Endoscopic assessment of the J pouch in ulcerative colitis: A narrative review.

Patients with ulcerative colitis sometimes need a total colectomy with ileal pouch-anal anastomosis due to medically refractory disease or colitis-associated neoplasia. Up to 50% of patients with ulcerative colitis postoperatively develop pouchitis and the rate of chronic inflammatory pouch conditions requiring pouch excision or diverting ileostomy is reported to be 10%. In order to diagnose and monitor pouchitis, pouchoscopy is essential to assess endoscopic inflammatory findings of the J pouch and to survey neoplasia development, particularly in the remnant distal rectum. However, endoscopic protocols for the evaluation of the pouch may not be standardized worldwide and the reliability of existing disease activity indices for pouchitis has been questioned due to the lack of validation. Recently, reliable endoscopic scoring systems based on an observation of the anatomical location of the J pouch were reported and a significant association between the distribution pattern of endoscopic inflammation (i.e., endoscopic phenotype) and pouch outcomes was also uncovered. In this review, we discuss how to survey the J pouch using pouchoscopy, endoscopic indices for pouchitis disease activity, endoscopic phenotypes and classification, and the pathological mechanisms of pouchitis phenotype in patients with ulcerative colitis.

Sinomenine hydrochloride improves DSS-induced colitis in mice through inhibition of the TLR2/NF-κB signaling pathway.

BACKGROUND: Sinomenine hydrochloride (SH) has anti-inflammatory and immunosuppressive effects, and its effectiveness in inflammatory diseases, such as rheumatoid arthritis, has been demonstrated. However, whether SH has a therapeutic effect on dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) in mice and its mechanism of action have not been clarified. This study aimed to investigate the therapeutic effects and mechanism of action of SH on UC. METHODS: Twenty-four mice were randomly divided into control, model, SH low-dose (SH-L, 20mg/kg), and SH high-dose (SH-H, 60mg/kg) groups with six mice in each group. Disease activity index (DAI), colonic mucosal damage index, and colonic histopathology scores were calculated. The expression levels of related proteins, genes, and downstream inflammatory factors in the Toll-like receptor 2/NF-κB (TLR2/NF-κB) signaling pathway were quantified. RESULTS: SH inhibited weight loss, decreased DAI and histopathological scores, decreased the expression levels of TLR2, MyD88, P-P65, P65 proteins, and TLR2 genes, and also suppressed the expression of inflammatory factors TNF-α, IL-1 ß, and IL-6 in the peripheral blood of mice. CONCLUSION: The therapeutic effect of SH on DSS-induced UC in mice may be related to the inhibition of the TLR2/NF-κB signaling pathway.

Combined gut microbiome and metabolomics to reveal the mechanism of proanthocyanidins from the roots of Ephedra sinica Stapf on the treatment of ulcerative colitis.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) that primarily affects mucosa and submucosa of colon and rectum. Although the exact etiology of UC remains elusive, increasing evidence has demonstrated that the gut microbiome and its interaction with host metabolism plays an important role in UC development. The objective of this study was to investigate the therapeutic potential and mechanism of dimeric proanthocyanidins (PAC) enriched from ethyl acetate extract of Ephedra roots on UC from the perspective of gut microbiota and metabolic regulation. In this study, a bio-guided strategy integrating LC-MS analysis, DMAC assay, antioxidant screening, and antiinflammation activity screening was used to enrich dimeric PAC from Ephedra roots, then untargeted metabolomics combined with gut microbiota analysis was performed to investigate the therapeutic mechanism of PRE on UC. This is the first study that combines a bio-guided strategy to enrich dimeric PAC from Ephedra roots and a comprehensive analysis of their effects on gut microbiota and host metabolism. Oral administration of PRE was found to significantly relieve dextran sodium sulfate (DSS)-induced ulcerative colitis symptoms in mice, characterized by the reduced disease activity index (DAI), increased colon length and improved colon pathological damage, together with the down-regulation of colonic inflammatory and oxidative stress levels. In addition, 16 S rRNA sequencing combined with untargeted metabolomics was conducted to reveal the effects of PRE on gut microbiota composition and serum metabolites. PRE improved gut microbiota dysbiosis through increasing the relative abundance of beneficial bacteria Lachnospiraceae_NK4A136_group and decreasing the level of potentially pathogenic bacteria such as Escherichia-Shigella. Serum metabolomics showed that the disturbed tryptophan and glycerophospholipid metabolism in UC mice was restored after PRE treatment. Collectively, PRE was proved to be a promising anti-UC candidate, which deserves further investigation in future research.

