Search Results (101)

Background: Hydrogen breath testing is commonly used to assess intestinal fermentation and diagnose small intestinal bacterial overgrowth (SIBO). However, it remains unclear whether hydrogen production reflects systemic inflammatory or metabolic status. This study evaluated the relationship between hydrogen production dynamics and systemic biomarkers using a data-driven analytical approach. Methods: This cross-sectional study included 162 adults undergoing lactulose hydrogen breath testing. Hydrogen production was characterized using continuous measures, including area under the curve (AUC), early and late hydrogen responses, and unsupervised clustering-derived hydrogen response groups. Associations with serum 25-hydroxyvitamin D, C-reactive protein (CRP), leukocyte count, and interleukin-6 (IL-6) were assessed using multivariable regression models adjusted for age and body mass index (BMI). Results: Hydrogen production showed substantial interindividual variability. Unsupervised analysis identified low-, intermediate-, and high-hydrogen response groups. Differences between groups were driven mainly by overall fermentation intensity rather than distinct temporal response profiles. No significant associations were observed between hydrogen production metrics and systemic biomarkers. Hydrogen-related variables were not independently associated with vitamin D, CRP, leukocyte count, or IL-6 concentrations. In contrast, BMI was consistently associated with inflammatory markers, particularly CRP and IL-6. Correlation analyses demonstrated strong relationships among hydrogen-derived variables but weak associations with systemic parameters. Conclusions: Data-driven analysis revealed marked heterogeneity in intestinal hydrogen production but no detectable association with systemic inflammatory or metabolic markers within the present cohort. These findings suggest that hydrogen breath test metrics primarily reflect local intestinal fermentation rather than systemic physiological status. Hydrogen breath testing remains useful for assessing gastrointestinal function, but no evidence supporting its value as a marker of systemic inflammation was identified in the present cohort. Full article

Background: Small intestine bacterial overgrowth (SIBO) is associated with steatohepatitis (SH) in subjects with metabolic-associated steatotic liver disease (MASLD). The impact of ileocecal valve (ICV) incontinence, a major cause of SIBO in patients with MASLD, remains unknown because of the unmet need for a non-X-ray-dependent diagnosis. Methods: Exploiting water as contrast medium and colonic irrigation via a hydro-colon machine (Clean Colon Srl, Monza, Italy), we developed a new abdominal ultrasound (US) procedure for diagnosing and grading ICV incontinence. In a pilot, observational, feasibility and safety study, we correlated a new ICV incontinence parameter with irritable bowel syndrome (IBS, ROMA IV criteria), serum transaminases (AST, ALT), platelet counts, FIB-4, US liver steatosis and stiffness (LS, measured by Shear Wave and Transient Elastography, SWE and TE). Results: We prospectively studied 32 consecutive subjects with IBS who underwent a pre-colonoscopy colon cleansing after informed consent: 19 males (59%), body mass index (BMI) 26.6 ± 2.6 kg/m², age 57 ± 19 years, 16 (50%) with US liver steatosis. The half-hour (27 min, range 20–35 min) procedure was safe and well tolerated except in two males with prostate hypertrophy. ICV incontinence was graded (after 2500–3000 mL irrigation) according to cecum/right-colon distention with/without (immediate or delayed) reflux into terminal ileum (TI): 0 = cecum distension without TI reflux; 1 = cecum distension with TI reflux; 2 = absence of cecum distension with TI reflux. Cecum/right-colon distention (grade 0 or 1) was perceived by the patients whereas the right colon irrigation with complete ICV incontinence (grade 2) was symptomless. ICV continence associated with LS (p ≤ 0.0001). A histologic diagnosis of non-alcoholic steatohepatitis was confirmed in a 35-year-old obese male with SIBO and LS > 8 kPa (8.7/8.5 kPa by SWE/TE):steatosis (grade S3) with hepatocyte ballooning, lobular inflammation (grade 6/8) without fibrosis (stage 0/4, F0). Conclusions: The new US-based approach provides a feasible, easy-to-perform, mini-invasive tool for the diagnosis and grading of ICV incontinence. Preliminary results prompt prospective studies investigating the impact of ICV incontinence as a possible co-factor of steatohepatitis in patients with MASLD. Full article

