Search Results (160)

Background/Objectives: Short-term low-fermentable oligo-, di-, and monosaccharide and polyol (FODMAP) diets can reduce exercise-associated gastrointestinal symptoms (Ex-GIS); however, their effects on the gut microbiome, short-chain fatty acids (SCFAs), and gastrointestinal biomarkers remain unclear. This study explored the effects of 48 h dietary FODMAP manipulation within a high-carbohydrate diet on faecal bacterial and SCFA profiles, and their relationships with exercise-induced gastrointestinal syndrome (EIGS) biomarkers, Ex-GIS, and performance. Methods: Twelve endurance athletes experiencing Ex-GIS were randomly allocated to a 48 h high-carbohydrate (mean ± SD: 12.1 ± 1.8 g∙d⁻¹)–high-FODMAP (HC-HFOD) (54.8 ± 10.5 g∙d⁻¹) and a 48 h high-carbohydrate–low-FODMAP (HC-LFOD) (3.0 ± 0.2 g∙d⁻¹) diet before 2 h of running at 60% $\dot{V}$O_2max, followed by a 1 h distance test (22.9 ± 1.2 °C, 46 ± 8% RH). Baseline faecal samples were collected before exercise trials to determine faecal bacterial and SCFA profiles. Blood samples were collected pre- and post-exercise to determine plasma I-FABP, sCD14, and CRP concentrations. Ex-GIS were recorded every 15 min throughout exercise. Results: Faecal bacterial α-diversity and relative abundance (RA%) at the phylum level were unchanged following both diets, while several family- and genus-level taxa RA% values were changed (p < 0.05), with greater shifts after HC-HFOD. HC-HFOD significantly increased faecal total-SCFA (p = 0.004), acetic (p = 0.002), and butyric (p = 0.028) acid concentrations. Strong positive and negative correlations between bacterial RA% and EIGS biomarkers and Ex-GIS were observed. Strong negative correlations with bacterial RA% and performance were observed. Conclusions: The 48 h HC-HFOD resulted in greater increases in bacterial RA% and SCFA concentrations compared with baseline. Bacterial RA% correlated bidirectionally with EIGS biomarkers and Ex-GIS, alongside strong negative associations with performance. Full article

Alterations in the intestinal microbiota have been implicated in both irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). However, their biological significance and therapeutic implications differ substantially between the two conditions. Although dysbiosis is a common feature, the mechanisms by which alterations in the microbiota contribute to disease pathophysiology and clinical expression are distinct. Some pathways are more prominent in IBS (e.g., the gut–brain axis), whereas others are more prominent in IBD (e.g., reduced microbial diversity). Equally important are pathways that appear to play a role exclusively in IBD [e.g., Adherent-invasive Escherichia coli (AIEC) and Paneth cells], as well as others that seem to be specific to IBS (e.g., mast cell activation). In IBD, microbiota changes are primarily linked to immune dysregulation, mucosal barrier impairment, and inflammation-driven pathways, whereas in IBS, they are mainly associated with functional disturbances mediated by neuroimmune signaling and microbial metabolites. Furthermore, several microbiome-associated biomarkers differ between these two diseases, and some are already assessed by international guidelines. Although the microbiota plays a key role in IBS and IBD pathophysiology, microbiome-based treatments remain limited, especially in IBD. There are clinically available treatments in IBS (e.g., rifaximin, low-FODMAP diet), but in IBD, only the probiotic VSL#3 is guideline-approved in ulcerative colitis pouchitis prophylaxis. Nevertheless, the dynamic nature of the microbiota continues to support the investigation of already studied (e.g., probiotics, fecal microbiota transplantation) and potential novel therapeutic approaches at the research level. The aim of this review is to compare the gut-microbiota-related pathophysiological pathways and biomarkers between IBS and IBD, to summarize the microbiome-related medications that have already been studied in both diseases, and to suggest new potential therapeutic options based on the gut microbiota. Full article

