Global research trend and hotspot in the low FODMAP diet: a bibliometric analysis

BACKGROUND

According to national guidelines, a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) is a second-line therapy option for irritable bowel syndrome (IBS) and improves functional intestinal symptoms. Numerous noteworthy results have been published in this field over the past fifteen years. This study aims to analyze the global research trend and hotspot of the low FODMAP diet research, and provide a comprehensive perspective and direction for researchers.

METHODS

The Science Citation Index-Expanded of the Web of Science Core Collection (WoSCC) was used to identify low FODMAP diet-related articles and reviews. Three bibliometric programs (CiteSpace, VOSviewer, Scimago Graphic) were utilized to analyze and visualize the annual publications, authors, countries, institutions, journals, citations, and keywords.

RESULTS

In total, 843 documents related to the low FODMAP diet research were published in 227 journals by 3,343 authors in 1,233 institutions from 59 countries. The United States, which was the most engaged nation in international collaboration, had the largest annual production and the fastest growth. The most productive organization was Monash University, and the most fruitful researcher was Gibson PR. Nutrients ranked first in terms of the number of published documents. The article "A diet low in FODMAPs reduces symptoms of irritable bowel syndrome" (Halmos EP, 2014) received the most co-citations. Keywords that appear frequently in the literature mainly involve two main aspects: the clinical efficacy evaluation and mechanism exploration of the low FODMAP diet. The term "gut microbiota" stands out as the most prominent keyword among the burst keywords that have remained prevalent till date.

CONCLUSION

The restriction stage of the low FODMAP diet is superior to other dietary therapies for IBS in terms of symptom response, but it has a negative impact on the abundance of gut Bifidobacteria and diet quality. Identification of biomarkers to predict response to the low FODMAP diet is of great interest and has become the current research hotspot.

All FODMAPs Aren't Created Equal: Results of a Randomized Reintroduction Trial in Patients With Irritable Bowel Syndrome

BACKGROUND & AIMS

A diet low in fermentable oligo, di, monosaccharides, and polyols (FODMAPs) is one of the recommended management strategies for irritable bowel syndrome (IBS). However, while effective, adherence to restricting dietary FODMAPs can be challenging and burdensome. The question remains whether limiting all FODMAPs during the restrictive phase of the diet is necessary for symptomatic improvement in the dietary treatment of IBS, or if targeting selected groups of FODMAPs for restriction is sufficient for clinical response. Our study aimed to determine which individual FODMAPs are most likely to lead to symptom generation in patients with IBS who have improved with fodmap restriction.

METHODS

Patients meeting Rome IV criteria for IBS were invited to participate in a 12-week study to identify individual FODMAP sensitivities. Those subjects who demonstrated symptom improvement after a 2- to 4-week open-label FODMAP elimination period were recruited to a 10-week blinded-phased FODMAP reintroduction phase of 7 days for each FODMAP. Throughout the study period, daily symptom severity (0-10 point numerical rating system) was recorded. A mixed effect statistical analysis model was used.

RESULTS

Between 2018 and 2020, 45 subjects were enrolled. Twenty-five subjects improved with FODMAP elimination, and 21 patients continued into the reintroduction phase of the study. Fructans and galacto-oligosaccharides (GOS) both were associated with worsened abdominal pain (P = .007 and P = .04, respectively). GOS were associated with an increase in bloating (P = 03). Both bloating and abdominal pain worsened throughout the study, regardless of the FODMAP reintroduction (P = .006).

CONCLUSION

Our results suggest that the reintroduction of select FODMAPs may be responsible for symptom generation in patients with IBS who have responded to a low FODMAP diet, and provide a strong rationale for performing a future trial comparing the treatment effects of a limited low-FODMAP diet and a standard low-FODMAP diet.

CLINICALTRIALS

GOV: NCT03052439.

Unlocking the potential of low FODMAPs sourdough technology for management of irritable bowel syndrome

Consumption of high FODMAP (Fermentable Oligo-, Di-, and Monosaccharides and Polyols) diet is the leading cause of alteration in the human gut microbiome, thereby, causing irritable bowel syndrome (IBS). Therefore, sourdough technology can be exploited for reduction of FODMAPs in various foods to alleviate the symptoms of IBS. Several microorganisms viz. Pichia fermentans, Lactobacillus fetmentum, Saccharomyces cerevisiae, Torulaspora delbrueckii, Kluyveromyces marxianus etc. have been identified for the production of low FODMAP type II sourdough fermented products. However, more research on regulation of end-product and volatilome profile is required for maximal exploitation of FODMAP-reducing microorganisms. Therefore, the present review is focused on utilisation of lactic acid bacteria and yeasts, alone and in synergy, for the production of low FODMAP sourdough foods. Moreover, the microbial bioprocessing of cereal and non-cereal based low FODMAP fermented sourdough products along with their nutritional and therapeutic benefits have been elaborated. The challenges and future prospects for the production of sourdough fermented low FODMAP foods, thereby, bringing out positive alterations in gut microbiome, have also been discussed.

Low fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet is associated with increased risk of uninvestigated chronic dyspepsia and its symptoms in adults

BACKGROUND

Assessing the potential effects of a low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) diet on functional gastrointestinal symptoms, particularly upper gastrointestinal symptoms, is not clearly understood. The current study aimed to explore the association of a diet low in FODMAPs with uninvestigated chronic dyspepsia (UCD) and functional dyspeptic symptoms in a large population of Iranian adults.

METHODS

This cross-sectional study was conducted on 2987 adults. Dietary FODMAPs intake estimated using a validated food-frequency questionnaire. UCD, early satiation, postprandial fullness and gastric pain were determined using a modified and validated version of the Rome III Questionnaire.

RESULTS

After controlling for various confounders, consumption of a diet low in FODMAPs was associated with increased risk of UCD in the whole population (OR=1.85; 95% CI: 1.23-2.78; P=0.009) and women (OR=2.41; 95% CI: 1.46-3.95; P=0.004), but not in men. Higher consumption of a low-FODMAPs diet was related to increased risk of postprandial fullness (OR=1.38; 95% CI: 1.08-1.78; P=0.046). The inverse association between FODMAPs and epigastric pain tended to be significant after controlling for eating behaviors (OR=1.31; 95% CI: 0.98-1.76; P=0.084). No significant association was observed for early satiation.

