Effect of Personalized Prebiotic and Probiotic Supplements on the Symptoms of Irritable Bowel Syndrome: An Open-Label, Single-Arm, Multicenter Clinical Trial.

BACKGROUND/OBJECTIVES: Prebiotics and probiotics have been reported to improve symptoms of irritable bowel syndrome (IBS). Nevertheless, the effects of prebiotics/probiotics can vary depending on the IBS subtypes. The purpose of this study was to investigate the effects of personalized prebiotic and probiotic supplements based on intestinal microbiota and IBS subtypes in patients. METHODS: Patients with diarrhea-type IBS (IBS-D), constipation-type IBS (IBS-C), and mixed-type IBS (IBS-M) were enrolled (n = 40 per group; total: n = 120). Personalized prebiotic and probiotic supplements were determined according to the IBS subtypes and intestinal microbiota. The patients received supplements for 4 weeks. The primary outcome was the change in the IBS-severity scoring system from baseline to week 4. RESULTS: The IBS-severity scoring system significantly decreased in all patients (-38.0 [95% confidence interval (CI): -53.6, -22.4]; p < 0.001), in patients with IBS-D (-44.5 [95% CI: -70.6, -18.5]; p = 0.004) and IBS-C (-51.2 [95% CI: -79.4, -22.9]; p = 0.002), but not in those with IBS-M (-20.0 [95% CI: -48.0, 8.1]; p = 0.47). In this study, no serious adverse events were observed that had a causal relationship with the intervention. CONCLUSIONS: In conclusion, personalized prebiotic and probiotic supplements selected according to individual intestinal microbiota and IBS subtype may alleviate the severity of IBS symptoms, particularly in patients with IBS-C and IBS-D.

Adapted Low-FODMAP Diet in IBS Patients with and without Fibromyalgia: Long-Term Adherence and Outcomes.

BACKGROUND/OBJECTIVES: A low-FODMAPs Diet (LFD) is considered a "second line" dietary strategy for irritable bowel syndrome (IBS) but, after a period of strict restriction of all FODMAP foods, it has to be adapted and tailored to each patient (AdLFD). Fibromyalgia often coexists with IBS in up to 65% of cases. Our aims were to evaluate if comorbid fibromyalgia influenced the long-term clinical outcomes and adherence to an AdLFD in IBS patients. METHODS: IBS patients with or without fibromyalgia who had started an AdLFD were enrolled. Patients had been evaluated before starting the LFD (T0). After a mean follow-up of 62.5 ± 22.7 months (T1), they were re-evaluated using questionnaires on disease severity, bowel habits, psychological status, and adherence to AdLFD. RESULTS: In total, 51 IBS patients entered the study. Nineteen of them had comorbid fibromyalgia. Thirty patients reported a reduction in symptom severity at T1 in comparison with T0. Despite some slight differences in single IBS Symptom Severity Score items, comorbid fibromyalgia did not influence the IBS-SSS total score at T1. Patients with comorbid fibromyalgia showed a higher Hospital Anxiety and Depression Scale (HADS) score at baseline. A total of 44 patients showed good long-term adherence to the AdLFD. All patients improved their HADS score and had long-term adherence to the AdLFD. CONCLUSIONS: Comorbid fibromyalgia showed only a slight influence on long-term outcomes of an AdLFD on IBS symptoms, without affecting the relief of global symptoms. No influence on long-term adherence to AdLFD was detected. Hence, this approach can be taken into account in fibromyalgia patients for a nonpharmacological management of IBS symptoms. However, multicentric studies on larger samples would be welcome in the future.

A New Strategy for Dietary Nutrition to Improve Intestinal Homeostasis in Diarrheal Irritable Bowel Syndrome: A Perspective on Intestinal Flora and Intestinal Epithelial Interaction.