Introduction: Alterations of the microbiota–gut–brain axis, including increased intestinal permeability (IP), changes in microbial activity, and immune activation, are central to the pathophysiology of irritable bowel syndrome with diarrhea (IBS-D). The low-fermentable oligo-di-monosaccharides and polyols (FODMAP) diet (LFD) is an established therapy for IBS, yet its systemic effects, particularly in patients with elevated depressive symptoms, remain incompletely characterized. Methods: This single-arm pre–post study investigated associations between depressive symptom severity and markers of small IP (s-IP), endotoxin exposure, inflammation, and erythrocyte membrane polyunsaturated fatty acid (PUFA) composition in 43 IBS-D patients undergoing a 12-week personalized LFD. Patients were classified using the Symptom Checklist-90-Revised depression subscale into those with (d+, n = 23) and without (d−, n = 20) clinically elevated depressive symptoms. Results: At baseline, d+ patients exhibited higher s-IP, circulating lipopolysaccharide levels, inflammatory markers, and a more pro-inflammatory PUFA profile. Following LFD, significant improvements in symptoms and several biological parameters were observed in the overall cohort. Greater absolute changes in d+ patients were consistent with their higher baseline values rather than indicating differential responsiveness. Baseline depressive symptoms were not significantly associated with the magnitude of post-intervention changes in IP or inflammatory markers. Conclusions: These findings suggest that elevated depressive symptoms identify an IBS-D subgroup characterized by greater baseline biological burden. Results should be interpreted as associative given the single-arm design, absence of a control group, and the concurrent reduction in body weight, which may have influenced the observed changes. Randomized controlled studies are needed to clarify the role of dietary interventions in modulating gut–brain axis-related pathways in IBS-D. Full article

Background/Objectives: Irritable bowel syndrome (IBS) is primarily treated via dietary modifications. Several diets have been shown to improve symptoms with similar efficacy. Other aspects of IBS, such as insufficient nutrient intake and being overweight, should also be considered when planning treatment options. The present scoping review aimed to identify various diets investigated in IBS-related clinical trials and to map the measured outcomes. Methods: We performed a systematic search of three databases: PubMed, Embase, and CINAHL Ultimate. Our search was limited to papers published between January 2000 and February 2026, and included human studies published as peer-reviewed original articles in English that described dietary interventions in adult patients (≥18 years) with IBS. Results: The titles and abstracts of 1261 studies were screened; 1147 studies were excluded; and 114 full-text articles were assessed for eligibility. Excluding articles outside the scope of our research resulted in a total of 71 included articles from 57 unique clinical trials. The most common interventions were low fermentable oligo-, di-, and monosaccharides and polyols (FODMAP) (n = 43), traditional dietary advice (n = 13), and gluten-free diets (n = 11). The most common primary outcomes were the effect on IBS symptoms (n = 48), efficacy in terms of improving quality of life (n = 10), psychological well-being (n = 7), nutrient intake (n = 7), and adherence/applicability/feasibility to the diet (n = 7). Conclusions: In conclusion, the most studied dietary intervention in IBS was low FODMAP, and an effect on GI symptoms was the most common outcome. Considering other conditions associated with IBS, the effects on anthropometric, endocrine, metabolic, and nutritional parameters should also be evaluated. Full article

Diet is a major modifiable determinant of gastrointestinal (GI) health, influencing disease risk and progression through coordinated effects on the gut microbiome, immune regulation, epithelial barrier integrity, oxidative balance, and epigenetic mechanisms. This narrative review synthesizes epidemiological, mechanistic, and clinical evidence from the past decade to examine bidirectional relationships between dietary patterns and seven common GI disorders: celiac disease, irritable bowel syndrome (IBS), Crohn’s disease, ulcerative colitis, Helicobacter pylori-associated gastritis, peptic ulcer disease, and lactose intolerance. Western dietary patterns, characterized by high intake of ultra-processed foods and saturated fats and low fiber consumption, are consistently associated with microbial dysbiosis, impaired barrier function, and enhanced inflammatory signaling. In contrast, Mediterranean and plant-forward dietary patterns show protective associations across multiple GI conditions. Mechanistically, diet influences GI pathophysiology largely through microbiome-derived metabolites, particularly short-chain fatty acids, which regulate epithelial homeostasis, immune tolerance, and inflammatory pathways. Condition-specific dietary strategies remain clinically important. Gluten exclusion is essential in celiac disease, low- fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) approaches provide evidence-based symptom control in IBS, and exclusive enteral nutrition or targeted exclusion diets support remission induction in Crohn’s disease. Selected probiotics and emerging postbiotics may provide adjunctive benefits in specific contexts. Despite growing evidence, dietary research remains limited by methodological heterogeneity and interindividual variability. Precision nutrition approaches integrating microbiome profiling and artificial intelligence represent a promising translational direction. Overall, dietary patterns—rather than isolated nutrients—form the foundation of GI dietary therapy. Full article