CONCLUSIONS

Our data suggest that consumption of a low-FODMAPs diet may increase the risk of UCD and postprandial fullness; however, well-planned randomized controlled trials and prospective cohorts are required to ascertain the effect of FODMAPs on upper gastrointestinal symptoms.

The relationship between fermentable carbohydrates and post-prandial bowel symptoms in patients with functional bowel disorders

Background and aims

A low fermentable oligosaccharide, disaccharide, monosaccharide, and polyols (FODMAP) diet alleviates symptoms of irritable bowel syndrome (IBS). We aimed to investigate the relationship between habitual FODMAP intake and post-prandial bowel symptoms in adults with IBS, functional diarrhoea (FD), or constipation (FD) (functional bowel disorders), and in healthy adults (controls).

Methods

292 participants (173 with functional bowel disorders and 119 controls) completed a food and symptom times diary. Estimated meal portion sizes were entered into the Monash FODMAP Calculator to analyse FODMAP content. Wilcoxon and ANOVA tests were used to investigate the relationship between FODMAP intake and post-prandial bowel symptoms.

Results

IBS participants experienced more post-prandial bowel symptoms compared to participants with other functional bowel disorders or controls. Meals associated with abdominal pain contained on average increased excess fructose (0.31 g vs. 0.18 g, p < 0.05), sorbitol (0.27 g vs. 0.10 g, p < 0.01), and total FODMAP (3.46 g vs. 2.96 g, p < 0.05) compared to meals not associated with pain. Abdominal swelling was associated with increased sorbitol (0.33 g vs. 0.11 g, p < 0.01), and total FODMAP (3.26 g vs. 3.02 g, p < 0.05) consumption. Abdominal bloating was associated with increased galacto oligosaccharide consumption (0.18 g vs. 0.14 g, p < 0.05).

Conclusion

These findings support the role of FODMAP in post-prandial bowel symptom onset, however, the amount and type of FODMAP triggering symptoms vary between individuals. Future research should investigate the relationship between the effect of individual FODMAP consumption on post-prandial bowel symptoms for each subtype, the interaction of FODMAP with differing functional bowel disorders and whether longitudinally symptoms and dietary intake are stable.

The relationship between meal regularity with Irritable Bowel Syndrome (IBS) in adults

BACKGROUND

The irregular meal pattern and meal-skipping might be related to irritable bowel syndrome (IBS), however, findings of previous investigations are contradictory. We aimed to examine the relation of meal regularity with IBS in Iranian adult population.

METHODS

Data on 4599 adults who worked in 50 different health centers were used in this cross-sectional study. Dietary habits were measured using a pretested questionnaire. IBS identification was performed through the use of a modified version of Rome III questionnaire.

RESULTS

IBS was prevalent among 18.6% of men and 24.1% of women. After adjustment for potential confounders, those with regular meal pattern, in comparison to those with irregular meals, had 40% lower odds for IBS (OR:0.60, 95%CI: 0.41-0.87). Individuals with regular meals had also 82 lower risk for IBS-Mixed, in comparison to those who had irregular meals (OR:0.18, 0.95%CI: 0.08-0.43). Stratified analysis by gender revealed that women with regular meals, compared with those who did not, had 44% lower risk for IBS (OR: 0.56, 0.95%CI: 0.34-0.91). Normal-weight individuals who had regular meal pattern, compared to those who did not, had 63% lower risks for IBS (OR:0.37, 95%CI: 0.22-0.64). Furthermore, subjects who had regular meal pattern had 53% lower risk for severe symptoms of IBS (OR:0.47, 95%CI: 0.30-0.71).

CONCLUSION

We found that participants with regular meal pattern had reduced odds of IBS, IBS-Mixed and the syndrome severity. Meal regularity was also linked to reduced IBS prevalence in women, and in normal-weight individuals. More prospective studies are needed to affirm these associations.

Fermentable Oligo-, Di-, and Mono-Saccharides and Polyols (FODMAPs) Consumption and Irritable Bowel Syndrome in the French NutriNet-Santé Cohort

(1) Background: Specific foods, and more particularly, fermentable oligo-, di-, and mono-saccharides and polyols (FODMAPs) are often considered as triggers of digestive symptoms in Irritable Bowel Syndrome (IBS). Our aim was to study FODMAP consumption in controls and IBS participants in a large French population-based cohort; (2) Methods: Participants from the NutriNet-Santé cohort study completed the Rome IV and IBS-SSS questionnaire in a cross sectional study. Among them, 27,949 eligible participants had previously completed three 24-h recalls as well as anthropometrics, socio-demographical and lifestyle data. Total FODMAP intake (in g/day) was computed using a specific composition table. The association between FODMAPs and IBS was estimated through multivariable logistic regression models; (3) Results: Included participants were mainly women (75.4%) and the mean age was 43.4 ± 14.1 years. FODMAPs accounted for a mean daily intake of 19.4 ± 9.5 g/day. Overall 1295 participants (4.6%) were identified with an IBS. After adjusting for confounding factors, IBS participants had lower intakes in FODMAPs than non-IBS ones (aOR: 0.88, 95% CI: 0.82–0.95, p-value: 0.001). IBS severity was associated with more frequent low FODMAP intakes (<9 g/day); (4) Conclusions: Participants tended to consume 19 g of FODMAPs per day, but slightly less for IBS participants than for controls. In IBS participants, higher severity was associated with lower intakes.

Nutritional Contributions and Health Associations of Traditional Fermented Foods

The growing interest in the consumption and study of traditionally fermented food worldwide has led to the development of numerous scientific investigations that have focused on analyzing the microbial and nutritional composition and the health effects derived from the consumption of these foods. Traditionally fermented foods and beverages are a significant source of nutrients, including proteins, essential fatty acids, soluble fiber, minerals, vitamins, and some essential amino acids. Additionally, fermented foods have been considered functional due to their prebiotic content, and the presence of specific lactic acid bacterial strains (LAB), which have shown positive effects on the balance of the intestinal microbiota, providing a beneficial impact in the treatment of diseases. This review presents a bibliographic compilation of scientific studies assessing the effect of the nutritional content and LAB profile of traditional fermented foods on different conditions such as obesity, diabetes, and gastrointestinal disorders.