BACKGROUND AND OBJECTIVES: Although a reasonable diet is essential for promoting human health, precise nutritional regulation presents a challenge for different physiological conditions. Irritable Bowel Syndrome (IBS) is characterized by recurrent abdominal pain and abnormal bowel habits, and diarrheal IBS (IBS-D) is the most common, seriously affecting patients' quality of life. Therefore, the implementation of precise nutritional interventions for IBS-D has become an urgent challenge in the fields of nutrition and food science. IBS-D intestinal homeostatic imbalance involves intestinal flora disorganization and impaired intestinal epithelial barrier function. A familiar interaction is evident between intestinal flora and intestinal epithelial cells (IECs), which together maintain intestinal homeostasis and health. Dietary patterns, such as the Mediterranean diet, have been shown to regulate gut flora, which in turn improves the body's health by influencing the immune system, the hormonal system, and other metabolic pathways. METHODS: This review summarized the relationship between intestinal flora, IECs, and IBS-D. It analyzed the mechanism behind IBS-D intestinal homeostatic imbalance by examining the interactions between intestinal flora and IECs, and proposed a precise dietary nutrient intervention strategy. RESULTS AND CONCLUSION: This increases the understanding of the IBS-D-targeted regulation pathways and provides guidance for designing related nutritional intervention strategies.

A Starch- and Sucrose-Reduced Diet Has Similar Efficiency as Low FODMAP in IBS-A Randomized Non-Inferiority Study.

A diet with low content of fermentable oligo-, di-, and monosaccharides and polyols (FODMAP) is established treatment for irritable bowel syndrome (IBS), with well-documented efficiency. A starch- and sucrose-reduced diet (SSRD) has shown similar promising effects. The primary aim of this randomized, non-inferiority study was to test SSRD against low FODMAP and compare the responder rates (RR = ∆Total IBS-SSS ≥ -50) to a 4-week dietary intervention of either diet. Secondary aims were to estimate responders of ≥100 score and 50% reduction; effects on extraintestinal symptoms; saturation; sugar craving; anthropometric parameters; and blood pressure. 155 IBS patients were randomized to SSRD (n = 77) or low FODMAP (n = 78) for 4 weeks, with a follow-up 5 months later without food restrictions. The questionnaires Rome IV, IBS-severity scoring system (IBS-SSS), and visual analog scale for IBS (VAS-IBS) were completed at baseline and after 2 and 4 weeks and 6 months. Weight, height, waist circumference, and blood pressures were measured. Comparisons were made within the groups and between changes in the two groups. There were no differences between groups at baseline. The responder rate of SSRD was non-inferior compared with low FODMAPs at week 2 (79.2% vs. 73.1%; p = 0.661;95% confidence interval (CI) = -20-7.2) and week 4 (79.2% vs. 78.2%; p = 1.000;95%CI = -14-12). Responder rate was still high when defined stricter. All gastrointestinal and extraintestinal symptoms were equally improved (p < 0.001 in most variables). SSRD rendered greater reductions in weight (p = 0.006), body mass index (BMI) (p = 0.005), and sugar craving (p = 0.05), whereas waist circumference and blood pressure were equally decreased. Weight and BMI were regained at follow-up. In the SSRD group, responders at 6 months still had lowered weight (-0.7 (-2.5-0.1) vs. 0.2 (-0.7-2.2) kg; p = 0.005) and BMI (-0.25 (-0.85-0.03) vs. 0.07 (-0.35-0.77) kg/m2; p = 0.009) compared with baseline in contrast to non-responders. Those who had tested both diets preferred SSRD (p = 0.032). In conclusion, a 4-week SSRD intervention was non-inferior to low FODMAP regarding responder rates of gastrointestinal IBS symptoms. Furthermore, strong reductions of extraintestinal symptoms were found in both groups, whereas reductions in weight, BMI, and sugar craving were most pronounced following SSRD.

Low-FODMAP diet on postprandial distress syndrome type of functional dyspepsia with mixed type of irritable bowel syndrome patient: A case report.

