Active Colitis Research Articles

Lower vitamin D levels are associated with the pathogenesis of inflammatory bowel diseases.

Vitamin D plays a role in regulating immune homeostasis, inflammation and has an impact on the pathogenesis of inflammatory bowel diseases (IBD). IBD has a multifactorial pathogenesis primarily associated with immune dysregulation, dysbiosis, structurally altered intestinal mucosa, and genetic factors. The immunomodulatory function of this vitamin is linked to its control over innate and adaptive immunity, facilitated through its nuclear vitamin D receptor, leading to the inhibition of nuclear factor kappa-B. This study aimed to investigate serum vitamin D levels in patients with IBD compared to healthy individuals and to evaluate the relationship between vitamin D and inflammatory markers. Cross-sectional study. The study included 106 participants divided into 2 groups: patients with IBD (92), and healthy controls (14). The diagnosis of IBD was based on clinical, laboratory, fecal, endoscopic, and histological findings, following the European guidelines for diagnosis and follow-up ECCO-ESGAR guidelines for diagnostic assessment of IBD from 2019. Serum vitamin D levels were measured along with laboratory tests, imaging, and endoscopic examinations. IBD activity was evaluated using the Montreal classification and clinical and endoscopic indices. Data analysis involved calculating the mean, minimum, and maximum values, standard deviation, and Pearson coefficient. The level of statistical significance for this study was set at P < .05. The study found a prevalence of vitamin D deficiency in 32.6% of patients with IBD, while 66.3% had insufficiency, as compared with healthy individuals. The mean levels of vitamin D in UC and CD were 16 ± 8.6 ng/mL, whereas in the control healthy group, they were 26 ± 9.73 ng/mL. A statistically significant reverse correlation was observed between lower vitamin D levels and higher levels of the inflammatory markers. The study concluded that IBD patients exhibit lower levels of vitamin D, which is associated with inflammation and may contribute to the pathogenesis of the disease.

Astragalus polysaccharide protects experimental colitis through an aryl hydrocarbon receptor-dependent autophagy mechanism.

Disruption of intestinal barriers plays a vital role in the pathogenesis of colitis. The aryl hydrocarbon receptor (AhR) is a recognition sensor that mediates intestinal immune homeostasis and minimizes intestinal inflammation. Astragalus polysaccharide (APS) exerts pharmacological actions in colitis; however, the mechanism has not been elucidated. We investigated whether APS protects through AhR-dependent autophagy. The symptoms of dextran sulfate sodium (DSS)-induced colitis in mice involving intestinal barrier function and inflammatory injury were evaluated after APS administration. Intestinal-specific Becn1 conditional knockout (Becn1 cKO) mice were constructed and compared with wild-type mice. Autophagy and the effects of APS were investigated after the deactivation of AhRs. The relationship between APS-induced AhRs and autophagic Becn1 was investigated using a dual-luciferase reporter system and chromatin immunoprecipitation (ChIP)-quantitative polymerase chain reaction assay. Caco-2 cells were used to investigate inflammatory responses and AhR-dependent autophagy. APS improved intestinal barrier function in inflammatory injury in colitis mice. APS triggered autophagic flow; however, knockout of Becn1 in the gut increased susceptibility to colitis, leading to diminished epithelial barrier function and severe intestinal inflammation, impairing the protective effects of APS. Mechanistically, APS-triggered autophagy depends on AhR expression. Activated AhR binds to the promoter Becn1 to operate transcription of genes involved in anti-inflammation and intestinal barrier repair, while deactivation of AhR correlated with intestinal inflammation and the therapeutic function of APS. APS protects colitis mice by targeting autophagy, especially as the AhR stimulates the repair of damaged intestinal barrier functions.

Deep Learning Models Capture Histological Disease Activity in Crohn's Disease and Ulcerative Colitis with High Fidelity.