Effect of Inoculated Lactic Acid Fermentation on the Fermentable Saccharides and Polyols, Polyphenols and Antioxidant Activity Changes in Wheat Sourdough

Inoculation of sourdough allows the fermentation medium to be dominated by desired microorganisms, which enables determining the kinetics of the conversion of chemical compounds by individual microorganisms. This knowledge may allow the design of functional food products with health features dedicated to consumers with special needs. The aim of the study was to assess the dynamics of transformations of fermentable oligosaccharide, disaccharide, monosaccharide and polyol (FODMAP) compounds from wheat flour as well as their antioxidant activity during inoculated and spontaneous sourdough fermentation. The FODMAP content in grain products was determined by the fructan content with negligible amounts of sugars and polyols. To produce a low-FODMAP cereal product, the fermentation time is essential. The 72 h fermentation time of L. plantarum-inoculated sourdough reduced the FODMAP content by 91%. The sourdough fermentation time of at least 72 h also positively influenced the content of polyphenols and antioxidant activity, regardless of the type of fermentation. The inoculation of both L. plantarum and L. casei contributed to a similar degree to the reduction in FODMAP in sourdough compared to spontaneous fermentation.

Mast Cell Regulation and Irritable Bowel Syndrome: Effects of Food Components with Potential Nutraceutical Use

Mast cells are key actors in inflammatory reactions. Upon activation, they release histamine, heparin and nerve growth factor, among many other mediators that modulate immune response and neuron sensitization. One important feature of mast cells is that their population is usually increased in animal models and biopsies from patients with irritable bowel syndrome (IBS). Therefore, mast cells and mast cell mediators are regarded as key components in IBS pathophysiology. IBS is a common functional gastrointestinal disorder affecting the quality of life of up to 20% of the population worldwide. It is characterized by abdominal pain and altered bowel habits, with heterogeneous phenotypes ranging from constipation to diarrhea, with a mixed subtype and even an unclassified form. Nutrient intake is one of the triggering factors of IBS. In this respect, certain components of the daily food, such as fatty acids, amino acids or plant-derived substances like flavonoids, have been described to modulate mast cells' activity. In this review, we will focus on the effect of these molecules, either stimulatory or inhibitory, on mast cell degranulation, looking for a nutraceutical capable of decreasing IBS symptoms.

Management of Irritable Bowel Syndrome: Physician-Dietitian Collaboration

Irritable bowel syndrome (IBS) affects 10%-15% of adults in the United States and 12% of the worldwide population. Gastroenterologists as well as primary care practitioners are likely to be the first resource for patients with gastrointestinal (GI) symptoms. IBS is difficult to diagnose, as it is a functional GI disorder, determined after ruling out a myriad of other diagnoses. The 2016 Rome IV criteria define IBS as "a functional bowel disorder in which recurrent abdominal pain is associated with defecation or a change in bowel habits. Disordered bowel habits are typically present (ie, constipation, diarrhea, or a mix of constipation and diarrhea), as are symptoms of abdominal bloating/distension occurring over at least 6 months and not less than 3 months." Treatment of IBS historically has been through medical management; however, nutrition management of IBS using the FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) elimination diet is now a recommended, first-line therapy. FODMAPs are short-chain, poorly absorbed carbohydrates that are associated with symptoms in people with IBS. This diet intervention can be quite challenging, and therefore, patients should meet with a qualified dietitian who can provide the complex diet information in a practicable form. Physician-dietitian collaboration is invaluable for IBS patients to achieve a successful outcome.

Technological methods for reducing the content of fructan in rye bread

The irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal tract that may afflict even 12% of the European population. One of the ways to counteract IBS-related ailments is to implement a diet with reduced contents of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs). The prevailing components from the FODMAPs group that may be found in rye bread include fructans. The study was conducted with endosperm and wholemeal rye flours. Dough was prepared from both flours with the use of two methods: I-stage method—with the addition of dry leavening—and II-stage method with the use of a sourdough produced with Lactobacillus plantarum, and all with fermentation times of 90, 120, 150, and 180 min. After baking, bread loaves were subjected to quality and consumer analysis and fructan content determination. The endosperm rye flour used for bread-making revealed better baking properties. Bread made of this flour had a higher loaf volume and received higher scores in the consumer assessment than bread made with wholemeal. Study results conclude that the content of fructans in bread was significantly affected by the dough-making method, and that it was decreased by the use of the sourdough. In contrast, the extended fermentation time of dough failed to reduce the fructan content of the bread.

Healthy lifestyle score and irritable bowel syndrome: A cross-sectional study in adults

BACKGROUND

Lifestyle modifications play an important role in the management of irritable bowel syndrome (IBS), but there is limited information on any associations of combined lifestyle-related factors with IBS in Middle Eastern populations. We, therefore, assessed the associations of a "lifestyle score," in analogy to lifestyle scores applied in studies of other disorders, with IBS in adults.

METHODS

In a cross-sectional study on 3363 Iranian adults, a healthy lifestyle score (HLS) was constructed using information about dietary habits, dietary intake, physical activity, smoking status, and psychological distress, which was collected using validated questionnaires. A modified version of the Rome III questionnaire (in Persian) was used to diagnose IBS and its subtypes.

KEY RESULTS

Individuals with the highest HLS had a 65% lower odds of having IBS compared with those in the lowest category (OR: 0.35; 95% CI: 0.26-0.48). Participants with healthy dietary habits, including regular meal pattern, slow/moderate eating rate, moderate intra-meal fluid consumption, moderate/long meal-to-sleep interval, and low/moderate consumption of fatty foods, had significantly lower odds of having IBS compared with those with unhealthy dietary habits (OR: 0.81; 95% CI: 0.69-0.96). Moreover, individuals with lower levels of psychological distress, compared with those with higher levels of distress, had significantly lower odds of IBS (OR: 0.49; 95% CI: 0.40-0.60).

CONCLUSIONS AND INFERENCES

Our data suggest that having an overall "healthy lifestyle" is related to substantially reduced odds of IBS, suggesting that adhering to a healthy lifestyle pattern, including dietary habits, diet quality, physical activity, smoking, and psychological distress, can be considered as a key management strategy for IBS.

