International Digestive Endoscopy Network Consensus on the Management of Antithrombotic Agents in Patients Undergoing Gastrointestinal Endoscopy.

Antithrombotic agents, including antiplatelet agents and anticoagulants, are widely used in Korea because of the increasing incidence of cardiocerebrovascular disease and the aging population. The management of patients using antithrombotic agents during endoscopic procedures is an important clinical challenge. The clinical practice guidelines for this issue, developed by the Korean Society of Gastrointestinal Endoscopy, were published in 2020. However, new evidence on the use of dual antiplatelet therapy and direct anticoagulant management has emerged, and revised guidelines have been issued in the United States and Europe. Accordingly, the previous guidelines were revised. Cardiologists were part of the group that developed the guideline, and the recommendations went through a consensus-reaching process among international experts. This guideline presents 14 recommendations made based on the Grading of Recommendations, Assessment, Development, and Evaluation methodology and was reviewed by multidisciplinary experts. These guidelines provide useful information that can assist endoscopists in the management of patients receiving antithrombotic agents who require diagnostic and elective therapeutic endoscopy. It will be revised as necessary to cover changes in technology, evidence, or other aspects of clinical practice.

Insulin Resistance and Impaired Insulin Secretion Predict Incident Diabetes: A Statistical Matching Application to the Two Korean Nationwide, Population-Representative Cohorts.

Background: To evaluate whether insulin resistance and impaired insulin secretion are useful predictors of incident diabetes in Koreans using nationwide population-representative data to enhance data privacy. Methods: This study analyzed the data of individuals without diabetes aged >40 years from the Korea National Health and Nutrition Examination Survey (KNHANES) 2007-2010 and 2015 and the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS). Owing to privacy concerns, these databases cannot be linked using direct identifiers. Therefore, we generated 10 synthetic datasets, followed by statistical matching with the NHIS-HEALS. Homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of ß-cell function (HOMA-ß) were used as indicators of insulin resistance and insulin secretory function, respectively, and diabetes onset was captured in NHIS-HEALS. Results: A median of 4,580 (range, 4,463 to 4,761) adults were included in the analyses after statistical matching of 10 synthetic KNHANES and NHIS-HEALS datasets. During a mean follow-up duration of 5.8 years, a median of 4.7% (range, 4.3% to 5.0%) of the participants developed diabetes. Compared to the reference low-HOMA-IR/high-HOMA-ß group, the high-HOMA-IR/low- HOMA-ß group had the highest risk of diabetes, followed by high-HOMA-IR/high-HOMA-ß group and low-HOMA-IR/low- HOMA-ß group (median adjusted hazard ratio [ranges]: 3.36 [1.86 to 6.05], 1.81 [1.01 to 3.22], and 1.68 [0.93 to 3.04], respectively). Conclusion: Insulin resistance and impaired insulin secretion are robust predictors of diabetes in the Korean population. A retrospective cohort constructed by combining cross-sectional synthetic and longitudinal claims-based cohort data through statistical matching may be a reliable resource for studying the natural history of diabetes.

The Potential of Molecular Remission: Tissue Neutrophil Elastase Is Better Than Histological Activity for Predicting Long-Term Relapse in Patients With Ulcerative Colitis in Endoscopic Remission.

BACKGROUND: Growing interest exists in deep remission, beyond clinical and endoscopic remission, to enhance long-term prognosis in patients with ulcerative colitis (UC). Our study aimed to evaluate the risk of relapse according to tissue expression levels of calprotectin and neutrophil elastase (NE) in patients with quiescent UC. METHODS: Rectal biopsies were performed on 218 patients with UC in clinical and endoscopic remission. Histological activity was prospectively scored using the Robarts Histological Index. Tissue calprotectin and NE levels were evaluated using immunohistochemistry. Optimal tissue calprotectin and NE cutoffs for relapse were determined using log-rank analysis. Cox proportional hazard analyses evaluated relapse risk factors. RESULTS: Tissue calprotectin and NE levels were significantly higher in patients with histological activity than in those in histological remission (P < .001). The optimal cutoffs of tissue calprotectin and NE for relapse were 10.61 and 22.08 per mm2, respectively. The 3-year clinical relapse risk was significantly lower in the low-tissue NE group than in the high-tissue NE group (P = .009); however, it did not differ between the low- and high-tissue calprotectin group (P = .094). In multivariate analyses, a low level of tissue NE expression was independently associated with a lower risk of 3-year clinical relapse (adjusted hazard ratio = 0.453, 95% confidence interval = 0.225-0.911, P = .026), unlike histological index and tissue calprotectin. CONCLUSIONS: In patients with UC who have achieved clinical and endoscopic remission, tissue expression of NE is a better predictor of long-term relapse than histological activity.

