Fructose and irritable bowel syndrome

Nonallergic Diseases Associated With Foods

Clinicians are faced with evaluating real and alleged reactions to foods that may be allergic or nonallergic. Pathogenesis, diagnosis, and treatment of various non-IgE-mediated diseases are discussed in this review. These food-related conditions range from mild to severe. Referral for an allergy workup may be pursued despite the lack of IgE-mediated symptoms. Diagnostic testing is available for defined non-IgE-mediated food diseases that are either immunologic or nonimmunologic. These include celiac disease and related disorders, carbohydrate maldigestion, pancreatic insufficiency, and histamine intolerance. In contrast, there is a paucity of definitive studies to prove food intolerance diseases. There are no definitive diagnostic criteria or testing for nonceliac gluten sensitivity. Functional gastrointestinal disorders, such as irritable bowel syndrome, are better stratified diagnostically but still lack reliable testing. Both nonceliac gluten sensitivity and irritable bowel syndrome are linked to dietary triggers including fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. Therefore, dietary alteration alone may be diagnostic and therapeutic when all other conditions are ruled out. These conditions are important considerations when evaluating a patient with history of a food reaction. There is little evidence that foods are causative in other ailments such as acne, migraines, and nasal congestion and hypersecretion.

Food Intolerances, Food Allergies and IBS: Lights and Shadows

This narrative review delves into the intricate relationship between irritable bowel syndrome (IBS) and food intolerances. IBS, a chronic functional gastrointestinal disorder, is characterized by symptoms like abdominal pain and altered bowel habits. The prevalence of IBS has increased globally, especially among young adults. Food and dietary habits play a crucial role in IBS management. About 85-90% of IBS patients report symptom exacerbation linked to specific food consumption, highlighting the strong connection between food intolerances and IBS. Food intolerances often exhibit a dose-dependent pattern, posing a challenge in identifying trigger foods. This issue is further complicated by the complex nature of gastrointestinal physiology and varying food compositions. This review discusses various dietary patterns and their impact on IBS, including the low-FODMAP diet, gluten-free diet, and Mediterranean diet. It highlights the importance of a personalized approach in dietary management, considering individual symptom variability and dietary history. In conclusion, this review emphasizes the need for accurate diagnosis and holistic management of IBS, considering the complex interplay between dietary factors and gastrointestinal pathophysiology. It underlines the importance of patient education and adherence to treatment plans, acknowledging the challenges posed by the variability in dietary triggers and the psychological impact of dietary restrictions.

Association of fructose consumption with prevalence of functional gastrointestinal disorders manifestations: results from Hellenic National Nutrition and Health Survey (HNNHS)

The study aimed to assess the total prevalence of functional gastrointestinal disorders (FGID), and separately, irritable bowel syndrome (IBS) among adults and to determine their potential association with fructose consumption. Data from the Hellenic National Nutrition and Health Survey were included (3798 adults; 58·9 % females). Information regarding FGID symptomatology was assessed using self-reported physician diagnosis questionnaires the reliability of which were screened using the ROME III, in a sample of the population. Fructose intake was estimated from 24 h recalls, and the MedDiet score was used to assess adherence to the Mediterranean diet. The prevalence of FGID symptomatology was 20·2 %, while 8·2 % had IBS (representing 40·2 % of total FGID). The likelihood of FGID was 28 % higher (95 %CI: 1·03-1·6) and of IBS 49 % (95 %CI: 1·08-2·05) in individuals with higher fructose intake than with lower intake (3rd tertile compared with 1st). When area of residence was accounted for, individuals residing in the Greek islands had a significantly lower probability of FGID and IBS compared with those residing in Mainland and the main Metropolitan areas, with Islanders also achieving a higher MedDiet score and lower added sugar intake, comparatively to inhabitants of the main metropolitan areas. FGID and IBS symptomatology was most prominent among individuals with higher fructose consumption, and this was most conspicuous in areas with a lower Mediterranean diet adherence, suggesting that the dietary source of fructose rather than total fructose should be examined in relation to FGID.

