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Journal of Crohn's and Colitis

◐ Oxford University Press (OUP)

Preprints posted in the last 30 days, ranked by how well they match Journal of Crohn's and Colitis's content profile, based on 11 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.

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Longitudinal multi-omics profiling of tofacitinib response identifies a pre-existing Janus kinase-tractable inflammatory state in ulcerative colitis

Fung, I. C.; de Jong, D. C.; Liu, K.; Li Yim, A. Y.; van Gennep, S.; Ramkisoen, R. K.; Clasquin, E.; de Jong, J.; Gecse, K. B.; Lowenberg, M.; Mookhoek, A.; de Jonge, W. J.; D'Haens, G. R.

2026-10-08 gastroenterology 10.64898/2026.10.07.26364964 medRxiv
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BACKGROUND & OBJECTIVE Tofacitinib, a Janus kinase (JAK) inhibitor, is approved for ulcerative colitis (UC). We investigated baseline and longitudinal transcriptomics and proteomics in intestinal biopsies, peripheral blood, and serum from UC patients starting tofacitinib to characterise treatment-associated effects and identify which molecular compartment harbours the most predictive response-associated biomarkers. METHODS In this prospective, open-label study, patients with moderately to severely active UC started tofacitinib 10 mg BID for eight weeks. Clinical, biochemical, endoscopic, and histological data were collected at baseline and week 8. The primary outcome, histo-endoscopic mucosal improvement (HEMI), was defined as endoscopic Mayo subscore [≤]1 with histologic remission (Robarts Histopathology Index [≤]3, no mucosal neutrophils). Mucosal biopsies and peripheral blood were collected at baseline and week 8 for bulk RNA-sequencing (RNA-seq); biopsies and serum underwent proteomic profiling using Olink Explore 384 (Cardiometabolic, Inflammation, Neurology, Oncology panels). RESULTS In total, 127 paired multi-omic samples were collected longitudinally from 40 UC patients: 15 (38%) achieved HEMI at week 8 (responders), 13 (32.5%) were late responders, and 12 (30%) were non-responders. Pretreatment mucosal biopsies from future responders showed elevated interferon, IL-6-family, IL-2/common-{gamma}-chain, and T-cell-receptor signalling gene expression, which declined on treatment only in responders. A responder-specific JAK-STAT-dependent mechanism spanned interferon, cytokine-receptor, T-cell-receptor, and NF-{kappa}B signalling, with concordant gene- and protein-level reductions. Compared with a public infliximab dataset, JAK-STAT/interferon downregulation was shared and response-independent, while non-canonical NF-{kappa}B downregulation was tofacitinib-specific. In blood, shared pathway labels reflected distinct genes from mucosal effectors. CONCLUSION Response to tofacitinib depends on a JAK-tractable mucosal pathway absent in non-responders, suggesting a pretreatment biomarker for predicting treatment response.

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Machine learning predicts relapse after anti-TNF withdrawal in ulcerative colitis using rectal biopsy transcriptomics

Bouhddi, G.; Rapp, E.; Artiemjew, P.; Berset, I. P.; Lerang, F.; Hoff, D. A. L.; Bakkevold, E. S.; Lundin, K. E. A.; Jahnsen, F. L.; Domanska, D.

2026-10-07 gastroenterology 10.64898/2026.10.05.26364793 medRxiv
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Background There are currently no available biomarkers that predict the clinical outcome of ulcerative colitis (UC) patients after anti-TNF withdrawal. Here we developed a semi-supervised machine learning framework on RNA-seq data derived from rectal biopsies to predict relapse following anti-TNF discontinuation. Methods We included UC patients (n=136) enrolled in the prospective, randomized controlled BIOSTOP trial. Patients were assigned to a withdrawal group (stopped treatment immediately) or a maintenance group (stopped treatment after 2 years). A machine learning framework was trained on gene expression data from mucosal biopsies collected at baseline from the withdrawal group and validated in the maintenance group using baseline samples (test cohort) and 2-year follow-up samples (interference cohort). Results A semi-supervised machine learning model, combining a shared UMAP manifold representation with LabelSpreading on a targeted 38-gene panel achieved an AUC of 0.794, a sensitivity of 90.3%, and a specificity of 73.1% on the test cohort, and an AUC of 0.711, a sensitivity of 82.9%, and a specificity of 42.3% on the inference cohort. Applying Shapley Additive exPlanations (SHAP) we found that IL1B, TYROBP, REG1B, S100A8, and TNF showed the highest predictive importance for relapse risk, whereas MUC2, HMGCS2, and CDKN1A displayed the highest predictive importance for sustained remission. Conclusion The high sensitivity makes the model a promising screening tool to prevent withdrawal-related relapse, though its moderate specificity underscores the need for multi-center validation in larger, more diverse cohorts before clinical deployment.

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Serum proteins predict incident inflammatory bowel disease 14 years before diagnosis: a machine-learning and Cox modelling in the UK Biobank

Niebuhr, T. E.; Fieggen, J.; Segal, B. M.; Patel, A.; Clifton, D. A.; Clifton, L.