Small intestinal bacterial overgrowth (SIBO) refers to an abnormal increase in the number of bacteria in the small intestine and is observed in various diseases. SIBO can also develop after long-term use of proton pump inhibitors (drug-induced SIBO), bariatric surgery, gastrectomy, and other surgeries (postoperative SIBO). The aim of this narrative review is to summarize all of the published information on the treatment of SIBO in as much detail as possible and present it separately for each specific disease and intervention associated with SIBO. The most extensively studied drug for the treatment of SIBO is rifaximin. It eliminates SIBO in 63% of cases; however, most studies lack a control group. Small RCTs assessing the effects of this antibiotic on SIBO have reported conflicting results, and a meta-analysis showed no effect. A large RCT is required to verify the results of uncontrolled studies. Neomycin and norfloxacin showed efficacy in the treatment of SIBO in single RCTs, with elimination rates of 20 and 100%, respectively. Ciprofloxacin, rifamycin, metronidazole, and other antibiotics, as well as ursodeoxycholic acid, showed positive effects for the treatment of SIBO, but only in uncontrolled studies or in comparison with rifaximin or other drugs. The reported elimination rates were 54%, 67%, 79%, and 75%, respectively. Eradication therapy for Helicobacter pylori infection eliminated SIBO at a rate of approximately 70%. Probiotics have been tested for treatment of SIBO in various diseases. VSL#3 and Saccharomyces boulardii CNCM I-745 were effective in RCTs, with elimination rates of 58% and 80%, respectively. In conclusion, when selecting SIBO treatment regimens, those that have demonstrated the greatest efficacy for a specific concomitant disease should be preferred, despite the generally low level of evidence supporting these approaches in most cases. Full article

Background: Rifaximin is widely used in the management of small intestinal bacterial overgrowth (SIBO), but concerns remain regarding the potential risk of Clostridioides difficile infection (CDI), particularly with repeated antibiotic exposure. Aim: To evaluate the short-term risk of CDI following Rifaximin therapy in patients with SIBO. Materials and Methods: We conducted a retrospective cohort study using the TriNetX Collaborative Research Network. Adult patients with SIBO were identified and categorized based on Rifaximin exposure within 60 days of diagnosis. The primary analysis compared patients with SIBO treated with Rifaximin to those with SIBO who did not receive Rifaximin. Secondary analyses included comparisons between SIBO patients treated with Rifaximin and irritable bowel syndrome (IBS) patients receiving Rifaximin, as well as patients with SIBO receiving a single versus multiple Rifaximin courses. Propensity score matching (1:1) was performed to balance baseline characteristics. The primary outcome was CDI within 60 days of the index event. Secondary outcomes included hospitalization and emergency department (ED) visits. Results: After propensity score matching, 19,597 patients were included in each cohort in the primary comparison of SIBO treated with Rifaximin versus SIBO without Rifaximin. CDI occurred in 0.21% of Rifaximin-treated patients and 0.15% of untreated patients (p = 0.152). In the contextual comparison, CDI incidence was similar between SIBO patients receiving Rifaximin and IBS patients receiving Rifaximin (0.21% vs. 0.15%, p = 0.168). Among patients with SIBO receiving Rifaximin, CDI risk did not differ between single and multiple treatment courses (0.20% vs. 0.21%, p = 0.850). Conclusions: In this large real-world cohort, Rifaximin therapy for SIBO was not associated with a statistically significant increase in short-term CDI risk. However, given the low event rate, wide confidence intervals, and risk of type II error, these findings should be interpreted with caution. Full article

