 432, kcal/day), compared with subjects with the highest gluten intake (2305 ± 411, kcal/day), P < 0.001 for both. Analyses of the stratified fructan tertiles resulted in no significant differences in GSRS-IBS. CONCLUSIONS: The mean intake of gluten varies substantially among subjects with IBS, and IBS subjects with more severe GI symptoms have lower intake of gluten and calories. TRIAL REGISTRY: (http://www.clinicaltrials.gov): Registered under Clinical Trial number NCT02970591.