2026-10-14 gastroenterology 10.64898/2026.10.13.26365425 medRxiv
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Using an analysis pipeline that combines machine learning-based feature selection with classical statistical modelling, we aimed to predict incident inflammatory bowel disease (IBD) and to identify candidate proteins associated with disease development. We used UK Biobank data in an observational cohort study of 52,331 participants with proteomics data and without a history of IBD. The cohort was split into an 80/20 train/test dataset, and three separate extreme gradient boosting models were trained on the training dataset. Using Shapley values, we ranked the predictive importance of 2,912 proteins for incident IBD, Crohn's disease (CD), and ulcerative colitis (UC). The top 20 proteins per outcome served as features in multivariate Cox models predicting 350 incident cases over 14 years. All three proteomics Cox models showed moderate discrimination in the test dataset, with the UC model performing the best (C-index: 0.68), followed by IBD (C-index: 0.65), and CD (C-index: 0.60). All proteomics models outperformed clinical models. Smoking remained the only significant clinical predictor in the combined proteomics + clinical model. 48 unique proteins were identified across the three models, with 16 reaching statistical significance (p< 0.05). Machine learning-based feature selection with statistical survival modelling identifies plasma proteins that predict incident IBD and highlight biologically plausible, potentially targetable pathways in the preclinical phase of IBD.

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Cumulative disease-course phenotypes in Crohn's disease: a retrospective single center FAMD clustering study

Caridi, B.; Amoroso, C.; Pozzi, L.; Noviello, D.; Arcidiacono, A.; Baldari, L.; Boni, L.; Prati, M.; Costa, S.; Oreggia, B.; Facciotti, F.; Caprioli, F.

2026-09-23 gastroenterology 10.64898/2026.09.22.26363649 medRxiv
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Background and aimsCrohns disease (CD) is a highly heterogeneous disease. Patients with similar characteristics at baseline may end up on very different therapeutic and surgical paths. We aimed to identify disease-course trajectory phenotypes from a mix of clinical, treatment, surgical and comorbidity variables, and evaluate whether information already available at diagnosis could anticipate which trajectory a patient would follow. MethodsWe analysed a retrospective cohort of 98 unique CD patients enrolled at the IRCCS Ca Granda Policlinico Hospital, Milan. Factor analysis of mixed data (FAMD) was applied to 30 disease-course variables spanning demographic and Montreal descriptors, extra-intestinal manifestation burden, individual advanced-therapy drug exposures, surgical burden and comorbidity/symptom burden; clusters were then ranked by treatment burden using a line-weighted therapy score built separately from drug line positions and therapeutic-class weights. Clustering itself was carried out in the retained FAMD coordinate space, and cluster robustness was checked with silhouette metrics and bootstrap Jaccard stability. Baseline-associated variables were assessed separately, while advanced-therapy episodes were reconstructed from the therapy timeline. ResultsThree trajectory phenotypes emerged: C1 (n=56), C2 (n=31) and C3 (n=11). C3 was characterised by younger age at diagnosis, a heavier extra-intestinal manifestation burden, more intensive and prolonged therapy, greater biologic exposure and a higher cumulative number of surgeries, with comorbidity burden rising across the gradient. Montreal behaviour and comorbidity burden emerged as the strongest baseline correlate of trajectory membership, ahead of age at diagnosis and extra-intestinal manifestation burden; penetrating (B3) behaviour, notably, was actually more common in C1 than in C3. A model built on the diagnosis-available variables independently linked to trajectory membership (age at diagnosis, disease location and Montreal behaviour) showed moderate discrimination for the C3 trajectory (area under the curve, AUC=0.80, 95% CI 0.67-0.93). A sensitivity analysis that also added extra-intestinal manifestation count and comorbidity burden, whose timing relative to diagnosis we could not confirm, pushed discrimination to AUC=0.90. ConclusionsFAMD-space clustering identified stable, clinically interpretable CD-course trajectory phenotypes, including a small, high-burden C3 subgroup. This C3 trajectory, small, early-onset and treatment-refractory, shares clinical features that overlap with the difficult-to-treat CD phenotype, though C3 was derived by unsupervised clustering rather than validated against that frameworks own criteria; variables available at or near diagnosis showed exploratory discrimination for the high-burden C3 trajectory, though external validation and careful timing verification are needed before any clinical use.

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Identification of Transcriptional Hippo Response Signature Connecting Inflammatory Bowel Disease and Colorectal Cancer Progression

Noor, S.; Vignaish, K. S.; Joshi, P.

2026-09-26 gastroenterology 10.64898/2026.09.24.26363887 medRxiv
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Background: Inflammatory bowel disease (IBD) has been linked to a two- to eightfold increase in colorectal cancer (CRC) risk. However, particular genes that bridge intestinal dysbiosis and oncogenic transcriptional reprogramming remain unclear. The Hippo/YAP pathway is a major regulator of intestinal epithelial homeostasis whose effector YAP is hyperactivated in CRC, but its transcriptional engagement in IBD mucosa and its link to specific cancer-risk genes has not been thoroughly mapped. Methods: Bulk RNA-seq data were integrated from two independent cohorts: GSE235236 (IBD colon mucosa; UC/CD vs. healthy controls; n = 56) and TCGA-COAD/READ (CRC tumors stratified by YAP activity; n = 592). Differential expression analysis was conducted separately within each cohort using Welch's t-test with Benjamini-Hochberg FDR correction. YAP transcriptional activity was estimated per sample as the mean row-wise Z-score of seven canonical YAP target genes, and TCGA tumors were stratified into Hippo-High (Q4) and Hippo-Low (Q1) groups. Genes showing consistent dysregulation across both cohorts were identified and ranked to define a Dysbiosis-Hippo Response (DHR) module, which was further organized into functional gene archetypes. Results: IBD mucosa showed 2,848 significantly dysregulated genes (FDR < 0.05). Comparison with the CRC cohort identified 120 genes showing concordant dysregulation, forming the DHR module. These genes were significantly enriched in TNF-alpha signaling via NF-kB (adjusted p = 0.006), inflammatory response (adjusted p = 0.013), and Myogenesis (adjusted p = 0.013). DHR gene classification revealed three functional archetypes: (i) innate immune activation (SPI1, OSM, IL11, LILRA2, SLC11A1) reflecting convergent myeloid reprogramming; (ii) epithelial-mesenchymal transition (TWIST1, SNAI1, PRRX2, MMP9) priming invasive potential before malignancy; and (iii) tumor microenvironment immune regulation (TN-FRSF4, TNFRSF18, PDCD1, VASN, SPON2) shaping immune tolerance. Interestingly, the canonical YAP target genes (CTGF, CYR61, ANKRD1, AMOTL2, and FSTL1), sharply upregulated in Hippo-High CRC, were essentially unchanged in IBD mucosa. This signifies that the shared DHR programme operates through non-canonical YAP effectors. And yet, YAP target scores are positively correlated with DHR module expression across IBD samples (Spearman rho = 0.726, p = 2.5 x 10-10). Conclusions: Our findings define a three-archetype DHR module that links gut dysbiosis to YAP-driven oncogenesis at single-gene resolution. The programme shared between IBD and CRC is driven by innate immune activation, EMT priming, and remodeling of the immune microenvironment, not by the canonical CTGF/CYR61 YAP target axis, which appears only at the CRC stage. This gene-level framework provides tractable mechanistic targets for chemoprevention and biomarker development at the inflammation-to-cancer transition.