Pathogenesis of Celiac Disease and Other Gluten Related Disorders in Wheat and Strategies for Mitigating Them

Wheat is a major cereal crop providing energy and nutrients to the billions of people around the world. Gluten is a structural protein in wheat, that is necessary for its dough making properties, but it is responsible for imparting certain intolerances among some individuals, which are part of this review. Most important among these intolerances is celiac disease, that is gluten triggered T-cell mediated autoimmune enteropathy and results in villous atrophy, inflammation and damage to intestinal lining in genetically liable individuals containing human leukocyte antigen DQ2/DQ8 molecules on antigen presenting cells. Celiac disease occurs due to presence of celiac disease eliciting epitopes in gluten, particularly highly immunogenic alpha-gliadins. Another gluten related disorder is non-celiac gluten-sensitivity in which innate immune-response occurs in patients along with gastrointestinal and non-gastrointestinal symptoms, that disappear upon removal of gluten from the diet. In wheat allergy, either IgE or non-IgE mediated immune response occurs in individuals after inhalation or ingestion of wheat. Following a life-long gluten-free diet by celiac disease and non-celiac gluten-sensitivity patients is very challenging as none of wheat cultivar or related species stands safe for consumption. Hence, different molecular biology, genetic engineering, breeding, microbial, enzymatic, and chemical strategies have been worked upon to reduce the celiac disease epitopes and the gluten content in wheat. Currently, only 8.4% of total population is affected by wheat-related issues, while rest of population remains safe and should not remove wheat from the diet, based on false media coverage.

Low FODMAP Diet: Evidence, Doubts, and Hopes

Food is often considered to be a precipitating factor of irritable bowel syndrome (IBS) symptoms. In recent years, there has been a growing interest in FODMAPs (Fermentable Oligo-, Di-, Mono-saccharides, And Polyols), which can be found in many common foods. A low FODMAP diet (LFD) is increasingly suggested for IBS treatment. However, long-term, large, randomized controlled studies are still lacking, and certainties and doubts regarding LFDs have grown, often in a disorderly and confused manner. Some potential LFD limitations and concerns have been raised, including nutritional adequacy, cost, and difficulty in teaching the diet and maintaining it. Most of these limitations can be solved with the involvement of a skilled nutritionist, who can clearly explain the different phases of the LFD and ensure nutritional adequacy and compliance. Further studies should focus on new methods of teaching and learning the LFD and on predictors of response. Moreover, particular interest should be focused on the possible use of LFD in gastrointestinal diseases other than functional disorders and, possibly, also in non-gastrointestinal diseases. The aim of the present review was to clarify the effective and appropriate indications and limitations of an LFD and to discuss its possible future uses.

Gluten and FODMAPS-Sense of a Restriction/When Is Restriction Necessary?

Gluten-free diet (GFD) is enjoying increasingly popularity, although gluten-free products are considerably more expensive. GFD is absolutely necessary for patients with celiac disease, as in this case even minor amounts of gluten can lead to the destruction of the intestinal mucosa. In addition, GFD is currently the best therapy to improve clinical symptoms of patients with non-celiac gluten sensitivity (NCGS), although the diet may not be as strict as that for patients with celiac disease. Beside gluten, other wheat components such as oligosaccharides and amylase trypsin inhibitors are discussed as triggers of NCGS in this review. An overlap between gastrointestinal symptoms in NCGS and irritable bowel syndrome (IBS) is described. Patients with NCGS attribute their symptoms to the consumption of gluten, while patients with IBS rarely describe gluten as a trigger. Recently, several studies have demonstrated that the introduction of a low FODMAP (fermentable oligo-, di-, monosaccharides, and polyols) diet reduced gastrointestinal symptoms in patients with IBS and this diet is suggested as the first choice of therapy in IBS. However, a low FODMAP diet also eliminates prebiotica and may negatively influence the gut microbiota. For this reason, the diet should be liberalized after symptom improvement. There is no evidence that a GFD is healthier than the standard diet. In contrast, GFD often is accompanied by nutritional deficiencies, mainly minerals and vitamins. Therefore, GFD and low FODMAP diets are not recommended for healthy subjects. Since wheat contains fructans belonging to FODMAPs), a GFD is not only gluten-free but also has less FODMAPs. Thus, symptom improvement cannot be correctly correlated with the reduction of either one or the other.

A review of polyols - biotechnological production, food applications, regulation, labeling and health effects

Food research is constantly searching for new ways to replace sugar. This is due to the negative connotations of sugar consumption on health which has driven consumer demand for healthier products and is reflected on a national level by the taxation of sugary beverages. Sugar alcohols, a class of polyols, are present in varying levels in many fruits and vegetables and are also added to foods as low calorific sweeteners. The most commonly used polyols in food include sorbitol, mannitol, xylitol, erythritol, maltitol, lactitol and isomalt. Of these, microorganisms can produce sorbitol, mannitol, xylitol and erythritol either naturally or through genetic engineering. Production of polyols by microbes has been the focus of a lot of research for its potential as an alternative to current industrial scale production by chemical synthesis but can also be used for in situ production of natural sweeteners in fermented products using microbes approved for use in foods. This review on the generation of these natural sweetening compounds by microorganisms examines the current understanding and methods of microbial production of polyols that are applicable in the food industry. The review also considers the health benefits and effects of polyol usage and discusses regulations which are applicable to polyol use.

Management of Small Intestinal Bacterial Overgrowth in Adult Patients

The human gastrointestinal tract is a complex system of digestive pathways aided by mechanical processes, enzymes, transport molecules, and colonic bacteria. Occasionally, these bacterial components transplant to atypical locations due to various gastrointestinal imbalances or anatomical structural issues. This may lead to bacterial overgrowth of the small intestine, where minimal or no bacteria are normally found. Symptoms of small intestinal bacterial overgrowth may mimic those of various functional gastrointestinal diseases. Small intestinal bacterial overgrowth is typically diagnosed through hydrogen breath tests or jejunal aspirate culture. Current recommendations indicate antibiotics as the first-line treatment to eradicate or modify the bacterial overgrowth to a more favorable state. Nutritional support is also indicated to correct deficiencies and aid in symptom alleviation. As small intestinal bacterial overgrowth is common in other conditions, much of the research for this area is based on findings in codisease states rather than independent disease research. To provide accurate recommendations for small intestinal bacterial overgrowth, more targeted research is needed.

