The low FODMAP diet: recent advances in understanding its mechanisms and efficacy in IBS

Patients' perspectives on irritable bowel syndrome: a qualitative analysis based on social media in China

AIM

To explore the perspectives, experience, and concerns of patients with irritable bowel syndrome (IBS) in China.

METHODS

We used data mining to investigate posts shared in Baidu Tieba concerned with IBS; we collected the data through the crawler code, and mined the cleaned data's themes based on Latent Dirichlet allocation (LDA) and the Grounded theory.

RESULTS

We found 5746 network posts related to IBS. LDA analysis generated 20 topics, and grounded theory analysis established eight topics. Combining the two methods, we finally arranged the topics according to five concepts: difficulty in obtaining disease information; serious psychosocial problems; dissatisfied with the treatment; lack of social support; and low quality of life.

CONCLUSION

Social media research improved patient-centric understanding of patients' experiences and perceptions. Our study may facilitate doctor-patient communication and assist in the formulation of medical policies.

Exploring the Plasticity of Diet on Gut Microbiota and Its Correlation with Gut Health

Dietary habits have been proven to help alter the composition of gut microbiota, and exploring the impact of nutritional patterns on gut microbiota changes can help protect gut health. However, few studies have focused on the dietary impact on the gut microbiota over an experimental timeframe. In this study, 16S rRNA gene sequencing was employed to investigate the gut microbiota of mice under different dietary patterns, including AIN-93G diet (Control), high protein diet (HPD), high fiber diet (HFD), and switch diet (Switch). The alpha diversity of the HPD group significantly decreased, but HFD can restore this decline. During HPD, some genera were significantly upregulated (e.g., Feacalibaculum) and downregulated (e.g., Parabacteroides). However, after receiving HFD, other genera were upregulated (e.g., Akkermansia) and downregulated (e.g., Lactobacillus). In addition, the interaction between pathogenic bacteria was more pronounced during HPD, while the main effect was probiotics during HFD. In conclusion, the plasticity exhibited by the gut microbiota was subject to dietary influences, wherein disparate dietary regimens hold pivotal significance in upholding the well-being of the host. Therefore, our findings provide new ideas and references for the relationship between diets and gut microbiota.

Revolutionizing Inflammatory Bowel Disease Management: A Comprehensive Narrative Review of Innovative Dietary Strategies and Future Directions

This comprehensive narrative review delves into the intricate interplay between diet and inflammatory bowel disease (IBD), shedding light on the potential impact of dietary interventions in disease management. By analyzing nutritional interventions, risks, challenges, and future perspectives, this review serves as a vital resource for clinicians, researchers, and patients alike. The amalgamation of evidence underscores the significance of customizing dietary strategies for individual patients, considering disease phenotype and cultural factors. Through an exploration of dietary components' effects on IBD, including exclusive enteral nutrition and omega-3 fatty acids, this review offers pragmatic implementation advice and outlines avenues for further research. Bridging the gap between research findings and clinical applications, the review facilitates informed decision-making and patient-centric care. In the face of escalating IBD prevalence, this review emerges as an indispensable guide for healthcare professionals, empowering them to navigate the complexities of dietary management while enabling patients to actively participate in their care trajectory. Ultimately, this narrative review advances the understanding of diet's pivotal role in IBD management, fostering a more integrated approach to patient care and paving the way for improved research and policy initiatives in the field of inflammatory bowel diseases.

Irritable Bowel Syndrome: Treating the Gut and Brain/Mind at the Same Time

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal (GI) disorders in the world. Although IBS does not affect a person's life span, it can significantly influence their quality of life. The treatment of IBS should be tailored to each patient's specific symptomatology because it can often be difficult to manage. Given that the pathogenesis of IBS is not well understood, it places a tremendous load on healthcare resources. Over the years, IBS has been described as either a simple GI disorder or a more complex multi-symptomatic gut-brain axis disorder. Many persons with IBS have psychological issues in addition to gastrointestinal symptoms, offering the door to non-pharmacological therapies such as cognitive behavioral therapy, gut-directed hypnosis, or psychodynamic interpersonal therapy. Non-pharmacological therapies with no side effects should be used as first-line therapy. Diet, exercise, microbiota-targeted therapies, and psychological treatments are among the most significant interventions. This review goes into the details of all the non-pharmacological interventions that can be used to treat IBS.

Manipulation of the intestinal microbiome-a slow journey to primetime

The gut microbiota has important functions in the regulation of normal body functions. Alterations of the microbiota are being increasingly linked to various disease states. The microbiome has been manipulated via the administration of stool from animals or humans, for more than 1000 years. Currently, fecal microbiota transplantation can be performed via endoscopic administration of fecal matter to the duodenum or colon or via capsules of lyophilized stools. More recently fecal microbial transplantation has been shown to be very effective for recurrent Clostridoides difficile infection (CDI). In addition there is some evidence of efficacy in the metabolic syndrome and its hepatic manifestation, metabolic associated fatty liver disease (MAFLD), irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). We review the current literature regarding the microbiome and the pathogenesis and treatment of CDI, MAFLD, IBS and IBD.

Effects of FODMAPs and Gluten on Gut Microbiota and Their Association with the Metabolome in Irritable Bowel Syndrome: A Double-Blind, Randomized, Cross-Over Intervention Study

BACKGROUND

A mechanistic understanding of the effects of dietary treatment in irritable bowel syndrome (IBS) is lacking. Our aim was therefore to investigate how fermentable oligo- di-, monosaccharides, and polyols (FODMAPs) and gluten affected gut microbiota and circulating metabolite profiles, as well as to investigate potential links between gut microbiota, metabolites, and IBS symptoms.

METHODS

We used data from a double-blind, randomized, crossover study with week-long provocations of FODMAPs, gluten, and placebo in participants with IBS. To study the effects of the provocations on fecal microbiota, fecal and plasma short-chain fatty acids, the untargeted plasma metabolome, and IBS symptoms, we used Random Forest, linear mixed model and Spearman correlation analysis.

RESULTS

FODMAPs increased fecal saccharolytic bacteria, plasma phenolic-derived metabolites, 3-indolepropionate, and decreased isobutyrate and bile acids. Gluten decreased fecal isovalerate and altered carnitine derivatives, CoA, and fatty acids in plasma. For FODMAPs, modest correlations were observed between microbiota and phenolic-derived metabolites and 3-indolepropionate, previously associated with improved metabolic health, and reduced inflammation. Correlations between molecular data and IBS symptoms were weak.

CONCLUSIONS

FODMAPs, but not gluten, altered microbiota composition and correlated with phenolic-derived metabolites and 3-indolepropionate, with only weak associations with IBS symptoms. Thus, the minor effect of FODMAPs on IBS symptoms must be weighed against the effect on microbiota and metabolites related to positive health factors.