The tissue expression of neutrophil elastase is a better predictor of long-term relapse than histological activity in patients with ulcerative colitis who achieved clinical and endoscopic remission.

Real-World Application of Artificial Intelligence for Detecting Pathologic Gastric Atypia and Neoplastic Lesions.

PURPOSE: Results of initial endoscopic biopsy of gastric lesions often differ from those of the final pathological diagnosis. We evaluated whether an artificial intelligence-based gastric lesion detection and diagnostic system, ENdoscopy as AI-powered Device Computer Aided Diagnosis for Gastroscopy (ENAD CAD-G), could reduce this discrepancy. MATERIALS AND METHODS: We retrospectively collected 24,948 endoscopic images of early gastric cancers (EGCs), dysplasia, and benign lesions from 9,892 patients who underwent esophagogastroduodenoscopy between 2011 and 2021. The diagnostic performance of ENAD CAD-G was evaluated using the following real-world datasets: patients referred from community clinics with initial biopsy results of atypia (n=154), participants who underwent endoscopic resection for neoplasms (Internal video set, n=140), and participants who underwent endoscopy for screening or suspicion of gastric neoplasm referred from community clinics (External video set, n=296). RESULTS: ENAD CAD-G classified the referred gastric lesions of atypia into EGC (accuracy, 82.47%; 95% confidence interval [CI], 76.46%-88.47%), dysplasia (88.31%; 83.24%-93.39%), and benign lesions (83.12%; 77.20%-89.03%). In the Internal video set, ENAD CAD-G identified dysplasia and EGC with diagnostic accuracies of 88.57% (95% CI, 83.30%-93.84%) and 91.43% (86.79%-96.07%), respectively, compared with an accuracy of 60.71% (52.62%-68.80%) for the initial biopsy results (P<0.001). In the External video set, ENAD CAD-G classified EGC, dysplasia, and benign lesions with diagnostic accuracies of 87.50% (83.73%-91.27%), 90.54% (87.21%-93.87%), and 88.85% (85.27%-92.44%), respectively. CONCLUSIONS: ENAD CAD-G is superior to initial biopsy for the detection and diagnosis of gastric lesions that require endoscopic resection. ENAD CAD-G can assist community endoscopists in identifying gastric lesions that require endoscopic resection.

An artificial intelligence system for comprehensive pathologic outcome prediction in early gastric cancer through endoscopic image analysis (with video).

BACKGROUND: Accurate prediction of pathologic results for early gastric cancer (EGC) based on endoscopic findings is essential in deciding between endoscopic and surgical resection. This study aimed to develop an artificial intelligence (AI) model to assess comprehensive pathologic characteristics of EGC using white-light endoscopic images and videos. METHODS: To train the model, we retrospectively collected 4,336 images and prospectively included 153 videos from patients with EGC who underwent endoscopic or surgical resection. The performance of the model was tested and compared to that of 16 endoscopists (nine experts and seven novices) using a mutually exclusive set of 260 images and 10 videos. Finally, we conducted external validation using 436 images and 89 videos from another institution. RESULTS: After training, the model achieved predictive accuracies of 89.7% for undifferentiated histology, 88.0% for submucosal invasion, 87.9% for lymphovascular invasion (LVI), and 92.7% for lymph node metastasis (LNM), using endoscopic videos. The area under the curve values of the model were 0.992 for undifferentiated histology, 0.902 for submucosal invasion, 0.706 for LVI, and 0.680 for LNM in the test. In addition, the model showed significantly higher accuracy than the experts in predicting undifferentiated histology (92.7% vs. 71.6%), submucosal invasion (87.3% vs. 72.6%), and LNM (87.7% vs. 72.3%). The external validation showed accuracies of 75.6% and 71.9% for undifferentiated histology and submucosal invasion, respectively. CONCLUSIONS: AI may assist endoscopists with high predictive performance for differentiation status and invasion depth of EGC. Further research is needed to improve the detection of LVI and LNM.

