Short-chain carbohydrates and functional gastrointestinal disorders

Characterizing fermentable carbohydrate foods in the diets of children with abdominal pain-related disorders of gut-brain interaction and healthy children

OBJECTIVES

Restricting dietary fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) can alleviate symptoms in children with disorders of gut-brain interaction (DGBI). Due to the restrictions of a low FODMAP diet (LFD), a less restrictive FODMAP Gentle diet (FGD) has been suggested. However, the types and amounts of high FODMAP foods and carbohydrates commonly consumed by children have not been studied. We aimed to identify the high FODMAP foods and proportions of FODMAP carbohydrates consumed by children with DGBI and healthy children (HC) and to determine which usually ingested FODMAPs would be restricted on the FGD.

METHODS

Three-day diet records from both children with DGBI and HC were analyzed and compared to assess the type and amount of high FODMAP foods and carbohydrates ingested. Additionally, the ingested FODMAPs that would be restricted on the FGD were determined.

RESULTS

Diet records from 77 children with DGBI and 64 HC were analyzed. The number of foods ingested daily was similar between children with DGBI and HC (12.3 ± 4.2 vs 12.9 ± 3.4, respectively); high FODMAP foods comprised most foods eaten in both groups. Children with DGBI (vs. HC) ate fewer high FODMAP foods per day (6.5 ± 2.3 vs 8.7 ± 2.4, P < 0.0001, respectively). Fructans were the most consumed FODMAP carbohydrate in both groups, and children with DGBI (vs. HC) consumed fewer fructans, lactose, fructose, and polyols (all P < 0.0001). The top 3 food categories consumed in both groups were wheat-containing foods, dairy, and fruits/ 100% fruit juices. In children with DGBI, 80.9% of the high FODMAP foods consumed would be limited on the FGD.

CONCLUSIONS

Children with DGBI consume fewer high FODMAP foods and carbohydrates than HC, with the top consumed FODMAP carbohydrates being fructans, lactose, and fructose. A FGD would restrict most high FODMAP foods consumed by children with DGBI.

Mode of Action of Psyllium in Reducing Gas Production from Inulin and its Interaction with Colonic Microbiota: A 24-hour, Randomized, Placebo-Controlled Trial in Healthy Human Volunteers

BACKGROUND

Recent studies show that the increase in breath hydrogen (BH2) and symptoms after ingestion of inulin are reduced by coadministering psyllium (PI).

OBJECTIVES

To determine if slowing delivery of inulin to the colon by administering it in divided doses would mimic the effect of PI. Primary endpoint was the BH2 area under the curve AUC0-24 h. Secondary endpoints included BH2 AUC0-6 h, 6-12 h, and 12-24 h. Exploratory endpoints included the correlation of BH2 AUC0-24 h with dietary fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs) intake and in vitro fermentation results.

METHODS

A total of 17 healthy adults were randomly assigned to a single-blind, 3-arm, crossover trial. All consumed 20 g inulin (I) powder dissolved in 500 mL water and mixed with either 20 g maltodextrin (control) or 20 g PI consumed as a single dose or 20 g inulin given in divided doses (DDI), 62.5 mL every 45 min over 6 h. Twenty-four-hour BH2, dietary FODMAP intake, stool microbiota, and gas production in vitro were measured. Responders were defined as those whose AUC0-24 h BH2 was reduced by PI, whereas nonresponders showed no reduction.

RESULTS

Compared with control, PI did not reduce mean BH2 AUC0-24 h, whereas DDI increased it, P < 0.0002. DDI and PI both significantly reduced BH2 AUC0-6 h compared with the control, P < 0.0001. However, subsequently, DDI significantly increased BH2 from 6 to 12 h (P < 0.0001) and overnight (12-24 h) (P < 0.0001), whereas PI did so only overnight (P = 0.0002). Nonresponders showed greater release of arabinose during in vitro fermentation and higher abundance of 2 species, Clostridium spp. AM22_11AC and Phocaeicola dorei, which also correlated with BH2 production on PI. Dietary FODMAP intake tended to correlate inversely with BH2 AUC0-24 h (r = -0.42, P = 0.09) and correlated with microbiome community composition.

CONCLUSIONS

DDI, like PI, reduces early BH2 production. PI acts by delaying transit to the colon but not reducing colonic fermentation over 24 h. Dietary FODMAP intake correlates with BH2 response to inulin and the microbiome. This trial was registered at www.

CLINICALTRIALS

gov as NCT05619341.

Low-FODMAP Diet for Irritable Bowel Syndrome: Insights from Microbiome

Irritable bowel syndrome (IBS) is a prevalent gastrointestinal disorder characterized by chronic abdominal pain, bloating, and altered bowel habits. Low-FODMAP diets, which involve restricting fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, have emerged as an effective dietary intervention for alleviating IBS symptoms. This review paper aims to synthesize current insights into the impact of a low-FODMAP diet on the gut microbiome and its mechanisms of action in managing IBS. We explore the alterations in microbial composition and function associated with a low-FODMAP diet and discuss the implications of these changes for gut health and symptom relief. Additionally, we examine the balance between symptom improvement and potential negative effects on microbial diversity and long-term gut health. Emerging evidence suggests that while a low-FODMAP diet can significantly reduce IBS symptoms, it may also lead to reductions in beneficial microbial populations. Strategies to mitigate these effects, such as the reintroduction phase and the use of probiotics, are evaluated. This review highlights the importance of a personalized approach to dietary management in IBS, considering individual variations in microbiome responses. Understanding the intricate relationship between diet, the gut microbiome, and IBS symptomatology will guide the development of more effective, sustainable dietary strategies for IBS patients.

Lactose free diet as therapeutic strategy in low anterior resection syndrome: a case series

Low anterior resection syndrome (LARS) is a challenging complication following sphincter-preserving rectal surgery, characterized by bowel dysfunctions such as urgency, frequency, and incontinence. This case series investigates the potential role of lactose intolerance in exacerbating LARS symptoms. Three patients who developed LARS after rectal resections showed persistent symptoms despite conventional management with bulking agents, physiotherapy, and loperamide. However, all three experienced significant improvement in symptomatology, reflected by reductions in their LARS scores, after eliminating cow's milk from their diets. These findings suggest a potential link between lactose intolerance, including possible late-onset forms, and LARS symptoms. This study highlights the effectiveness of dietary modifications, particularly lactose elimination, as a simple and non-invasive strategy for managing LARS. The findings also support the need for dietary screening processes and recommendations for milk substitutes to enhance clinical care. Further research is necessary to validate these observations and refine therapeutic strategies.

Lactose intolerance - A practical approach, Part 1

The toxicology, immunology and gastroenterology aspects of food remain important in clinical practice, as anyone treating food related anaphylaxis, or chronic intolerance syndromes can attest. Although entire editions of journals could focus on any one aspect of adverse effects from food, the following review addresses the important and prevalent gastrointestinal condition lactose intolerance and gastrointestinal (GI) conditions that have similar presentation but require different treatment.

Proinflammatory Diet Increases the Risk of Irritable Bowel Syndrome: A Prospective Study of 129,408 UK Biobank Participants and Mendelian Randomization Analysis

BACKGROUND

Patients with irritable bowel syndrome (IBS) often have chronic low-grade inflammation in the intestinal mucosa. Some dietary components are known to be associated with inflammation. However, there is currently limited research on the relationship between dietary inflammatory potential and the risk of IBS.