Systematic review: effectiveness and safety of switching between originator infliximab and biosimilar infliximab in patients with inflammatory bowel disease.

INTRODUCTION: Infliximab (IFX) biosimilars are available to treat inflammatory bowel disease (IBD), offering cost reductions versus originator IFX in some jurisdictions. However, concerns remain regarding the efficacy and safety of originator-to-biosimilar switching. This systematic literature review evaluated safety and effectiveness of switching between IFX products in patients with IBD, including multiple switchers. METHODS: Embase, PubMed, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials were searched to capture studies (2012-2022) including patients with IBD who switched between approved IFX products. Effectiveness outcomes: disease activity; disease severity; response to treatment; patient-reported outcomes (PROs). Safety outcomes: incidence and rate of adverse events (AEs); discontinuations due to AEs, failure rate; hospitalizations; surgeries. Immunogenicity outcomes (n, %): anti-drug antibodies; patients receiving concomitant immunomodulatory medication. RESULTS: Data from 85 publications (81 observational, two randomized controlled trials) were included. Clinical effectiveness outcomes were consistent with the known profile of originator IFX with no difference after switching. There were no unexpected/serious AEs after switching, and rates of AEs were generally consistent with the known profile of IFX. CONCLUSIONS: Most studies reported that clinical, PROs, and safety outcomes for originator-to-biosimilar switching were clinically equivalent to originator responses. Limited data are available regarding multiple switches. PROTOCOL REGISTRATION: www.crd.york.ac.uk/prospero identifier is CRD42021289144.

AGA Clinical Practice Update on the Role of Intestinal Ultrasound in Inflammatory Bowel Disease: Commentary.

DESCRIPTION: In the past 3 years, the use of intestinal ultrasound (IUS) for monitoring inflammatory bowel disease in clinical practice has grown substantially in the United States. This American Gastroenterological Association (AGA) Institute Clinical Practice Update (CPU) aims to review the available evidence and guidance regarding the role of intestinal ultrasound in inflammatory bowel disease care. METHODS: This CPU was commissioned and approved by the AGA Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the CPUC and external peer review through standard procedures of Clinical Gastroenterology and Hepatology. This expert commentary incorporates important and recently published studies in this field, and it reflects the experiences of the multidisciplinary group of authors composed of adult and pediatric gastroenterologists.

Integrating plasma proteomics with genome-wide association data to identify novel drug targets for inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a chronic disease that includes Crohn's disease (CD) and ulcerative colitis (UC). Although genome-wide association studies (GWASs) have identified many relevant genetic risk loci, the impact of these loci on protein abundance and their potential utility as clinical therapeutic targets remain uncertain. Therefore, this study aimed to investigate the pathogenesis of IBD and identify effective therapeutic targets through a comprehensive and integrated analysis. We systematically integrated GWAS data related to IBD, UC and CD (N = 25,305) by the study of de Lange KM with the human blood proteome (N = 7213) by the Atherosclerosis Risk in Communities (ARIC) study. Proteome-wide association study (PWAS), mendelian randomisation (MR) and Bayesian colocalisation analysis were used to identify proteins contributing to the risk of IBD. Integrative analysis revealed that genetic variations in IBD, UC and CD affected the abundance of five (ERAP2, RIPK2, TALDO1, CADM2 and RHOC), three (VSIR, HGFAC and CADM2) and two (MST1 and FLRT3) cis-regulated plasma proteins, respectively (P < 0.05). Among the proteins identified via Bayesian colocalisation analysis, CADM2 was found to be an important common protein between IBD and UC. A drug and five druggable target genes were identified from DGIdb after Bayesian colocalisation analysis. Our study's findings from genetic and proteomic approaches have identified compelling proteins that may serve as important leads for future functional studies and potential drug targets for IBD (UC and CD).