Functional dyspepsia is a complex collection of symptoms from the gastroduodenal, while irritable bowel syndrome (IBS) is a disease that chronically weakens gastrointestinal. The occurrences of both of these diseases are common; however, the new approach therapy introducing the low-FODMAP diet (low fructose, oligosaccharides, disaccharides, monosaccharides, and polyols) is rarely discussed. The aim of this case report was to present a case of functional dyspepsia with IBS mixed type treated with a low-FODMAP diet. A female 37 years old reported complaints of heartburn worsening over the last seven months. Based on IBS-symptom severity scale (IBS-SSS) assessment, the patient had 75% scale on belly pain and 50% abdominal distention, which interfered the daily activity significantly. The patient was diagnosed with functional dyspepsia subtype postprandial distress syndrome with IBS mixed type. In addition, the low-FODMAP diet was started immediately, together with pharmacological therapy (oral omeprazole and domperidone), and followed up each week. On the first week of evaluation, the patient was feeling much better as IBS-SSS assessment scores decreased, and the pharmacological therapy was stopped. On the second week of evaluation, the patient had no more complaints with IB-SSS assessment markedly decreased. This case highlights that low-FODMAP diet could be a new approach therapy for IBS that could improve the IBS symptoms.

Patients' experiences of dietary changes during a structured dietary intervention for irritable bowel syndrome.

BACKGROUND: Diet plays an important role in management of gastrointestinal (GI) symptoms in patients with irritable bowel syndrome (IBS). Restrictive diets have gained popularity as treatment for IBS, but no studies have examined the patients' experiences of implementing such diets. Thus, the present study aimed to explore the experience of patients with IBS undergoing a structured dietary intervention. METHODS: Using inductive content analysis, semi-structured interviews were conducted in 19 patients with IBS, who were recruited from a randomised controlled trial evaluating two different restrictive diets for 4 weeks: a diet low in total carbohydrates; and a diet low in fermentable oligo-, di- and monosaccharides and polyols (i.e., FODMAP) combined with traditional IBS dietary advice. RESULTS: Three main themes developed from the qualitative analysis and together they describe the dietary intervention as supportive, as well as the dietary changes as challenging and contributing to reflection. Patients found the dietary support effective in both initiating and adhering to their dietary changes. Despite the support, the implementation of the diet was perceived as challenging when it interfered with other important aspects of their lives. However, going through the dietary change process, the patients began to reflect on their eating behaviours, which enabled individual dietary adjustments. The adjustments that patients maintained were not only a result of alleviation of GI symptoms, but also based on personal preferences. CONCLUSIONS: Patients with IBS undergoing restrictive diets appear to benefit from structured support. However, considering the individual patient's life situation and personal preferences, individualised dietary options should be encouraged to achieve long-term dietary changes.

Microbiome-driven IBS metabotypes influence response to the low FODMAP diet: insights from the faecal volatome.

BACKGROUND: Irritable bowel syndrome (IBS) is a common and debilitating disorder manifesting with abdominal pain and bowel dysfunction. A mainstay of treatment is dietary modification, including restriction of FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols). A greater response to a low FODMAP diet has been reported in those with a distinct IBS microbiome termed IBS-P. We investigated whether this is linked to specific changes in the metabolome in IBS-P. METHODS: Solid phase microextraction gas chromatography-mass spectrometry was used to examine the faecal headspace of 56 IBS cases (each paired with a non-IBS household control) at baseline, and after four-weeks of a low FODMAP diet (39 pairs). 50% cases had the IBS-P microbial subtype, while the others had a microbiome that more resembled healthy controls (termed IBS-H). Clinical response to restriction of FODMAPs was measured with the IBS-symptom severity scale, from which a pain sub score was calculated. FINDINGS: Two distinct metabotypes were identified and mapped onto the microbial subtypes. IBS-P was characterised by a fermentative metabolic profile rich in short chain fatty acids (SCFAs). After FODMAP restriction significant reductions in SCFAs were observed in IBS-P. SCFA levels did not change significantly in the IBS-H group. The magnitude of pain and overall symptom improvement were significantly greater in IBS-P compared to IBS-H (p = 0.016 and p = 0.026, respectively). Using just five metabolites, a biomarker model could predict microbial subtype with accuracy (AUROC 0.797, sensitivity 78.6% (95% CI: 0.78-0.94), specificity 71.4% (95% CI: 0.55-0.88). INTERPRETATION: A metabotype high in SCFAs can be manipulated by restricting fermentable carbohydrate, and is associated with an enhanced clinical response to this dietary restriction. This implies that SCFAs harbour pro-nociceptive potential when produced in a specific IBS niche. By ascertaining metabotype, microbial subtype can be predicted with accuracy. This could allow targeted FODMAP restriction in those seemingly primed to respond best. FUNDING: This research was co-funded by Addenbrooke's Charitable Trust, Cambridge University Hospitals and the Wellcome Sanger Institute, and supported by the NIHR Cambridge Biomedical Research Centre (BRC-1215-20014).