METHODS

A total of 129,408 participants in the UK Biobank were included in this study. Energy-Adjusted Dietary Inflammatory Index (E-DII) based on 26 nutrients and the Empirical Dietary Inflammatory Pattern (EDIP) based on 17 food groups were constructed, and on the basis of the tertiles, the continuous score was categorized into proinflammatory, neutral, and antiinflammatory categories. Associations between IBS and E-DII and EDIP were investigated by multivariable Cox proportional hazard models. Potential confounders including sociodemographic, lifestyle, body mass index (BMI), psychological state, type 2 diabetes, and thyroiditis were adjusted. In addition, subgroup analysis and sensitivity analysis were also performed. Finally, a two-sample Mendelian randomization (MR) analysis was employed to explore the independent causality of nutrients and dietary-derived serum antioxidants with IBS.

RESULTS

In the cohort study, over a median follow-up period of 13.26 years, 2421(1.87%) participants developed IBS. In the E-DII categories, after adjusting for the confounders, individuals in the proinflammatory diet category had a higher risk of IBS compared with the antiinflammatory category (HR 1.15, 95% CI 1.03-1.28, p = 0.015, p trend = 0.017) and neutral category (HR 1.13, 95% CI 1.01-1.26, p = 0.030, p trend = 0.017). In the EDIP categories, after adjusting for the confounders, individuals in the proinflammatory diet category had a higher risk of IBS compared with antiinflammatory category (HR 1.19, 95% CI 1.06-1.33, p = 0.002, p trend = 0.002) but no significant association compared with neutral category (HR 1.10, 95% CI 0.99-1.23, p = 0.067, p trend = 0.002). In the MR analysis, genetically determined intake levels of 16 nutrients and 6 dietary sources of circulating antioxidants did not have a causal effect on IBS.

CONCLUSIONS

Our findings indicate that proinflammatory dietary components are independent risk factors for IBS. However, there is no causal relationship between individual nutrient intake or serum antioxidants from dietary sources and IBS.

Study on the Therapeutic Effects and Mechanisms of Gintonin in Irritable Bowel Syndrome and Its Relationship with TRPV1, TRPV4, and NaV1.5

Irritable bowel syndrome (IBS) is a gastrointestinal (GI) disease accompanied by changes in bowel habits without any specific cause. Gintonin is a newly isolated glycoprotein from ginseng that is a lysophosphatidic acid (LPA) receptor ligand. To investigate the efficacy and mechanisms of action of gintonin in IBS, we developed a zymosan-induced IBS murine model. In addition, electrophysiological experiments were conducted to confirm the relevance of various ion channels. In mice, gintonin restored colon length and weight to normal and decreased stool scores, whilst food intake remained constant. Colon mucosal thickness and inflammation-related tumor necrosis factor-α levels were decreased by gintonin, along with a reduction in pain-related behaviors. In addition, the fecal microbiota from gintonin-treated mice had relatively more Lactobacillaceae and Lachnospiraceae and less Bacteroidaceae than microbiota from the control mice. Moreover, gintonin inhibited transient receptor potential vanilloid (TRPV) 1 and TRPV4 associated with visceral hypersensitivity and voltage-gated Na+ 1.5 channels associated with GI function. These results suggest that gintonin may be one of the effective components in the treatment of IBS.

Therapeutic microbiome modulation: new frontiers in HIV treatment

PURPOSE OF REVIEW

Dysbiosis may be a key driver of systemic inflammation, which increases the risk of non-AIDS events in people living with HIV (PLWH). Modulation of the microbiome to reverse this dysbiosis may be a novel approach to decrease inflammation and therefore morbidity and mortality in PLWH.

RECENT FINDINGS

Fecal microbiota transplantation (FMT), probiotics, prebiotics, synbiotics, postbiotics, and dietary modifications have the potential to modulate the microbiome. These interventions have been well tolerated in clinical trials to date. However, these interventions have not resulted in consistent or lasting changes to the microbiome or consistent changes in biomarkers of intestinal permeability, microbial translocation, inflammation, immune activation, or CD4 + T cell counts. Sustained engraftment may require prebiotics and/or dietary modifications added to either probiotics or FMT.

SUMMARY

Adequately powered randomized controlled trials are needed to elucidate whether microbiome modulation can be achieved and impact systemic inflammation in PLWH.

Efficacy and Findings of a Blinded Randomized Reintroduction Phase for the Low FODMAP Diet in Irritable Bowel Syndrome

BACKGROUND & AIMS

The efficacy of a low fermentable oligo-, di-, monosaccharides and polyols (FODMAP) diet in irritable bowel syndrome (IBS) is well established. After the elimination period, a reintroduction phase aims to identify triggers. We studied the impact of a blinded reintroduction using FODMAP powders to objectively identify triggers and evaluated the effect on symptoms, quality of life, and psychosocial comorbidities.

METHODS

Responders to a 6-week low FODMAP diet, defined by a drop in IBS symptom severity score (IBS-SSS) compared with baseline, entered a 9-week blinded randomized reintroduction phase with 6 FODMAP powders (fructans, fructose, galacto-oligosaccharides, lactose, mannitol, sorbitol) or control (glucose). A rise in IBS-SSS (≥50 points) defined a FODMAP trigger. Patients completed daily symptom diaries and questionnaires for quality of life and psychosocial comorbidities.

RESULTS

In 117 recruited patients with IBS, IBS-SSS improved significantly after the elimination period compared with baseline (150 ± 116 vs 301 ± 97, P < .0001, 80% responders). Symptom recurrence was triggered in 85% of the FODMAP powders, by an average of 2.5 ± 2 FODMAPs/patient. The most prevalent triggers were fructans (56%) and mannitol (54%), followed by galacto-oligosaccharides, lactose, fructose, sorbitol, and glucose (respectively 35%, 28%, 27%, 23%, and 26%) with a significant increase in abdominal pain at day 1 for sorbitol/mannitol, day 2 for fructans/galacto-oligosaccharides, and day 3 for lactose.

CONCLUSION

We confirmed the significant benefit of the low FODMAP diet in tertiary-care IBS. A blinded reintroduction revealed a personalized pattern of symptom recurrence, with fructans and mannitol as the most prevalent, and allows the most objective identification of individual FODMAP triggers. Ethical commission University hospital of Leuven reference number: s63629; Clinicaltrials.gov number: NCT04373304.

Factors Associated With Adherence to a Low Fermentable Carbohydrate Diet in Children With Functional Gastrointestinal Disorders

BACKGROUND

The low-fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet (LFD) has been associated with reduced symptomology in pediatric functional gastrointestinal disorders (FGIDs). The LFD is a complex dietary intervention that may be difficult to follow; thus, there is great interest in determining factors that contribute to adherence.

OBJECTIVE

To examine whether baseline abdominal pain, emotional/behavioral problems, or quality of life predict adherence to the LFD in children with FGIDs.

DESIGN

This was a single-group pre-post intervention design within a larger randomized controlled trial.

PARTICIPANTS/SETTING

Thirty 7- to 12-year-old children with FGIDs were recruited from pediatric gastrointestinal and primary care settings throughout Texas from 2019 to 2021. Evaluated participants were randomized to an LFD intervention as part of a larger randomized controlled trial.

INTERVENTION

Participants received dietary counseling and followed the LFD for 3 weeks.

MEASURES

Emotional or behavioral problems and quality of life were obtained via parent report, and abdominal pain was measured via child report. Adherence was assessed by using diet records and computed by a decrease in consumption of overall FODMAP intake.

STATISTICAL ANALYSES PERFORMED

A hierarchical generalized linear mixed regression model examined factors associated with adherence.

RESULTS

Greater baseline quality of life was associated with better adherence to the LFD (beta coefficient β = -.02, P = 0.03), and baseline emotional/behavioral problems and abdominal pain complaints were not significantly associated with adherence (all Ps > 0.28).