The microRNA expression in crypt-top and crypt-bottom colonic epithelial cell populations demonstrates cell-type specificity and correlates with endoscopic activity in ulcerative colitis.

BACKGROUND AND AIMS: Colonic epithelial barrier dysfunction is one of the early events in ulcerative colitis (UC) and microRNAs (miRNAs) participate in its regulation. However, cell type-specific miRNome during UC is still unknown. Thus, we aimed to explore miRNA expression patterns in colon tissue and epithelial cells at active and quiescent UC. METHODS: Small RNA-sequencing in colon tissue, crypt-bottom (CD44+), and crypt-top (CD66a+) colonic epithelial cells from two cohorts of UC patients (n=74) and healthy individuals (n=50) was performed. Data analysis encompassed differential expression, weighted gene co-expression network, correlation, gene-set enrichment analyses. RESULTS: Differentially expressed colonic tissue miRNAs showed potential involvement in regulation of interleukin-4 and interleukin-13 signalling during UC. As this pathway plays role in intestinal barrier regulation, consecutive analysis of spatially distinct colonic epithelial cell populations was performed. Cell-type (crypt-top and crypt-bottom) specific miRNA expression patterns were identified in both active and quiescent UC. Target genes of differentially expressed epithelial miRNAs at different disease activity were overrepresented in epithelial cell migration and therefore intestinal barrier integrity regulation. The pro-inflammatory miRNA co-expression module M1 correlated with endoscopic disease activity and successfully distinguished active and quiescent UC not only in both epithelial cell populations, but also in the colon tissue. The anti-inflammatory module M2 was specific to crypt-bottom cells and significantly enriched in the quiescent UC patients. CONCLUSIONS: miRNA expression was specific to colonic epithelial cell populations and UC state, reflecting endoscopic disease activity. Irrespective of the UC state, deregulated epithelial miRNAs were associated with regulation of intestinal barrier integrity.

Concurrent occurrence of ulcerative duodenitis and ulcerative colitis displaying unique responses to golimumab and ustekinumab.

Recent studies have reported the occurrence of upper gastrointestinal (UGI) inflammation in patients with ulcerative colitis (UC). However, whether UC-associated UGI and colorectal lesions share pathogenic cytokine profiles and responses to biologics remains unknown. Herein, we report a case of concurrent UC and ulcerative duodenitis (UD) that displayed unique responses to biologic treatment. Although treatment with prednisolone (PSL) failed to induce remission in both disorders, golimumab (GLM) and ustekinumab (UST) were effective against UD and UC, respectively, and remission of both disorders was achieved using UST. Immunofluorescence analyses revealed that numbers of immune cells expressing TNF-α were comparable in both duodenal and rectal mucosa before the treatment. GLM or UST treatment markedly decreased numbers of TNF-α-expressing duodenal immune cells, suggesting the presence of correlation between TNF-α expression and disease activity of UD. In contrast, TNF-α expression was not parallel to disease activity of UC because GLM or PSL failed to induce remission despite a marked reduction in TNF-α expression. Responsiveness to GLM or UST together with immunofluorescence studies suggests that TNF-α and IL-12/23p40 are pathogenic cytokines causing UD and UC, respectively, in the present case.

O80:H2-Associated Hemolytic Uremic Syndrome without Hemorrhagic Colitis: A Case Report.