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Disrupted microbial queuosine biosynthesis contributes to dysbiosis of human inflammatory bowel disease

An, Y.; Xia, Y.; Sun, J.

2026-10-14 gastroenterology 10.64898/2026.10.12.26365231 medRxiv
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Background and Aims: As a microbiome/diet-derived vitamin, queuine (q) is a micronutrient that eukaryotes acquire from microbiota or diet. Vitamin q, the free base form of queuosine (Q), is used for Q-modification of transfer RNA (tRNA). Although tRNA-Q-modification in regulating eukaryotic cell physiology is recognized, the relationship between Q-tRNA-modification and the human microbiome in health and inflammatory bowel diseases (IBD) remains unknown. Which bacteria produce q and how the q-producing bacteria contributing to human health and IBD are not explored. Here, we hypothesize that disrupted microbial Q-biosynthesis contributes to the dysbiosis of human IBD. We performed comprehensive multi-omics integrative analyses using publicly available datasets. Specifically, we re-analyzed publicly available shotgun metagenomic, single-cell RNA sequencing (scRNA-seq), metabolic datasets, and completed meta-analysis. Methods: To systematically investigate microbial Q-biosynthesis in healthy individuals and IBD patients, we performed a systematic secondary analysis by integrating 9 publicly available metagenomic datasets, 15 scRNA-seq datasets and one metabolic dataset published prior to 2026. We present a novel secondary bioinformatic reanalysis of sequence outputs mapped to the latest microbial taxonomy, functional pathways and microbial Q-related genes. Longitudinal study of shotgun metagenomics across the human lifespan (3146 samples) enabled taxonomic and functional profiling. Results: We first identified key q-producing bacteria (e.g., Bacteroides and Alistipes) in healthy populations. We then found that patients with IBD had significantly reducation of q-producing bacteria and a coordinated downregulation of the Q-related pathways, including Q, preQ0, de novo guanosine ribonucleotide biosynthesis and de novo guanosine deoxyribonucleotide biosynthesis pathways. This functional impairment was primarily driven by reduced contributions from Bacteroides, Alistipes and Akkermansia. The longitudinal stability of the q-producing bacteria community across the human lifespan (1638 samples). We observed a significant negative correlation between host age and the abundance of q-producing bacteria in patients with UC. Moreover, Queuine tRNA-ribosyltransferase 1 (QTRT1) expression in human intestinal epithelial cells was significantly reduced in patients with IBD compared to healthy controls. Conclusions: Our study used multi-omics datasets to define a novel functional dysbiosis characterized by a reduction of microbial Q-biosynthesis in patients with IBD. Vitamin q and its tRNA modification is lesser-recognized in human IBD. Understanding the cellular and organismal mechanisms of this microbiome-dependent micronutrient will advance the prevention of IBD and improve the quality of life of patients with IBD.

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Characterisation of Genetically-Derived Patient Clusters Highlights Genetic Heterogeneity of Inflammatory Bowel Disease

Vazquez Lopez, F.; Kadhim, A. Z.; Green, Z.; Nazari, I.; Cheng, G.; Cohen, L. J.; Chou, J. M.; Beattie, R. M.; Ennis, S.; Ashton, J. J.

2026-10-12 bioinformatics 10.64898/2026.10.05.754100 medRxiv
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Background and aims. Inflammatory Bowel Disease (IBD) is a complex immune-mediated condition with a strong genetic contribution. The genetics of IBD are highly complex, with inflammation, autoimmunity, and mucosal immunity pathways involved in its pathogenicity. GenePy is a gene-level disease burden metric. The integration of clinical and genetic data and the application of machine learning methods can aid patient stratification for personalised care. Methods. Lists of consensus IBD pathway genes were curated. GenePy scores were computed from whole exome sequencing data. A K-Means algorithm was optimised using clustering quality and stability metrics on the GenePy scores of genes in each IBD pathway, and the results replicated in three independent IBD cohorts (SPARC IBD, MSCCR IBD, and Southampton IBD). Chi-square tests assessed the association between cluster assignment and phenotypic features, and were multiple test corrected via Benjamini-Hochberg FDR. Results. A strong association was replicated for NOD signalling genes driving IBD subtype, Crohns disease behaviour, and IBD surgery across all cohorts, as well as granuloma in Southampton IBD. This was mainly driven by NOD2. Similar genetic clustering patterns were observed across all cohorts, with additional phenotypic enrichment in clusters driven by NLRP1 (surgery in MSCCR IBD), and nominally significant enrichment for disease behaviour linked to BIRC2 (B2 in Southampton IBD and B2B3 in SPARC IBD). Conclusions. This analysis identified a common genetic architecture across NOD signalling genes across IBD cohorts, replicated a signal for NOD2 as a monogenic driver of disease with a strong phenotypic enrichment, and identified other putative genetic drivers of IBD, such as the NLRP1 gene.