Histological disease activity in inflammatory bowel disease [IBD] is associated with clinical outcomes and is an important endpoint in drug development. We developed deep learning models for automating histological assessments in IBD. Histology images of intestinal mucosa from phase 2 and phase 3 clinical trials in Crohn's disease [CD] and ulcerative colitis [UC] were used to train artificial intelligence [AI] models to predict the Global Histology Activity Score [GHAS] for CD and Geboes histopathology score for UC. Three AI methods were compared. AI models were evaluated on held-back testing sets, and model predictions were compared against an expert central reader and five independent pathologists. The model based on multiple instance learning and the attention mechanism [SA-AbMILP] demonstrated the best performance among competing models. AI-modelled GHAS and Geboes subgrades matched central readings with moderate to substantial agreement, with accuracies ranging from 65% to 89%. Furthermore, the model was able to distinguish the presence and absence of pathology across four selected histological features, with accuracies for colon in both CD and UC ranging from 87% to 94% and for CD ileum ranging from 76% to 83%. For both CD and UC and across anatomical compartments [ileum and colon] in CD, comparable accuracies against central readings were found between the model-assigned scores and scores by an independent set of pathologists. Deep learning models based upon GHAS and Geboes scoring systems were effective at distinguishing between the presence and absence of IBD microscopic disease activity.

Psychometric validation of the French Multidimensional Chronic Asthenia Scale (MCAS) in a sample of 621 patients with chronic fatigue

BackgroundPsychometric validation of the Multidimensional Chronic Asthenia Scale (MCAS) was conducted in order to provide an effective tool for assessing the health-related quality of life of French-speaking patients with chronic asthenia (CA).MethodsItems resulting from the initial formulation of the self-reported MCAS (along with other materials) were completed by French-speaking volunteers with inactive or active inflammatory bowel disease (IBD-I vs. IBD-A) or chronic fatigue syndrome (CFS). Responses from 621 participants (180 patients with IBD-A, 172 with IBD-I, 269 with CFS) collected in a single online survey were divided into three subsamples to test the construct validity of the MCAS (Step 1, N = 240), to confirm its factorial structure (Step 2, N = 204) and to explore its convergent-discriminant validity with the Fatigue Symptoms Inventory (FSI) and revised Piper Fatigue Scale (r-PFS, Step 3, N = 177).ResultsSteps 1 and 2 showed that, as expected, MCAS has four dimensions: feeling of constraint (FoC), physical (PC), life (LC) and interpersonal consequences (IC), which are also related to the duration of CA (i.e., the longer it lasts, the more the dimensions are impacted). The results further showed that the MCAS is sensitive enough to capture between-group differences, with the CFS group being the most impaired, followed by IBD-A and IBD-I. While convergent-discriminant validity between the 4 factors of MCAS and FSI and r-PFS, respectively, was satisfactory overall, Step 3 also pointed to some limitations that call for future research (e.g., shared variances between the PC and IC dimensions of MCAS and behavioral dimension of r-PFS).ConclusionDespite these limitations, the MCAS clearly constitutes a promising tool for measuring quantitative differences (i.e., severity/intensity) in CA associated with various diseases, but also, and importantly, the clinically important differences in domains of its expression (i.e., qualitative differences).

The Effect of Serotonin Transmission on Depressive and Insomnia Symptoms in Inflammatory Bowel Diseases.

The serotonergic pathway may impact the pathogenesis and the course of inflammatory bowel diseases (IBDs). The aim of this study was to investigate the relationship between 5-HT, the serotonin transporter (SERT), and the clinical course of the disease with the occurrence of sleep and mood disorders. Participants completed sleep questionnaires and the Beck Depression Inventory (BDI). Serum 5-HT, SERT protein expression, and mRNA levels were quantified. Additionally, patients treated with anti-TNF therapy were examined before and after treatment. In this study, 77 patients with IBD and 41 healthy controls (HCs) were enrolled and 24 of them were treated with anti-TNF therapy. Patients with IBD had higher 5-HT levels and SERT protein expression than the HCs, but not mRNA SERT levels (p = 0.015, p = 0.001, p = 0.069, respectively). Similar results were obtained for patients in the active state of the disease compared to the non-active state. There was a positive relationship between insomnia severity and SERT protein expression. BDI did not correlate with serotonin or SERT. After anti-TNF therapy, only 5-HT levels were decreased. 5-HT and SERT protein are overexpressed in active IBD and may represent a candidate for novel disease activity biomarkers. The correlation between the SERT protein level and the severity of insomnia symptoms might be among the underlying biochemical factors of sleep disturbances. Anti-TNF treatment might contribute to the reduction in 5-HT levels.

"Clinicians Are From Mars and Pathologists Are From Venus" Revisited: Synoptic Reports Improve Clinician Comprehension of Pathology Reports in Inflammatory Bowel Disease.