Introduction: Hemolytic uremic syndrome (HUS) is characterized by progressive kidney injury accompanied by thrombotic microangiopathy, which is clinically defined as microangiopathic hemolytic anemia with thrombocytopenia and organ injury. Shiga toxin-producing Escherichia coli (STEC)-HUS is caused by infection with pathogenic E. coli strains, typically O157, O26, and O111. However, the prevalence of other types of pathogenic E. coli has been increasing, and these pathogens sometimes cause atypical clinical manifestations of STEC-HUS. Case Presentation: We report the case of a 3-year-old girl diagnosed with STEC-HUS associated with a rare O80:H2 stx2 serotype, characterized by an atypical clinical course. She presented with severe hemolytic anemia and mild renal dysfunction but did not have enterohemorrhagic diarrhea. The first culture test of her stool sample collected using a swab upon admission yielded no signs of STEC, leading to an initial diagnosis of atypical HUS; thus, eculizumab was administered adding to red blood cell transfusion and recombinant thrombomodulin alfa and haptoglobin. However, a subsequent culture test of her second stool sample revealed the presence of O80:H2 stx2, confirming the diagnosis of STEC-HUS. Subsequently, the patient's condition improved, and her serum creatinine level gradually normalized over the course of 3 months. Conclusion: Diligently diagnosis is crucial in cases lacking typical STEC-HUS symptoms. We advocate for repeated stool culture testing to ensure accurate identification and timely management of such cases.

What Happens to Patients with Inflammatory Bowel Disease Who Are Intolerant to Thiopurines?

Introduction: The clinical consequences for patients with inflammatory bowel disease (IBD) who stop treatment owing to side effects have not been fully investigated. Methods: This retrospective observational study aimed to compare patients who discontinued thiopurine treatment due to side effects with those who tolerated thiopurine treatment in the use of other IBD drugs, surgery, and fecal calprotectin values in the first 5 years after the start of thiopurine treatment. Results: The proportion of patients with IBD who initiated thiopurine treatment at our clinic was 44% (32% ulcerative colitis and 64% Crohn's disease) and 31% (n = 94) of those patients had to stop thiopurine treatment within 5 years due to side effects. Patients who discontinued thiopurine treatment due to intolerance were significantly older (median age 33 vs. 27 years, p = 0.003), significantly more often used prednisolone (89 vs. 76%, p = 0.009), and used to a lesser extent TNF inhibitors at the start of thiopurine treatment (3% vs. 9%, p = 0.062). Budesonide treatment and non-TNF inhibitor second-line therapy were significantly more commonly used in patients who discontinued thiopurine treatment owing to side effects, but there were no statistically significant differences in the use of other treatments. The proportion of patients with a median FC >200 µg/g was significantly higher during follow-up in patients with UC who discontinued thiopurine treatment owing to side effects. Conclusions: Patients who discontinued thiopurines owing to side effects were prescribed more budesonide and non-TNF inhibitor second-line therapy, but there were no differences in the use of TNF inhibitors, prednisolone, or surgery.

Development and Validation of an E-Learning Educational Program for Acquiring Basic Knowledge in Inflammatory Bowel Disease Nursing.

Introduction: This study focuses on developing and validating an e-learning educational program for nurturing inflammatory bowel disease (IBD) nursing specialists. Methods: The program was developed using the attention, relevance, confidence, and satisfaction models within the instructional design framework. The program validation encompassed four steps: (1) nurses took a basic IBD knowledge test (pretest), (2) participants scoring <80% were encouraged to undergo web-based training, (3) a follow-up test (posttest) gauged post-training improvement, and (4) participant satisfaction with e-learning was assessed. Results: The analysis included 63 participants. The average score in the pretest was 81.3%, 40 participants exceeded the pretest passing score, which is 80% (average: 88.3%), and 23 participants failed (average: 69.1%). Of those who failed, 19 participants showed improvement after undergoing web-based training, with their posttest scores exceeding the passing threshold (average: 97.4%). The comparison results between the passing and failing groups revealed no correlation between the baseline characteristics of the participants. The participants were highly satisfied with the e-learning program. Conclusion: The program was effective as an educational program for acquiring basic knowledge to foster IBD nursing professionals. The learning design was adapted to the participants' lifestyles and tailored to the readiness of the nurse, ensuring a satisfactory e-learning user experience for the nurses.