The Bowel-Associated Arthritis-Dermatosis Syndrome (BADAS): A Systematic Review

Bowel-associated arthritis-dermatosis syndrome (BADAS) is a rare neutrophilic dermatosis that was first described in 1971 in patients who underwent bypass surgery for obesity. Over the years, the number of reported cases associated with medical gastroenterological conditions, particularly inflammatory bowel disease (IBD), has progressively increased. To date, there are no systematic reviews in the literature on BADAS. The design of an a priori protocol was based on PRISMA guidelines, and a search of PubMed and Scopus databases was conducted for articles published between 1971 and 2023 related to the topic. Fifty-one articles including 113 patients with BADAS were analyzed in this systematic review. Bariatric surgery and IBD were the most frequently reported causes of BADAS, accounting for 63.7% and 24.7% of all cases, respectively. A total of 85% of cases displayed the typical dermatological presentation, including urticarial maculopapular lesions centered by a vesicopustule, with the majority of lesions located on the upper limbs (73.5%). Polyarthralgia or localized arthritis were always present. Atypical presentations included cellulitis-like, erythema-nodosum-like, Sweet-syndrome-like and pyoderma-gangrenosum-like manifestations. Gastrointestinal symptoms were frequently observed in IBD-related cases (67.9%). The histopathology showed a neutrophilic infiltrate (96.6%). The most commonly used treatment regimens consisted of systemic corticosteroids, metronidazole and tetracyclines, either alone or in combination. A relapsing-remitting course was observed in 52.1% of patients. In conclusion, BADAS is a neutrophilic dermatosis that presents with a wide variety of cutaneous manifestations, both typical and atypical. Gastrointestinal symptoms are frequently observed, particularly in cases related to IBD. The histopathology is clear but not specific compared with other neutrophilic dermatoses. The diagnosis can be challenging, but the relapsing-remitting course and the strong association with polyarthralgia and gastrointestinal disease can aid in the diagnosis.

The role of complex interactions between the intestinal flora and host in regulating intestinal homeostasis and inflammatory bowel disease

Pharmacological treatment of inflammatory bowel disease (IBD) is inefficient and difficult to discontinue appropriately, and enterobacterial interactions are expected to provide a new target for the treatment of IBD. We collected recent studies on the enterobacterial interactions among the host, enterobacteria, and their metabolite products and discuss potential therapeutic options. Intestinal flora interactions in IBD are affected in the reduced bacterial diversity, impact the immune system and are influenced by multiple factors such as host genetics and diet. Enterobacterial metabolites such as SCFAs, bile acids, and tryptophan also play important roles in enterobacterial interactions, especially in the progression of IBD. Therapeutically, a wide range of sources of probiotics and prebiotics exhibit potential therapeutic benefit in IBD through enterobacterial interactions, and some have gained wide recognition as adjuvant drugs. Different dietary patterns and foods, especially functional foods, are novel therapeutic modalities that distinguish pro-and prebiotics from traditional medications. Combined studies with food science may significantly improve the therapeutic experience of patients with IBD. In this review, we provide a brief overview of the role of enterobacteria and their metabolites in enterobacterial interactions, discuss the advantages and disadvantages of the potential therapeutic options derived from such metabolites, and postulate directions for further research.

Gut Symptoms during FODMAP Restriction and Symptom Response to Food Challenges during FODMAP Reintroduction: A Real-World Evaluation in 21,462 Participants Using a Mobile Application

BACKGROUND

There is limited evidence regarding the use of low FODMAP diet apps. This study aimed to evaluate the effectiveness of an app intended to reduce symptoms in FODMAP restriction and symptoms and tolerance of high FODMAP food challenges during FODMAP reintroduction and personalisation.

METHODS

Data were collected from 21,462 users of a low FODMAP diet app. Self-reported gut symptoms during FODMAP restriction, reintroduction, and personalisation and dietary triggers were identified from symptom response data for FODMAP food challenges.

RESULTS

Compared with baseline, at the end of FODMAP restriction, participants (n = 20,553) reported significantly less overall symptoms (11,689 (57%) versus 9105 (44%)), abdominal pain (8196 (40%) versus 6822 (33%)), bloating (11,265 (55%) versus 9146 (44%)), flatulence (10,318 (50%) 8272 (40%)), and diarrhoea (6284 (31%) versus 4961 (24%)) and significantly more constipation (5448 (27%) versus 5923 (29%)) (p < 0.001 for all). During FODMAP reintroduction, participants (n = 2053) completed 8760 food challenges; the five most frequent challenges and n/N (%) of dietary triggers identified were wheat bread 474/1146 (41%), onion 359/918 (39%), garlic 245/699 (35%), milk 274/687 (40%), and wheat pasta 222/548 (41%). The most frequently reported symptoms during food challenges were overall symptoms, abdominal pain, bloating, and flatulence.

CONCLUSIONS

In a real-world setting, a low FODMAP diet app can help users improve gut symptoms and detect dietary triggers for long-term self-management.

Survey-Based Analysis of the Clinical Treatment Status of Irritable Bowel Syndrome in Korea

BACKGROUND

The quality-of-life of patients with irritable bowel syndrome is low; incorrect diagnosis/treatment causes economic burden and inappropriate consumption of medical resources. This survey-based study aimed to analyze the current status of irritable bowel syndrome treatment to examine differences in doctors' perceptions of the disease, and treatment patterns.

METHODS

From October 2019 to February 2020, the irritable bowel syndrome and Intestinal Function Research Study Group of the Korean Society of Neurogastroenterology and Motility conducted a survey on doctors working in primary, secondary, and tertiary healthcare institutions. The questionnaire included 37 items and was completed anonymously using the NAVER platform (a web-based platform), e-mails, and written forms.

RESULTS

A total of 272 doctors responded; respondents reported using the Rome IV diagnostic criteria (amended in 2016) for diagnosing and treating irritable bowel syndrome. Several differences were noted between the primary, secondary, and tertiary physicians' groups. The rate of colonoscopy was high in tertiary healthcare institutions. During a colonoscopy, the necessity of random biopsy was higher among physicians who worked at tertiary institutions. 'The patient did not adhere to the diet' as a reason for ineffectiveness using low-fermentable oligo-, di-, and mono-saccharides, and polyols diet treatment was higher among physicians in primary/secondary institutions, and 'There are individual differences in terms of effectiveness' was higher among physicians in tertiary institutions. In irritable bowel syndrome constipation predominant subtype, the use of serotonin type 3 receptor antagonist (ramosetron) and probiotics was higher in primary/secondary institutions, while serotonin type 4 receptor agonist was used more in tertiary institutions. In irritable bowel syndrome diarrhea predominant subtype, the use of antispasmodics was higher in primary/secondary institutions, while the use of serotonin type 3 receptor antagonist (ramosetron) was higher in tertiary institutions.

CONCLUSION

Notable differences were observed between physicians in primary/secondary and tertiary institiutions regarding the rate of colonoscopy, necessity of random biopsy, the reason for the ineffectiveness of low-fermentable oligo-, di-, and mono-saccharides, and polyols diet, and use of drug therapy in irritable bowel syndrome. In South Korea, irritable bowel syndrome is diagnosed and treated according to the Rome IV diagnostic criteria, revised in 2016.