Relationship between Markers of Gut Barrier Function and Erythrocyte Membrane PUFAs in Diarrhea-Predominant IBS Patients Undergoing a Low-FODMAP Diet.

Many patients with irritable bowel syndrome (IBS) have a compromised intestinal barrier associated with low-grade inflammation. Polyunsaturated fatty acids (PUFAs) are potential mediators of inflammation: omega-6 PUFAs are pro-inflammatory, while omega-3 PUFAs are antioxidant and anti-inflammatory. Zonulin is a potential biomarker for small intestinal permeability (s-IP). This study investigated the relationship between PUFAs and gastrointestinal (GI) barrier integrity in IBS patients with predominant diarrhea (IBS-D). We evaluated GI barrier function indicators in the urine and bloodstream and erythrocyte membrane PUFA composition in 38 IBS-D patients (5 men, 33 women, 44.11 ± 1.64 years), categorized at baseline by fecal zonulin levels into high (≥107 ng/mL, H-FZ) and normal (<107 ng/mL N-FZ) groups. Evaluations were conducted prior to and following a 12-week diet low in FODMAPs (LFD). At baseline, H-FZ patients had s-IP significantly higher than the reference value, lower n-3 PUFAs levels, and higher n-6/n-3 PUFAs and arachidonic acid (AA) to eicosapentaenoic acid (EPA) ratios than N-FZ. After LFD, H-FZ patients showed significant increases in n-3 PUFAs levels; decreases in n-6 PUFAs, n-6/n-3 PUFAs and AA/EPA ratios; and improved s-IP. The n-6/n-3 PUFAs ratio positively correlated with fecal zonulin levels in all subjects. These findings highlight the relationship between PUFAs and the intestinal barrier, suggesting their role in IBS-D pathophysiology and confirming the positive effects of LFD in managing IBS-D.

Lactiplantibacillus plantarum Regulates Intestinal Physiology and Enteric Neurons in IBS through Microbial Tryptophan Metabolites.

Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disorder characterized by visceral pain and gut dysmotility. However, the specific mechanisms by which Lactobacillus strains relieve IBS remain unclear. Here, we screened Lactobacillus strains from traditional Chinese fermented foods with potential IBS-alleviating properties through in vitro and in vivo experiments. We demonstrated that Lactiplantibacillus plantarum D266 (Lp D266) administration effectively modulates intestinal peristalsis, enteric neurons, visceral hypersensitivity, colonic inflammation, gut barrier function, and mast cell activation. Additionally, Lp D266 shapes gut microbiota and enhances tryptophan (Trp) metabolism, thus activating the aryl hydrocarbon receptor (AhR) and subsequently enhancing IL-22 production to maintain gut homeostasis. Mechanistically, Lp D266 potentially modulates colonic physiology and enteric neurons by microbial tryptophan metabolites. Further, our study indicates that combining Lp D266 with Trp synergistically ameliorates IBS symptoms. Together, our experiments identify the therapeutic efficacy of tryptophan-catabolizing Lp D266 in regulating gut physiology and enteric neurons, providing new insights into the development of probiotic-mediated nutritional intervention for IBS management.