Alterations in tryptophan metabolism and de novo NAD+ biosynthesis within the microbiota-gut-brain axis in chronic intestinal inflammation.

Background: Inflammatory bowel disease is an incurable and idiopathic disease characterized by recurrent gastrointestinal tract inflammation. Tryptophan metabolism in mammalian cells and some gut microbes comprise intricate chemical networks facilitated by catalytic enzymes that affect the downstream metabolic pathways of de novo nicotinamide adenine dinucleotide (NAD+) synthesis. It is hypothesized that a correlation exists between tryptophan de novo NAD+ synthesis and chronic intestinal inflammation. Methods: Transcriptome analysis was performed using high-throughput sequencing of mRNA extracted from the distal colon and brain tissue of Winnie mice with spontaneous chronic colitis and C57BL/6 littermates. Metabolites were assessed using ultra-fast liquid chromatography to determine differences in concentrations of tryptophan metabolites. To evaluate the relative abundance of gut microbial genera involved in tryptophan and nicotinamide metabolism, we performed 16S rRNA gene amplicon sequencing of fecal samples from C57BL/6 and Winnie mice. Results: Tryptophan and nicotinamide metabolism-associated gene expression was altered in distal colons and brains of Winnie mice with chronic intestinal inflammation. Changes in these metabolic pathways were reflected by increases in colon tryptophan metabolites and decreases in brain tryptophan metabolites in Winnie mice. Furthermore, dysbiosis of gut microbiota involved in tryptophan and nicotinamide metabolism was evident in fecal samples from Winnie mice. Our findings shed light on the physiological alterations in tryptophan metabolism, specifically, its diversion from the serotonergic pathway toward the kynurenine pathway and consequential effects on de novo NAD+ synthesis in chronic intestinal inflammation. Conclusion: The results of this study reveal differential expression of tryptophan and nicotinamide metabolism-associated genes in the distal colon and brain in Winnie mice with chronic intestinal inflammation. These data provide evidence supporting the role of tryptophan metabolism and de novo NAD+ synthesis in IBD pathophysiology.

Uncommon Etiologies of Acute Abdominal Pain: A Case Report on Omental Infarction.

Omental infarction is an uncommon cause of abdominal pain. The condition is often misdiagnosed due to its clinical similarity to more common abdominal pathologies like appendicitis and cholecystitis. This report presents the case of a 57-year-old female with a one-week history of left-sided abdominal pain, initially aggravated by eating and defecation. The patient, a long-term smoker with a complex medical history that includes deep vein thrombosis and pulmonary embolism, was hemodynamically stable on presentation. A CT scan revealed a nodular infiltration consistent with an omental infarct. Conservative management was pursued, resulting in symptom resolution by the third day of hospitalization. This case underscores the diagnostic challenges associated with omental infarction, particularly its differentiation from other causes of acute abdominal pain. It highlights the importance of considering rare etiologies in patients with atypical presentations and emphasizes the role of imaging, particularly CT scans, in accurate diagnosis. The patient's successful conservative management aligns with current recommendations, which advocate for non-surgical treatment in most cases. This approach avoids unnecessary surgical interventions and ensures a favorable prognosis with low complication rates in patients with prompt and appropriate management.

Primary Sclerosing Cholangitis Associated With Ulcerative Colitis Coexisting With Cholangiocarcinoma: A Case Report.

Primary sclerosing cholangitis (PSC) is a rare chronic inflammatory disease in which multifocal fibrosis of bile ducts causes eventually narrowing and even blocking, forming multifocal strictures alternated to dilatations. Here, we reported an extremely rare case of PSC associated with ulcerative colitis (UC) and coexisting with cholangiocarcinoma in a 33-year-old male presented with right upper quadrant pain and dark urine. Liver function tests were deranged, and ERCP found a beaded cholangiography appearance due to multifocal bile duct strictures alternating with normal and dilated segments of the common hepatic duct and the intrahepatic bile ducts. We aim to document this typical case of PSC associated with UC and coexisted with cholangiocarcinoma to add the existing data on these rare pathologies.