CONCLUSIONS

Higher child quality of life as reported by parents was related to increased adherence to this complex dietary intervention.

Genetically Determined Circulating Lactase/Phlorizin Hydrolase Concentrations and Risk of Colorectal Cancer: A Two-Sample Mendelian Randomization Study

Previous research has found that milk is associated with a decreased risk of colorectal cancer (CRC). However, it is unclear whether the milk digestion by the enzyme lactase-phlorizin hydrolase (LPH) plays a role in CRC susceptibility. Our study aims to investigate the direct causal relationship of CRC risk with LPH levels by applying a two-sample Mendelian Randomization (MR) strategy. Genetic instruments for LPH were derived from the Fenland Study, and CRC-associated summary statistics for these instruments were extracted from the FinnGen Study, PLCO Atlas Project, and Pan-UK Biobank. Primary MR analyses focused on a cis-variant (rs4988235) for LPH levels, with results integrated via meta-analysis. MR analyses using all variants were also undertaken. This analytical approach was further extended to assess CRC subtypes (colon and rectal). Meta-analysis across the three datasets illustrated an inverse association between genetically predicted LPH levels and CRC risk (OR: 0.92 [95% CI, 0.89-0.95]). Subtype analyses revealed associations of elevated LPH levels with reduced risks for both colon (OR: 0.92 [95% CI, 0.89-0.96]) and rectal cancer (OR: 0.92 [95% CI, 0.87, 0.98]). Consistency was observed across varied analytical methods and datasets. Further exploration is warranted to unveil the underlying mechanisms and validate LPH's potential role in CRC prevention.

The low FODMAP diet in clinical practice: where are we and what are the long-term considerations?

A diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) improves functional bowel symptoms and is a second-line dietary management strategy for the treatment of irritable bowel syndrome (IBS). The diet is complex and involves three stages: restriction, reintroduction and personalisation and clinical effectiveness is achieved with dietitian-led education; however, this is not always available. The aim of this review is to provide an update on the evidence for using the low FODMAP diet, with a focus on the impact of FODMAP restriction and reintroduction considering long-term management of IBS in a clinical setting. Randomised controlled trials have assessed symptom response, quality of life, dietary intake and changes to the gut microbiota during FODMAP restriction. Systematic reviews and meta-analyses consistently report that FODMAP restriction has a better symptom response compared with control diets and a network analysis reports the low FODMAP diet is superior to other dietary treatments for IBS. Research focused on FODMAP reintroduction and personalisation is limited and of lower quality, however common dietary triggers include wheat, onion, garlic, pulses and milk. Dietitian-led delivery of the low FODMAP diet is not always available and alternative education delivery methods, e.g. webinars, apps and leaflets, are available but remove the personalised approach and may be less acceptable to patients and may introduce safety concerns in terms of nutritional adequacy. Predicting response to the low FODMAP diet using symptom severity or a biomarker is of great interest. More evidence on less restrictive approaches and non-dietitian-led education delivery methods are needed.

The Role of the FODMAP Diet in IBS

The low FODMAP (fermentable oligosaccharide, disaccharide, monosaccharide, and polyol) diet is a beneficial therapeutic approach for patients with irritable bowel syndrome (IBS). However, how the low FODMAP diet works is still not completely understood. These mechanisms encompass not only traditionally known factors such as luminal distension induced by gas and water but also recent evidence on the role of FOMAPs in the modulation of visceral hypersensitivity, increases in intestinal permeability, the induction of microbiota changes, and the production of short-chain fatty acids (SCFAs), as well as metabolomics and alterations in motility. Although most of the supporting evidence is of low quality, recent trials have confirmed its effectiveness, even though the majority of the evidence pertains only to the restriction phase and its effectiveness in relieving abdominal bloating and pain. This review examines potential pathophysiological mechanisms and provides an overview of the existing evidence on the effectiveness of the low FODMAP diet across various IBS subtypes. Key considerations for its use include the challenges and disadvantages associated with its practical implementation, including the need for professional guidance, variations in individual responses, concerns related to microbiota, nutritional deficiencies, the development of constipation, the necessity of excluding an eating disorder before commencing the diet, and the scarcity of long-term data. Despite its recognized efficacy in symptom management, acknowledging these limitations becomes imperative for a nuanced comprehension of the role of a low FODMAP diet in managing IBS. By investigating its potential mechanisms and evidence across IBS subtypes and addressing emerging modulations alongside limitations, this review aims to serve as a valuable resource for healthcare practitioners, researchers, and patients navigating the intricate landscape of IBS.

Lactose malabsorption and intolerance: What is the correct management in older adults?

Lactose malabsorption is a very common condition due to intestinal lactase deficiency. Post weaning, a genetically programmed and irreversible reduction of lactase activity occurs in the majority of the world's population. Lactose malabsorption does not necessarily result in gastrointestinal symptoms, i.e. lactose intolerance, which occurs in approximately one third of those with lactase deficiency. In the absence of well-established guidelines, the common therapeutic approach tends to exclude milk and dairy products from the diet. However, this strategy may have serious nutritional disadvantages. Mainly in particular categories, such as the older adults, the approach to lactose malabsorption may deserve careful considerations. Milk and dairy products are an important supply of a wide range of nutrients that contribute to meet the nutritional needs in different life stages. Dietary composition can significantly impact the mechanisms leading to age-related loss of bone mineral density, skeletal muscle mass or function and overall risk of sarcopenia. Moreover, in the latest years, different lines of evidence have highlighted an association between dairy intake and prevention of chronic diseases as well as all-cause mortality. The aim of this opinion paper is to provide an overview of lactose malabsorption and intolerance in the older adults and their implications in clinical practice.

Myths and Facts about Food Intolerance: A Narrative Review

Most adverse reactions to food are patient self-reported and not based on validated tests but nevertheless lead to dietary restrictions, with patients believing that these restrictions will improve their symptoms and quality of life. We aimed to clarify the myths and reality of common food intolerances, giving clinicians a guide on diagnosing and treating these cases. We performed a narrative review of the latest evidence on the widespread food intolerances reported by our patients, giving indications on the clinical presentations, possible tests, and dietary suggestions, and underlining the myths and reality. While lactose intolerance and hereditary fructose intolerance are based on well-defined mechanisms and have validated diagnostic tests, non-coeliac gluten sensitivity and fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) intolerance are mainly based on patients' reports. Others, like non-hereditary fructose, sorbitol, and histamine intolerance, still need more evidence and often cause unnecessary dietary restrictions. Finally, the main outcome of the present review is that the medical community should work to reduce the spread of unvalidated tests, the leading cause of the problematic management of our patients.

Assesment of functional gastrointestinal diseases in obese children

Functional gastrointestinal disorders (FGID) are disorders of gut-brain interactions characterized by chronic recurrent gastrointestinal symptoms and are reported to be more common in obese individuals. The aim of the study was to evaluate FGID in obese children. A total of 405 children (6-18 years) were enrolled in this cross sectional study. The children were divided into two groups according to body mass index (BMI) as < 85th percentile and > 95th percentile. Diagnosis of FGID was based on ROME VI criteria. Demographic and clinical characteristics of the patients were evaluated. FGID and subgroups were determined. The mean age of the children was 12.73 ± 3.17 years; 52% (n = 211) of them was female and 47.9% (n = 194) was male. A total of 50.6% patients had BMI > 95th percentile, and 55.1% of those patients had FGID. The subgroups of FGID, functional abdominal pain disorders and functional defecation disorders were significantly more common in obese children than non-obese group (P < 0.01). Additionally, constipation-predominant irritable bowel syndrome (IBS), diarrhea-predominant IBS, functional diarrhea, and abdominal distention were significantly more common in obese children than non-obese children (P < 0.01).