EVALUATION OF CARBOHYDRATE AND FIBER CONSUMPTION IN PATIENTS WITH IRRITABLE BOWEL SYNDROME IN OUTPATIENT TREATMENT

BACKGROUND

Irritable bowel syndrome (IBS) is a chronic functional condition, which main symptoms of pain, discomfort and abdominal distension, constipation, diarrhea, altered fecal consistency and sensation of incomplete evacuation can be influenced by the presence of dietary fiber and fermentable carbohydrates (FODMAPs). This study aimed to assess the relationship between the quantity of fermentable carbohydrates (FODMAP) and fiber consumed by individuals diagnosed with IBS, and their classification according to the Rome III criteria.

METHODS

A transversal study was carried out in the Intestinal Outpatient Clinic of the Gastroenterology Discipline of UNIFESP. The nutrients of interest for the study were: fiber, general carbohydrates and FODMAPs, with intake quantity measured in grams, analyzed through portions consumed. A nutrition log was used, along with a semi-quantitative questionnaire of consumption frequency.

RESULTS

The sample included 63 adult patients; 21 with constipated IBS, 21 with diarrhea IBS, and 21 with mixed IBS. Carbohydrate intake was suboptimal in 55.6% of patients in all groups; excessive consumption was identified in 38.1% of the diarrhea group, 14.3% of the mixed group and 38.1% of the constipated group. Low consumption of carbohydrates was found in 28.6% of diarrhea patients and 47.6% of the mixed group. A mean intake of 23 g of fiber per day was identified, lower than recommended.

CONCLUSION

The study identified a number of inadequacies in the consumption of different nutrients, excessive carbohydrate intake, especially FODMAPs, identified by the respondents as responsible for a worsening of their conditions. By contrast, other food groups such as meat, eggs and dairy were consumed by the sample population in insufficient quantities.

Adherence with a low-FODMAP diet in irritable bowel syndrome: are eating disorders the missing link?

OBJECTIVES

The low-FODMAP diet has emerged as an option for the treatment of irritable bowel syndrome (IBS). This diet is very restrictive, and compliance is usually low. Preliminary findings suggest an association between eating disorders (EDs) and the risk of developing IBS. The aim of this study was to assess the correlation between compliance with a low-FODMAP diet and the risk of ED behaviours among patients with IBS.

PATIENTS AND METHODS

A single-centre prospective study was carried out among 233 IBS patients (79.8% females) at University College London Hospital, who commenced a low FODMAPs group programme for IBS (Rome III or IV). Self-reported diet adherence at the end of the 6-week programme was measured. At baseline, and at the 6-week follow-up visit, participants completed the validated IBS-Symptom Severity Score, the SCOFF ED screening questionnaire and the Hospital Anxiety and Depression Scale.

RESULTS

Adherence with a low-FODMAP diet was found in 95 (41%) patients. Overall, 54 (23%) patients were classified to be at risk for ED behaviour. Adherence was 57% in the ED group (31/54) versus 35% in the non-ED group (64/179); P<0.05. Adherence with a low-FODMAP diet was highest (51%) in the IBS with diarrhoea subtype and lowest (10%) in IBS with constipation. There was no significant correlation between IBS-Symptom Severity Score and either adherence (P=0.39) or ED behaviour (P=0.28).

CONCLUSION

In this IBS cohort, greater adherence to a low-FODMAP diet is associated with ED behaviour. The implications of our study are important in clinical practice for a clinician to have a high index of suspicion of EDs in IBS patients when a high level of low-FODMAP diet achieved.

Review article: implementation of a diet low in FODMAPs for patients with irritable bowel syndrome-directions for future research

BACKGROUND

Despite the efficacy of a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) for patients with irritable bowel syndrome, many questions remain unanswered with respect to its clinical implementation.

AIM

To review literature to identify, synthesise, and provide direction for future research in the implementation and evaluation of the low FODMAP diet.

METHODS

Bibliographical searches were performed in Ovid Medline, CINAHL, Scopus and PubMed from database commencement until September 2018, with search terms focused on the population (irritable bowel syndrome) and intervention of interest (FODMAP).

RESULTS

Predictors of response to a low FODMAP diet remain under investigation, with preliminary data supporting faecal microbiota or faecal volatile organic compound profiling. Training of clinicians, and standards for the education of patients about the phases of a low FODMAP diet, as well as the role of Apps, require formal evaluation. There are limited data on the longer term efficacy and safety of the low FODMAP diet with respect to sustained symptom control, effect on quality of life and healthcare utilisation, nutritional adequacy, precipitation of disordered eating behaviours, effects on faecal microbiota and metabolomic markers, and subsequent translation to clinical effects.

CONCLUSIONS

Many gaps in implementation of the low FODMAP diet in clinical practice, as well as long-term safety and efficacy, remain for further investigation.

Motility Disorders in Celiac Disease and Non-Celiac Gluten Sensitivity: The Impact of a Gluten-Free Diet

Background: There is evidence that digestive motor disorders are frequently present in untreated celiac disease (CD) patients. Similarly, non-celiac gluten sensitivity (NCGS) can be associated with gut motor disorders. In both cases, gut dysmotility can improve or be completely reversed with a gluten-free diet (GFD). Methods: A literature search for motility disorders in CD and NCGS patients was carried out using the online databases PubMed, Medline and Cochrane. Results: Esophageal, gastric, small bowel and gallbladder motor disorders are common in both children and adults with CD. Although the clinical consequences of these disorders are not clearly defined, gastric dysfunction could affect drug absorption and metabolism in the thyroid and neurological conditions associated with CD. The impact of a GFD on motility disorders is, however, controversial. No systematic studies are available on NCGS. NCGS frequently overlaps with irritable bowel syndrome (IBS) and similar pathophysiological mechanisms may be hypothesized. Conclusions: Mucosal damage may affect gut motility in untreated CD through perturbation of hormonal and neuro-immunomodulatory regulation. A persistent low-grade mucosal inflammation could explain the cases of persistent motor disorders despite a GFD. Further studies are needed to definitely assess the role of gut motor disorders in NCGS.