Screening and Application of Novel Homofermentative Lactic Acid Bacteria Results in Low-FODMAP Whole-Wheat Bread

FODMAPs are fermentable oligo-, di-, monosaccharides, and polyols. The application of homofermentative lactic acid bacteria (LAB) has been investigated as a promising approach for producing low-FODMAP whole-wheat bread. The low-FODMAP diet is recommended to treat irritable bowel syndrome (IBS). Wheat flour is staple to many diets and is a significant source of fructans, which are considered FODMAPs. The reduction of fructans via sourdough fermentation, generally associated with heterofermentative lactic acid bacteria (LAB), often leads to the accumulation of other FODMAPs. A collection of 244 wild-type LAB strains was isolated from different environments and their specific FODMAP utilisation profiles established. Three homofermentative strains were selected for production of whole-wheat sourdough bread. These were Lactiplantibacillus plantarum FST1.7 (FST1.7), Lacticaseibacillus paracasei R3 (R3), and Pediococcus pentosaceus RYE106 (RYE106). Carbohydrate levels in flour, sourdoughs (before and after 48 h fermentation), and resulting breads were analysed via HPAEC-PAD and compared with whole-wheat bread leavened with baker’s yeast. While strain R3 was the most efficient in FODMAP reduction, breads produced with all three test strains had FODMAP content below cut-off levels that would trigger IBS symptoms. Results of this study highlighted the potential of homofermentative LAB in producing low-FODMAP whole-wheat bread.

Microbiota and probiotics: chances and challenges - a symposium report

The 10th International Yakult Symposium was held in Milan, Italy, on 13-14 October 2022. Two keynote lectures covered the crewed journey to space and its implications for the human microbiome, and how current regulatory systems can be adapted and updated to ensure the safety of microorganisms used as probiotics or food processing ingredients. The remaining lectures were split into sections entitled "Chances" and "Challenges." The "Chances" section explored opportunities for the science of probiotics and fermented foods to contribute to diverse areas of health such as irritable bowel syndrome, major depression, Parkinson's disease, immune dysfunction, infant colic, intensive care, respiratory infections, and promoting healthy longevity. The "Challenges" section included selecting appropriate clinical trial participants and methodologies to minimise heterogeneity in responses, how to view probiotics in the context of One Health, adapting regulatory frameworks, and understanding how substances of bacterial origin can cross the blood-brain barrier. The symposium provided evidence from cutting-edge research that gut eubiosis is vital for human health and, like space, the microbiota deserves further exploration of its vast potential.

Small Intestinal Bacterial Overgrowth and Non-Alcoholic Fatty Liver Disease: What Do We Know in 2023?

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease associated with the pathological accumulation of lipids inside hepatocytes. Untreated NAFL can progress to non-alcoholic hepatitis (NASH), followed by fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). The common denominator of the above-mentioned metabolic disorders seems to be insulin resistance, which occurs in NAFLD patients. Obesity is the greatest risk factor for lipid accumulation inside hepatocytes, but a part of the NAFLD patient population has a normal body weight according to the BMI index. Obese people with or without NAFLD have a higher incidence of small intestinal bacterial overgrowth (SIBO), and those suffering from NAFLD show increased intestinal permeability, including a more frequent presence of bacterial overgrowth in the small intestine (SIBO). The health consequences of SIBO are primarily malabsorption disorders (vitamin B12, iron, choline, fats, carbohydrates and proteins) and bile salt deconjugation. Undetected and untreated SIBO may lead to nutrient and/or energy malnutrition, thus directly impairing liver function (e.g., folic acid and choline deficiency). However, whether SIBO contributes to liver dysfunction, decreased intestinal barrier integrity, increased inflammation, endotoxemia and bacterial translocation is not yet clear. In this review, we focus on gut–liver axis and discuss critical points, novel insights and the role of nutrition, lifestyle, pre- and probiotics, medication and supplements in the therapy and prevention of both SIBO and NAFLD.

Low FODMAP Diet Relieves Visceral Hypersensitivity and Is Associated with Changes in Colonic Microcirculation in Water Avoidance Mice Model

(1) Background: Irritable bowel syndrome (IBS) is a global public health problem, the pathogenesis of which has not been fully explored. Limiting fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) can relieve symptoms in some patients with IBS. Studies have shown that normal microcirculation perfusion is necessary to maintain the primary function of the gastrointestinal system. Here, we hypothesized that IBS pathogenesis might be related to abnormalities in colonic microcirculation. A low-FODMAP diet could alleviate visceral hypersensitivity (VH) by improving colonic microcirculation; (2) Methods: C57BL/6 mice were raised to establish an IBS-like rodent model using water avoidance (WA) stress or SHAM-WA as a control, one hour per day for ten days. The mice in the WA group were administered different levels of the FODMAP diet: 2.1% regular FODMAP (WA-RF), 10% high FODMAP diet (WA-HF), 5% medium FODMAP diet (WA-MF), and 0% low FODMAP diet (WA-LF) for the following 14 days. The body weight and food consumption of the mice were recorded. Visceral sensitivity was measured as colorectal distention (CRD) using the abdominal withdrawal reflex (AWR) score. Colonic microcirculation was assessed using laser speckle contrast imaging (LCSI). Vascular endothelial-derived growth factor (VEGF) was detected using immunofluorescence staining; (3) Results: The threshold values of CRD pressure in the WA-RF, WA-HF, and WA-MF groups were significantly lower than those in the SHAM-WA group. Moreover, we observed that colonic microcirculation perfusion decreased, and the expression of VEGF protein increased in these three groups of mice. Interestingly, a low-FODMAP dietary intervention could reverse this situation. Specifically, a low-FODMAP diet increased colonic microcirculation perfusion, reduced VEGF protein expression in mice, and increased the threshold of VH. There was a significant positive correlation between colonic microcirculation and threshold for VH; (4) Conclusions: These results demonstrate that a low-FODMAP diet can alter VH by affecting colonic microcirculation. Changes in intestinal microcirculation may be related to VEGF expression.

Gastrointestinal Manifestations and Low-FODMAP Protocol in a Cohort of Fabry Disease Adult Patients

Fabry disease (FD) is an X-linked lysosomal disorder caused by α-galactosidase A enzyme deficiency. Gastrointestinal (GI) manifestations are reported in FD with a prevalence of about 50%, usually treated by Enzymatic Replacement Therapy (ERT) or oral treatment. Since FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) can be involved in GI manifestations and dysbiosis in FD patients, a low-FODMAP diet could represent an alternative adjunctive treatment in FD subjects, as well as being useful for reducing symptoms in Irritable Bowel Syndrome (IBS). We retrospectively assessed data from 36 adult FD patients followed at the Inherited Metabolic Rare Diseases Adult Centre of the University Hospital of Padova (mean age 47.6 ± 16.2 years). Patients were screened for GI symptoms by IBS severity score and Gastrointestinal Symptom Rating Scale (GSRS) questionnaires. In symptomatic patients, the low-FODMAP diet was proposed in order to improve GI manifestations; it consists of a phase of elimination of fermentable saccharides, succeeded by a gradual reintegration of the same. Severe or moderate GI symptoms were found in 61.1% of patients, with no correlation to the therapy in use, and significantly more severe in the classical form of FD. The protocol was completed by seven patients affected by severe GI manifestations, significantly higher than the others. The low-FODMAP diet significantly improved indigestion, diarrhoea, and constipation. This dietetic protocol seemed to have a positive impact on intestinal symptoms, by identifying and reducing the intake of the foods most related to the onset of disorders and improving the clinical manifestations. A low-FODMAP diet may be an effective alternative approach to improve intestinal manifestations and quality of life, and nutrition can play an important role in the multidisciplinary care of patients with FD.