CONCLUSION

 FGID in obese children was found to be increased significantly. Assessment of functional gastrointestinal symptoms in obese children will prevent unnecessary examinations.

WHAT IS KNOWN

• Functional gastrointestinal disorders are reported to be more common in obese individuals.

WHAT IS NEW

• Functional abdominal pain disorders and functional defecation disorders were significantly more common in obese children than non-obese group. • Constipation-predominant irritable bowel syndrome (IBS), diarrhea-predominant IBS, functional diarrhea, and abdominal distention were significantly more common in obese children than non-obese children.

An Exploratory Study Investigating the Prevalence of Gastrointestinal Symptoms in Collegiate Division I American Football Athletes

Gastrointestinal (GI) symptoms may limit performance, but their prevalence and impact among team sports athletes is not well-documented. The objective of this study was to examine the prevalence of GI symptoms in a small sample of collegiate DI American football athletes, using a survey including the Gastrointestinal Symptoms Ratings Scale (GSRS). Forty-six athletes responded to the survey and reported scores for the 15-question GSRS with additional questions about dietary habits and supplement use. A total of 44 athletes were included in the study (45% of the current roster, age: 20.7 ± 1.7 years, 50% Afro-American or black, 39% skill position, 18% NSAIDs use, and 41% reporting protein supplement use); approximately half of the athletes (52%) reported experiencing GI complaints during exercise. Two-thirds of the athletes (61%) reported at least one or more GI symptoms in general, and 50% reported at least four moderate complaints. Seven athletes (16%) reported ≥2 severe GI symptoms with 5-13 moderate complaints. The most reported symptom was stomach pain (39%, n = 17), followed by hunger pain (36%, n = 16). Athletes reporting the use of protein supplements reported a higher GSRS score (22.0 and interquartile range (IQR) 17.0-31.8) vs. athletes not reporting protein use (15.0 and IQR 15.0-19.3), p = 0.001. Most athletes surveyed reported experiencing GI symptoms. A small group of these athletes reported multiple, varied, and severe symptoms that were associated with self-reported protein supplement use. In conclusion, the number of complaints varied among athletes, confirming the value of integrating the GSRS for screening purposes, and the expected need for individual dietary treatment approaches.

Dietary fibre definition revisited - The case of low molecular weight carbohydrates

Low molecular weight (LMW) non-digestible carbohydrates (namely, oligosaccharides and inulin) are accepted as dietary fibre in many countries worldwide. The inclusion of oligosaccharides as dietary fibre was made optional within the Codex Alimentarius definition in 2009, which has caused great controversy. Inulin is accepted as dietary fibre by default, due to being a non-digestible carbohydrate polymer. Oligosaccharides and inulin occur naturally in numerous foods and are frequently incorporated into commonly consumed food products for a variety of purposes, such as to increase dietary fibre content. LMW non-digestible carbohydrates, due to their rapid fermentation in the proximal colon, may cause deleterious effects in individuals with functional bowel disorders (FBDs) and, as such, are excluded on the low FODMAP (fermentable oligosaccharides, disaccharides, and polyols) diet and similar protocols. Their addition to food products as dietary fibre allows the use of associated nutrition/health claims, causing a paradox for those with FBDs, which is further complicated by lack of clarity on food labelling. Therefore, this review aimed to discuss whether the inclusion of LMW non-digestible carbohydrates within the Codex definition of dietary fibre is warranted. This review provides justification for the exclusion of oligosaccharides and inulin from the Codex definition of dietary fibre. LMW non-digestible carbohydrates could, instead, be placed in their own category as prebiotics, recognised for their specific functional properties, or considered food additives, whereby they are not promoted for being beneficial for health. This would preserve the concept of dietary fibre being a universally beneficial dietary component for all individuals.

Effects of a Low-FODMAP Diet on Irritable Bowel Syndrome in Both Children and Adults-A Narrative Review

Irritable bowel syndrome is a typical gastrointestinal disease that causes bloating, flatulence, abdominal pain, diarrhoea, constipation, or alteration of the last two in adults and children. A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) is one of the potential treatment strategies to reduce abdominal symptoms and increase the quality of life. The present narrative review aims to present a general overview of current studies that have evaluated the efficacy of a low-FODMAP diet against other diets in gastrointestinal symptoms, nutrient intake in adults and children, and lifestyle quality. The research was performed using seven searchable databases, which included the Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews (CDSR), Excerpta Medica Database (EMBASE), Medline, PubMed, Scopus, and Web of Science, up to March 2023. In conclusion, there is significant evidence that the follow-up of a low-FODMAP diet might be a feasible first-line therapeutic strategy to reduce stomach discomfort, pain, bloating, and quality of life for patients with irritable bowel syndrome.

In Vitro Effect of Enzymes and Human Milk Oligosaccharides on FODMAP Digestion and Fecal Microbiota Composition

Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) cause intestinal discomfort in patients with irritable bowel syndrome (IBS). An enzyme mix (2500 SU invertase, 2400 GalU α-galactosidase, 10,000 ALU β-galactosidase) optimized for FODMAP digestion, and/or human milk oligosaccharides (HMO) (2′-FL, DFL, and LNnT), were evaluated for effects on microbial community activity and composition in short-term colonic incubations using the fecal microbiota of four patients with IBS-D symptoms under the following test conditions: (i) FODMAP, (ii) pre-digested (with enzyme mix) FODMAP, (iii) FODMAP + HMO, and (iv) pre-digested FODMAP + HMO. Pre-digested FODMAP reduced short-chain fatty acid (SCFA) production versus FODMAP; HMO restored this. A 10-day experiment with the simulator of the human intestinal microbial ecosystem (SHIME®), using fecal samples from two patients with IBS-D, further evaluated these findings. FODMAP resulted in decreased microbial diversity versus blank. Pre-digestion with the enzyme mix restored microbial diversity, improved FODMAP digestibility, and reduced gas pressure versus undigested FODMAP; however, SCFA production decreased. HMO restored SCFA production along with an increase in gas pressure and increased abundance of Lachnospiraceae. When used in combination, the FODMAP enzyme mix and HMO may resolve FODMAP-related IBS symptoms while maintaining a healthy gut microbiome via prebiotic activity.

Effects of dragon fruit oligosaccharides on immunity, gut microbiome, and their metabolites in healthy adults – a randomized double-blind placebo controlled study

Healthy food has wide popularity and relates positively to health. Our previous studies have shown that dragon fruit oligosaccharides (DFO) have prebiotic activities, balancing the gut microbiota in a simulated human colon system, and are safe and stimulate the immune system in rats. The effects of DFO on immune stimulation gut microbe modulation and the correlation of gut microbiota and nutrients were investigated in a human trial. This clinical study was a randomized, double-blinded, placebo-controlled trial. The participants were 107 healthy adults, divided into 3 groups that received DFO in drinking waterdoses of 4 and 8 g/day, compared to the placebo group for 4 consecutive weeks. DFO consumption at 4 g/day increased IgA level (11.31 mg/dL or 10.95% from baseline) and 8 g/day outstandingly promoted the growth of Bifidobacterium spp. (8.41%) and Faecalibacterium (1.99%) and decreased harmful bacteria, especially, Escherichia coli (8.44%). The relationship between gut microbes and nutrient intake was explored and significant (p < 0.05) correlations between specific microbial groups and intakes of specific macro- and micronutrients were observed. The potential dose of DFO for healthy adults was established as 4 g/day for improving IgA level and 8 g/day for promoting beneficial gut microbiota.