Gastric microbiome signature for predicting metachronous recurrence after endoscopic resection of gastric neoplasm.

BACKGROUND: Changes in gastric microbiome are associated with gastric carcinogenesis. Studies on the association between gastric mucosa-associated gastric microbiome (MAM) and metachronous gastric cancer are limited. This study aimed to identify gastric MAM as a predictive factor for metachronous recurrence following endoscopic resection of gastric neoplasms. METHOD: Microbiome analyses were conducted for 81 patients in a prospective cohort to investigate surrogate markers to predict metachronous recurrence. Gastric MAM in non-cancerous corporal biopsy specimens was evaluated using Illumina MiSeq platform targeting 16S ribosomal DNA. RESULTS: Over a median follow-up duration of 53.8 months, 16 metachronous gastric neoplasms developed. Baseline gastric MAM varied with Helicobacter pylori infection status, but was unaffected by initial pathologic diagnosis, presence of atrophic gastritis, intestinal metaplasia, or synchronous lesions. The group with metachronous recurrence did not exhibit distinct phylogenetic diversity compared with the group devoid of recurrence but showed significant difference in ß-diversity. The study population could be classified into two distinct gastrotypes based on baseline gastric MAM: gastrotype 1, Helicobacter-abundant; gastrotype 2: Akkermansia-abundant. Patients in gastrotype 2 showed higher risk of metachronous recurrence than gastrotype (Cox proportional hazard analysis, adjusted hazard ratio [95% confidence interval]: 5.10 [1.09-23.79]). CONCLUSIONS: Gastric cancer patients can be classified into two distinct gastrotype groups by their MAM profiles, which were associated with different risk of metachronous recurrence.

[IDEN Consensus on Management of Antithrombotic Agents in Patients Undergoing Gastrointestinal Endoscopy].

Antithrombotic agents, including antiplatelet agent and anticoagulants are widely used in Korea due to increasing incidence of cardio-cerebrovascular disease and aging population. The management of patients using antithrombotic agents during endoscopic procedures is an important clinical challenge. Clinical practice guideline regarding this issue which was developed by the Korean Society of Gastrointestinal Endoscopy was published in 2020. However, since then, new evidence has emerged for the use of dual antiplatelet therapy and direct anticoagulant management, and revised guidelines were issued in the US and Europe. Accordingly, the previous guidelines were revised, cardiologists also participated in the development group, and the recommendations went through a consensus process among international experts. This guideline presents 14 recommendations made according to the Grading of Recommendations, Assessment, Development, and Evaluation methodology, and was reviewed by multidisciplinary experts. This guideline provides useful information that can assist endoscopists in the management of patients on antithrombotic agents who require diagnostic and elective therapeutic endoscopy. It will be revised as necessary to cover changes in technology, evidence, or other aspects of clinical practice.

Efficacy of Tegoprazan in Patients With Functional Dyspepsia: A Prospective, Multicenter, Single-arm Study.