Probiotics in Functional Gastrointestinal Disorders.

The most frequent functional gastrointestinal disorders (FGID) in children include infantile colic, constipation, functional abdominal pain (FAP), and irritable bowel syndrome (IBS). Unfortunately, treatment options for FGID in children are limited, therefore many dietary interventions have been evaluated, including probiotics. This chapter summarizes currently available evidence and recommendations for probiotic use in the treatment of frequent FGIDs in children. The strongest evidence exists for the use of Limosilactobacillus (L.) reuteri DSM 17938 and Bifidobacterium animalis subsp. lactis BB-12 for the treatment of infantile colic in breastfed infants. Limited but yet encouraging evidence exists for Lacticaseibacillus rhamnosus GG (LGG) for the treatment of IBS and L. reuteri DSM 17938 for FAP.

Challenges of recruitment processes to a randomized dietary trial in irritable bowel syndrome.

Background: Irritable bowel syndrome (IBS) is common with a global prevalence of 4%. Dietary regimes with a low content of fermentable oligo-, di-, and monosaccharides and polyol (FODMAP) or a starch- and sucrose-reduced diet (SSRD) have proven to be efficient. The aim of the present study was to describe the recruitment process for a randomized dietary trial with low FODMAP or SSRD for 4 weeks with a follow-up period of 5 months. The results of the dietary trial itself are not included in this paper but will be presented in another publication. Methods: The County of Skåne, with 1,41 million inhabitants, was used as a base to perform a dietary trial in which IBS patients, age 18-70 years, were randomized to either low FODMAP or SSRD for 4 weeks. The estimated number of IBS patients in the actual age span was approximately 32,000. The trial was announced through lectures, letters to all primary healthcare centers (n=203), social media (two campaigns), and invitations to IBS patients identified in medical records (n=744). Results: Three referrals arrived from the healthcare system, 17 patients contacted the investigators in person after receiving information from their healthcare center, and four patients contacted the investigators after recommendations from friends. Of these, 14 were enrolled in the study. From social media, 218 names were delivered, of which 93 fulfilled the study criteria and were willing to participate when contacted by the investigators (42.7%). Of the 3587 identified IBS patients in medical records in close proximity to the hospital, 744 were randomly contacted. Forty-eight patients (6.5 %) were willing to be included in the study. Thus, 155 patients with IBS were included in this study. Conclusions: The inclusion rate for dietary intervention was very low considering the large population informed about the study. Announcements on social media seem to be the best way to recruit patients for intervention. Trial registration: NCT05192603, 29/11/2021, ClinicalTrials.gov. The PRS URL is https://register.clinicaltrials.gov.

The low-FODMAP diet.

In this article we present a protocol for the use of the low-FODMAP diet in paediatric patients and review of the current evidence on its efficacy. These short-chain carbohydrates, which can be fermented by the intestinal microbiota, are found in a wide variety of foods, mainly of plant origin. The low-FODMAP diet is a therapeutic tool used for the management of gastrointestinal disorders such as irritable bowel syndrome. The sources we used were PubMed, Web of Science, Google Scholar and institutional websites. Following consumption of FODMAP-rich foods, a series of end products are generated that are not absorbed, giving rise to symptoms. Before starting a low-FODMAP diet, it is important to carry out a diagnostic evaluation including any applicable tests. Treatment is structured in 3 phases: elimination, reintroduction and personalization phase. In the first phase, FODMAP-rich foods are eliminated for 2-3 weeks. In the second phase, lasting 8 weeks, FODMAP-rich foods are gradually reintroduced. The last phase consists in customizing the diet according to individual tolerance. This article details which foods contain FODMAPs and possible substitutes. In addition, specific food diary/intake tracking and educational materials are provided in a series of appendices to facilitate adherence to the diet. Although most studies have been conducted in adults, there is also some evidence on the beneficial effects in the paediatric age group, with a reduction of symptoms, especially in patients with functional gastrointestinal disorders. Nevertheless, more research is required on the subject.