Fungal feelings in the irritable bowel syndrome: the intestinal mycobiome and abdominal pain

Although the gut microbiota consists of bacteria, viruses, and fungi, most publications addressing the microbiota-gut-brain axis in irritable bowel syndrome (IBS) have a sole focus on bacteria. This may relate to the relatively low presence of fungi and viruses as compared to bacteria. Yet, in the field of inflammatory bowel disease research, the publication of several papers addressing the role of the intestinal mycobiome now suggested that these low numbers do not necessarily translate to irrelevance. In this review, we discuss the available clinical and preclinical IBS mycobiome data, and speculate how these recent findings may relate to earlier observations in IBS. By surveying literature from the broader mycobiome research field, we identified questions open to future IBS-oriented investigations.

Abdominophrenic Dyssynergia: A Narrative Review

Chronic bloating and abdominal distension are common and highly bothersome gastrointestinal symptoms. Although the differential diagnoses for bloating and distension are broad, these symptoms are frequently associated with disorders of the gut-brain interaction. Functional abdominal bloating may be a result of visceral hypersensitivity, whereas abdominal distension seems to be a somatic behavioral response associated with abdominophrenic dyssynergia, featuring diaphragmatic contraction and abdominal wall relaxation. We review the available literature regarding abdominophrenic dyssynergia and comment on its epidemiology, diagnosis, treatment, and avenues to address in the near future.

Food intolerances in children and adolescents in Switzerland

Adverse food reactions have become an important health concern in pediatrics. There are discrepancies between diagnosed and self-reported food allergies and intolerances, leading to food avoidance with possible psychological and nutritional implications in the latter. There is no data available so far on the number of children and adolescents, who reduce or completely avoid certain foods in their diet. The aim of this study was to determine the prevalence of children and adolescents in the Northwest of Switzerland, who omit foods from their diet because of a self-reported intolerance, as well as the prevalence of children and adolescents who eliminate well-tolerated foods for presumed health reasons. This is a cross-sectional study conducted in the Children's hospitals of Aarau and Basel (Switzerland) and in 4 pediatric private practices. A total of 2036 children and adolescents (54% male and 46% female) between 1 month and 18 years (mean age: 7.4 years) were included, of which 316 (16%) participants reported to avoid foods due to intolerance. Lactose intolerance is the most frequent one. In 55% of all cases, no medical tests had been performed to confirm such an intolerance. Avoiding tolerated foods for presumed health reasons was stated by 251 (12%) participants.  Conclusions: Clinicians should be aware of the high frequency of food avoidance in the pediatric population due to true intolerance, functional diseases, or due to lifestyle reasons. Milk is the most avoided food and half of the affected patients avoid foods without guidance by professional dieticians, therefore risking possible negative impacts on their physical and mental health. Pediatricians should perform further investigations or advise nutritional guidance if an avoidance of foods or specific diets occurs. What is Known: • The prevalence of food intolerances in children and adolescents is unknown. • Eating behavior in children is influenced by the consumption of social media. What is New: • Based on this large cross-sectional study, it was shown that 16% of children and adolescents avoid foods, half of them without any medical advice. • Food avoidance is common among this Swiss cohort of children because of different reasons: lifestyle habits, functional diseases, true intolerances with possible consequences such as micronutrient deficiencies if not properly monitored.

Diet-induced gut dysbiosis and inflammation: Key drivers of obesity-driven NASH

Sucrose, the primary circulating sugar in plants, contains equal amounts of fructose and glucose. The latter is the predominant circulating sugar in animals and thus the primary fuel source for various tissue and cell types in the body. Chronic excessive energy intake has, however, emerged as a major driver of obesity and associated pathologies including nonalcoholic fatty liver diseases (NAFLD) and the more severe nonalcoholic steatohepatitis (NASH). Consumption of a high-caloric, western-style diet induces gut dysbiosis and inflammation resulting in leaky gut. Translocation of gut-derived bacterial content promotes hepatic inflammation and ER stress, and when either or both of these are combined with steatosis, it can cause NASH. Here, we review the metabolic links between diet-induced changes in the gut and NASH. Furthermore, therapeutic interventions for the treatment of obesity and liver metabolic diseases are also discussed with a focus on restoring the gut-liver axis.

Diet-induced modifications to human microbiome reshape colonic homeostasis in irritable bowel syndrome

Changes in microbiome composition are associated with a wide array of human diseases, turning the human microbiota into an attractive target for therapeutic intervention. Yet, clinical translation of these findings requires the establishment of causative connections between specific microbial taxa and their functional impact on host tissues. Here, we infuse gut organ cultures with longitudinal microbiota samples collected from therapy-naive patients with irritable bowel syndrome (IBS) under a low-fermentable oligo-, di-, mono-saccharides and polyols (FODMAP) diet. We show that post-diet microbiota regulates intestinal expression of inflammatory and neuro-muscular gene sets. Specifically, we identify Bifidobacterium adolescentis as a diet-sensitive pathobiont that alters tight junction integrity and disrupts gut barrier functions. Collectively, we present a pathway discovery platform for mechanistic dissection and identification of functional diet-host-microbiota modules. Our data support the hypothesis that the gut microbiota mediates the beneficial effects of a low-FODMAP diet and reinforce the potential feasibility of microbiome-based therapies in IBS.

Recent Research and Application Prospect of Functional Oligosaccharides on Intestinal Disease Treatment

The intestinal tract is an essential digestive organ of the human body, and damage to the intestinal barrier will lead to various diseases. Functional oligosaccharides are carbohydrates with a low degree of polymerization and exhibit beneficial effects on human intestinal health. Laboratory experiments and clinical studies indicate that functional oligosaccharides repair the damaged intestinal tract and maintain intestinal homeostasis by regulating intestinal barrier function, immune response, and intestinal microbial composition. Functional oligosaccharides treat intestinal disease such as inflammatory bowel disease (IBD) and colorectal cancer (CRC) and have excellent prospects for therapeutic application. Here, we present an overview of the recent research into the effects of functional oligosaccharides on intestinal health.

The Role of Short Chain Fatty Acids in Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder that is characterized by abdominal pain and disordered bowel habits. The etiology of IBS is multifactorial, including abnormal gut-brain interactions, visceral hypersensitivity, altered colon motility, and psychological factors. Recent studies have shown that the intestinal microbiota and its metabolites short chain fatty acids (SCFAs) may be involved in the pathogenesis of IBS. SCFAs play an important role in the pathophysiology of IBS. We discuss the underlying mechanisms of action of SCFAs in intestinal inflammation and immunity, intestinal barrier integrity, motility, and the microbiota-gut-brain axis. Limited to previous studies, further studies are required to investigate the mechanisms of action of SCFAs in IBS and provide more precise therapeutic strategies for IBS.