Diet and gut microbial associations in irritable bowel syndrome according to disease subtype

The role of diet and the gut microbiome in the etiopathogenesis of irritable bowel syndrome (IBS) is not fully understood. Therefore, we investigated the interplay between dietary risk factors and gut microbiota in IBS subtypes using a food frequency questionnaire and stool metagenome data from 969 participants aged 18-65 years in the ZOE PREDICT 1 study, an intervention study designed to predict postprandial metabolic responses. We identified individuals with IBS subtype according to the Rome III criteria based on predominant bowel habits during symptom onset: diarrhea (i.e. looser), constipation (i.e. harder), and mixed. Participants with IBS-D (n = 59) consumed more healthy plant-based foods (e.g. whole grains, leafy vegetables) and fiber, while those with IBS-C (n = 49) tended to consume more unhealthy plant-based foods (e.g. refined grains, fruit juice) than participants without IBS (n = 797). Microbial diversity was nominally lower in patients with IBS-D than in participants without IBS or with IBS-C. Using multivariable-adjusted linear regression, we identified specific microbiota variations in IBS subtypes, including slight increases in pro-inflammatory taxa in IBS-C (e.g. Escherichia coli) and loss of strict anaerobes in IBS-D (e.g. Faecalibacterium prausnitzii). Our analysis also revealed intriguing evidence of interactions between diet and Faecalibacterium prausnitzii. The positive associations between fiber and iron intake and IBS-diarrhea were stronger among individuals with a higher relative abundance of Faecalibacterium prausnitzii, potentially driven by carbohydrate metabolic pathways, including the superpathway of β-D-glucuronide and D-glucuronate degradation. In conclusion, our findings suggest subtype-specific variations in dietary habits, gut microbial composition and function, and diet-microbiota interactions in IBS, providing insights into potential microbiome-informed dietary interventions.

A personalized management approach in disorders of the irritable bowel syndrome spectrum

Symptoms of the disorders across the irritable bowel syndrome (IBS) spectrum include several different, usually postprandial, abdominal complaints. Up to date, dietary treatments of the IBS have neither been personalized nor diagnosed with sufficient scientific evidence. They have mostly been treated using 'one-size-fits-all' approaches. Such include exclusion diets, a low fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet, and gluten-free diets, lactose-free diets, a diet recommended by the UK National Institute for Health and Care Excellence, and a wheat-free diet. The exact pathophysiology of IBS disorders across the spectrum is still unclear. However, the symptom profile of IBS spectrum disorders seems similar to that of food intolerance/malabsorption syndromes. Celiac disease, fructose malabsorption, histamine intolerance and lactose intolerance represent food intolerance/malabsorption disorders based on the indigestion of sugars and/or proteins. Helicobacter pylori infection may potentially promote the development of IBS and, when facing a case of IBS-like symptoms, a search for intolerance/malabsorption and H. pylori should be added to find the correct treatment for the respective patient. This review will discuss why the 'one-size-fits-all' dietary approach in the treatment of complaints across the IBS spectrum cannot be successful. Hence, it will provide an overview of the most common overall dietary approaches currently used, and why those should be discouraged. Alternatively, a noninvasive diagnostic workup of the pathophysiologic factors of food intolerance/malabsorption in each patient with symptoms of the IBS spectrum is suggested. Additionally, if H. pylori is found, eradication therapy is mandatory, and if food intolerance/malabsorption is detected, an individual and personalized dietary intervention by a registered dietician is recommended.

Does sourdough bread provide clinically relevant health benefits?

During the last decade, scientific interest in and consumer attention to sourdough fermentation in bread making has increased. On the one hand, this technology may favorably impact product quality, including flavor and shelf-life of bakery products; on the other hand, some cereal components, especially in wheat and rye, which are known to cause adverse reactions in a small subset of the population, can be partially modified or degraded. The latter potentially reduces their harmful effects, but depends strongly on the composition of sourdough microbiota, processing conditions and the resulting acidification. Tolerability, nutritional composition, potential health effects and consumer acceptance of sourdough bread are often suggested to be superior compared to yeast-leavened bread. However, the advantages of sourdough fermentation claimed in many publications rely mostly on data from chemical and in vitro analyzes, which raises questions about the actual impact on human nutrition. This review focuses on grain components, which may cause adverse effects in humans and the effect of sourdough microbiota on their structure, quantity and biological properties. Furthermore, presumed benefits of secondary metabolites and reduction of contaminants are discussed. The benefits claimed deriving from in vitro and in vivo experiments will be evaluated across a broader spectrum in terms of clinically relevant effects on human health. Accordingly, this critical review aims to contribute to a better understanding of the extent to which sourdough bread may result in measurable health benefits in humans.