Assessing anorectal function in patients with recurrent ulcerative colitis.

PURPOSE: Ulcerative colitis (UC) is an inflammatory bowel disease with an unclear etiology that can lead to irreversible changes in distal colonic function in chronic patients. This study investigated anorectal function in recurrent UC patients and identified influencing factors. METHODS: This prospective study enrolled 33 recurrent UC patients and 40 newly diagnosed patients from January 2019 to December 2022. Data collection included clinical records, scores, and anorectal function assessments. Regression analyses were used to identify factors impacting anorectal function. RESULTS: Recurrent UC patients had higher baseline CRP and fecal calprotectin levels, increased anxiety and depression, and more severe fecal incontinence. They also had lower BMIs, serum Hb and albumin (ALB) levels, and Inflammatory Bowel Disease Questionnaire scores than did initial-onset UC patients. Multivariate linear regression analysis revealed that long disease duration (coef. - 0.376, P < 0.001) and high fecal calprotectin level (coef. - 0.656, P < 0.001) independently influenced the initial sensation threshold in recurrent UC patients. Additionally, high fecal calprotectin (coef. - 0.073, P = 0.013) and high Zung Self-Rating Anxiety Scale score (coef. - 0.489, P = 0.001) were identified as two independent determinants of the defecation volume threshold. For the defecation urgency threshold, the independent factors included high disease duration (coef. - 0.358, P = 0.017) and high fecal calprotectin level (coef. - 0.499, P = 0.001). Similarly, the sole independent factor identified for the maximum capacity threshold was high fecal calprotectin (coef. - 0.691, P = 0.001). CONCLUSION: Recurrent UC patients had increased rectal sensitivity and compromised anorectal function, which significantly impacted quality of life. Proactively managing the disease, reducing UC relapses, and addressing anxiety are effective measures for improving anorectal function in these patients.

Functional evaluation of pure natural edible Ferment: protective function on ulcerative colitis.

Purpose: To investigate the therapeutic efficiency of a novel drink termed "Ferment" in cases of ulcerative colitis (UC) and its influence on the gut microbiota. Method: In this study, we developed a complex of mixed fruit juice and lactic acid bacteria referred to as Ferment. Ferment was fed to mice for 35 days, before inducing UC with Dextran Sulfate Sodium Salt. We subsequently investigated the gut microbiome composition using 16S rRNA sequencing. Result: After Ferment treatment, mouse body weight increased, and animals displayed less diarrhea, reduced frequency of bloody stools, and reduced inflammation in the colon. Beneficial bacteria belonging to Ileibacterium, Akkermansia, and Prevotellacea were enriched in the gut after Ferment treatment, while detrimental organisms including Erysipelatoclostridium, Dubosiella, and Alistipes were reduced. Conclusion: These data place Ferment as a promising dietary candidate for enhancing immunity and protecting against UC.

Real-World Data on the Effectiveness and Safety of Filgotinib for Ulcerative Colitis in Japanese Patients: A Single-Center Experience.