Fecal microbiota transplantation in patients with post-infectious irritable bowel syndrome: A randomized, clinical trial

INTRODUCTION

Research in recent years has shown the potential benefits of fecal microbiota transplantation (FMT) for irritable bowel syndrome (IBS). Acute infectious gastroenteritis is a well-established risk factor for developing such forms of IBS as post-infectious IBS (PI-IBS). However, the effective use of FMT in patients with IP-IBS has not yet been clarified.

AIM

The study aimed to conduct a single-center, randomized clinical trial (RCT) to assess FMT's safety, clinical and microbiological efficacy in patients with PI-IBS.

MATERIALS AND METHODS

Patients with PI-IBS were randomized into two groups: I (standard-care, n = 29) were prescribed basic therapy, namely a low FODMAP diet, as well as Otilonium Bromide (1 tablet TID) and a multi-strain probiotic (1 capsule BID) for 1 month; II (FMT group, n = 30), each patient with PI-IBS underwent a single FMT procedure with fresh material by colonoscopy. All patients underwent bacteriological examination of feces for quantitative and qualitative microbiota composition changes. The clinical efficacy of treatment was evaluated according to the dynamics of abdominal symptoms, measured using the IBS-SSS scale, fatigue reduction (FAS scale), and a change in the quality of life (IBS-QoL scale).

RESULTS

FMT was associated with rapid onset of the effect, manifested in a significant difference between IBS-SSS points after 2 weeks of intervention (p < 0.001). In other time points (after 4 and 12 weeks) IBS-SSS did not differ significantly across both groups. Only after 3 months of treatment did their QoL exceed its initial level, as well value for 2 and 4 weeks, to a significant extent. The change in the ratio of the main microbial phenotypes in the form of an increase in the relative abundance of Firmicutes and Bacteroidetes was recorded in all patients after 4 weeks. It should be noted that these changes were significant but eventually normalized only in the group of PI-IBS patients who underwent FMT. No serious adverse reactions were noted.

CONCLUSION

This comparative study of the results of FMT use in patients with PI-IBS demonstrated its effectiveness compared to traditional pharmacotherapy, as well as a high degree of safety and good tolerability.

Inflammatory Bowel Disease and Customized Nutritional Intervention Focusing on Gut Microbiome Balance

Inflammatory bowel disease (IBD) represents a chronic relapsing-remitting condition affecting the gastrointestinal system. The specific triggering IBD elements remain unknown: genetic variability, environmental factors, and alterations in the host immune system seem to be involved. An unbalanced diet and subsequent gut dysbiosis are risk factors, too. This review focuses on the description of the impact of pro- and anti-inflammatory food components on IBD, the role of different selected regimes (such as Crohn's Disease Exclusion Diet, Immunoglobulin Exclusion Diet, Specific Carbohydrate Diet, LOFFLEX Diet, Low FODMAPs Diet, Mediterranean Diet) in the IBD management, and their effects on the gut microbiota (GM) composition and balance. The purpose is to investigate the potential positive action on IBD inflammation, which is associated with the exclusion or addition of certain foods or nutrients, to more consciously customize the nutritional intervention, taking also into account GM fluctuations during both disease flare-up and remission.

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.

Modest Conformity Between Self-Reporting of Bristol Stool Form and Fecal Consistency Measured by Stool Water Content in Irritable Bowel Syndrome and a FODMAP and Gluten Trial

INTRODUCTION

Altered bowel habits constitute a criterion of irritable bowel syndrome (IBS), with the Bristol Stool Form Scale (BSFS) as the recommended tool for assessment of fecal consistency. However, BSFS is devoid of a comprehensive objective evaluation in subjects with IBS. Therefore, we aimed to evaluate the concordance between subjective reporting of BSFS and objective stool water content in subjects with IBS. Furthermore, we evaluated whether intake of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) or gluten would affect stool water content.

METHODS

Data from a previous crossover trial in IBS with 1-week provocations of FODMAPs, gluten, or placebo were subanalyzed. After each intervention, fecal consistency was subjectively assessed using the BSFS and stool samples were collected. The stool water content was analyzed, where ≤68.5% water content was classified as hard stool, while ≥78% was classified as diarrhea.

RESULTS

BSFS correlated to stool water content ( r = 0.36, P < 0.0001). The BSFS score increased in parallel with increasing water content, but with considerable overlap between BSFS scores. Stool water content differed between the BSFS categories 1-2, 3-5, and 6-7 (hard, normal, and loose, respectively) ( P < 0.0001). For BSFS categories 1-2, 77% had water content ≤68.5%, whereas for BSFS categories 6-7, 52% had water content ≥78%. There was no difference in stool water content after consumption of FODMAPs, gluten, or placebo ( P = 0.94).

DISCUSSION

Subjective reporting of BSFS conforms only modestly with stool water content in IBS, warranting caution when subtyping IBS according to the BSFS. High intake of FODMAPs and gluten does not affect stool water content.

Dietary Approaches and Nutritional Complexities of Autism Spectrum Disorder

Background:

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by poor social interaction, repetitive behavior, learning difficulties, cognitive issues, and unusual eating patterns. Different factors including genetic and environmental variables have been identified to increase the risk of developing ASD.

Objective:

The main objective of the present review is to investigate the dietary approaches and modifications to reduce the intricacies related to ASD.

Results:

Studies included in this review suggested that abnormalities in the gut microbiota are involved in the pathogenesis and severity of the disease. Medical nutrition therapy for ASD consists of excluding harmful food components such as gluten, casein, processed foods, and excessive sugars and increasing the consumption of omega-3 fats, vitamins and minerals, probiotics, and antioxidants. Furthermore, awareness regarding food labels might help to avoid food allergens in diet.

Conclusion:

Active dietary treatments including the use of dietary supplements and elimination of processed foods appear to reduce the complexities of ASD. Furthermore, support of health care professionals and adopting public health approaches might help to prevent adverse outcomes related to ASD. Future research is required to determine the prevalence of ASD and related outcomes in low/middle income countries as this area is highly neglected.

A Low FODMAP Diet Reduces Symptoms in Treated Celiac Patients With Ongoing Symptoms-A Randomized Controlled Trial

BACKGROUND & AIMS

A gluten-free diet usually leads to mucosal remission in celiac disease, but persistent symptoms are common. A low fermentable oligo-, di-, monosaccharides and polyols (FODMAP) diet is an established treatment for irritable bowel syndrome (IBS). We have assessed the efficacy of a moderately low FODMAP diet on persistent symptoms in treated celiac patients.

METHODS

A randomized controlled trial was performed from 2018 to 2019 in 70 adults with biopsy-proven celiac disease. Inclusion criteria were as follows: persistent gastrointestinal symptoms defined by a Gastrointestinal Symptom Rating Scale (GSRS)-IBS version score of 30 or higher, gluten-free diet adherence for 12 months or longer, and serologic and mucosal remission. Participants were randomized to a low FODMAP-gluten-free diet (intervention) or usual gluten-free diet (control). The GSRS-IBS score was recorded at baseline and at weeks 1 to 4, and the Celiac Symptom Index at baseline and at week 4. Statistics included marginal models for repeated data and analyses of covariance.