Mechanisms underlying food-related symptoms in disorders of gut-brain interaction: Course ahead in research and clinical practice

A subgroup of patients with a disorder of gut-brain interaction (DGBI) report symptoms such as abdominal pain, gas-related symptoms, dyspeptic symptoms and loose stool or urgency after meal intake. Therefore, the effect of several dietary therapies including fibre-rich or restrictive diets have already been studied in patients with irritable bowel syndrome, functional abdominal bloating or distention, and functional dyspepsia. However, there is a paucity of studies in the literature on the mechanisms underlying food-related symptoms. Therefore, this review focuses on these potential mechanisms and explains the role of nutrient sensing and tasting, physical considerations, malabsorption or allergy-like reaction to food and its interaction with microbiota. In addition, it emphasizes the importance of future research and clinical practice regarding food-related symptoms in patients with a DGBI.

Fructose Metabolism and Its Effect on Glucose-Galactose Malabsorption Patients: A Literature Review

Glucose-galactose malabsorption is a rare inherited autosomal recessive genetic defect. A mutation in the glucose sodium-dependent transporter-1 gene will alter the transportation and absorption of glucose and galactose in the intestine. The defect in the SGLT-1 leads to unabsorbed galactose, glucose, and sodium, which stay in the intestine, leading to dehydration and hyperosmotic diarrhea. Often, glucose-galactose malabsorption patients are highly dependent on fructose, their primary source of carbohydrates. This study aims to investigate all published studies on congenital glucose-galactose malabsorption and fructose malabsorption. One hundred published studies were assessed for eligibility in this study, and thirteen studies were identified and reviewed. Studies showed that high fructose consumption has many health effects and could generate life-threatening complications. None of the published studies included in this review discussed or specified the side effects of fructose consumption as a primary source of carbohydrates in congenital glucose-galactose malabsorption patients.

The low-FODMAP diet and the gluten-free diet in the management of functional abdominal bloating and distension

This review summarizes current knowledge on the role of low-FODMAP diet and gluten-free diet in functional abdominal bloating and distension, an emerging disorder of gut-brain interaction characterized by remarkable costs for healthcare systems and a significant impact on the patient's quality of life. Ingested food plays a key role in the pathophysiology of disorders of gut-brain interaction as up to 84% of patients with irritable bowel syndrome (IBS) report food-triggered symptoms. Potential pathogenetic mechanisms of food-related symptoms in these patients are discussed, focusing on bloating and abdominal distension. These mechanisms provide the rationale for dietary treatment in patients with functional abdominal bloating and distension. The role of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) and gluten in functional abdominal bloating and distension is examined. Current literature evaluating the efficacy of the low-FODMAP diet and the gluten-free diet in abdominal bloating and distension is analyzed. Available evidence originates mainly from studies on patients with IBS, since clinical studies on selected cohorts of patients with only functional abdominal bloating and distension have been missing to date. Promising evidence on the potential efficacy of the low-FODMAP diet in functional abdominal bloating and distension is provided by the reduction of the bloating observed in patients with IBS. Regarding the gluten-free diet, there is insufficient evidence to recommend it to reduce bloating and abdominal distension. In conclusion, this review asserts the need for a close collaboration with experts in nutrition to optimize the management of these patients and reduce the risks associated with elimination diets.