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder characterized by recurrent abdominal pain and altered bowel habits that significantly impair patients’ quality of life. Dietary triggers of IBS symptoms are common, and consequently, diet-based treatments are often prescribed. We conducted a review of current evidence on dietary interventions for IBS, focusing specifically on the evaluation of the scientific rationale and effectiveness of the most commonly adopted diets. Clinical trials and guideline recommendations were analyzed to assess each diet’s efficacy in symptom relief and patient adherence. Traditional dietary advice, although not a structured diet, but rather a set of lifestyle and dietary recommendations, is commonly recommended as first-line therapy and provides a solid base for symptom improvement in almost half of patients with IBS. Conversely, the low-FODMAP diet is a strict dietary pattern characterized first by the exclusion and then by the gradual and personalized reintroduction of several foods. Several clinical trials have demonstrated the efficacy of a low-FODMAP diet in reducing global IBS symptoms, and due to the established evidence, it is now incorporated into many clinical guidelines as a second- or even first-line approach for patients with IBS. Limited data supports the starch- and sucrose-reduced diet as an option for symptom relief, with evidence stemming from the relatively recent finding of hypomorphic variants of the sucrose-isomaltase gene in a subset of patients with IBS. Nonetheless, its application in clinical practice is still very limited. Data on gluten-free diet is more controversial as although it may benefit a subset of patients with IBS, strong evidence is still lacking for identifying the best candidates for a restrictive diet with a high burden in terms of economical, psychological and social costs. Beyond exclusion diets, a few studies on the Mediterranean diet suggest it may be a potential option with benefits that go beyond IBS symptom relief. Overall, dietary modification can significantly alleviate IBS symptoms. Tailoring recommendations to individual patient triggers may further enhance outcomes. Full article

Background: Endometriosis is a chronic inflammatory gynecological disease affecting approximately 10% of women of reproductive age and is associated with pelvic pain, infertility, and reduced quality of life. Increasing evidence suggests that diet may influence endometriosis development and symptom severity through modulation of inflammation, oxidative stress, and hormone metabolism. This scoping review aimed to map current evidence on the role of nutrition in endometriosis. Methods: This scoping review was conducted in accordance with PRISMA-ScR guidelines. PubMed and Scopus were searched for original human studies published in English between 2014 and 2024. Eligible studies examined dietary patterns, food groups, micronutrients, bioactive compounds, body mass index, or fat consumption in relation to endometriosis risk, progression, or symptoms. Results: Diets rich in fruits and vegetables, including Mediterranean and low-FODMAP dietary patterns, were associated with reduced pain symptoms and improved quality of life. Antioxidant and anti-inflammatory nutrients, particularly vitamins C and D, zinc, and curcumin, were linked to modulation of oxidative stress, inflammation, angiogenesis, and cellular proliferation. Evidence regarding dairy intake, gluten, carbohydrates, dietary fat, and BMI was inconsistent or limited. Considerable heterogeneity across study designs and outcome measures was observed. Conclusions: Dietary factors may contribute to the modulation of endometriosis-related symptoms and underlying pathogenic mechanisms. Nutrients with antioxidant and anti-inflammatory properties appear promising as complementary, non-invasive strategies; however, methodological heterogeneity highlights the need for high-quality randomized controlled trials. Full article