Background: Small intestinal bacterial overgrowth (SIBO) is characterized by excessive microbial colonization of the small intestine and is commonly diagnosed using hydrogen breath tests. However, most studies focus primarily on diagnostic thresholds rather than the overall dynamics of hydrogen production during the test. Methods: This cross-sectional study included 162 adults with chronic gastrointestinal symptoms who underwent a lactulose hydrogen breath test. Hydrogen concentrations were measured every 20 min over a 180 min period. Total hydrogen production was quantified using the area under the concentration–time curve (AUC), and hydrogen levels during the early (0–60 min) and late (>60 min) phases of the test were analyzed. Results: Among the participants, 100 (61.7%) were classified as SIBO-positive and 62 (38.3%) as SIBO-negative. Individuals with SIBO exhibited significantly higher total hydrogen production compared with those with a negative breath test result (mean AUC: 6938 vs. 2292 ppm × min, p < 0.001). Early hydrogen levels were also higher in the SIBO-positive group (8.7 vs. 4.5 ppm, p < 0.001). The most pronounced difference was observed during the late phase of the test, where hydrogen concentrations were markedly elevated in SIBO-positive individuals (52.7 vs. 12.0 ppm, p < 0.001). Conclusions: SIBO is associated with markedly increased hydrogen production during lactulose breath testing, particularly during the later stages of the test. These findings improve understanding of hydrogen production dynamics during lactulose breath testing and provide additional descriptive information regarding hydrogen response patterns; however, further studies are needed before clinical application. The observed differences should also be interpreted within the applied breath test classification framework. Full article

Background: Choline is an essential nutrient crucial for liver function. It is required for bile and lipoprotein secretion and the synthesis of both phosphatidylcholine (PC) to ensure tissue homeostasis and betaine as a methyl donor. Choline deficiency has been implicated in the pathogenesis of intestinal failure-associated liver disease (IFALD), with the strongest evidence for its contribution to hepatic steatosis in patients with short bowel syndrome (SBS). Contributing factors are (1) an impaired recycling of choline from bile PC, leading to fecal choline losses; (2) small bowel bacterial overgrowth resulting in choline degradation prior to absorption; and (3) parenteral nutrition (PN) insufficient to meet choline requirements. However, data on choline status and its metabolites in pediatric patients with SBS are scarce. Objective: To investigate plasma levels of choline and choline-related metabolites in children with SBS and evaluate differences according to PN dependency and the presence of hepatic steatosis. Methods: Retrospective analysis of data from SBS patients managed at our intestinal rehabilitation program between March 2021 and July 2025. Target parameters in plasma samples were measured using tandem mass spectrometry. Statistical analysis and group comparison of laboratory and clinical data were performed. Results: A total of 127 samples from 80 children with SBS (0.2–17.9 years) were analyzed. Plasma choline, betaine, and PC concentrations were low, with 25% of patients showing markedly reduced choline and betaine levels below 6.4 µmol/L and 16 µmol/L, respectively. TMAO concentrations, indicating bacterial choline degradation, showed extreme variability (0–30 µmol; normal < 3 µmol/L), being inversely correlated with plasma choline levels. PC subgroups containing eicosapentaenoic acid and docosahexaenoic acid were increased in patients receiving PN. However, the only difference between steatotic and non-steatotic patients was the decreased plasma concentrations of both choline and betaine. Conclusions: Patients with SBS, with and without PN, are at risk of choline and betaine deficiency, which is associated with IFALD-steatosis. Controlled trials on choline supplementation in pediatric patients with SBS are warranted. Full article