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.

Role of Low-FODMAP diet in functional dyspepsia: "Why", "When", and "to Whom"

Functional dyspepsia (FD) is a frequent disorder of gut-brain interaction, affecting 5-7% of people globally, with significant impairment in quality of life. The management of FD is challenging due to the lack of specific therapeutic approaches. Although food seems to play a role in symptom production, its pathophysiologic role in patients with FD is not fully understood. Most FD patients report that their symptoms are triggered by food, especially in the post-prandial distress syndrome (PDS) group, although evidence to support the use of dietary interventions are limited. FODMAPs can increase production of gas in the intestinal lumen, through fermentation by intestinal bacteria, can exert osmotic effects by increasing water volume and can cause an excessive production of short-chain fatty acids (propionate, butyrate, and acetate). Emerging scientific evidence, confirmed by recent clinical trials, suggest that FODMAPs could be involved in the pathogenesis of FD. Given the consolidated approach of the Low-FODMAP Diet (LFD) in irritable bowel syndrome (IBS) management and emerging scientific evidence regarding the LFD in FD, a therapeutic role of this diet may be hypothesized also in FD, either alone or in combination with other therapies.

Effect of oat or rice flour on pulse-induced gastrointestinal symptoms and breath hydrogen in subjects sensitive to pulses and controls - a randomised cross-over trial with two parallel groups

Pulses are healthy and sustainable but induce gut symptoms in people with a sensitive gut. Oats, on the contrary, have no fermentable oligo- di-, monosaccharides and polyols compounds and are known for the health effects of their fibres. This 4-day cross-over trial investigated the effects of oat and rice flour ingested with pulses on gut symptoms and exhaled gases (4th day only) in subjects with a sensitive gut or IBS (n 21) and controls (n 21). The sensitive group perceived more symptoms after both meals than controls (P = 0·001, P = 0·001). Frequency, intensity or quality of the symptoms did not differ between meals during the first 3 d in either group. More breath hydrogen was produced after an oat than rice containing meal in both groups (AUC, P = 0·001, P = 0·001). No between-group difference was seen in breath gases. During day 4, both sensitive and control groups perceived more symptoms after the oat flour meal (P = 0·001, P = 0·0104, respectively) as mainly mild flatulence. No difference in moderate or severe symptoms was detected. Increased hydrogen production correlated to a higher amount of perceived flatulence after the oat flour meal in both the sensitive and the control groups (P = 0·042, P = 0·003, respectively). In summary, ingestion of oat flour with pulses increases breath hydrogen levels compared with rice flour, but gastrointestinal symptoms of subjects sensitive to pulses were not explained by breath hydrogen levels. Additionally, consumer mindsets towards pulse consumption and pulse-related gut symptoms were assessed by an online survey, which implied that perceived gut symptoms hinder the use of pulses in sensitive subjects.

A nutritional supplement based on a synbiotic combination of Bacillus subtilis DSM 32315 and L-alanyl-L-glutamine improves glucose metabolism in healthy prediabetic subjects - A real-life post-marketing study

Introduction

Impaired glucose homeostasis is a significant risk factor for cardiometabolic diseases, whereas the efficacy of available standard therapies is limited, mainly because of poor adherence. This post-marketing study assessed the glucose-lowering potential of a synbiotic-based formulation.

Methods

One hundred ninety-two participants were enrolled in a digital nutrition program with continuous glucose monitoring (CGM) and received a study product comprising Bacillus subtilis DSM 32315 and L-alanyl-L-glutamine. Participants underwent a first sensor phase without supplementation, followed by a 14-day supplementation phase without sensor, and completed by a second sensor phase while continuing supplementation. Fasting glucose levels were determined before and after supplementation by CGM. In addition, the postprandial glycemic response to an oral glucose challenge, body weight, HbA1c concentrations, and BMI was analyzed. Subgroup analyses of subjects with elevated glucose and HbA1c levels vs. normoglycemic subjects were performed.

Results

Supplementation with the study product resulted in significant improvements in glucose parameters (delta values: fasting glucose -2,13% ± 8.86; iAUC0-120 -4.91% ± 78.87; HbA1c: -1.20% ± 4.72) accompanied by a significant weight reduction (-1.07 kg ± 2.30) in the study population. Subgroup analyses revealed that the improvements were mainly attributed to a prediabetic subgroup with elevated fasting glucose and HbA1c values before supplementation (delta values: fasting glucose -6.10% 4± 7.89; iAUC0-120 -6.28% ± 115.85; HbA1c -3.31% ± 4.36; weight: -1.47 kg ± 2.82).

Conclusion

This study indicates that the synbiotic composition is an effective and convenient approach to counteract hyperglycemia. Further placebo-controlled studies are warranted to test its efficacy in the treatment of cardiometabolic diseases.

Effectiveness of diet, psychological, and exercise therapies for the management of bile acid diarrhoea in adults: A systematic review

BACKGROUND

Bile acid diarrhoea (BAD) causes chronic diarrhoea and is primarily treated pharmacologically. This systematic review aimed to evaluate the effectiveness of non-pharmacological therapies for evidence-based management of BAD in adults.

METHODS

A systematic review of the medical literature was performed from 1975 to 13 July 2021 to identify studies on diet, psychological, and exercise therapies that met diagnostic criteria for BAD in adults with diarrhoea. Effectiveness was judged by responder or improvement in diarrhoea at study endpoint according to each study's definition of diarrhoea. Therapeutic effect on abdominal pain and flatulence was also measured. Risk of bias was assessed using the Risk Of Bias In Non-Randomised Studies of Interventions tool. A narrative review was conducted using 'Synthesis Without Meta-analysis' guidance. Certainty of the evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation.

RESULTS

Eight prospective cohort studies were identified on diet therapies from 2 weeks to over 2 years involving 192 patients. No psychological or exercise therapies were found. Carbohydrate modification (one study, n = 2) in primary BAD, and dietary fat intake reductions (five studies, n = 181) and an exclusive elemental diet therapy (two studies, n = 9) in secondary BAD, showed beneficial directions of effect on diarrhoea, abdominal pain, and flatulence. Risks of bias for each study and across studies for each therapy type were serious. Certainty of the evidence was very low for all outcomes.

CONCLUSIONS

No conclusions could be drawn on the effectiveness of diet, psychological, or exercise therapies on diarrhoea, abdominal pain, and flatulence for the management of BAD in adults. High-quality randomised controlled trials are needed.

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.

Children with functional abdominal pain disorders successfully decrease FODMAP food intake on a low FODMAP diet with modest improvements in nutritional intake and diet quality

BACKGROUND

We sought to determine how a low fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) diet (LFD) affected high FODMAP food intake, nutrient intake, and diet quality in children with functional abdominal pain disorders (FAPD).

METHODS

Children (ages 7-13 years) with Rome IV FAPD began a dietitian-guided LFD. Three-day food records were captured at baseline and 2-3 weeks into the LFD. Intake of high FODMAP foods, energy, macronutrients, micronutrients, food groups, and ultra-processed foods were determined.

KEY RESULTS

Median age of participants was 11 years, and 19/31 (61%) were female. Twenty-eight (90%) decreased high FODMAP food intake on the LFD: overall median (25-75%) high FODMAP foods/day decreased from 5.7 (3.6-7.3) to 2 (0.3-3.7) (p < 0.001). A more adherent subset (n = 22/71%) of participants consumed on average ≤3 high FODMAP foods per day during the LFD. Baseline nutritional intake and quality were generally poor with several micronutrient deficiencies identified. Diet quality improved on the LFD with increased servings of vegetables and protein and decreased consumption of ultra-processed foods, trans-fatty acids, and added sugars. On the LFD, there were significant decreases in total carbohydrates and thiamin (remained within recommended intake) and significant increases in vitamin B6 (p = 0.029), vitamin C (p = 0.019), and vitamin E (p = 0.009). Children more adherent to the LFD further increased vitamin D, magnesium, potassium, and fat servings.