Background/Aims: Acid-suppressive drugs, such as proton pump inhibitors (PPIs), are treatment options for functional dyspepsia (FD). However, the efficacy of potassium-competitive acid blockers (P-CABs) in treating FD has not yet been established. This prospective multicenter clinical trial-based study aimed to assess the efficacy and safety of tegoprazan as a P-CAB treatment in patients with FD. Methods: FD was diagnosed using the Rome IV criteria. All patients received tegoprazan 50 mg once daily for 8 weeks. Dyspeptic symptoms were assessed using a dyspepsia symptom questionnaire (5-point Likert scale, Nepean Dyspepsia Index-Korean [NDI-K], and gastroesophageal reflux disease-health-related quality of life [GERD-HRQL]). The main outcome was satisfactory symptom relief rates at 8 weeks. Results: In this study, from the initial screening of 209 patients, 173 were included in the per-protocol set analysis. Satisfactory symptom relief rates at 8 and 4 weeks were 86.7% and 74.6%, respectively. In addition, the NDI-K and GERD-HRQL scores significantly improved at 8 and 4 weeks compared with the baseline scores. The efficacy of tegoprazan was not influenced by the FD subtype or Helicobacter pylori status. In patients with overlapping FD and GERD, there was a greater improvement in the NDI-K and GERD-HRQL scores than in patients with FD symptoms only. No serious drug-related adverse events occurred during this study. Conclusion: Tegoprazan (50 mg) administered once daily provided satisfactory symptom relief for FD.

Risk of Ischemic Stroke in Relation to Helicobacter pylori Infection and Eradication Status: A Large-Scale Prospective Observational Cohort Study.

Background/Aims: : A few studies have suggested the association between Helicobacter pylori (HP) infection and ischemic stroke. However, the impact of HP eradication on stroke risk has not been well evaluated. This study aimed to assess the influence of HP eradication on the incidence of ischemic stroke, considering the potential effect of sex. Methods: : This prospective observational cohort study was conducted at Seoul National University Bundang Hospital, from May 2003 to February 2023, and involved gastroscopy-based HP testing. Propensity score (PS) matching was employed to ensure balanced groups by matching patients in the HP eradicated group (n=2,803) in a 3:1 ratio with patients in the HP non-eradicated group (n=960). Cox proportional hazard regression analysis was used to evaluate the risk of ischemic stroke. Results: : Among 6,664 patients, multivariate analysis after PS matching indicated that HP eradication did not significantly alter the risk of ischemic stroke (hazard ratio, 0.531; 95% confidence interval, 0.221 to 1.270; p=0.157). Sex-specific subgroup analyses, both univariate and multivariate, did not yield statistically significant differences. However, Kaplan-Meier analysis revealed a potential trend: the females in the HP eradicated group exhibited a lower incidence of ischemic stroke than those in the HP non-eradicated group, although this did not reach statistical significance (p=0.057). Conclusions: : This finding suggests that HP eradication might not impact the risk of ischemic stroke. However, there was a trend showing that females potentially had a lower risk of ischemic stroke following HP eradication, though further investigation is required to establish definitive evidence.

Differences in the risk of clinical failure between thiopurine and methotrexate in bio-naïve patients with Crohn's disease: a Korean nationwide population-based study.

Background: Although immunomodulators are widely prescribed in patients with Crohn's disease (CD), it is unclear whether there is a difference in treatment outcomes between thiopurines and methotrexate (MTX). Objective: To compare the risk of clinical failure between thiopurines and MTX in bio-naïve patients with CD. Design: Nationwide, population-based study. Methods: We used claims data from the Korean National Health Insurance Service. After inverse probability of treatment weighting, logistic regression and Cox proportional hazard analyses were used to evaluate the risk of clinical failure in bio-naïve patients with CD treated with thiopurine (thiopurine group) or MTX (MTX group). Results: Overall, 10,296 adult and pediatric patients with CD [9912 (96.3%) and 384 (3.7%) in the thiopurine and MTX groups, respectively] were included. The odds ratios (ORs) of failure to induce remission were significantly higher in the MTX group than in the thiopurine group [adjusted OR (aOR), 1.115; 95% confidence interval (CI), 1.045-1.190; p = 0.001]. However, the opposite result was observed only in patients without concomitant steroid use: the MTX group had a lower risk of induction failure than the thiopurine group (aOR, 0.740; 95% CI, 0.673-0.813; p < 0.001). The risk of overall maintenance failure was higher in the MTX group than in the thiopurine group [adjusted hazard ratio (aHR), 1.117; 95% CI, 1.047-1.191; p = 0.001]. The risk of overall maintenance failure was higher in the standard-dose MTX group than in the low-dose MTX group (aHR, 1.296; 95% CI, 1.134-1.480; p < 0.001). There was no significant difference in the risk of maintenance failure according to the administration route of MTX. Conclusion: Thiopurine is more effective than MTX in inducing and maintaining remission in bio-naïve patients with CD; however, the concomitant use of steroids influences inducing remission.