Small-intestinal bacterial overgrowth (SIBO) is defined by an excessive microbial presence in the small intestine and is associated with a range of gastrointestinal symptoms. Its management remains complex due to diagnostic limitations and high recurrence rates following treatment. A narrative review was conducted using MEDLINE (PubMed) and Cochrane databases to identify relevant studies published between 1984 and 2024. Search terms included small intestinal bacterial overgrowth SIBO, FODMAP, probiotics, prebiotics, synbiotics, and low-carbohydrate diets. Reference lists were also screened for additional studies. Antibiotics, particularly rifaximin, are commonly used for SIBO treatment but recurrence is frequent. Dietary strategies, such as low-FODMAP and low-carbohydrate diets, may help reduce symptoms, especially in patients with complications like D-lactic acidosis. Evidence for biotic agents (probiotics, prebiotics, synbiotics) is mixed, with limited high-quality studies and inconsistent outcomes. Some probiotic strains show symptom improvement, but effects on breath-test results are variable. A tailored, multidisciplinary approach combining dietary and medical therapies may offer optimal symptom control in SIBO. However, heterogeneity in study designs and limited evidence highlight the need for further research to inform standardised, evidence-based clinical practice. Full article

Background/Objectives: Intense physical activity can cause gastrointestinal symptoms, negatively impacting athletic performance. A low-FODMAP diet has the potential to reduce these symptoms and is increasingly being considered by physically active individuals. The aim of this review is to present the current knowledge on the importance of FODMAPs in sports nutrition. Methods: A narrative review was conducted in PubMed, Web of Science, ScienceDirect, and Google Scholar, covering publications published up to October 2025. Original studies, reviews, and meta-analyses addressing the relationship between FODMAP intake and gastrointestinal symptoms during physical activity were included. Selected articles were assessed for specific criteria, and the results were grouped thematically to present the current state of knowledge. Results: FODMAP consumption increases the risk of intestinal symptoms. Short-term FODMAP restriction, especially before and during exercise, reduced the severity of symptoms in most of the analyzed studies. Data on the long-term effects of a low FODMAP diet on the health, nutrition, and gut microbiota of athletes remain limited. Conclusions: A strategy of short-term FODMAP restriction in athletes’ diets shows potential for reducing gastrointestinal symptoms. An optimal approach requires individualization. Further research is needed to monitor potential side effects and long-term outcomes. Full article

Background/Objectives: Recent reports on the co-occurrence of allergies and endometriosis have provided grounds for expanding research in this area, suggesting that diagnostics should be extended to women with endometriosis. However, numerous studies on nutrients and antioxidants do not specify the type of diet that supports the treatment process. In our review, we focus on the types of food elimination and dietary approaches that have been used. Methods: This systematic review was conducted according to the PRISMA guidelines. We searched the EMBASE, PUBMED and SCOPUS databases, as well as the bibliographies of research papers and reviews, including the latest reports from June 2025. The search keywords were “endometriosis” and “type of diet”, “nutrition”, “food products”, “nutrients”, “elimination diet”, and “allergies”. Results: Excluding coexisting allergies and introducing an anti-inflammatory diet low in animal products, limiting butter and margarine, and eliminating fried foods and refined simple sugars may be the best solution to help treat endometriosis. Conclusions: Personalised nutritional counselling for patients with endometriosis is particularly helpful and necessary, as there is no single elimination diet that can be recommended for all patients with endometriosis. The first step should be an anti-inflammatory diet, such as the Mediterranean diet or the MIND diet (Mediterranean-DASH diet intervention for neurological delay), followed by more in-depth allergy screening. The phenotypic diversity of this group of patients may require the use of a low-FODMAP (fermentable oligo-, di-, monosaccharides and polyols), low-nickel, gluten-free or other elimination diet. Full article