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Single-cell profiling reveals stromal niche and α5β1 regulation of neutrophil phenotypes in ulcerative colitis

Zhou, Y.; Canas, J.; Ye, J.; Hoang, J.; Ferkel-Soltau, S.; Holman, D.; Sojwal, R.; Fardeen, T.; Vazques, G.; Huang, Y.; Peterson, K.; Nolan, G.; Sinha, S.; Rogalla, S.; Gubatan, J.

2026-09-23 immunology 10.64898/2026.09.21.753318 medRxiv
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Background and Aims: Fibroblast-neutrophil interactions are implicated in ulcerative colitis (UC) treatment resistance, but whether fibroblasts modify neutrophil inflammatory activity remains unclear. We investigated responses to fibroblast exposure, stromal depletion, and 5{beta}1-directed treatment. Methods: We integrated human and mouse colonic single-cell RNA sequencing (scRNA-seq), spatial protein profiling (CODEX), fibroblast-neutrophil coculture, and dextran sulfate sodium (DSS) mouse colitis with fibroblast activation protein (FAP) ablation or 5{beta}1-directed treatment. Readouts included cellular representation and protein fluorescence via flow cytometry, neutrophil extracellular trap (NET)-associated elastase activity, RNA programs and epithelial responses using scRNA-seq. Results: Inflamed UC tissue contained higher fractions of inflammatory fibroblasts and oncostatin M (OSM)- and CXCR4-associated neutrophils. Inflammatory fibroblasts had higher FAP-5{beta}1 module scores, and proximity to FAP-high fibroblasts was associated with higher neutrophil OSM and CXCR4 fluorescence. UC fibroblasts increased neutrophil OSM, CXCR4 and myeloperoxidase (MPO) fluorescence and NET-associated elastase activity relative to control fibroblasts, while 5{beta}1-directed treatment attenuated these responses. Both mouse FAP ablation and 5{beta}1 blockade in DSS colitis reduced histologic inflammation and overall neutrophil frequency. Ablation broadly reduced recovered neutrophil representation, whereas blockade increased OSM-positive and PADI4-positive percentages within neutrophils despite lower MPO fluorescence within these subsets. Both interventions were associated with lower epithelial chemokine scores but distinct absorptive and mucus/secretory responses. Conclusions: Fibroblast exposure modifies neutrophil inflammatory phenotype and effector-associated activity, identifying candidate therapeutic pathways in UC. Evaluating these responses alongside neutrophil representation and tissue inflammation could inform pharmacodynamic assessment of stromal-directed therapies.

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Prediction of incident inflammatory bowel disease from routine electronic health records: development and external validation of a longitudinal machine learning model

Onal, G.; Ayati, A.; Chen, M.-Y.; Mukherjee, A.; Rudrapatna, V. A.

2026-10-13 gastroenterology 10.64898/2026.10.12.26365307 medRxiv
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BACKGROUND & AIMS: Inflammatory bowel disease (IBD) is often diagnosed months to years after symptoms begin, and diagnostic delay is associated with complications. We tested whether longitudinal machine learning using electronic health record (EHR) data can identify incident IBD before diagnosis, and quantified lead time and deployment burden. METHODS: We studied adults with an IBD-compatible symptom, sign, or finding at UCSF (2012-2024). Incident cases were confirmed by structured filtering and validated large language model note review. We trained a state space model (Mamba) and comparators on pre-diagnostic EHR data, excluding diagnostic-workup features, and assessed discrimination at 6- and 12-month landmarks. We externally tested Mamba without recalibration at ZSFG, a safety-net hospital serving a demographically and socioeconomically distinct population, and simulated diagnosis-code-only deployment at UCSF. RESULTS: Six months after presentation, among patients still undiagnosed (67% of UCSF test cases), Mamba achieved an AUROC of 0.969 (95% CI, 0.928-0.999) at UCSF and 0.965 (0.952-0.976) at ZSFG. Median lead time was 20 months at UCSF and 15 months at ZSFG. Among future cases with an initially normal colonoscopy (N=32) or a histological finding of acute inflammation without chronicity (N=63), the model flagged 84% and 89% of these patients, respectively, before those procedures, indicating the potential for pre-diagnostic detection. Among 358,886 symptomatic patients not used for training (60 incident cases), the diagnosis-code-only model achieved an AUROC of 0.926; reviewing 20 alerts/month identified 34 cases (PPV, 1.09%; 64-fold above baseline). CONCLUSIONS: Longitudinal machine learning can identify increased IBD risk months to years before diagnosis and may define a population for prospective studies of early IBD biology. Prospective evaluation should determine whether earlier identification reduces diagnostic delay.

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A microbiota-dependent gut bile acid axis links germline mutant p53 to distal tumour growth.

Ong, N. W. Y.; Fischer, N. W.; Giovino, C.; Quaglietta, P. R.; Park, Y.; Traubici, R.; Malkin, D.