Dietary Effects on Microbiota-New Trends with Gluten-Free or Paleo Diet

A well-balanced diet is the basis for a healthy life. Both the western diet and special diets can have a relevant impact on the microbiome and promote the development of various diseases. There has been an increase in food-related disorders in recent years, largely associated with dramatic changes in food consumption trends and main nutrients. A major response to food intolerances has been the adoption of new dietary trends involving the reduction or exclusion of specific food ingredients. Especially gluten-containing, but also gluten-free cereals are in the cross-fire. Supporters of the gluten-free diet argue that gluten triggers inflammation and related diseases, while followers of the Paleo diet drastically impeach all cereals as dangerous for human health. To date, no controlled studies support or reject a positive health effect of a gluten-free or cereal-free diet. Future large-scale studies need to evaluate the effect of gluten-containing and gluten-free cereals and the various diets on human health, inflammatory parameters, clinical symptoms, and the gut microbiota (including the bacteria, fungi, and viruses). Dietary-associated changes in compositional and functional microbiota traits should be correlated with the health status for the future development of dietary recommendations and potential clinical interventions.

Effects of a Gluten-Containing Meal on Gastric Emptying and Gallbladder Contraction

The ingestion of gluten has been associated with gastrointestinal symptoms even in the absence of detectable immune responses. Little is known about the pathophysiological effects of gluten on the upper gastrointestinal tract. We aimed to assess whether the ingestion of gluten leads to an impairment of the physiological mechanisms of gastric emptying, gallbladder contraction and relaxation. A total of 17 healthy subjects underwent ultrasound evaluation of gastric emptying dynamics and gallbladder contractions at baseline and every 30 min after a standard gluten-containing and gluten-free meal (250 kcal, 70% carbohydrates). The pattern of gastric emptying was similar after a standard meal with or without gluten, but differed in terms of the peak of the antral filling curve, which was wider (mean area 5.69, median 4.70, range 3.71‒9.27 cm² vs. mean 4.89, median 4.57, 2.27‒10.22 cm², p = 0.023) after the gluten-containing meal. The pattern of gallbladder contractions was different after the gluten-free meal (p < 0.05), with higher gallbladder volumes in the late refilling phases. The results of this study show that gluten ingestion exerts objective effects on gastric and gallbladder motility. Although the underlying pathophysiological mechanism remains unknown, these results could account for some of the gluten-related symptoms reported by patients with celiac disease and non-celiac gluten sensitivity.

[Implementation of a low FODMAP diet for functional abdominal pain]

INTRODUCTION

The low FODMAP diet (fermentable oligosaccharides, monosaccharides, disaccharides, and polyols) has shown to be effective in adult patients with irritable bowel syndrome, but there are few studies on paediatric patients. The aim of this study is to assess the implementation and the outcomes of a low FODMAP diet in the treatment of functional abdominal pain in children from a Mediterranean area.

MATERIAL AND METHODS

A table was designed in which foods were classified according to their FODMAP content, as well as a 'Symptoms and Stools Diary'. A prospective study was conducted on children with functional abdominal pain in our Paediatric Gastroenterology Unit.

RESULTS

A total of 22 patients were enrolled in the trial, and 20 completed it. Data were collected of the abdominal pain features over a period of 3 days, and then patients followed a two-week low FODMAP diet. Afterwards, information about abdominal pain features was collected again. After the diet, they showed fewer daily abdominal pain episodes compared to baseline (1.16 [IQR: 0.41-3.33] versus 2 [IQR: 1.33-6.33] daily episodes, P=.024), less pain severity compared to baseline (1.41cm [IQR: 0.32-5.23] versus 4.63cm [IQR: 2.51-6.39] measured by 10-cm Visual Analogue Scale, P=.035), less interference with daily activities, and less gastrointestinal symptoms. Only 15% of patients found it difficult to follow the diet.

CONCLUSIONS

The implementation of a low FODMAP diet for 2 weeks in a Mediterranean paediatric population diagnosed with functional abdominal pain is possible with adapted diets. It was highly valued by patients, and they showed an improvement in abdominal pain symptoms assessed by objective methods.

The low FODMAP diet: fundamental therapy in the management of irritable bowel syndrome

PURPOSE OF REVIEW

The low FODMAP diet is now recognized as first-line therapy for treatment of irritable bowel syndrome (IBS) symptoms including abdominal pain, gas, bloating, diarrhea and or constipation. This information must be disseminated for application to clinical practice.

RECENT FINDINGS

There are many people with IBS worldwide who can benefit from following the low FODMAP diet to alleviate or minimize symptoms. Clinical studies and trials demonstrating the positive outcomes of the low FODMAP diet have been based on diet education provided by dietitians. Understanding the types of carbohydrates that are high in FODMAPs and the associated symptoms, nutrition intervention can be targeted using the low FODMAP diet. The nutrition intervention is relatively in expensive, noninvasive and basically without side-effects if monitored by a dietitian and clinical team.

SUMMARY

Applying the low FODMAP diet in IBS can greatly improve health and quality of life outcomes by alleviating or significantly improves symptoms.

Low fermentable, oligo-, di-, mono-saccharides and polyol diet in the treatment of irritable bowel syndrome: A systematic review and meta-analysis

OBJECTIVES

The aim of this review was to systematically assess and meta-analyze the effects of a low fermentable, oligo-, di-, mono-saccharides and polyol (FODMAP) diet (LFD) on the severity of symptoms, quality of life, and safety in patients with irritable bowel syndrome (IBS).

METHODS

The MEDLINE/PubMed, Scopus, and Cochrane Library databases were screened through January 19, 2016. Randomized controlled trials (RCTs) that compared LFD to other diets were included if they assessed symptoms of IBS or abdominal pain in patients with IBS. Safety, quality of life, anxiety, depression, and effect on gut microbiota were defined as secondary outcomes. Standardized mean difference (SMD) and 95% confidence interval (CI) were calculated.

RESULTS

Nine RCTs with a total of 596 subjects were included. Three RCTs compared LFD with a habitual diet, two RCTs provided all meals and compared LFD with a western diet, one RCT each compared LFD with a diet high in FODMAPs or a sham diet, and two RCTs compared with other diet recommendations for IBS. A meta-analysis revealed significant group differences for LFD compared with other diets with regard to gastrointestinal symptoms (SMD = -0.62; 95% CI = -0.93 to -0.31; P = 0.0001), abdominal pain (SMD = -0.50; 95% CI = -0.77 to -0.22; P = 0.008), and health-related quality of life (SMD = 0.36; 95% CI = 0.10-0.62; P = 0.007). Three studies reported a significant reduction in luminal bifidobacteria after LFD. Adverse events were assessed in three RCTs only and no intervention-related adverse events were reported.