Dietetic Management of Irritable Bowel Syndrome: A National Survey of Dietary Approaches and Decision-making Factors.

BACKGROUND AND AIMS: There has been a growing emphasis on dietary therapies for irritable bowel syndrome (IBS). Furthermore, there has been an evolving evidence base for the low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet, gluten-free diet (GFD), and lactose-free diet. This study examines the dietary approaches employed and the factors influencing dietetic decision-making for IBS interventions. METHODS: Participants, including registered dietitians and nutritionists, were recruited from diverse healthcare settings at the point of registration for the 4th Sheffield National Dietetic Gastroenterology Symposium, 2023. A 15-question online survey investigated the practices of dietitians and nutritionists in managing IBS patients, covering dietary approaches, decision-making factors, and patient education. The evidence base for different dietary interventions was provided and a follow-up survey assessed symposium attendees, views on current IBS dietary practices. RESULTS: Out of 731 respondents, primarily registered dietitians (93%) and females (93%), 54% spent 10-50% of clinic time on IBS. Respondents noted that a GFD (34%), low lactose (32%), and traditional dietary advice (TDA) (18%) were the most frequently used dietary interventions that patients try before seeking professional advice. Delegates were asked to rank their dietary intervention preferences pre- and post-meeting (after the evidence base had been presented): TDA pre-meeting 75% versus post-meeting 87% (p=0.04), fibre modification 59% versus 6% (p<0.0001), low FODMAP 25% versus 10% (p=0.0001), low lactose 12% versus 62% (p<0.0001) and GFD 6% to 23% (p<0.0001). CONCLUSIONS: TDA remains the choice of diet for dietitians. After our educational event, the use of low-lactose and gluten-free diet significantly increased. Factors influencing the decision-making process were based on patient acceptability, counselling time, supporting evidence base and dietary triggers.

A diet low in fermentable oligo-, di-, monosaccharides and polyols improves abdominal and overall symptoms in persons with all subtypes of irritable bowel syndrome.

BACKGROUND: A diet low in fermentable oligo-, di-, monosaccharides and polyols (LFD) improves symptoms in patients with irritable bowel syndrome (IBS). Previous studies have focused on patients with IBS and diarrhea (IBS-D). It is unclear whether LFD is effective for IBS with constipation (IBS-C) or IBS with mixed bowel habits (IBS-M). This open-label, real-world study evaluates the relative effectiveness of the LFD among IBS subtypes. METHODS: This study analyzes data from a service that provides low-FODMAP meals to individuals with IBS. Participants met with a registered dietitian and completed the IBS symptom severity survey (IBS-SSS) before and after undergoing a 2-4-week period of FODMAP restriction. The primary endpoint was the proportion of participants with ≥50-point decrease in IBS-SSS between the three IBS subtypes. KEY RESULTS: After FODMAP restriction, 90% of participants with IBS-D, 75% with IBS-C, and 84% with IBS-M met the primary endpoint (p = 0.045). Similar improvement was seen for a 100-point decrease, but the difference between IBS subtypes was not significant (p = 0.46). After FODMAP restriction, all groups had statistically significant improvement in total IBS-SSS as well as individual symptom categories. Improvement in IBS-SSS subcategories was similar among the groups except for the categories of bloating severity (IBS-M had greatest improvement) and bowel movement satisfaction (IBS-C had less improvement). CONCLUSION & INFERENCES: Though the proportion of responders was highest for IBS-D and lowest for IBS-C, the LFD led to robust improvement in overall symptoms in all IBS subtypes. Key individual symptoms also showed significant improvements in all IBS subtypes.

Changes in Fecal Short-Chain Fatty Acids in IBS Patients and Effects of Different Interventions: A Systematic Review and Meta-Analysis.