2026-10-06 cancer biology 10.64898/2026.10.05.753853 medRxiv
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The gut microbiome can influence cancer development, but its contribution to cancer predisposition in Li-Fraumeni Syndrome (LFS) remains poorly understood. Here, we investigated whether germline mutant p53 alters the intestinal environment using Trp53R172H/+ mice. Tumour-naive mutant mice exhibited increased intestinal permeability and a pro-inflammatory colonic phenotype, including elevated inflammatory cytokines and enhanced NF-{kappa}B signalling. Untargeted metabolomic profiling revealed a striking alteration in bile acid metabolism, with targeted analysis identifying increases in multiple primary and microbiota-derived secondary bile acids. Notably, these changes occurred despite no detectable differences in overall microbial community composition, suggesting altered host-microbial metabolic output in the absence of broad compositional change. Several faecal bile acids were positively associated with distal tumour burden, with the microbiota-derived secondary bile acid deoxycholic acid (DCA) showing the strongest relationship. Microbiota depletion reduced distal tumour growth in mutant mice and attenuated intestinal barrier dysfunction, colonic inflammation and the altered faecal bile acid profile, including DCA. Conversely, transfer of cell-free faecal filtrate from mutant donors to WT recipients induced colonic inflammation and enhanced distal tumour growth. Together, these findings identify a mutant p53-gut axis in which germline mutant p53 establishes a microbiota-shaped metabolic and inflammatory intestinal environment capable of promoting tumour growth beyond the gut.

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Metabolic Dysfunction-Associated Steatotic Liver Disease In Patients With Inflammatory Bowel Disease: Association With Body Mass Index And Disease Severity

Antoniv, A.; Antoniv, N.

2026-10-13 gastroenterology 10.64898/2026.10.12.26365296 medRxiv
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The aim of this study was to determine whether the frequency of metabolic dysfunction-associated steatotic liver disease (MASLD) and the severity profile of inflammatory bowel disease (IBD) differ across body mass index (BMI) categories. A retrospective analysis was performed using 400 inpatient medical records from 2023-2024 with verified ulcerative colitis or Crohn's disease and sufficient information on anthropometry, hepatic status, and intestinal disease activity. The cohort comprised 118 patients with normal BMI, 176 with overweight, and 106 with obesity. MASLD status was reconstructed from routine clinical documentation and required hepatic steatosis in the appropriate cardiometabolic context. Ultrasonography was the principal source of evidence for steatosis; laboratory findings, non-invasive indices, and elastography were considered supportive when available. Ulcerative colitis activity was assessed with the Mayo Score and Crohn's disease activity with the Crohn's Disease Activity Index; disease-specific results were harmonized into mild, moderate, and severe categories for pooled comparisons. MASLD was identified in 181 of 400 patients (45.3%). Its frequency increased from 20.3% in the normal-BMI group to 49.4% in the overweight group and 66.0% in the obesity group (chi2=49.29; p<0.001). The largest absolute increase, 29.1 percentage points, occurred between normal BMI and overweight. The proportion of severe IBD rose in the same order, from 6.8% to 14.8% and 32.1% across the three BMI strata (chi2=39.45; p<0.001). In unadjusted pairwise comparisons, the odds of MASLD were higher with overweight than with normal BMI (OR=3.83; 95% CI 2.24-6.55) and higher with obesity than with normal BMI (OR=7.62; 95% CI 4.17-13.91); obesity also differed from overweight (OR=1.99; 95% CI 1.21-3.28). These findings demonstrate an ordered BMI-related pattern in which MASLD becomes more frequent and severe IBD represents a larger share of cases. However, MASLD was still documented in approximately one fifth of patients with normal BMI, indicating that BMI is useful for clinical prioritization but not for excluding steatotic liver disease. Because the study was retrospective, liver assessment reflected routine care, and the effect estimates were not adjusted for treatment exposure, disease duration, or other metabolic covariates, the observed relationships should be interpreted as associations rather than causal effects.

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Change in irritable bowel syndrome symptom severity among members of a multi-omic digital food-as-medicine program: a retrospective single-arm cohort study with estimates corrected for regression to the mean

Pedroso, I.; Kumbhare, S.; Saravanan, S.; Sinha, R.; Almonacid, D.; Sinha, R.

2026-10-02 gastroenterology 10.64898/2026.10.01.26364558 medRxiv
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Background: Real-world evidence on food-as-medicine programs for irritable bowel syndrome (IBS) is scarce, and single-arm evaluations overstate improvement because of regression to the mean (RTM). We estimated change in the IBS Symptom Severity Scale (IBS-SSS, 0-500) in a multi-omics personalized digital health food-as-medicine program, unadjusted and RTM-corrected. Methods: Retrospective single-arm cohort. Of 15,933 members with a valid baseline, 2,254 had a follow-up reading and 1,683 one at least 14 days after baseline. Change at 4, 12 (primary) and 26 weeks was estimated by baseline severity stratum, unadjusted and RTM-corrected by analysis of covariance. A responder fell by at least 50 points (the minimal clinically important difference benchmark). Sensitivity analyses covered equity, inverse-probability weighting and tipping-point analyses for members without a reading in each landmark window, a negative-control stratum and medication. The association of weight loss and dietary nutrient density with symptom change was evaluated within and between members. Results: At 12 weeks (n = 430) IBS-SSS fell by 43.88 points unadjusted (95% confidence interval [CI] -52.44 to -35.32; p < 0.001) and by 47.73 RTM-corrected (-55.48 to -39.98; p < 0.001); 720 of 1,339 symptomatic members (53.8%; 95% CI 51.1 to 56.4) fell by at least 50 points. Larger improvement in more severe members persisted after RTM correction (severe stratum, n = 37: unadjusted -127.43, RTM-corrected -60.71, 95% CI -97.75 to -23.68, p = 0.001). A higher meal nutrient density was associated with lower IBS-SSS within a member's own trajectory (p = 0.018) while weight change was not (p = 0.361). Improvement was similar across groups in spite of baseline differences by age and sex: RTM-corrected 12-week change did not differ by age (p = 0.458), body-mass index (p = 0.328), sex (p = 0.749), income (p = 0.486) or ethnicity (p = 0.170). Estimates were robust to weighting for members without a reading in the landmark window (RTM-corrected estimates moved by less than 2 points), and the change of those members would have had to be 39 to 73 points worse than observed before the mean change reached zero. Baseline medication use and starting a GLP-1 receptor agonist did not explain symptom changes. Conclusions: IBS-SSS fell significantly among program participants, with steeper improvement in the more severe group, even after RTM correction. The improvement was comparable across socioeconomic characteristics, age and sex and robust to the confounders and missing-data assumptions evaluated. These associations from a self-selected single-arm cohort warrant replication in independent studies.