A prior study in this journal, "Clinicians Are from Mars and Pathologists Are From Venus," demonstrated that clinicians can erroneously interpret pathology reports up to 30% of the time. After noticing reporting heterogeneity in the setting of inflammatory bowel disease (IBD), we speculated that a standardized synoptic report could improve gastroenterologist comprehension. To investigate the effect of a synoptic table on gastroenterologist comprehension of IBD pathology reports. We recruited gastroenterology fellows and faculty to participate in this study. All participants were given 6 pathology reports and asked if the following were present: active inflammation, chronic inflammation, IBD, and dysplasia. Participants were also asked to rate their confidence. After a 6-week washout period, the same questionnaire was distributed with a synoptic report. We performed paired t-tests to compare the mean accuracy and confidence scores between the preintervention and postintervention responses. A total of 39 physicians participated: 9 fellows and 30 faculty. Mean accuracy scores were higher after the intervention (0.81 versus 0.86; P < .001). Mean confidence was also higher after intervention, but this was not statistically significant (3.91 versus 3.98; P = .24). The improvement in accuracy scores after intervention confirms that clinician comprehension improved with the synoptic table. A synoptic report may provide a standardized way of communicating diagnostic information to clinicians in the setting of IBD and potentially other inflammatory conditions.

Modificación de la dosis de mesalazina en función de los niveles de calprotectina fecal en pacientes con colitis ulcerosa en remisión clínica

BackgroundFaecal calprotectin (FC) shows an excellent correlation with endoscopic and histological activity of ulcerative colitis (UC) and it is the best predictor of clinical relapse. Our aim was to evaluate the usefulness of modifying the dose of mesalazine based on FC levels, in clinical practice. MethodsRetrospective, single-centre study in UC patients in clinical remission while treated with mesalazine which dosage was decreased (DOWN) or increased (UP) according to FC levels. The main endpoint was the long-term maintenance of clinical remission. ResultsA total of 56 patients were included (39 DOWN, 17 UP). In the DOWN group, the median baseline dose of mesalazine was 3.6g/day and the median baseline FC was 36μg/g. After a median follow-up of 22 months, 28% required rescue therapy. The cumulative relapse-free survival after tapering was 91% and 82% at 12 and 24 months, respectively. In the UP group, the median baseline dose of mesalazine was 2.4g/day, with a median baseline FC of 524μg/g. After a median follow-up of 12 months, 29% required rescue therapy. The cumulative relapse-free survival after dose increase was 86% and 72% at 12 and 24 months, respectively. ConclusionsMesalazine dose modification based on FC monitoring seems to be a safe strategy in patients with UC in clinical remission, with a probability of clinical relapse around 20% at two years.

Incidence and disease-related risk factors for cerebrovascular accidents in patients with inflammatory bowel diseases: A systematic review and meta-analysis.

Risk of cerebrovascular accidents (CVAs) in patients with inflammatory bowel disease (IBD) remains inconclusive. In this systematic review and meta-analysis, we aimed to estimate the incidence of and identify the risk factors for CVA in patients with IBD. PubMed, EMBASE and Web of Science were searched for articles published up to January 13, 2023 to identify those reported the incidence of CVA in IBD patients, along with the total person-years or related data to calculate it. The main outcomes were the incidence of and risk factors for CVA in IBD. Based on the analysis of 10 studies, the pooled incidence of CVA in IBD patients was 2.74 per 1000 person-years (95% confidence interval [CI] 1.83-4.10 person-years; I2 = 99.2%), which was higher than that in the general population (incidence rate ratio [IRR] 1.21, 95% CI 1.09-1.34, P = 0.0002; I2 = 84.8%). Risk factors for CVA in IBD patients were age (significance in different definitions), ulcerative colitis (IRR 1.214, 95% CI 1.000-1.474, P = 0.0499; I2 = 81.9%), disease flares (IRR 1.699, 95% CI 1.359-2.122, P < 0.0001; I2 = 28.7%) and chronic activity (IRR 2.202, 95% CI 1.378-3.519, P = 0.0010; I2 = 83.0%). The risk of CVA modestly increased in IBD patients. Both the traditional and IBD-related risk factors should be managed to prevent CVA in these patients. Since the effects of risk factors were derived from pooled results of only 2-3 studies, further research is needed to confirm our results.