RESULTS

We included 34 participants in the intervention group and 36 in the control group. Time development of GSRS-IBS total scores differed significantly between the groups (P_interaction < .001), evident after 1 week (mean difference in intervention vs control, -8.2; 95% CI, -11.5 to -5.0) and persisting through week 4 (mean difference in intervention vs control, -10.8; 95% CI, -14.8 to -6.8). Moreover, significantly lower scores were found for the dimensions of pain, bloating, diarrhea, and satiety (P_interaction ≤ .04), but not constipation (P_interaction = .43). FODMAP intake during the intervention was moderately low (mean, 8.1 g/d; 95% CI, 6.7-9.3 g/d). The Celiac Symptom Index was significantly lower in the intervention group at week 4 (mean difference, -5.8; 95% CI, -9.6 to -2.0).

CONCLUSIONS

A short-term moderately low FODMAP diet significantly reduced gastrointestinal symptoms and increased celiac disease-specific health, and should be considered for the management of persistent symptoms in celiac disease.

CLINICALTRIALS

gov: NCT03678935.

Diet, Digestion, and the Dietitian: A Survey of Clinicians' Knowledge, Attitudes and Practices to Advance the Treatment of Gastrointestinal Disturbances in Individuals with Anorexia Nervosa

Despite advances in treatment of anorexia nervosa (AN), current therapeutic approaches do not fully consider gastrointestinal disturbances (GID), often present in AN. Addressing GID, both symptoms and disorders, is likely to improve treatment adherence and outcomes in people with AN. GID are complex and are linked to a range of factors related to eating disorder symptomology and can be impacted by nutritional treatment. It is not known which dietetic practices are currently used to address GID in AN. Therefore, this survey aimed to explore the perceived knowledge, attitudes, and practices (KAP) of Australian dietitians treating AN and co-occurring GID. Seventy dietitians participated by completing an online survey. Knowledge scores were calculated based on correct responses to knowledge items (total: 12 points); and two groups were generated: higher knowledge (≥10 points, n = 31) and lower knowledge (≤9 points, n = 39). A greater proportion of dietitians with higher knowledge recognized the role of GID in pathogenesis of AN (p = 0.002) and its impact on quality of life (p = 0.013) and screened for GID (p ≤ 0.001), compared with those with lower knowledge. These results suggest that attitudes and practices toward patients presenting with AN and GID differ depending on level of knowledge. This may have important implications for treatment outcomes for individuals with AN and GID.

Dietary Patterns and Gut Microbiota Changes in Inflammatory Bowel Disease: Current Insights and Future Challenges

Inflammatory bowel disease (IBD) is a result of a complex interplay between genes, host immune response, gut microbiota, and environmental factors. As one of the crucial environmental factors, diet plays a pivotal role in the modulation of gut microbiota community and the development of IBD. In this review, we present an overview of dietary patterns involved in the pathogenesis and management of IBD, and analyze the associated gut microbial alterations. A Westernized diet rich in protein, fats and refined carbohydrates tends to cause dysbiosis and promote IBD progression. Some dietary patterns have been found effective in obtaining IBD clinical remission, including Crohn's Disease Exclusion Diet (CDED), Mediterranean diet (MD), Anti-Inflammatory Diet (AID), the low-"Fermentable Oligo-, Di-, Mono-saccharides and Polyols" (FODMAP) diet, Specific Carbohydrate Diet (SCD), and plant-based diet, etc. Overall, many researchers have reported the role of diet in regulating gut microbiota and the IBD disease course. However, more prospective studies are required to achieve consistent and solid conclusions in the future. This review provides some recommendations for studies exploring novel and potential dietary strategies that prevent IBD.

Fecal Microbiota Transplantation Combined with a Low FODMAP Diet for the Treatment of Irritable Bowel Syndrome with Predominant Diarrhea

BACKGROUND

Fecal microbiota transplantation (FMT) has been found to be effective in irritable bowel syndrome with predominant diarrhea (IBS-D). We conducted this study to determine the impact of a low FODMAP diet (LFD) on the gut microbiota and the efficacy of FMT in the treatment of IBS-D.

METHODS

A retrospective analysis of a single-arm open-label prospective study was conducted to investigate the impact of FMT alone (n = 40) and FMT+LFD (n = 40) in refractory IBS-D. The IBS-quality of life (QOL), IBS-severity scoring system (SSS), gastrointestinal symptom rating scale (GSRS), Hamilton anxiety scale (HAMA), and Hamilton depression scale (HAMD) were used to evaluate the efficacy, and partial 16S rDNA amplicon sequencing was used to profile the microbiota.

RESULTS

The response rates were higher in the FMT+LFD group than in the FMT group (1 mo, 3 mo, 6 mo: 70.0% vs. 55.0%, 67.5% vs. 57.5%, 62.5% vs. 27.5%, respectively). The FMT+LFD group showed significantly better improvement in IBS-QOL at 1, 3, and 6 months; IBS-SSS at 6 months; and GSRS at 1 month compared to FMT alone. Changes in HAMA and HAMD were similar in the two groups. The LFD significantly upregulated the FMT-induced microbial diversity (OTUs: 666 vs. 574, Adonis: P = 0.02) and significantly strengthened the upregulation of Bacteroides, Alistipes, and Ruminococcaceae_UCG-002 and the downregulation of Bifidobacterium.

CONCLUSION

An LFD enhanced the efficacy of FMT, increased the gut microbial diversity after FMT, and strengthened the inhibitory effect of FMT on conditional pathogens.

Dietary Modification for the Restoration of Gut Microbiome and Management of Symptoms in Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder leading to chronic debilitating issues. A healthy diet plays an integral role in maintaining the gut microbiota equilibrium, thus promoting digestive health. The structure and function of gut microbiota are affected by genetics and environmental factors, such as altered dietary habits, gastroenteritis, stress, increased use of alcohol and drugs, and medication use. Whereas there are various management approaches cited in the literature to manage symptoms of IBS, the purpose of this article is to focus on dietary options that will restore the gut microbiome and help in managing IBS symptoms. Some of the diets that are discussed in this article include a low-FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet, gluten-free/wheat-free diet, high-fiber diet, dietary and herbal supplements (psyllium, peppermint oil), and probiotics/prebiotics/synbiotics. The clinical practice guidelines recommended by the American College of Gastroenterology outlines evidence-based dietary recommendations for patients with IBS to manage symptoms. Recent advancements in the dietary management of IBS highlighting the use of a patient-centered, personalized nutrition approach along with lifestyle changes, pharmacological therapies, and psychosocial and behavioral interventions are also reviewed and discussed.

Diets for inflammatory bowel disease: What do we know so far?

In recent years, the role of diet in the pathogenesis of inflammatory bowel disease (IBD) has gained great interest within the scientific community. Eating habits from industrialised countries (the so-called western diet or WD) have been associated with a higher incidence of IBD in observational studies, although the dietary factors responsible for the development of the disease are still to be elucidated. Some components of the diet with proinflammatory potential may cause changes in immunity and intestinal microbiota, leading to the inflammatory reaction that causes IBD-related lesions. The quality of available evidence is low, due to methodological issues, such as the lack of intervention studies, small sample size and heterogeneity of studies. For this reason, scientific societies have offered their recommendations using clinical practice guidelines and consensus documents, in order to establish a common criterion in the nutritional treatment of patients with IBD. The objective of this review was to summarise the data published regarding diet in IBD and review the recommendations given by scientific societies.