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Early-life colonization by enterotoxigenic Bacteroides fragilis remodels gut epithelial stem cell states to drive colorectal cancer susceptibility

Russell, S. K.; Valguarnera, E.; Pak, J. J.; Bubeck Wardenburg, J.

2026-09-29 cancer biology 10.64898/2026.09.28.755180 medRxiv
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Early-life microbial exposures can shape lifelong disease risk, yet how developmental timing influences the host-microbe interaction remains unclear. During neonatal colonization by enterotoxigenic Bacteroides fragilis (ETBF), the metalloprotease toxin BFT enables lamina propria niche entry and remodeling of colonic epithelial cell states. Early-life ETBF exposure expands murine Lgr5+ stem cells, enhances Atoh1+ secretory differentiation, and induces distal colon-specific Wnt hyperactivation. These epithelial alterations coincide with increased formation of precancerous lesions in ApcMin/+ mice. ETBF preferentially forms intracellular bacterial aggregates within these lesions, establishing a persistent reservoir that reinforces epithelial remodeling. Colonization with non-toxigenic B. fragilis during this critical developmental window prevents lesion formation, revealing that developmental context dictates whether microbial colonization imprints protection or predisposition toward colorectal cancer.

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Psychometric properties of the Alimetry Gut-Brain Wellbeing Survey-II: A revised, unidirectional mental health scale for patients with chronic gastroduodenal symptoms

Law, M.; Pickering, I.; Schamberg, G.; Daker, C.; Gharibans, A. A.; O'Grady, G.; Andrews, C. N.; Calder, S.

2026-10-02 psychiatry and clinical psychology 10.64898/2026.09.30.26364444 medRxiv
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Objective: The Alimetry Gut-Brain Wellbeing (AGBW) Survey is a validated 10-item scale developed to assess mental health in patients with chronic gastroduodenal symptoms. While the original scale demonstrated strong psychometric properties overall, as part of an ongoing commitment to continuous instrument optimization, this study evaluated a revised, unidirectional version of the scale (AGBW-II) to enhance measurement precision. Methods: The psychometric properties of the revised AGBW-II were evaluated via an anonymous online questionnaire in a sample of 161 patients with chronic gastroduodenal symptoms. Score distributions, factor analysis, reliability, and validity were analyzed and compared with data from the validation study of the original scale (n= 311). Results: The AGBW-II total and subscale scores demonstrated robust reliability and validity, outperforming the original AGBW Survey. Notable improvements in the reliability and validity of the stress subscale were observed following item rewording. Confirmatory factor analysis verified the three-factor model separating the depression, stress, and anxiety subscales, with the AGBW-II showing improved model fit indices. Conclusions: The revised, unidirectional AGBW-II demonstrated improved reliability and validity, while maintaining the underlying psychometric properties of the original scale. Consequently, the AGBW-II provides a reliable, valid, and brief mental health assessment for patients with chronic gastroduodenal symptoms.

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Mesaconic acid delivery via biomaterials and engineered probiotics to the gut reduces inflammation in Crohn's Diseases mouse models

Qian, H.; Singh, D.; Chen, Z.; Zhao, W.; Zhang, B.; Knodaei, T.; Thumsi, A.; Pathak, S.; Suresh, A.; Menghini, P.; Schiek, J.; Rabara, V.; Salvo, C. D.; Baskaran, H.; Aso, Y.; Jaggarapu, M. M. C. S.; Basson, A. R.; Acharya, A. P.

2026-10-07 immunology 10.64898/2026.10.01.756006 medRxiv
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Mesaconate (MES, an immunosuppressive metabolite) but not itaconate is upregulated in stool of Crohns Disease (CD) patients, albeit below therapeutic levels.. However, colonic MES level is difficult to maintain because of its high absorption rate, limiting its therapeutic potential for CD. Herein, we developed two strategies that elevate MES level and suppress inflammation: EcN-CAD, an engineered probiotic Escherichia coli Nissle 1917 (EcN) that overexpresses cis-aconitate decarboxylase (CAD, produces itaconic acid that is converted to MES); and MES+Zn, a Zinc-MES ionically crosslinked formulation. Mechanistically, MES modulates T cell function by downregulating glycolytic and mitochondrial activity and decrease ROR{gamma}t expression. In preclinical SAMP1/YitFC dexamethasone-withdrawal model and TNFDARE model, MES+Zn decreased gut permeability significantly compared to controls and reduced myeloperoxidase (MPO, an inflammatory marker) 1000-fold compared to controls. EcN-CAD probiotics decreased ROR{gamma}t expression in CD4+ and CD8+ T cells, gut permeability and inflammation in preventive SAMP1/YitFC model, and SAMP1/YitFC dexamethasone-withdrawal model. Overall, MES rewires T cell responses and technologies that enhance MES levels can be effective in gut-related inflammatory diseases.