CONCLUSIONS AND INFERENCES

The majority of children with FAPD on a dietitian-led LFD successfully decreased high FODMAP food intake. Children with FAPD on the LFD (vs. baseline) modestly improved micronutrient intake and diet quality.

Potential tolerability of ancient grains in non-celiac wheat sensitivity patients: A preliminary evaluation

BACKGROUND AND AIMS

A wheat-free diet (WFD) represents the elective treatment for Non-celiac Wheat Sensitivity (NCWS) patients. Preliminary reports have shown a possible better tolerability of ancient grains in these subjects. The aim of this observational study was to evaluate the frequency of consumption of ancient grains and its correlation with clinical manifestations in NCWS patients.

METHODS

223 NCWS patients were recruited, and their consumption of ancient grains was monitored. Participants were first administered a modified version of the Pavia/Biagi questionnaire to investigate their adherence to "modern WFD." The appearance/exacerbation of symptoms after ingestion of ancient grains was then assessed with WHO toxicity grading scale.

RESULTS

50.2% of the recruited patients reported consuming ancient grains before NCWS diagnosis; the diagnostic delay in this group was significantly higher than in non-consumers [median (range) 72 (6-612) vs. 60 months (3-684), P = 0.03] and these patients reported lower frequency of constipation (P = 0.04). Of the 107 patients with optimal adherence to modern WFD, 14 reported eating ancient wheat after NCWS diagnosis. Among them, 5 reported milder symptoms than those caused by modern wheat intake and 3 had an excellent tolerability without symptoms. Timilia/Tumminia variety was the most frequently used ancient grain.

CONCLUSIONS

NCWS patients who consume ancient grains may receive a late diagnosis due to the possible clinical benefit (tolerability) obtained with these grains. Even after diagnosis, 10% of the patients still consumed ancient grains and had mild or no symptoms. Further studies are required to define the pathophysiological mechanism behind their putative greater tolerability.

Diet for Functional Gastrointestinal Disorders/Disorders of Gut-Brain Interaction

Dietary interventions may alleviate symptoms related to functional gastrointestinal disorders, now termed disorders of gut-brain interaction. We reviewed which interventions have high-quality data to support their use in gastroesophageal reflux disease (GERD), functional dyspepsia (FD), irritable bowel syndrome, and chronic idiopathic constipation.

A therapeutic guide on pediatric irritable bowel syndrome and functional abdominal pain-not otherwise specified

Disorders of the gut-brain interaction negatively impact quality of life and carry a substantial socioeconomic burden. Irritable bowel syndrome (IBS) and functional abdominal pain-not otherwise specified (FAP-NOS) are common functional abdominal pain disorders in childhood. The pathophysiology is not fully understood, and high-quality intervention trials and international guidelines are missing. Therefore, the management of these disorders remains challenging. This review aims to provide an up-to-date overview of therapeutic possibilities for pediatric IBS or FAP-NOS and recommends management strategies. To prevent unnecessary referrals and extensive costs, it is fundamental to make a positive diagnosis of IBS or FAP-NOS in children with chronic abdominal pain with only minimal investigations. A tailor-made approach for each patient, based on the accompanying physical and psychological symptoms, is proposed to date.

CONCLUSION

Shared decision-making including non-pharmacological and pharmacological interventions should be considered and discussed with the family.

WHAT IS KNOWN

• Irritable bowel syndrome and functional abdominal pain-not otherwise specified are common in childhood. • Although the number of treatment options has grown recently, managing these disorders can be challenging and unsatisfactory, and no evidence-based international management guidelines are available.

WHAT IS NEW

• We suggest using a stepwise individualized approach to management, where after first-line management, both non-pharmacological and pharmacological interventions should be discussed.

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.

A Comparison of the Low-FODMAPs Diet and a Tritordeum-Based Diet on the Gastrointestinal Symptom Profile of Patients Suffering from Irritable Bowel Syndrome-Diarrhea Variant (IBS-D): A Randomized Controlled Trial

The dietary approach low in oligosaccharides, disaccharides, monosaccharides, and fermentable polyols (FODMAPs-LFD) is a good strategy for treating irritable bowel syndrome (IBS). Beyond the LFD, other dietary approaches with beneficial effects may be hypothesized. Among them, consumption of Tritordeum-based foods (TBD, bread, bakery products, and pasta) in substitution of other cereals seem to achieve promising results. In a randomized controlled trial, we compared the effects of 12 weeks of LFD to TBD in improving the symptom profile of IBS-diarrhea (IBS-D) patients. The two diets equally improved gastrointestinal symptoms and QoL, measured by the IBS Severity Scoring System (IBS-SSS) questionnaire, reducing the total score after four weeks and maintaining this range until the end of treatment (IBS-SSS total score change: −132.1; 95% CI: −74.9 to −189.4 and −130.5; 95% CI: −73.2 to −187.7; p < 0.0001 after LFD and TBD, respectively). The two diets did not modify the micronutrients content when extended for 12 weeks. LFD could be regarded as a first-line dietary approach for IBS-D patients. However, TBD may represent a valid alternative, with high palatability, especially among Italian patients, for whom pasta is considered one of the main assets of dietetic culture, and would be easier to manage in their daily habits.

Efficacy of FODMAP Elimination and Subsequent Blinded Placebo-Controlled Provocations in a Randomised Controlled Study in Patients with Ulcerative Colitis in Remission and Symptoms of Irritable Bowel Syndrome: A Feasibility Study

Background: Patients with inflammatory bowel disease (IBD) and symptoms of irritable bowel syndrome (IBS) may be intolerant to fermentable carbohydrates (FODMAPs). The aim of this study was to test the feasibility of eliminating and subsequently reintroducing FODMAPs in patients with IBS symptoms as part of the IBD manifestation and to compare the severity of IBS symptoms and pain, bloating and quality of life (QoL). Methods: An eight-week randomised open-label FODMAP elimination with double-blinded, crossover provocations of FODMAP and placebo. Diet patients were on a low-FODMAP diet for eight weeks with blinded two-week provocations after two and six weeks. Questionnaires, blood and stool samples were collected. Results: Patient enrolment was challenging. Nineteen participants were included in the study. Eliminating low FODMAP for two weeks resulted in significant decreases in pain and bloating scores (p < 0.003), whereas there were no statistical differences in pain scores between diet patients and controls. Pain and bloating scores increased, returning to baseline levels after two weeks of double-blinded provocations with placebo, (p > 0.05). Conclusions: The results document the possibility of performing a randomised controlled study following the gold standard for testing food intolerance with blinding of the Low FODMAP diet. Recruitment of participants was challenging.