Mechanisms Underlying Food-Triggered Symptoms in Disorders of Gut-Brain Interactions

There has been a dramatic increase in clinical studies examining the relationship between disorders of gut-brain interactions and symptoms evoked by food ingestion in the upper and lower gastrointestinal tract, but study design is challenging to verify valid endpoints. Consequently, mechanistic studies demonstrating biological relevance, biomarkers and novel therapeutic targets are greatly needed. This review highlights emerging mechanisms related to nutrient sensing and tasting, maldigestion, physical effects with underlying visceral hypersensitivity, allergy and immune mechanisms, food-microbiota interactions and gut-brain signaling, with a focus on patients with functional dyspepsia and irritable bowel syndrome. Many patients suffering from disorders of gut-brain interactions exhibit these mechanism(s) but which ones and which specific properties may vary widely from patient to patient. Thus, in addition to identifying these mechanisms and the need for further studies, biomarkers and novel therapeutic targets are identified that could enable enriched patient groups to be studied in future clinical trials examining the role of food in the generation of gut and non-gut symptoms.

Temporal Relationships Between Abdominal Pain, Psychological Distress and Coping in Patients With IBS - A Time Series Approach

OBJECTIVE

Irritable bowel syndrome (IBS) is a chronic disease leading to abdominal pain that is often related to psychological distress. The aim of the study was to investigate the temporal relationships between abdominal pain and psychological variables in patients with IBS.

METHODS

This longitudinal diary study included eight patients from a waiting group, recruited in the frame of a pilot intervention study. During their waiting time of 3 months the patients answered questions daily regarding somatic and psychological variables using an online diary. All patients were considered and analyzed as single cases. The temporal dynamics between the time series of psycho-somatic variables were analyzed using a vector autoregressive (VAR) modeling approach.

RESULTS

For all patients, positive same-day correlations between somatic and psychological time series were observed. The highest same-day correlations were found between somatic symptoms and pain-related discomfort (r = 0.40 to r = 0.94). Altogether, n = 26 significant lagged relationships were identified; n = 17 (65%) indicated that somatic values were predictive of psychological complaints on the following days. N = 9 (35%) lagged relationships indicated an opposite relationship in that psychological complaints were predictive of somatic symptoms. Three patients showed a significant positive same-day correlation between abdominal pain and use of a positive coping strategy. However, significant lagged relationships in two patients showed that for these patients the use of positive thinking as a coping strategy was unhelpful in reducing pain on the following days.

CONCLUSIONS

In patients with IBS abdominal symptoms appear to be closely related to psychological symptoms. For some patients, somatic complaints predict psychological complaints, in other patients the directionality is opposite. The impact of coping strategies on somatic symptoms varies among patients, therefore their role for a possible reduction of pain should be further explored. The results suggest the need of characterizing patientsindividually for effective health interventions. Individual time series analyses provide helpful tools for finding reasonable person-level moderators.

Perceived Gastrointestinal Symptoms and Association With Meals in a French Cohort of Patients With Irritable Bowel Syndrome

Background/Aims

The aim of our study is to evaluate the association between meals and perceived gastrointestinal symptoms in real life in a French cohort of irritable bowel syndrome (IBS) patients.

Methods

This prospective cross-sectional observational study included patients from the French association (association des patients souffrant du syndrome de l’intestin irritable [APSSII]) of IBS. Data were collected on demographics, IBS subtype, dietary food, and meal-induced gastrointestinal symptoms from patient filled self-questionnaires or questionnaires.

Results

Eighty-four patients with IBS were included; 82.3% female with a mean age of 46.9 ± 15.7 years. Each transit pattern subtype represented one-third of the population. Forty-five percent of patients had severe IBS according to IBS-Severity Scoring System; mean IBS Quality of Life score was 53.9 ± 18.3. Patients believed that food could trigger or exacerbate gastrointestinal symptoms in 73.3% and 93.4%, respectively. Eighty-nine percent had already tried diets, mostly lactose free diet and low fermentable, oligosaccharides, disaccharides, monosaccharides, and polyols diet in 61.3% and 53.6% of cases. Thirty-nine percent of meals induced gastrointestinal symptoms. Meal-induced gastrointestinal symptoms were associated with severity and subtype but not with quality of life.

Conclusions

This study has confirmed the important link between gastrointestinal symptoms and food. Gastrointestinal symptoms induced by meals are frequent and associated with severity and IBS-diarrhea subtype. Our study also underlines patients’ interest in food and diet. More knowledge is needed on food that triggers IBS symptoms but also on diet conditions in order to improve this condition.