Differences in treatment efficacy between thiopurine and methotrexate in patients with Crohn's disease who were not treated with biologics Immunomodulators (IMMs) used in the treatment of Crohn's disease (CD) include medications such as thiopurine and methotrexate (MTX). Although IMMs are widely prescribed for patients with CD, it remains unclear whether treatment outcomes differ according to the specific types and dosages of IMMs and administration routes of MTX. In this study, we investigated the risk of treatment failure between thiopurines and MTX in CD patients not undergoing biologic treatment. Patients treated with MTX had a higher risk of maintenance failure than those treated with thiopurines. There was no difference in the risk of treatment failure according to the dosage of thiopurine. However, the risk of maintenance failure was higher in patients receiving standard-dose MTX than in those receiving low-dose MTX. There was no difference in the risk of maintenance failure according to the administration route of MTX. Our study enriches the knowledge regarding the treatment efficacy of thiopurines and MTX for patients with CD and may help clinicians develop appropriate treatment plans.

Impact of Smoking and Alcohol Consumption on Early-Onset Gastric Cancer Development in Young Koreans: A Population-Based Study.

PURPOSE: Although smoking and alcohol consumption are known risk factors for gastric cancer (GC), studies assessing their effects on early-onset GC are limited. In this nationwide, population-based, prospective cohort study, we assessed the effects of smoking and alcohol consumption on early-onset GC in patients aged <50 years. MATERIALS AND METHODS: We analyzed data of patients aged 20-39 years who underwent cancer and general health screening in the Korean National Health Screening Program between 2009 and 2012. We calculated the adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for GC incidence until December 2020. RESULTS: We enrolled 6,793,699 individuals (men:women=4,077,292:2,716,407) in this cohort. The mean duration of follow-up was 9.4 years. During follow-up, 9,893 cases of GC (men:women=6,304:3,589) were reported. Compared with the aHRs (95% CI) of never-smokers, those of former and current-smokers were 1.121 (1.044-1.205) and 1.282 (1.212-1.355), respectively. Compared with the aHRs (95% CI) of non-consumers, those of low-moderate- and high-risk alcohol consumers were 1.095 (1.046-1.146) and 1.212 (1.113-1.321), respectively. GC risk was the highest in current-smokers and high-risk alcohol consumers (1.447 [1.297-1.615]). Interestingly, alcohol consumption and smoking additively increased the GC risk in men but not in women (Pinteraction=0.002). CONCLUSION: Smoking and alcohol consumption are significant risk factors for early-onset GC in young Koreans. Further studies are needed to investigate sex-based impact of alcohol consumption and smoking on GC incidence in young individuals.

Sex Difference in the Effect of Bifidobacterium longum on Repeated Water Avoidance Stress-induced Gut Dysbiosis in Wistar Rats.

Dysbiosis in gut microbiota is known to contribute to development of irritable bowel syndrome. We tried to investigate the effect of Bifidobacterium longum on repeated water avoidance stress (WAS) in a Wistar rat model. The three groups (no-stress, WAS, and WAS with B. longum) of rats were allocated to sham or WAS for 1 hour daily for 10 days, and B. longum was administered through gavage for 10 days. Fecal pellet numbers were counted at the end of each 1-hour session of WAS. After 10 days of repeated WAS, the rats were eutanized, and the feces were collected. WAS increased fecal pellet output (FPO) significantly in both sexes (P < 0.001), while the female B. longum group showed significantly decreased FPO (P = 0.005). However, there was no consistent change of myeloperoxidase activity and mRNA expression of interleukin-1ß and TNF-α. Mast cell infiltration at colonic submucosa increased in the female WAS group (P = 0.016). In terms of fecal microbiota, the repeated WAS groups in both sexes showed different beta-diversity compared to control and WAS with B. longum groups. WAS-induced mast cell infiltration was reduced by the administration of B. longum in female rats. Moreover, administration of B. longum relieved WAS-caused dysbiosis, especially in female rats. In conclusion, B. longum was beneficial for WAS-induced stress in rats, especially in females.