FUNCTIONAL ABDOMINAL PAIN IS THE MAIN ETIOLOGY AMONG CHILDREN REFERRED TO TERTIARY CARE LEVEL FOR CHRONIC ABDOMINAL PAIN

ABSTRACT Background Chronic abdominal pain (CAP) carries a significant burden of disease. The last edition of the Rome Criteria (Rome IV) allows the diagnosis of functional gastrointestinal disorders (FGIDs) according to symptoms-based criteria; however, patients continue to experience a delay in their diagnosis and to be submitted to different interventions before the establishment of a positive diagnosis. Objective We aimed to characterize etiology, clinical features, and interventions in a pediatric cohort of patients with CAP secondary to FGIDs, who were referred to our tertiary care university-affiliated hospital, in Brazil. Methods A retrospective descriptive study of children and adolescents (aged 20 years and younger) referred to our institution, from January/2013 to December/2018, for CAP, and who fulfilled criteria for FGIDs classified according to Rome IV criteria. Results Three hundred twenty-eight patients with CAP were screened, of which 67.9% (223 patients) fulfilled the criteria for FGIDs and were included in the study. Sixty percent were female, with a mean age of 8.3 years. At the time of referral, the mean duration of symptoms was 2.8 years. Length/height for age and weight for age mean z-scores were -0.08±1.87 and -0.38±1.62, respectively. Functional abdominal pain not otherwise specified was overall the most common diagnosis (70.4%). Before establishing the diagnosis of FGIDs, multiple pharmacological interventions were described, while after, the mainstay of therapy was education/reassurance and dietary interventions. Thirty-two percent of patients did not further require specialized follow-up. Conclusion Even at the tertiary care level, FGIDs were still the most common etiology of chronic abdominal pain, particularly functional abdominal pain not otherwise specified. Despite the relatively long duration of symptoms at referral, cessation of specialized care follow-up was possible in approximately a third of the cases.

Gut-brain axis dysfunction underlies FODMAP-induced symptom generation in irritable bowel syndrome

BACKGROUND

FODMAPs produce similar small bowel water and colonic gas in patients with irritable bowel syndrome (IBS) and healthy controls (HCs), despite IBS patients reporting increased gastrointestinal (GI) symptoms.

AIM

To unravel the mechanisms underlying FODMAP-induced symptom reporting, we investigated gut and brain responses to fructan administration in IBS patients and HC.

METHODS

This randomised, double-blind, cross-over study consisted of three visits where fructans (40 g/500 mL saline), glucose (40 g/500 mL saline) or saline (500 mL) were infused intragastrically during 1 h MR brain scanning; abdominal MRI was performed before, 1 h, and 2 h post-infusion. Symptoms were rated using validated scales.

RESULTS

In IBS (n = 13), fructans induced more cramps, pain, flatulence and nausea compared to glucose (P = 0.03, 0.001, 0.009 and <0.001 respectively), contrary to HC (n = 13) (all P > 0.14), with between-group differences for cramps and nausea (P = 0.004 and 0.023). Fructans increased small bowel motility and ascending colonic gas and volume equally in IBS and HC (between-group P > 0.25). The difference in colonic gas between fructans and saline covaried with differences in bloating and cramps in IBS (P = 0.008 and 0.035 respectively). Pain-related brain regions responded differentially to fructans in IBS compared to HC, including the cerebellum, supramarginal gyrus, anterior and midcingulate cortex, insula and thalamus (p_{FWE-corrected}  < 0.05); these brain responses covaried with symptom responses in IBS.

CONCLUSIONS

Fructans increase small bowel motility and colon gas and volume similarly in IBS patients and HC. Increased symptom responses to fructans in IBS covary with altered brain responses in pain-related regions, indicating that gut-brain axis dysregulation may drive FODMAP-induced symptom generation in IBS.

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.

Performance and Interpretation of Hydrogen and Methane Breath Testing Impact of North American Consensus Guidelines

BACKGROUND

Hydrogen and methane breath tests (HMBT) are widely used clinical investigations but lack standardization. To address this, the North American Consensus (NAC) group published evidence-based recommendations for HMBT.

AIMS

To evaluate results obtained using NAC recommendations for HMBT, compared to retrospective data that utilized guidelines previously recommended.

METHODS

HMBT data from 725 patients referred for small intestinal bacterial overgrowth (SIBO) and/or carbohydrate malabsorption (CM) testing were analyzed. Data were compared regarding dose of substrate for SIBO testing (16 vs. 10 g lactulose, and 50 vs. 75 g glucose) and the effect of post-ingestion sampling period for malabsorption testing. The effect of different recommended cut-off values for SIBO were examined.

RESULTS

Substrate dose did not affect methane production. 10 g lactulose significantly reduced positive SIBO results compared to 16 g lactulose (42 vs. 53%, p = 0.04). 75 g glucose significantly increased positive results compared to 50 g glucose (36 vs. 22%, p = 0.04). Provoked symptoms were significantly more prevalent in patients testing positive by both North American Consensus and Ledochowski cut-off values. 34.5% of patients tested positive for CM at 180-min compared to 28% at 120-min (not significant, p = 0.19).

CONCLUSIONS AND INFERENCES

10 g lactulose substrate produces fewer positive SIBO results than 16 g lactulose, while 75 g glucose dose produces more positive SIBO results than 50 g. Performing CM breath tests for 180 min increases number of positive results when compared to 120 min. SIBO cut-off timings require further investigation, but our findings broadly support the NAC recommendations for SIBO and CM testing.

Fructose intolerance is not associated with malabsorption in patients with functional gastrointestinal disorders

BACKGROUND

Symptoms following fructose ingestion, or fructose intolerance, are common in patients with functional gastrointestinal disorders (FGID) and are generally attributed to intestinal malabsorption. The relationships between absorption, symptoms, and intestinal gas production following fructose ingestion were studied in patients with FGID.

METHODS

Thirty FGID patients ingested a single dose of fructose 35 g or water in a randomized, double-blind, crossover study. Blood and breath gas samples were collected, and gastrointestinal symptoms rated. Plasma fructose metabolites and short-chain fatty acids were quantified by targeted liquid chromatography-tandem mass spectrometry. Patients were classified as fructose intolerant or tolerant based on symptoms following fructose ingestion.

KEY RESULTS

The median (IQR) areas under the curve of fructose plasma concentrations within the first 2 h (AUC_0-2 h ) after fructose ingestion were similar for patients with and without fructose intolerance (578 (70) µM·h vs. 564 (240) µM·h, respectively, p = 0.39), as well as for the main fructose metabolites. There were no statistically significant correlations between the AUC_0-2 h of fructose or its metabolites concentrations and the AUCs of symptoms, breath hydrogen, and breath methane. However, the AUCs of symptoms correlated significantly and positively with the AUC_0-2 h of hydrogen and methane breath concentrations (r = 0.73, r = 0.62, respectively), and the AUCs of hydrogen and methane concentrations were greater in the fructose-intolerant than in the fructose-tolerant patients after fructose ingestion (p ≤ 0.02).

CONCLUSIONS & INFERENCES

Fructose intolerance in FGID is not related to post-ingestion plasma concentrations of fructose and its metabolites. Factors other than malabsorption, such as altered gut microbiota or sensory function, may be important mechanisms.

Food Allergies and Intolerances: A Clinical Approach to the Diagnosis and Management of Adverse Reactions to Food

Food allergy is an aberrant immunological response to food antigen, which can result in potentially life-threatening reactions. It is often challenging to differentiate food allergy from other adverse reactions to food because their presentations can be indistinguishable. The purpose of this article is to give an overview of the classification, evaluation, and management of adverse food reactions, key differentiating features of food allergy, roles and limitations of various food allergy testing, and promising areas of emerging research. Case studies are used to highlight some of the clinical pearls in diagnosing and managing food-related diseases.

Feasibility of a low FODMAPs diet without initial dietician intervention in the management of patients with irritable bowel syndrome: a prospective study

BACKGROUND AND AIMS

Efficiency of a low FODMAPs diet (LFD) to relieve symptoms in patients with irritable bowel syndrome (IBS) has been proved in several studies. Our study aimed to evaluate the management of IBS-patients when explanations about LFD are given by the physician without dietician intervention.