Irritable bowel syndrome (IBS) is a disorder of gut–brain interaction characterized by recurrent abdominal pain associated with a change in the frequency and/or form of stools. Approximately one in three patients with quiescent inflammatory bowel disease (IBD), defined as the absence of endoscopic evidence of active inflammation, experience IBS-type symptoms. These symptoms are associated with reduced quality of life and increased psychological burden, and can complicate clinical assessment by mimicking conditions such as small intestinal bacterial overgrowth, bile acid malabsorption, or post-inflammatory complications. This up-to-date narrative review examines the mechanisms, diagnostic challenges, and management of IBS-type symptoms in quiescent IBD. Evidence suggests that these symptoms arise from a complex “matrimony” of functional and organic processes, including low-grade residual inflammation, altered intestinal permeability, microbiota dysbiosis, visceral hypersensitivity, and psychosocial impairment. Diagnosing IBS-type symptoms in IBD requires a “positive”, symptom-focused approach while carefully excluding active inflammation. Management should adopt a biopsychosocial approach, integrating dietary strategies (e.g., low-FODMAP diet), brain–gut behavioral therapy, biofeedback therapy, and/or pharmacological treatments such as antispasmodics, antidiarrheals, laxatives, and neuromodulators to address both physiological and psychological factors. Future research should integrate sensitive biomarkers and longitudinal follow-up to enhance diagnostic precision and guide personalized therapy. Understanding and addressing the overlap between IBS and IBD is essential to reduce the multidimensional burden on physical health, psychological well-being, and daily functioning. Full article

Background and Objectives: Fibromyalgia (FM) is associated with chronic pain, oxidative stress, low-grade inflammation, and disturbances in signalling along the gut–brain axis. These pathways may be modulated by plant-derived phytonutrients. This narrative review summarises mechanistic and clinical evidence on phytonutrient-based strategies in FM. Materials and Methods: Following SANRA guidelines, we searched PubMed, Web of Science, Scopus and ScienceDirect for human and relevant preclinical studies published between 2005 and October 2025 that evaluated phytonutrient-rich dietary patterns or isolated bioactives in relation to FM symptoms or underlying mechanisms. Results: There is a consistent association between FM and increased oxidative damage and reduced antioxidant defences. Adopting plant-based diets, particularly Mediterranean-type and low-FODMAP diets, has been linked to improvements in pain, fatigue, sleep, and gastrointestinal symptoms, as well as modest gains in quality of life. However, the effects on inflammatory markers are conflicting. Trials of selected bioactive compounds, such as coenzyme Q10, curcumin-based formulations, L-carnitine and certain probiotics, suggest beneficial effects on symptoms, whereas others show little or no effect. Studies of the microbiome indicate a loss of butyrate-producing bacteria and altered microbial metabolites. Early dietary or probiotic interventions may partially mitigate these changes to some extent. Preclinical studies have identified SIRT1 as a potential mediator, but there is a lack of human data. Reporting on safety, dosage and formulation is often inadequate. Conclusions: Given the narrative design of this review and the methodological heterogeneity of the included studies, the overall certainty of the evidence cannot be formally graded and should be regarded as limited and heterogeneous. Nevertheless, current data supports phytonutrient-rich, food-based approaches as adjuncts rather than alternatives to standard FM care. Well-designed randomised trials with standardised outcomes and reporting of dose, formulation and relevant biomarkers are needed to identify the most effective strategies and the patient subgroups most likely to benefit. Full article

Non-coeliac wheat sensitivity (NCWS) is characterised by gastrointestinal and extra-intestinal symptoms following gluten/wheat ingestion in individuals without coeliac disease or wheat allergy but remains controversial due to symptom overlap with irritable bowel syndrome (IBS). This narrative review aims to provide a comprehensive, critical analysis of NCWS as a clinical and biological entity, examining the evidence for its distinction from related disorders. While self-reported rates are high (often >10%) in the general population, rigorous double-blind, placebo-controlled challenge (DBPCC) studies confirm the diagnosis in only a minority of cases (typically <30%). The clinical presentation is heterogeneous, combining IBS-like symptoms with systemic complaints such as “brain fog,” headaches, and fatigue. The pathophysiology is distinct from coeliac disease, involving innate immune activation, altered intestinal barrier function, and gut dysbiosis. Non-gluten wheat components, particularly fructans and amylase-trypsin inhibitors, are implicated as potential triggers. Diagnosis is challenging, requiring the exclusion of other disorders and adherence to complex dietary challenge protocols such as the Salerno Experts’ Criteria, which are impractical for routine clinical use. The search for validated biomarkers is a key research area and investigated candidates include serological markers such as IgG anti-gliadin antibodies, inflammatory markers such as faecal calprotectin, and proteins related to intestinal permeability such as zonulin, but results have been conflicting and require further validation. Management primarily involves elimination of wheat and gluten from the diet, although a low-FODMAP diet has also proven effective as an adjunctive treatment. In conclusion, NCWS is a clinical entity whose study and management are critically hampered by the absence of validated diagnostic criteria and biomarkers. Progress requires methodologically rigorous DBPCC trials to elucidate its mechanisms and develop reliable diagnostic tools. Full article