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Immunotherapy restores therapeutic efficacy of fecal microbiome transplants to treat Clostridioides difficile

Mridha, S.; Alam, M. Z.; Denny, J. E.; Hulit, E. N.; Tran Ha, M.; Mears, K. S.; Brown, D. D.; Alameh, M.-G.; Abt, M. C.

2026-09-23 immunology 10.64898/2026.09.17.752434 medRxiv
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Microbiome-based therapeutics to treat enteric bacterial infections requires stable engraftment of transplanted beneficial bacteria that target and eliminate the pathogen. The host factors that determine whether a microbiome transplant engrafts remain largely unresolved. Here we demonstrate that Interleukin-10 (IL-10) signaling deficiency leads to impaired fecal microbiota transplantation (FMT) engraftment and failure to resolve Clostridioides difficile infection in mice. In the absence of IL-10-mediated immunoregulation provided by Foxp3+ Treg cells, increased IFN-{gamma} signaling in the intestine leads to elevated production of reactive oxygen/nitrogen species (ROS/RNS) by neutrophils and epithelial cells that supports the growth of inflammation-tolerant microbes, inhibits FMT engraftment, and impairs resolution of C. difficile. FMT treatment success can be restored by antibody-mediated blockade of IFN-{gamma} signaling, neutrophil depletion or inhibition of ROS/RNS production. Lastly, we developed an Il10-mRNA-LNP immunotherapy to boost IL-10 signaling in FMT Non-Responsive mice and demonstrate that Il10-mRNA-LNP administration is sufficient to restore FMT engraftment and subsequent resolution of C. difficile. Combined, these data support a mechanism by which IL-10 released by Treg cells limits IFN-{gamma} mediated intestinal inflammation thereby promoting an intestinal microenvironment receptive to FMT engraftment and resolution of C. difficile. These data demonstrate that the host's immune status can be therapeutically modulated to improve microbiome-based approaches to treat infection.

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Understanding Psychological Health in Adults with Irritable Bowel Syndrome: A Cross-Sectional Study Using the All of Us Research Program

Wu, W.; Li, A.; Chen, J.; You, E.; Liu, P.; Rodriguez, L.; Chen, M.-H.; Cong, X.

2026-10-21 gastroenterology 10.64898/2026.10.20.26365988 medRxiv
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Background: Psychological health is an important aspect of health and well-being among adults with irritable bowel syndrome, yet the interrelationships among individual vulnerabilities, social experiences, perceived stress, and psychological health outcomes remain poorly understood. Objective: To characterize psychological health and examine direct and indirect associations of childhood adversity and adult attention-deficit/hyperactivity disorder-related symptoms within an adapted Stress Process Model. Design: Cross-sectional secondary analysis. Setting: The United States All of Us Research Program. Participants: 2,417 adults with electronic health record-documented irritable bowel syndrome and complete data on the primary analysis variables and covariates. Methods: Separate structural equation models examined childhood adversity and adult attention-deficit/hyperactivity disorder-related symptoms in relation to perceived stress, anxiety and depressive symptoms, and positive psychological well-being, with loneliness and perceived social support as psychosocial pathways. Models adjusted for sociodemographic and social-context factors. Results: The median age was 54.39 years; 80.7% were female and 84.4% were White. Moderate-to-high perceived stress was reported by 56.2%, at least moderate anxiety symptoms by 21.0%, and at least moderate depressive symptoms by 24.3%. Higher ACE-8 scores were associated with greater perceived stress, anxiety symptoms, and depressive symptoms and lower psychological well-being ({beta} = 0.063, 0.089, 0.116, and -0.100, respectively); corresponding associations for higher ASRS-6 scores were {beta} = 0.299, 0.355, 0.390, and -0.260. Loneliness-specific indirect associations were positive for perceived stress, anxiety, and depressive symptoms (ACE-8: {beta} = 0.023-0.034; ASRS-6: {beta} = 0.043-0.075) and negative for psychological well-being (ACE-8: {beta} = -0.039; ASRS-6: {beta} = -0.089; all p < .001). Social support-specific indirect associations were not significant in the ACE-8 model and were small and significant only for anxiety and depression in the ASRS-6 model ({beta} = 0.003-0.004). Conclusions: Psychological health among adults with irritable bowel syndrome was associated with interconnected individual and social factors within an adapted Stress Process Model. Childhood adversity and adult attention-deficit/hyperactivity disorder-related symptoms showed direct and indirect associations with psychological health, with loneliness emerging as the most consistent social factor. These findings support prospective investigation of individual vulnerabilities and social experiences in psychological health. The cross-sectional design does not establish temporal ordering or causal mediation.

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Divergent Eosinophilic and Paradoxical Inflammatory Adverse-Event Signatures Across Five Type 2 Asthma Biologics: A FAERS Active-Comparator Disproportionality Analysis

Iancu, A. C.; Kobtan, M.; Soliman, N.; Abdellatif, S.