PATIENTS AND METHODS

Patients with IBS were evaluated prospectively after explanations about the LFD were given with the help of a leaflet. A first questionnaire evaluating trigger foods and diet acceptability was submitted to the patient after the consultation. Six weeks later, a second questionnaire evaluated patient's understanding and adherence to the diet, the evolution of symptoms, and the need for a specific dietetic support.

RESULTS

Thirty-five patients were included (69% female; mean age 45±15). Seventy-four percent of the patients thought that their symptoms were related to food ingestion, and 97% were ready to go on a diet to improve their symptoms. During the second visit, 91% of the patients reported understanding correctly the explanations, 52% followed LFD regularly, 28% sometimes and 20% did not follow LFD at all or barely. Multiple non-adherence factors were reported. All symptoms, except constipation, decreased significantly six weeks after starting LFD. Finally, 77% of the patients reported satisfaction with care and 69% were willing to be supported by a dietician.

CONCLUSIONS

Most IBS patients understood explanations given by GI physicians, but low compliance to the diet and a wish for dietician support was highlighted, suggesting that a dietician intervention should be scheduled when LFD is implemented.

Functional dyspepsia: A critical appraisal of the European consensus from a global perspective

The European Society for Neurogastroenterology and Motility's (ESNM) consensus document on functional dyspepsia (FD) has provided a critical review of the evidence for 36 statements highly relevant to the diagnosis and treatment of FD. We provide here our expert opinion on the North American, Australian and Asian assessments of the same topics discussed, and provide evidence where the ESNM consensus may deviate from those in the other continents. New and exciting data about the pathogenesis of FD are emerging including the possible central role of duodenal micro-inflammation (most notably eosinophilic duodenitis and intestinal mast cell disease), but this is a very dynamic field with several gaps remaining in our understanding that are summarized in this review. Identification of non-invasive biomarkers and testing of targeted therapies, including assessing the benefits of multidisciplinary teams in the management of FD, should be future priorities.

Dietary modulation of gut microbiota for the relief of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a frequently diagnosed gastrointestinal (GI) disorder characterized by recurrent abdominal pain, bloating, and changes in the stool form or frequency without any structural changes and overt inflammation. It is not a life-threatening condition but causes a considerable level of discomfort and distress. Among the many pathophysiologic factors, such as altered GI motility, visceral hypersensitivity, and low-grade mucosal inflammation, as well as other immunologic, psychologic, and genetic factors, gut microbiota imbalance (dysbiosis), which is frequently found in IBS, has been highlighted as an etiology of IBS. Dysbiosis may affect gut mucosal homeostasis, immune function, metabolic regulation, and even visceral motor function. As diet is shown to play a fundamental role in the gut microbiota profile, this review discusses the influence of diet on IBS occurring through the modulation of gut microbiota. Based on previous studies, it appears that dietary modulation of the gut microbiota may be effective for the alleviation of IBS symptoms and, also an effective IBS management strategy based on the underlying mechanism; especially because, IBS currently has no specific treatment owing to its uncertain etiology.

Screening dietary fibres for fermentation characteristics and metabolic profiles using a rapid in vitro approach: implications for irritable bowel syndrome

The therapeutic value of specific fibres is partly dependent on their fermentation characteristics. Some fibres are rapidly degraded with the generation of gases that induce symptoms in patients with irritable bowel syndrome (IBS), while more slowly or non-fermentable fibres may be more suitable. More work is needed to profile a comprehensive range of fibres to determine suitability for IBS. Using a rapid in vitro fermentation model, gas production and metabolite profiles of a range of established and novel fibres were compared. Fibre substrates (n 15) were added to faecal slurries from three healthy donors for 4 h with gas production measured using real-time headspace sampling. Concentrations of SCFA and ammonia were analysed using GC and enzymatic assay, respectively. Gas production followed three patterns: rapid (≥60 ml/g over 4 h) for fructans, carrot fibre and maize-derived xylo-oligosaccharide (XOS); mild (30-60 ml/g) for partially hydrolysed guar gum, almond shell-derived XOS and one type of high-amylose resistant starch 2 (RS2) and minimal (no differences with blank controls) for methylcellulose, another high-amylose RS2, acetylated or butyrylated RS2, RS4, acacia gum and sugarcane bagasse. Gas production correlated positively with total SCFA (r 0·80, P < 0·001) and negatively with ammonia concentrations (r -0·68, P < 0·001). Proportions of specific SCFA varied: fermentation of carrot fibre, XOS and acetylated RS2 favoured acetate, while fructans favoured butyrate. Gas production and metabolite profiles differed between fibre types and within fibre classes over a physiologically relevant 4-h time course. Several fibres resisted rapid fermentation and may be candidates for clinical trials in IBS patients.

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.

A randomized double-blind placebo-controlled crossover pilot study: Acute effects of the enzyme α-galactosidase on gastrointestinal symptoms in irritable bowel syndrome patients

BACKGROUND

Postprandial symptoms presumably related to intestinal gas production are common in patients with irritable bowel syndrome (IBS). The aim of the study was to assess if oral α-galactosidase is superior to placebo in reducing gastrointestinal (GI) symptoms and intestinal gas production after ingestion of carbohydrate-rich meals in adult patients with IBS.

METHODS

We studied the effect of 1200 GaIU/meal α-galactosidase (Nogasin^® ) or placebo capsules on GI symptoms in patients with IBS after three standardized, meals high in oligosaccharides, in a randomized, double-blind, crossover study. The intensity of eight GI symptoms was rated, and breath hydrogen and methane were measured every 30 min during 7.5 h. The severity of GI symptoms the following morning was assessed and compared with baseline.

S KEY RESULTS

Twenty adult patients with IBS (19 females), mean age 49 years (range 22-75 years), were included. All test meals were well tolerated but induced a gradual increase in GI symptom severity. Neither GI symptom ratings over time, nor hydrogen and methane concentrations differed between the days with α-galactosidase or placebo. The severity of abdominal pain and bloating was lower the following morning, but with no differences between α-galactosidase and placebo.

CONCLUSIONS & INFERENCES

The use of α-galactosidase together with meals high in oligosaccharides was in this pilot study not superior to placebo in reducing postprandial GI symptoms or the concentration of hydrogen and methane in expired air in IBS.

Lactose intolerance: An update on its pathogenesis, diagnosis, and treatment

Lactose intolerance has a high prevalence worldwide, ranging between 57% and 65%. It is caused by a reduction or loss of the activity of the intestinal enzyme lactase-phlorizin hydrolase, responsible for the digestion of lactose. This alteration determines an increased osmotic load in the small intestine and the fermentation of lactose by the bacterial flora, which leads to a high production of short-chain fatty acids and gas. This is followed by the onset of abdominal pain, diarrhea, and flatulence. In addition to these problems, it was found that subjects with lactose intolerance have an increased risk of developing various extra-intestinal diseases, including cancers. The diagnosis is essential to undertake an adequate treatment and, for this purpose, different methods have been tested. These include genetic test, hydrogen breath test (HBT), quick lactase test, and lactose tolerance test. HBT is the most used method because it is non-invasive, inexpensive, and highly sensitive and specific, as well as easy to perform. In clinical practice, the other methods are mainly used as HBT integration tests. There are also many therapeutic options. An appropriate intervention concerns the dietetic style, such as the consumption of lactose-free foods, but with nutritional characteristics comparable to dairy products. Other valid choices are represented by the use of exogenous enzymes, probiotics, prebiotics, the selection of milk containing specific types of beta-caseins. This review is intended to illustrate the diagnostic methods currently available and the possible therapeutic options for lactose intolerance.