Association between menopausal hormone therapy and the risk of gastric cancer: A Korean nationwide population-based cohort study.

OBJECTIVE: Gastric cancer (GC) is more common in men than women, but also more common among postmenopausal than premenopausal women. The protective effect of reproductive hormones against GC remains unclear. Therefore, we evaluated the association between menopausal hormone therapy (MHT) and the risk of GC in women. METHODS: We investigated the national cohort data of women aged over 40 years who underwent health checkups by the Korean National Health Insurance Service in 2009. After excluding individuals with missing data and those previously diagnosed with cancer, 1,354,621 postmenopausal women were included and divided into groups according to their MHT history. We followed the study population until 2018 and analyzed the hazard ratios (HR) with 95 % confidence intervals (CIs) for the incidence rate of GC in a multivariate adjusted model. RESULTS: The number of women with and without a history of MHT was 214,723 (15.9 %) and 1,139,898 (84.1 %), respectively. During the mean 8.32 ± 0.8 years of follow-up, a total of 12,496 GC cases developed in the study population (10,962 MHT non-users; 1534 MHT users). In the adjusted model, MHT was associated with a 12 % decrease in the development of GC relative to non-use of MHT (HR 0.88; 95 % CI 0.83-0.93). Exposure to MHT for >2 years was linked to a reduction in GC risk, particularly when initiated before the age of 50, giving a 45 % risk reduction. CONCLUSIONS: According to our large-scale prospective national cohort study, exogenous MHT is associated with a decreased risk of GC in postmenopausal women.

Prediction of the efficacy of proton-pump inhibitors in patients with contact granuloma using 24-hour combined dual channel pH/impedance monitoring.

OBJECTIVES: We aimed to evaluate the treatment outcomes of proton-pump inhibitors (PPIs) in patients with contact granuloma (CG) and to investigate the parameters of 24 h combined dual channel pH/impedance (24 h pH/MII) monitoring, which are reliable for predicting the response to PPI of CG patients. METHODS: We reviewed the medical records of patients with CG who had been treated with PPIs and had completed more than 6 months of follow-up. We classified the patients into two groups (cured vs. persistent), according to their PPI treatment outcomes. Reflux events were categorized into three groups based on pharyngeal pH during reflux: 1) acid reflux (pH < 4), 2) weak acid reflux (4 < pH < 7), and 3) weak alkaline reflux (pH >7), as detected by a proximal probe. We compared the results of 24h-pH/MII between the two groups and used receiver operating characteristic curve (ROC) analysis to determine the cutoff values of significant parameters for predicting responses to PPIs. RESULTS: Among 22 patients who completed at least 6 months of PPI treatment and follow-up, weak acid reflux events were more frequently observed in persistent group than in the cured group (p = 0.046), and the proportion of weak acid reflux was also higher in the persistent group (p = 0.031) than in the cured group. Reliable parameters predictive of a poor response to PPIs were a number of weak acid reflux events ≥ 11 (area under the curve [AUC], 0.775; p = 0.03) and a proportion of weak acid reflux events ≥ 56.7 % (AUC, 0.763; p = 0.038) in ROC analyses. CONCLUSION: Weak acid reflux was identified as a significant factor associated with the treatment outcomes of PPIs in patients with CG. A number of weak acid reflux events ≥ 11 is considered to be the most reliable predictor of a poor response to PPIs in patients with CG.

International Digestive Endoscopy Network consensus on the management of antithrombotic agents in patients undergoing gastrointestinal endoscopy.