Irritable Bowel Syndrome (IBS) is a prevalent and heterogeneous functional gastrointestinal disorder with a complex and multifactorial pathophysiology. Traditional treatment approaches have focused on symptom relief, often overlooking the underlying biological mechanisms driving the disease. Τhis review summarizes the current evidence linking core pathophysiological pathways of IBS with mechanism- and diet- based therapeutic strategies to guide personalized treatment. Serotonergic signaling, microbial dysbiosis, immune activation, epithelial barrier dysfunction, and bile acid malabsorption interact to shape the diverse phenotypes of IBS, contributing to altered motility, visceral hypersensitivity, and gut-brain axis dysregulation. Increasing evidence supports that targeted dietary and biological interventions including low-FODMAP and Mediterranean low-FODMAP diets, targeted use of probiotics and psychobiotics, and vitamin D supplementation can modulate microbial composition, reduce luminal irritants, support barrier integrity, and attenuate immune system activation. Similarly, pharmacologic therapies including serotonergic receptor modulators, bile acid sequestrants and neuroimmune agents act on specific mechanistic pathways, reflecting a shift from symptom-based to mechanism-driven management. Collectively, these findings highlight that integrating dietary, microbial, neuroimmune, and serotonergic modulation within a unified therapeutic framework can support a more rational and individualized approach to IBS management and long term symptom control. Full article

Background/Objectives: Irritable bowel syndrome (IBS) is presented with both gastrointestinal and extraintestinal symptoms. In addition, overweight/obesity and metabolic syndrome is prevalent in IBS. Dietary interventions with a low content of fermentable oligo-, di-, and monosaccharides and polyols (FODMAP) or a starch- and sucrose-reduced diet (SSRD) efficiently reduce symptoms and weight. Our hypothesis was that not only nutrition composition but also weight reduction is of importance for symptom relief. The aim was to merge two randomized trials and examine symptoms, weight, nutrition intake, and lipid levels at baseline and during nutritional intervention. Methods: One study with 105 IBS patients randomized to either an SSRD (n = 80) or control diet (n = 25) and one study with 155 IBS patients randomized to an SSRD (n = 77) or low FODMAP (n = 78) were merged. Symptom and food questionnaires were analyzed together with weight/body mass index (BMI) and lipid levels. Results: Patients had moderate or severe IBS at baseline, and half of them were overweight/obese. Energy intake was reduced by both diets, with the most pronounced carbohydrate reduction after the SSRD. The cholesterol levels were highest in the second cohort, possibly due to the higher fat and lower starch intake. About 25% had high-density lipoprotein below reference levels. Gastrointestinal and extraintestinal symptoms, as well as weight/BMI, were reduced by the SSRD and low FODMAP, but not in the control group. The SSRD in the second cohort and low FODMAP rendered lower levels of total cholesterol, low-density lipoprotein, and non-high-density lipoprotein levels. Weight/BMI were more often associated with lipid levels and symptoms than nutrient composition at baseline, and weight/BMI reductions correlated with carbohydrate reduction and were associated with a reduction in gastrointestinal and extraintestinal symptoms. Conclusions: Not only food components, but also overweight/obesity may be of importance for the development and severity of IBS and related symptoms. Full article