Background: Small intestinal bacterial overgrowth (SIBO) has been implicated in the pathogenesis of MASLD; however, large-scale clinical data characterizing prevalence patterns, phenotypic subtypes, and disease-specific associations remain limited. Methods: This cross-sectional study enrolled 2549 MASLD patients with gastrointestinal symptoms undergoing lactulose methane–hydrogen breath testing and transient elastography. Univariate and multivariable analysis identified independent risk factors for SIBO. We also explore the distribution of SIBO subtypes and their associations with comorbidity profiles across the MASLD spectrum. Results: The overall prevalence of SIBO was 66.3%, escalating from 65.9% in MASL to 72.8% in at-risk MASH and 78.9% in cirrhosis, alongside a notable enrichment of the intestinal methanogen overgrowth (IMO) phenotype. Multivariable analysis identified advanced fibrosis (stage F4; OR = 1.75, 95% CI: 1.03–2.96), gastroesophageal reflux disease (GERD; OR = 1.66, 95% CI: 1.22–2.28), and coronary artery disease (CAD; OR = 1.80, 95% CI: 1.06–3.06) as independent predictors of SIBO. Additionally, elevated ALT (OR = 1.01, 95% CI: 1.01–1.13) showed a modest association with SIBO. Subtype analysis revealed that IMO was associated with GERD, alcohol consumption, CAD, and obesity, while a history of cholecystectomy and elevated triglycerides were linked to early-phase hydrogen peaks. Conclusions: SIBO is highly prevalent among patients with MASLD, with its prevalence and phenotypic subtype distribution being closely associated with disease severity. The identification of fibrosis-specific risk factors and subtype–clinical associations suggest consideration of SIBO assessment in advanced MASLD, particularly in patients with cardiometabolic or gastrointestinal comorbidities. Full article

Background: Small intestinal bacterial overgrowth (SIBO) has been linked to systemic inflammation and vitamin D deficiency, but its independent clinical relevance remains uncertain. Methods: In this cross-sectional study, 162 adults undergoing hydrogen breath testing were evaluated. Serum 25-hydroxyvitamin D [25(OH)D], leukocyte count, red blood cell distribution width—standard deviation (RDW-SD), and C-reactive protein were analyzed. Associations were assessed using unadjusted comparisons and multivariable regression models adjusted for age, sex, and BMI. Hydrogen increment was additionally examined as a continuous variable. Results: In unadjusted analyses, SIBO-positive individuals had lower 25(OH)D levels and higher leukocyte counts. However, after adjustment for age, sex, and BMI, SIBO status was not independently associated with 25(OH)D, leukocyte count, or RDW-SD. BMI was independently associated with leukocyte count, and age with RDW-SD. Hydrogen increment was not correlated with laboratory parameters. Conclusions: SIBO was not independently associated with vitamin D status or systemic hematological markers. Host-related factors, particularly BMI and age, appeared to have a greater influence on laboratory variability than SIBO. Full article

This narrative review explores the intricate dynamics of Small Intestinal Bacterial Overgrowth (SIBO), a condition marked by an excessive growth of bacteria in the small intestine. We delve into the multifaceted etiology of SIBO, including its associations with gastrointestinal disorders, motility issues, and alterations in gut architecture. The review examines current diagnostic methodologies, emphasizing the distinctions between breath testing and direct aspiration techniques. Furthermore, we assess the various treatment approaches, ranging from antibiotics and dietary modifications to emerging therapeutic options. By synthesizing the latest research findings, we aim to enhance understanding of SIBO’s implications for gut health and provide insights into effective management strategies. Full article

Rosacea is a chronic skin condition characterized by persistent inflammation, manifesting primarily on the face and causing redness, papules, pustules, and phymatous changes. The etiology of rosacea is multifactorial, with immune system factors playing a crucial role in its pathogenesis. The scientific literature contains an increasing number of studies that suggest a correlation between rosacea and the gut microbiota. Small intestinal bacterial overgrowth (SIBO) is defined as an excessive proliferation of potentially pathogenic bacteria within the small intestine of the gastrointestinal system. Multiple factors have been posited to explain the pathogenesis of rosacea, and the presence of SIBO has been identified as a potential factor in its occurrence. A decrease in the Lactobacillus genus, Prevotella copri, Lachnospiraceae, and Faecalibacterium within the gut microbiota may initiate inflammation related to rosacea. These bacterial species are crucial for regulating the intestinal mucosa. The findings indicate that there is an increase in Bacteriodes, Acidaminococcus, Megasphaera, and Ruminococcus in the gut microbiome of patients with rosacea. Probiotics can be advantageous for managing the intestinal microbiome, while Rifaximin treatment has shown efficacy in addressing inflammatory rosacea lesions associated with SIBO. The present review has been undertaken with the objective of enhancing our comprehension of SIBO in rosacea. The emphasis has been placed on the pathogenetic mechanisms and the shift in the gut microbiota that will lead to understanding probiotic benefits and therapy options in rosacea patients. Full article