2026-09-22 allergy and immunology 10.64898/2026.09.21.26363575 medRxiv
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Background: Five biologics target sequential nodes of the type 2 (T2) inflammatory axis in severe asthma and have each been anecdotally linked to eosinophilic or paradoxical inflammatory adverse events. Whether these reflect a class effect or drug-specific signatures is untested. Methods: We performed a case-noncase disproportionality analysis of FAERS, 2022-2024. Asthma-indication reports naming tezepelumab, dupilumab, mepolizumab, benralizumab, or omalizumab as primary suspect were compared against the pooled other four (active-comparator design) across 7 pre-specified eosinophilic, vasculitic (including EGPA), cutaneous, and ocular outcomes. A signal was robust if the reporting odds ratio (ROR) 95% CI lower bound exceeded 1 and a Bayesian criterion was also met. Results: Among 50,360 reports (dupilumab n=29,652; mepolizumab n=8,846; omalizumab n=5,484; benralizumab n=4,372; tezepelumab n=2,006), benralizumab showed robust signals for EGPA (ROR 5.06), vasculitis (ROR 4.60), and peripheral eosinophilia (ROR 1.80). Mepolizumab showed a robust vasculitis signal (ROR 1.85); its similarly sized EGPA association narrowly missed the robustness criterion despite significance after correction for multiple testing. Dupilumab showed no EGPA/vasculitis excess but a robust ocular-inflammation signal (ROR 7.81). Tezepelumab and omalizumab showed no robust signal in any domain. EGPA/vasculitis onset occurred earlier after dupilumab (median 20-44 days) than anti-IL-5-axis agents (median 195-550 days; p[&le;]0.012); mepolizumab's signal did not reproduce over the full 2015-2024 window (calendar-time confounding). Conclusion: FAERS active-comparator analysis reveals drug-specific, not class-uniform, adverse-event reporting patterns: anti-IL-5-axis agents disproportionately report EGPA/vasculitis, and dupilumab disproportionately reports ocular inflammation with markedly earlier onset. These hypothesis-generating signals cannot establish causality and require confirmation through case-level or comparative pharmacoepidemiological studies.

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The Impact of the Lab4 Probiotic on the Wellbeing of Healthcare Workers: An Exploratory, Double-Blind, Randomised, Placebo-Controlled Study

Dokic, D.; Jack, A. A.; Coates, N.; John, D. A.; Garaiova, I.; McDonald, J. A. K.; Marchesi, J. R.; Wang, D.; Plummer, S. F.; Michael, D. R.

2026-10-01 nutrition 10.64898/2026.09.29.26364268 medRxiv
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Healthcare workers face substantial occupational demands and exposure to respiratory infections during winter, but evidence that probiotics improve their health and wellbeing remains limited. This exploratory, double-blind, randomised, placebo-controlled trial assessed whether daily Lab4 supplementation affected upper respiratory tract infection (URTI) frequency and supported wellbeing in 104 healthcare workers. Daily diaries recorded symptoms defining URTI episodes, general-practitioner visits, illness-related work absence and antibiotic use. Wellbeing was assessed at baseline and weeks 8 and 16, and faecal microbiota were assessed using 16S rRNA gene sequencing. Participants receiving Lab4 reported better wellbeing than those receiving placebo. For probiotic versus placebo, the risk ratio (RR) for URTI occurrence was 0.60 (95% confidence interval [CI]: 0.30-1.20; p=0.1477), the incidence rate ratio (IRR) for episodes was 0.58 (95% CI: 0.27-1.23; p=0.1581), and the mean ratio for episode duration was 0.98 (95% CI: 0.72-1.32; p=0.8776). For general-practitioner visits, the RR for at least one visit was 0.48 (95% CI: 0.21-1.07; p=0.0737) and the IRR was 0.44 (95% CI: 0.18-1.06; p=0.0677). For illness-related work absence, the RR for at least one day absent was 0.75 (95% CI: 0.18-3.22; p=0.6991) and the IRR for absence days was 0.74 (95% CI: 0.16-3.32; p=0.6914). For antibiotic use, the RR for any use was 0.48 (95% CI: 0.20-1.18; p=0.1111) and the IRR for antibiotic-use days was 0.42 (95% CI: 0.16-1.12; p=0.0820). No significant between-group differences in gut microbiota were detected in the subset providing faecal samples. Illness-related estimates generally favoured Lab4, although between-group differences were not statistically significant. These exploratory findings support evaluation in a larger, prospectively powered trial.

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A detectability floor for treatment-response labels in rheumatology transcriptomics

Yang, H.; Huang, Y.; Xu, J.; Zhang, S.; Liao, R.

2026-10-06 rheumatology 10.64898/2026.10.04.26364671 medRxiv
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Objectives. Before-and-after transcriptomics in rheumatic disease often yields no reproducible treatment signal, though disease-state stratification is robust. We asked whether exposure and response-prediction labels fall below the detection floor of the designs defining them, while matched disease-state labels do not. Methods. Eight public datasets were analysed (paired juvenile dermatomyositis n = 10; RA before/after methotrexate, n = 28 pairs; lupus nephritis n = 10; controlled exposures; a single-cell dose series). Response labels in current use (one benchmark trajectory, five published signatures) were audited in every analysable source cohort, using effect sizes (dz) against each design's exact minimum detectable effect. Results. Disease-state labels were detectable: the interferon signature declined in 10/10 juvenile dermatomyositis patients (p = 0.002; 59.5% of score variance). No exposure label cleared its design floor in any clinical cohort; a drug-matched methotrexate prior was nominally significant in juvenile dermatomyositis yet did not clear its floor (dz = -0.80; CI spanning it). Exposure became detectable only where prior-context and intensity were jointly favourable (multi-day target tissue dz = 1.24, q = 0.018; well-level pseudobulk dz = +3.70, floor 1.80). Audited response labels failed in 14 of 15 cohorts (93%; descriptive binomial 95% CI 68-100): eleven below their floors, three sign-reversed; the largest training cohort pooled to zero (dz = +0.07; I2 = 69%). Effect size ordered reported AUCs monotonically. Conclusion. Under conventional treatment intensities, exposure and response-prediction labels are either undetectable below the design floor or detected with a sign that does not replicate; disease-state labels are detectable. Part of the negative literature reflects a design floor.