Introduction Filgotinib is a JAK-1 selective inhibitor approved for ulcerative colitis (UC) treatment in Japan. Its effectiveness has been confirmed but remains unknown in actual clinical practice. Therefore, we aimed to evaluate the effectiveness and safety of filgotinib and identify suitable patients in the Japanese population. Methods We retrospectively reviewed the background, clinical course, and laboratory data of patients treated with filgotinib 200 mg for UC between May 2022 and December 2023. Results The median observation period for the 25 patients was 232 days (interquartile ranges (IQR) 102-405). The median age of the patients was 43 years (IQR 29-55), disease duration was nine years (IQR 2-12), and 36% (9/25) of patients were biologic or small molecule naïve. The median patient-reported outcome (PRO2) and partial Mayo (pMayo) scores at agent initiation were 3 (IQR 1-4) and 4.5 (IQR 3-6), respectively. The PRO2 and pMayo scores improved significantly two weeks after treatment initiation (p < 0.05). Clinical remission rates at 24 weeks after treatment initiation were 60% (15/25) for PRO2 ≤ 1 and 52% (13/25) for pMayo ≤ 1. The Mayo endoscopic subscore significantly improved after filgotinib initiation (p=0.04), and the endoscopic remission rate was 47% (8/17). At 24 weeks, patients in clinical remission, compared to those not in remission, had significantly lower baseline PRO2 and pMayo scores and longer disease duration (p=0.03, p=0.03, and p=0.04, respectively). The filgotinib persistence rate was 68% (17/25), with no discontinuation because of adverse events. Patients who continued treatment had significantly lower PRO2, pMayo scores, and blood neutrophil counts at initiation than those who discontinued (p=0.02, p=0.03, and p=0.02, respectively). Conclusion Filgotinib appears to be effective and safe in Japanese patients with UC. Effectiveness and persistence were high in patients whose PRO2 and pMayo scores were low at the time of treatment initiation.

Association of diet and outdoor time with inflammatory bowel disease: a multicenter case-control study using propensity matching analysis in China.

Objective: To investigate the association between dietary and some other environmental factors and the risk of inflammatory bowel diseases (IBD) in Chinese population. Materials and methods: A multicenter case-control study was conducted involving 11 hospitals across China. A total of 1,230 subjects were enrolled consecutively, and diet and environmental factor questionnaires were collected. IBD patients were matched with healthy controls (HC) using propensity-score matching (PSM) at a 1:1 ratio with a caliper value of 0.02. Multivariate conditional logistic regression analyses were performed to evaluate the associations between diet, environmental factors, and IBD. Results: Moderate alcohol and milk consumption, as well as daily intake of fresh fruit, were protective factors for both Crohn's disease (CD) and ulcerative colitis (UC). Conversely, the consumption of eggs and chocolate increased the risk of IBD. Outdoor time for more than 25% of the day was a protective factor only for CD. In eastern regions of China, CD patients had higher egg consumption and less outdoor time, while UC patients consumed more chocolate. IBD patients from urban areas or with higher per capita monthly income consumed more fruit, eggs, and chocolate. Conclusions: This study reveals an association between specific foods, outdoor time, and the emergence of IBD in the Chinese population. The findings emphasize the importance of a balanced diet, sufficient outdoor time and activities, and tailored prevention strategies considering regional variations.

SERENE ER Analysis Part 2 SERENE-UC: Exposure-response Analysis of Higher Versus Standard Adalimumab Dosing Regimens for Patients with Moderately to Severely Active Ulcerative Colitis.

SERENE UC (NCT02065622) evaluated whether a higher adalimumab induction regimen improved patients with ulcerative colitis (UC) response, but a flat dose-response relationship was found in the induction study. We investigated exposure-response (ER) relationships in induction and maintenance studies considering patients' baseline characteristics. Adalimumab exposures were simulated using the established population pharmacokinetic model. Multivariable logistic regressions were used to assess the efficacy endpoints (clinical remission, endoscopic remission, endoscopic improvement) at weeks 8 and 52. In the induction study, an increasing ER trend with heterogeneity between induction regimens was shown, suggesting average concentration (Cavg) had a significant impact on primary efficacy endpoints within each group. However, data were not described by a single ER curve. Using inverse effective clearance as the exposure metric described trends across induction regimens with a single curve. Patients with inherently lower effective adalimumab clearance responded better. The patient response rates at week 52 showed no heterogeneity. A short-term increase in adalimumab dose did not drive better responses for induction, and apparent ER relationships were better explained by patient-inherent lower clearance. Conversely, during maintenance up to week 52, increasing the concentration via dose translated to better responses more robustly. The ER findings for SERENE UC were consistent with SERENE CD.