CONCLUSIONS

This meta-analysis found evidence of the short-term efficacy and safety of LFD in patients with IBS. However, only a preliminary recommendation for LFD can be made until long-term effects are investigated.

A Systematic Review of the Effects of Polyols on Gastrointestinal Health and Irritable Bowel Syndrome

Polyols are sugar alcohols found in certain fruits, vegetables, and sugar-free sweeteners. They make up a component of the diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, which is gaining popularity in the treatment of patients with irritable bowel syndrome (IBS). We conducted a systematic review to evaluate the effects of polyols on the gastrointestinal tract in healthy men and women and in patients with IBS. Utilizing PubMed, Ovid, and Embase databases, we conducted a search on individual polyols and each of these terms: fermentation, absorption, motility, permeability, and gastrointestinal symptoms. Standard protocols for a systematic review were followed. We found a total of 1823 eligible articles, 79 of which were included in the review. Overall, available work has shown that polyol malabsorption generally occurs in a dose-dependent fashion in healthy individuals, and malabsorption increases when polyols are ingested in combination. However, studies in patients with IBS have shown conflicting results pertaining to polyol malabsorption. Polyol ingestion can lead to intestinal dysmotility in patients with IBS. Regarding the microbiome, moderate doses of polyols have been shown to shift the microbiome toward an increase in bifidobacteria in healthy individuals and may therefore be beneficial as prebiotics. However, data are limited regarding polyols and the microbiome in patients with IBS. Polyols can induce dose-dependent symptoms of flatulence, abdominal discomfort, and laxative effects when consumed by both healthy volunteers and patients with IBS. Further research is needed to better understand the effects of specific polyols on gastrointestinal function, sensation, and the microbiome in health and gastrointestinal disorders such as IBS.

Fructose use in clinical nutrition: metabolic effects and potential consequences

PURPOSE OF REVIEW

The current article presents recent findings on the metabolic effects of fructose.

RECENT FINDINGS

Fructose has always been considered as a simple 'caloric' hexose only metabolized by splanchnic tissues. Nevertheless, there is growing evidence that fructose acts as a second messenger and induces effects throughout the human body.

SUMMARY

Recent discoveries made possible with the evolution of technology have highlighted that fructose induces pleiotropic effects on different tissues. The fact that all these tissues express the specific fructose carrier GLUT5 let us reconsider that fructose is not only a caloric hexose, but could also be a potential actor of some behaviors and metabolic pathways. The physiological relevance of fructose as a metabolic driver is pertinent regarding recent scientific literature.

Abdominal Pain in Children: From the Eternal City to the Examination Room

Abdominal pain is a common presenting symptom in children. The differential diagnosis of abdominal pain is extensive; however, a vast majority of patients ultimately are diagnosed with functional abdominal pain disorders. Functional gastrointestinal disorders are defined using the recently released Rome IV criteria. These are not diagnoses of exclusion. If there are no alarm signs, the diagnosis may be made with a focused evaluation. Treatment of these disorders requires a biopsychosocial approach to the disorder and an individualized and multipronged treatment plan.

Bioelectrical impedance vector analysis in patients with irritable bowel syndrome on a low FODMAP diet: a pilot study

BACKGROUND

The aim of this study was to determine the effects of a low fermentable oligo-, di- and monosaccharides and polyols (FODMAP) diet on the nutritional status and body composition, abdominal symptoms, quality of life, anxiety/depression and sleep quality of patients with irritable bowel syndrome (IBS).

METHODS

Consecutive patients were given a low FODMAP diet for 8 weeks. At baseline and after 8 weeks, blood tests were taken to evaluate nutritional status and a bioelectrical impedance analysis was performed to assess body composition. Anthropometric data, IBS Symptom Severity Score, results of a bowel habits questionnaire, Bristol Stool Chart classification, SF36, Hamilton Depression Anxiety Scale outcome and Pittsburgh Sleep Quality Index were also recorded. During the 8-week diet period, the patients were phoned periodically by the nutritionist to verify their compliance.

RESULTS

Twenty-six IBS patients with a mean age of 46.2 ± 13.8 years were studied. After 8 weeks, there were no abnormalities in anthropometric data, bioelectrical impedance parameters and blood tests. The patients' IBS Symptom Severity Score improved (305.2 ± 84.1 vs 156.3 ± 106.4; p < 0.0001), as did bowel habits, Bristol Stool Chart classification, quality of life and HADS anxiety score, whereas sleeping quality and depression were unchanged. The degree of relief from symptoms and satisfaction with the diet was high.

CONCLUSIONS

A low FODMAP diet improved IBS symptoms without effects on nutritional status and body composition.

Low FODMAPs and gluten-free foods for irritable bowel syndrome treatment: Lights and shadows

Irritable bowel syndrome (IBS) is a functional bowel disorder with a global prevalence of 10-20% and in which abdominal pain or discomfort is associated with defecation or a change in bowel habit. IBS strongly impairs quality of life, social function, work productivity, and brings substantial costs to health care services. The etiology of IBS remains poorly understood and the search for biomarkers is ongoing. Bloating, distension, and disordered defecation are commonly associated features. The role of dietary components in inducing IBS symptoms is difficult to explore. To date, foods are not generally considered a cause but rather symptom-triggering factors, and are a significant component of the management pathway for many individuals. The use of functional foods in the management of IBS has been limited to dairy products, with particular interest in the use of probiotics. Particular interest has been given to gluten-free and low fermentable oligosaccharides, disaccharides, monosaccharides, and polyol (FODMAP) approach to treatment of IBS. There is scope to modify some of the existing products in the cereal market, in such a way that they would then comply with the gluten-free/low FODMAP diet. This modification could then in turn, help individual patients to experience a beneficial reduction in the symptoms of IBS. This literature review is intended to provide a discussion on the diet disease link between IBS and gluten-free/low FODMAP diet, for the purpose of creating an academic foundation on which to develop functional foods, suitable for patients with IBS.