Modulating the gut microenvironment as a treatment strategy for irritable bowel syndrome: a narrative review

Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction with a complex pathophysiology. Growing evidence suggests that alterations of the gut microenvironment, including microbiota composition and function, may be involved in symptom generation. Therefore, attempts to modulate the gut microenvironment have provided promising results as an indirect approach for IBS management. Antibiotics, probiotics, prebiotics, food and faecal microbiota transplantation are the main strategies for alleviating IBS symptom severity by modulating gut microbiota composition and function (eg. metabolism), gut barrier integrity and immune activity, although with varying efficacy. In this narrative review, we aim to provide an overview of the current approaches targeting the gut microenvironment in order to indirectly manage IBS symptoms.

Effect and Mechanism of Flavored Tongxie Yaofang Decoction for Diarrheal Irritable Bowel Syndrome under Intestinal Microecology

This research was to analyze the effect of flavored Tongxie Yaofang on diarrheal irritable bowel syndrome (IBS) by the situation of intestinal microecology. The treatment mechanism was analyzed, so as to provide a more effective treatment method for patients clinically. 60 IBS patients were selected as the research objects and were divided according to the different treatment methods. For the control group (n = 20 cases), oral pinaverium bromide tablets were given. For the treatment group (n = 40 cases), the flavored Tongxie Yaofang decoction was given in addition to conventional treatment. The curative effects on the two groups of patients were evaluated in combination with the changes in intestinal microecology. With the syndrome score, the total effective rate of the treatment group (92.5%) was obviously superior to the control group (80%) (P < 0.05). The clinical symptoms such as abdominal pain, abdominal distension, and diarrhea in the treatment group were significantly relieved after treatment in contrast to the control group (P < 0.05). Intestinal Bifidobacterium, Escherichia coli, and Bifidobacterium/Escherichia coli (B/E) ratio were all greatly higher than those in the control group (P < 0.05). In summary, flavored Tongxie Yaofang had a good effect in improving the symptoms of patients with diarrheal IBS and improved the microflora of Bifidobacterium and Escherichia coli in the intestinal tract of patients.

Review article: exclude or expose? The paradox of conceptually opposite treatments for irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a heterogeneous disorder of gut-brain interaction (DGBI) maintained by interacting biological, psychological, and social processes. Interestingly, there are two contrasting yet evidence-based treatment approaches for reducing IBS symptoms: exclusion diets such as those low in fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) and exposure-based cognitive-behavioural therapy (CBT). Exclusion diets recommend patients avoid foods thought to be symptom-inducing, whereas exposure-based CBT encourages patients to expose themselves to foods.

AIMS

To address the paradox of conceptually opposite exclusion diets and exposure-based CBT for IBS.

METHODS

In this conceptual review, we describe the rationale, practical implementation, evidence base and strengths and weaknesses of each treatment. We conducted up-to-date literature search concerning the low FODMAP diet and CBT, and performed a secondary analysis of a previously conducted trial to illustrate a key point in our review.

RESULTS

The low FODMAP diet has demonstrated efficacy, but problems with adherence, nutritional compromise, and heightened gastrointestinal-specific anxiety raise caution. Exposure-based CBT has demonstrated efficacy with substantial evidence for gastrointestinal-specific anxiety as a key mechanism of action. Mediation analysis also showed that increased FODMAP intake mediated decreased symptom severity in exposure-based CBT. However, there is minimal evidence supporting which treatment "works best for whom" and how these approaches could be best integrated.

CONCLUSIONS

Even though exclusion diets and exposure-based CBT are conceptually opposite, they each have proven efficacy. Clinicians should familiarise themselves with both treatments. Further research is needed on predictors, mechanisms and moderators of treatment outcomes.

Orthorexia nervosa is a concern in gastroenterology: A scoping review

There is concern that use of restrictive therapeutic diets, such as those used in disorders of the gut-brain interaction (DGBI), may increase disordered eating. In this issue of Neurogastroenterology and Motility, Burton Murray et al. and Peters et al. both demonstrate a high prevalence of disordered eating in patients with gastrointestinal conditions, particularly those with DGBI. Given these findings, it is likely that orthorexia is common in this patient group, although this was not directly examined in these studies. Orthorexia nervosa is described as an obsessive and unsafe focus on eating foods perceived as healthy. This mini-review therefore focuses on orthorexia by conducting a scoping review, as per the PRISMA extension for scoping reviews, aimed to assess the prevalence of orthorexia, and associations between orthorexia and restrictive eating practices. While a wide range of orthorexia prevalence has been reported (0%-97%) across the 57 studies included, no studies assessed prevalence specifically in gastrointestinal conditions. Four of eight studies describing diseases associated with specific dietary patterns suggested that participants who followed a diet for "digestive issues" or "food intolerances" were at higher orthorexia risk. These results suggest that dietary modifications may be a factor contributing to orthorexia. Additionally, we provide a commentary on the clinical implications of the findings for gastrointestinal conditions including a clinical flow chart. Clinicians should consider if a restrictive diet is appropriate for individuals with DGBI and include screening for disordered eating prior to implementation of dietary modifications. Future prospective studies should evaluate orthorexia within this patient group.

Efficacy of a Restrictive Diet in Irritable Bowel Syndrome: A Systematic Review and Network Meta-analysis

BACKGROUND/AIMS

Dietary factors can aggravate the symptoms of irritable bowel syndrome (IBS). Many IBS patients try restrictive diets to relieve their symptoms, but the types of diets with an exacerbating factor are unknown. Therefore, this paper reports the results of a systematic review and network meta-analysis of randomized-controlled trials (RCTs) reviewing the efficacy of food restriction diets in IBS.

METHODS

The MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov databases were searched until July 21, 2021, to retrieve RCTs assessing the efficacy of restriction diets in adults with IBS. Two independent reviewers performed the eligibility assessment and data abstraction. RCTs that evaluated a restriction diet versus a control diet and assessed the improvement in global IBS symptoms were included. These trials reported a dichotomous assessment of the overall response to therapy.

RESULTS

A total of 1,949 citations were identified. After full-text screening, 14 RCTs were considered eligible for the systematic review and network meta-analysis. A starch- and sucrose-reduced diet and a diet with low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) showed significantly better results than a usual diet. Symptom flare-ups in patients on a gluten- free diet were also significantly lower than in those on high-gluten diets.

CONCLUSIONS

These findings showed that the starch- and sucrose-reduced, low FODMAP, and gluten-free diets had superior effects in reducing IBS symptoms. Further studies, including head-to-head trials will be needed to establish the effectiveness of dietary restrictions on IBS symptoms.

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.