Irritable bowel syndrome (IBS) and small intestinal bacterial overgrowth (SIBO) share symptoms such as abdominal pain, bloating, and altered bowel habits. Both are linked to dysbiosis and gut–brain axis dysfunction. IBS is a multifactorial disorder characterized by abnormal motility, visceral hypersensitivity, low-grade inflammation, and alterations in the microbiota. In contrast, SIBO is defined by excessive bacterial colonization of the small intestine that can mimic or worsen IBS symptoms. Gut microbes and their metabolites influence motility, immune activation, barrier integrity, and gas production; methanogen overgrowth is associated with constipation-predominant presentations, while hydrogen- and hydrogen sulfide-related pathways may contribute to diarrhea and bloating. Because recurrent or empiric antibiotic use is common—particularly in suspected SIBO—yet carries risks of resistance, microbiome disruption, and relapse, there is a strong rationale to prioritize effective non-antibiotic strategies. Accordingly, this review synthesizes current evidence on IBS/SIBO pathophysiology and microbiota interactions. It evaluates non-pharmacological interventions including dietary approaches, probiotics/prebiotics, herbal therapies, and mind–body treatments (e.g., cognitive behavioral therapy and gut-directed hypnotherapy). We emphasize an integrative framework that supports symptom control and quality of life while helping reduce unnecessary antibiotic exposure. Full article

Small intestinal bacterial overgrowth (SIBO) is an increasingly recognized condition that influences immune responses. It may be linked to atopic disorders such as bronchial asthma (BA), food allergies (FA), chronic spontaneous urticaria (CSU), and mast cell activation syndrome (MCAS). The aim of our study was to perform a structured literature search to assess the possible correlation between SIBO and the presentation of atopic disorders. The prevalence of SIBO was highest in patients with BA (60–100%) and FA (50–87.5%), followed by MCAS (30.9%) and CSU (27.9%). The diagnosis of SIBO was based on lactulose or glucose breath tests. SIBO exacerbated symptoms of atopic diseases, and treating it within BA and MCAS improved the symptoms, in contrast to CSU. The present evidence suggests a possible crosslink between SIBO and atopic manifestations. Bacterial overgrowth appears to trigger the Th2 immune response via the mucosal pathway and low-grade endotoxemia. These result in the increased synthesis of interleukins involved in allergic reactions (IL-4, IL-5, IL-13). Further studies are essential to confirm the clinical significance of this association. The “gut–allergy axis” may offer new therapeutic options and possibly improve quality of life in patients with atopy. 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

The gut microbiota is one of the key elements responsible for maintaining the body’s homeostasis. Its diverse composition affects, among others, the digestive and immune systems and also the circulatory system. Imbalances within the microbial community, referred to as dysbiosis, may lead to increased intestinal barrier permeability, chronic inflammation, and abnormal immune responses, which can be associated with the development of numerous diseases. Gut dysbiosis results in disturbances in the production of short-chain fatty acids, which exert anti-inflammatory effects, regulate blood pressure, and inhibit cardiac fibrosis. At the same time, it promotes the increased synthesis of trimethylamine N-oxide, a metabolite linked to inflammation, endothelial dysfunction, a higher risk of thrombosis, and the occurrence of arrhythmias. Additionally, small intestinal bacterial overgrowth (SIBO) may increase inflammation and contribute to metabolic and cardiovascular diseases (CVDs). The gut microbiota also influences the immune system through the production of neurotransmitters and modulation of T-cell activity, which may play a role in the development of autoimmune diseases. Reduced microbial diversity and an increased abundance of pathogenic bacteria are observed in individuals with hypertension and CVD, underscoring the importance of the microbiota as both a preventive and therapeutic factor. These findings highlight the crucial role of the gut microbiota in maintaining cardiovascular health and emphasize the need for further research into its modulation in the treatment of chronic diseases. 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