CONTEXT: Short-chain fatty acids (SCFAs) have been reported to be associated with the pathogenesis of irritable bowel syndrome (IBS), but the results are conflicting. OBJECTIVE: Here, a systematic review of case-control studies detecting fecal SCFAs in IBS patients compared with healthy controls (HCs) and self-controlled studies or randomized controlled trials (RCTs) investigating fecal SCFA alterations after interventions were identified from several databases. DATA SOURCES: A systematic search of databases (PubMed, Web of Science, and Embase) identified 21 studies published before 24 February 2023. Data extractions: Three independent reviewers completed the relevant data extraction. DATA ANALYSIS: It was found that the fecal propionate concentration in IBS patients was significantly higher than that in HCs, while the acetate proportion was significantly lower. Low-FODMAP diets significantly reduced the fecal propionate concentration in the IBS patients while fecal microbiota transplantation and probiotic administration did not significantly change the fecal propionate concentration or acetate proportion. CONCLUSIONS: The results suggested that the fecal propionate concentration and acetate proportion could be used as biomarkers for IBS diagnosis. A low-FODMAP diet intervention could potentially serve as a treatment for IBS while FMT and probiotic administration need more robust trials.

Is the Mediterranean Low Fodmap Diet Effective in Managing Irritable Bowel Syndrome Symptoms and Gut Microbiota? An Innovative Research Protocol.

INTRODUCTION: Irritable bowel syndrome (IBS) symptoms can be effectively managed with the low FODMAP diet. However, its efficacy in reducing inflammation is not yet proven. On the contrary, the Mediterranean diet has anti-inflammatory properties with proven efficacy in treating chronic low-grade inflammation-related diseases. AIM: To publicly share our protocol evaluating the efficacy of the Mediterranean low-FODMAP (MED-LFD) versus NICE recommendations (British National Institute for Health and Care Excellence) diet in managing IBS symptoms and quality of life. MATERIALS AND METHODS: Participants meeting the Rome IV criteria will be randomly assigned to MED-LFD or NICE recommendations and they will be followed for six months. Efficacy, symptom relief, quality of life and mental health will be assessed using validated questionnaires. In addition, fecal samples will be analyzed to assess gut microbiota, and to measure branched and short-chain fatty acids, and volatile organic compounds (metabolic byproducts from bacteria). Expected results and discussion: By publicly sharing this clinical study protocol, we aim to improve research quality in the field of IBS management by allowing for peer review feedback, preventing data manipulation, reducing redundant research efforts, mitigating publication bias, and empowering patient decision-making. We expect that this protocol will show that MED-LFD can effectively alleviate IBS symptoms and it will provide pathophysiology insights on its efficacy. The new dietary pattern that combines the LFD and the MED approaches allows for the observation of the synergistic action of both diets, with the MED's anti-inflammatory and prebiotic properties enhancing the effects of the LFD while minimizing its limitations. Identifier in Clinical Trials: NCT03997708.

Current and future pharmacotherapies for the management of constipation-predominant irritable bowel syndrome.

INTRODUCTION: Irritable bowel syndrome (IBS) is a common gastrointestinal disorder affecting 9-23% of the world's population, with a higher prevalence among women. IBS is a complex disorder influenced by psychosocial, physiological, and genetic factors, exacerbated by stress. AREAS COVERED: Research confirms that the most common subtype of IBS is IBS-C. Therefore, new therapies are being developed to speed up bowel movement and reduce constipation, with drugs such as linaclotide, plecanatide, lubiprostone, or tegaserod available to reduce IBS-C symptoms. In addition, patients' condition is improved by foods rich in fiber and low in FODMAP and the use of biotics. EXPERT OPINION: The topic is of great importance due to the growing number of patients suffering from IBS-C and its significant impact on quality of life. Current clinical trials of new therapeutic options are not too successful, and it seems that one of the plausible treatment options could be the multi-drug cocktail with some, or perhaps even all its ingredients emerging from drug re-purposing. Another important path that needs to be explored further in IBS-C patients is the adjustment of dietary habits and/or introduction of dietary or nutritional intervention.