Gastrointestinal Disturbances Associated with the Consumption of Sugar Alcohols with Special Consideration of Xylitol: Scientific Review and Instructions for Dentists and Other Health-Care Professionals

Sugar alcohols (polyols) are used in food manufacturing and in medical tests and examinations. d-Glucitol (sorbitol) and d-mannitol were previously the most common alditols used for these purposes. After the 1960s, xylitol became a common ingredient in noncariogenic confectioneries, oral hygiene products, and diabetic food. Erythritol, a polyol of the tetritol type, can be regarded as the sweetener of the "next generation." The disaccharide polyols maltitol, lactitol, and isomalt have also been used in food manufacturing and in medical tests. Consumption of pentitol- and hexitol-type polyols and disaccharide polyols may cause gastrointestinal disturbances at least in unaccustomed subjects. The occurrence of disturbances depends on consumer properties and on the molecular size and configuration of the polyol molecule. Adaptation may take place as a result of enzyme induction in the intestinal flora. Some of the literature on xylitol has been difficult to access by health-care professionals and will be reviewed here. Research and clinical field experience have found no pathology in polyol-associated osmotic diarrhea-the intestinal mucosa having normal basic structure, except in extreme instances. Xylitol is better tolerated than hexitols or the disaccharide polyols. Erythritol, owing to its smaller molecular weight and configuration that differ from other alditols, normally avoids the gastrointestinal reactions encountered with other polyols. This review will also touch upon the FODMAPs diet concept.

Effects of Prebiotics and Synbiotics on Functional Constipation

The objective was to determine the effects of prebiotics and synbiotics on adults with functional constipation (FC). Medline, Embase and the Cochrane Library were searched for literature published up to February 2015. We selected randomized controlled trials (RCTs) that reported administration of prebiotics or synbiotics to adults with FC. The end points included stool frequency, stool consistency and other symptoms related to constipation. Mean differences (MD) or standard mean differences (SMD) were used for continuous outcomes and risk ratios for discontinuous outcomes using a random-effects model. The Cochrane Risk of Bias Tool was used to determine the quality of the trials. Funnel plots and Egger's test were used to analyze for publication bias. We included 5 RCTs involving 199 patients who were administered prebiotics and 8 RCTs involving 825 patients who were administered synbiotics. Prebiotics increased weekly stool frequency (MD: 1.01bowel movements/week, 95% CI: 0.04-1.99) and improved stool consistency (SMD: -0.59, 95% CI: -1.16 to -0.02). Subgroup analysis showed specific effects for galacto-oligosaccharides on stool frequency, consistency, ease of defecation and abdominal pain. Synbiotics significantly improved stool frequency (MD: 1.15bowel movements/week, 95% CI: 0.58-1.71), consistency (SMD: 0.63, 95% CI: 0.33-0.92) and reduced whole-gut transit time (MD: 13.52, 95% CI: -26.56 to -0.49) in patients with FC. Subgroup analysis showed specific effects for fructo-oligosaccharides and probiotic combinations on stool frequency, consistency, straining defecation and bloating. Galacto-oligosaccharides and synbiotics made up of fructo-oligosaccharides with probiotic combinations may improve stool frequency, consistency and some other symptoms related to constipation.

Macronutrient intakes in obese subjects with or without small intestinal bacterial overgrowth: an alimentary survey

OBJECTIVE

Obesity is a multifactorial disorder with a possible microbiota derangement in its pathogenesis. Moreover, in obese patients the likelihood of small intestinal bacterial overgrowth (SIBO) is greater than in controls, although few studies are currently available. This study investigates the prevalence of SIBO and the possible role of dietary macronutrients in obesity.

MATERIALS AND METHODS

Sixty obese patients and normal lean controls were enrolled for SIBO detection. Diagnosis of SIBO was performed by a glucose breath test. A 24-hour recall questionnaire was administered to investigate macronutrient daily intake between the two obese patient subgroups (with/without SIBO).

RESULTS

The presence of SIBO in obese and controls was respectively 23.3% and 6.6% (p = 0.02, OR = 4.26, 95% Confidence interval = 1.31-13.84). Obese patients with SIBO ingested more carbohydrates (252.75 ± 30.53 vs 201 ± 70.76 g/day, p = 0.01), more refined sugars (104.15 ± 28.69 vs 73.32 ± 44.93 g/day, p = 0.02) and less total and insoluble fibers (9.6 ± 1.97 vs 14.65 ± 8.80 g/day, p = 0.04 and 4.7 ± 1.11 vs 8.82 ± 5.80 g/day, p = 0.01, respectively). There were no significant differences in lipid and protein intake between the two groups.

CONCLUSIONS

SIBO is widespread in obese subjects. Carbohydrates might promote the development of SIBO in obesity and fibers provide a protective function. Our results suggest a close relationship between diet and SIBO in obesity, thus supporting a possible role for intestinal microbiota.

Gut Microbiota Dysbiosis as Risk and Premorbid Factors of IBD and IBS Along the Childhood-Adulthood Transition

Gastrointestinal disorders, although clinically heterogeneous, share pathogenic mechanisms, including genetic susceptibility, impaired gut barrier function, altered microbiota, and environmental triggers (infections, social and behavioral factors, epigenetic control, and diet). Gut microbiota has been studied for inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) in either children or adults, while modifiable gut microbiota features, acting as risk and premorbid factors along the childhood-adulthood transition, have not been thoroughly investigated so far. Indeed, the relationship between variations of the entire host/microbiota/environmental scenario and clinical phenotypes is still not fully understood. In this respect, tracking gut dysbiosis grading may help deciphering host phenotype-genotype associations and microbiota shifts in an integrated top-down omics-based approach within large-scale pediatric and adult case-control cohorts. Large-scale gut microbiota signatures and host inflammation patterns may be integrated with dietary habits, under genetic and epigenetic constraints, providing gut dysbiosis profiles acting as risk predictors of IBD or IBS in preclinical cases. Tracking dysbiosis supports new personalized/stratified IBD and IBS prevention programmes, generating Decision Support System tools. They include (1) high risk or flare-up recurrence -omics-based dysbiosis profiles; (2) microbial and molecular biomarkers of health and disease; (3) -omics-based pipelines for laboratory medicine diagnostics; (4) health apps for self-management of score-based dietary profiles, which can be shared with clinicians for nutritional habit and lifestyle amendment; (5) -omics profiling data warehousing and public repositories for IBD and IBS profile consultation. Dysbiosis-related indexes can represent novel laboratory and clinical medicine tools preventing or postponing the disease, finally interfering with its natural history.