Antithrombotic agents, including antiplatelet agents and anticoagulants, are widely used in Korea because of the increasing incidence of cardiocerebrovascular disease and the aging population. The management of patients using antithrombotic agents during endoscopic procedures is an important clinical challenge. The clinical practice guidelines for this issue, developed by the Korean Society of Gastrointestinal Endoscopy, were published in 2020. However, new evidence on the use of dual antiplatelet therapy and direct anticoagulant management has emerged, and revised guidelines have been issued in the United States and Europe. Accordingly, the previous guidelines were revised. Cardiologists were part of the group that developed the guideline, and the recommendations went through a consensus-reaching process among international experts. This guideline presents 14 recommendations made based on the Grading of Recommendations, Assessment, Development, and Evaluation methodology and was reviewed by multidisciplinary experts. These guidelines provide useful information that can assist endoscopists in the management of patients receiving antithrombotic agents who require diagnostic and elective therapeutic endoscopy. It will be revised as necessary to cover changes in technology, evidence, or other aspects of clinical practice.

Gut microbiome signature of metabolically healthy obese individuals according to anthropometric, metabolic and inflammatory parameters.

In this study, we investigated the characteristics of gut microbiome in the metabolically healthy obese (MHO) patients, and how they correlate with metabolic and inflammatory profiles. A total of 120 obese people without metabolic comorbidities were recruited, and their clinical phenotypes, metabolic and inflammatory parameters were analysed. The faecal microbial markers originating from bacterial cell and extracellular vesicle (EV) were profiled using 16S rDNA sequencing. The total study population could be classified into two distinct enterotypes (enterotype I: Prevotellaceae-predominant, enterotype II: Akkermansia/Bacteroides-predominant), based on their stool EV-derived microbiome profile. When comparing the metabolic and inflammatory profiles, subjects in enterotype I had higher levels of serum IL-1ß [false discovery rate (FDR) q = 0.050] and had a lower level of microbial diversity than enterotype II (Wilcoxon rank-sum test p < 0.01). Subjects in enterotype I had relatively higher abundance of Bacteroidetes, Prevotellaceae and Prevotella-derived EVs, and lower abundance of Actinobacteria, Firmicutes, Proteobacteria, Akkermansia and Bacteroides-derived EVs (FDR q < 0.05). In conclusion, HMO patients can be categorised into two distinct enterotypes by the faecal EV-derived microbiome profile. The enterotyping may be associated with different metabolic and inflammatory profiles. Further studies are warranted to elucidate the long-term prognostic impact of EV-derived microbiome in the obese population.

Molecular Activity of Inflammation and Epithelial-Mesenchymal Transition in the Microenvironment of Ulcerative Colitis.

Background/Aims: : The genetic expression in the active inflammatory regions is increased in ulcerative colitis (UC) with endoscopic activity. The aim of this study was to investigate the molecular activity of inflammation and tissue remodeling markers in endoscopically inflamed and uninflamed regions of UC. Methods: : Patients with UC (n=47) and controls (n=20) were prospectively enrolled at the Seoul National University Bundang Hospital. Inflamed tissue was obtained at the most active lesion, and uninflamed tissue was collected from approximately 15 cm above the upper end of the active lesion via colonoscopic biopsies. The messenger RNA expression levels of transforming growth factor ß (TGF-ß), interleukin (IL)-1ß, IL-6, IL-17A, E-cadherin, olfactomedin-4 (OLFM4), leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5), vimentin, fibroblast-specific protein-1 (FSP1), and α-smooth muscle actin (SMA) were evaluated. Mucosal healing (MH) was defined according to a Mayo endoscopic score of 0, 1 or non-MH (Mayo endoscopic score of 2 or 3). Results: : The messenger RNA expressions of TGF-ß, IL-1ß, OLFM4, FSP1, vimentin, and α-SMA were significantly higher, and that of E-cadherin was significantly lower in inflamed and uninflamed regions of patients with UC than those in controls. In the inflamed regions, patients in the non-MH group had significantly increased genetic expression of TGF-ß, FSP1, vimentin, and α-SMA compared to patients in the MH group. Similarly, the non-MH group had significantly higher genetic expression of TGF-ß, IL-1ß, IL-6, vimentin, and α-SMA than the MH group in the uninflamed regions. Conclusions: : Endoscopic activity in UC suggests inflammation and tissue remodeling of uninflamed regions similar to inflamed regions (ClinicalTrials.gov, NCT05653011).