Gut Microbiota Manipulation in Irritable Bowel Syndrome

Increased knowledge suggests that disturbed gut microbiota, termed dysbiosis, might promote the development of irritable bowel syndrome (IBS) symptoms. Accordingly, gut microbiota manipulation has evolved in the last decade as a novel treatment strategy in order to improve IBS symptoms. In using different approaches, dietary management stands first in line, including dietary fiber supplements, prebiotics, and probiotics that are shown to change the composition of gut microbiota, fecal short-chain fatty acids and enteroendocrine cells densities and improve IBS symptoms. However, the exact mixture of beneficial bacteria for each individual remains to be identified. Prescribing nonabsorbable antibiotics still needs confirmation, although using rifaximin has been approved for diarrhea-predominant IBS. Fecal microbiota transplantation (FMT) has recently gained a lot of attention, and five out of seven placebo-controlled trials investigating FMT in IBS obtain promising results regarding symptom reduction and gut microbiota manipulation. However, more data, including larger cohorts and studying long-term effects, are needed before FMT can be regarded as a treatment for IBS in clinical practice.

Global Research Trends in Irritable Bowel Syndrome: A Bibliometric and Visualized Study

Background

There are about 10–23% of adults worldwide suffering from irritable bowel syndrome (IBS). Over the past few decades, there are many aspects of uncertainty regarding IBS leading to an ongoing interest in the topic as reflected by a vast number of publications, whose heterogeneity and variable quality may challenge researchers to measure their scientific impact, to identify collaborative networks, and to grasp actively researched themes. Accordingly, with help from bibliometric approaches, our goal is to assess the structure, evolution, and trends of IBS research between 2007 and 2022.

Methods

The documents exclusively focusing on IBS from 2007 to 2022 were retrieved from the Science Citation Index Expanded of the Web of Science Core Collection. The annual productivity of IBS research, and the most prolific countries or regions, authors, journals and resource-, intellectual- and knowledge-sharing in IBS research, as well as co-citation analysis of references and keywords were analyzed through Microsoft Office Excel 2019, CiteSpace, and VOSviewer.

Results

In total, 4,092 publications were reviewed. The USA led the list of countries with the most publications (1,226, 29.96%). Mayo Clinic contributed more publications than any other institution (193, 4.71%). MAGNUS SIMREN stood out as the most active and impactful scholar with the highest number of publications and the greatest betweenness centrality value. The most high-yield journal in this field was Neurogastroenterology and motility: the official journal of the European Gastrointestinal Motility Society (275, 6.72%). Gastroenterology had the most co-citations (3,721, 3.60%). Keywords with the ongoing strong citation bursts were chromogranin A, rat model, peptide YY, gut microbiota, and low-FODMAP diet, etc.

Conclusion

Through bibliometric analysis, we gleaned deep insight into the current status of literature investigating IBS for the first time. These findings will be useful to scholars interested in understanding the key information in the field, as well as identifying possible research frontiers.

Clinical and Metabolomic Effects of Lactiplantibacillus plantarum and Pediococcus acidilactici in Fructose Intolerant Patients

Fructose intolerance (FI) is a widespread non-genetic condition in which the incomplete absorption of fructose leads to gastro-intestinal disorders. The crucial role of microbial dysbiosis on the onset of these intolerance symptoms together with their persistence under free fructose diets are driving the scientific community towards the use of probiotics as a novel therapeutic approach. In this study, we evaluated the prevalence of FI in a cohort composed of Romanian adults with Functional Grastrointestinal Disorders (FGIDs) and the effectiveness of treatment based on the probiotic formulation EQBIOTA® (Lactiplantibacillus plantarum CECT 7484 and 7485 and Pediococcus acidilactici CECT 7483). We evaluated the impact of a 30-day treatment both on FI subjects and healthy volunteers. The gastrointestinal symptoms and fecal volatile metabolome were evaluated. A statistically significant improvement of symptoms (i.e., bloating, and abdominal pain) was reported in FI patient after treatment. On the other hand, at the baseline, the content of volatile metabolites was heterogeneously distributed between the two study arms, whereas the treatment led differences to decrease. From our analysis, how some metabolomics compounds were correlated with the improvement and worsening of clinical symptoms clearly emerged. Preliminary observations suggested how the improvement of gastrointestinal symptoms could be induced by the increase of anti-inflammatory and protective substrates. A deeper investigation in a larger patient cohort subjected to a prolonged treatment would allow a more comprehensive evaluation of the probiotic treatment effects.

Diet and Pediatric Functional Gastrointestinal Disorders in Mediterranean Countries

Background: The increased intake of FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyol) rich foods has been suggested as a possible trigger of functional gastrointestinal disorders (FGIDs). Despite the high FODMAP content, the Mediterranean diet (MD) appears to have beneficial effects on health. Our aim was to evaluate whether the prevalence of FGIDs in different Mediterranean countries may be influenced by FODMAP consumption and adherence to the MD. Methods: A school-based, cross-sectional, multicenter study was performed in six countries in the Mediterranean area: Croatia, Greece, Israel, Italy, Macedonia, and Serbia. Subjects 4-18 years were examined in relation to their eating habits and the presence of FGIDs, using Rome IV criteria, 3-day food diaries and Mediterranean Diet Quality Index in Children and Adolescents (KIDMED) questionnaires. Results: We enrolled 1972 subjects between 4 and 9 years old (Group A), and 2450 subjects between 10 and 18 years old (Group B). The overall prevalence of FGIDs was 16% in Group A and 26% in Group B. FODMAP intake was significantly different among countries for both age groups. In both groups, no significant association was found between FGIDs and FODMAPs. Adherence to the MD in all countries was intermediate, except for Serbia, where it was low. In both groups, we found a statistically significant association between FGIDs and the KIDMED score (Group A: OR = 0.83, p < 0.001; Group B: OR = 0.93, p = 0.005). Moreover, a significant association was found between the KIDMED score and functional constipation (Group A: OR = 0.89, p = 0.008; Group B: OR = 0.93, p = 0.010) and postprandial distress syndrome (Group A: OR = 0.86, p = 0.027; Group B: OR = 0.88, p = 0.004). Conclusions: Our data suggest that the prevalence of FGIDs in the Mediterranean area is not related to FODMAP consumption, whereas adherence to the MD seems to have a protective effect.

Optimal Design of Clinical Trials of Dietary Interventions in Disorders of Gut-Brain Interaction

There is accumulating evidence for the fundamental role of diet in the integrated care of disorders of gut-brain interaction. Food is a complex mixture of components with individual, synergistic, and antagonistic effects, compared with the relative purity of a pharmaceutical. Food is also an inherent part of individuals' daily lives, and food choice is strongly tied to food preferences, personal beliefs, cultural and religious practices, and economic status, which can influence its ability to function as a therapeutic intervention. Hence, randomized controlled trials of dietary interventions carry unique methodological complexities that are not applicable to pharmaceutical trials that if disregarded can pose significant risk to trial quality. The challenges of designing and delivering the dietary intervention depend on the type of intervention (i.e., nutrient vs food supplementation or whole-diet intervention). Furthermore, there are multiple modes of delivery of dietary interventions, each with their own advantages (e.g., the high precision of feeding trials and the strong clinical applicability of dietary counseling trials). Randomized placebo-controlled trials of dietary interventions are possible with sufficient attention to their design and methodological nuances. Collaboration with experts in nutrition and dietetics is essential for the planning phase; however, even with expert input, not all challenges can be overcome. Researchers undertaking future dietary trials must be transparent in reporting these challenges and approaches for overcoming them. This review aims to provide guiding principles and recommendations for addressing these challenges to facilitate the conduct and reporting of high-quality trials that inform and improve clinical practice.