S3231 Use of Adalimumab During a Crohn’s Flare Up in the Setting of Active Cytomegalovirus Colitis

S3231 Use of Adalimumab During a Crohn’s Flare Up in the Setting of Active Cytomegalovirus Colitis

S1518 Effect of Inflammatory Bowel Disease Activity on Liver Transplantation Outcome in Patients With Primary Sclerosing Cholangitis

S1518 Effect of Inflammatory Bowel Disease Activity on Liver Transplantation Outcome in Patients With Primary Sclerosing Cholangitis

A Digital Health Intervention to Improve the Clinical Care of Inflammatory Bowel Disease Patients.

Inflammatory bowel disease (IBD) is a chronic condition that requires close monitoring. Digital health virtual care platforms can enable self-monitoring and allow providers to remotely surveil patients and efficiently identify those with active disease. The primary aim was to design and implement an IBD remote monitoring program, identify predictors of patient engagement, and determine who found the chat to be a valuable tool. We developed the IBD Virtual Care Chat, an electronic health record (EHR)-integrated chat to monitor electronic patient reported outcomes (ePROs), medication changes, and disease activity, and subsequently report concerning findings to providers via the EHR. All patients in the IBD practice over age 18 with a clinical encounter in the preceding 12 months were eligible to be enrolled. The primary aim was to identify predictors of patient engagement and determine who found the chat to be a valuable tool. Between May 2021 and March 2022, 2,934 patients were enrolled. A total of 1,160 engaged at least once and 687 (23.4%) continually engaged, submitting at least three ePROs. Disease severity (based on Harvey-Bradshaw Index or Simple Clinical Colitis Activity Index) did not impact ePRO submissions. Patients were significantly more likely to be continually engaged if they self-reported the presence of extraintestinal manifestations (7%, 95% confidence interval: 0.01-0.14; p = 0.04). Patient satisfaction remained moderately high with a median score of 8 (interquartile range: 5-10) on a scale of 1 (poor) to 10 (good). Our program demonstrates the potential for EHR-integrated digital health as part of routine IBD care to achieve sustained engagement with high patient satisfaction.

S1178 Appendiceal Histologic Inflammation Correlates With the Extent of Active Colitis in Patients With Ulcerative Colitis

S1178 Appendiceal Histologic Inflammation Correlates With the Extent of Active Colitis in Patients With Ulcerative Colitis

The Efficacy of Cichorium intybus L., Trigonella foenum-graecum L. and Foeniculum vulgare Mill. in Improvement of Ulcerative Colitis Symptoms: A Randomized Clinical Trial

Due to the lack of favorable response to synthetic drugs, the tendency to use traditional medicine to treat inflammatory bowel disease has risen. We aimed to assess the effect of Cichorium intybus L., Trigonella foenum-graecum L., and Foeniculum vulgare L. on the control of recurrent ulcerative colitis (UC) symptoms. This randomized clinical trial was performed on 60 patients suffering from mild-to-moderate UC. Patients were randomly assigned to control and intervention groups. Patients in both groups were treated with a standard dose of oral mesalazine (3 g daily) for eight weeks. In addition, the intervention group was given a mixture of 200 mg C. intybus, 350 mg T. foenum-graecum, and 1.5 mg F. vulgare (three times a day). The disease activity was evaluated before and 60 days after the intervention using a simple clinical colitis activity index (SCCAI). The baseline mean SCCAI score was similar in both groups. Although the SCCAI score significantly reduced in both groups 60 days after the initial assessment, this reduction was significantly higher in the group receiving the herbal combination than in the control group. The intervention-related side effects, such as bloating and dyspepsia, were well tolerated. The use of C. intybus, T. foenum-graecum, and F. vulgare can effectively control UC symptoms and thus, can be used as an effective and safe medication for treating UC.&#x0D;

Factors contributing to flares of ulcerative colitis in North India- a case-control study

BackgroundUlcerative colitis is a relapsing and remitting disease that may be associated with flares. The causes of flares in the Indian setting are not well recognized.MethodsThe present prospective case-control study was conducted at a single center in North India. Cases were defined as patients admitted for flare of ulcerative colitis, while controls were patients in remission enrolled from the outpatient department. The basis of the diagnosis of flare was a simple clinical colitis activity index (SCCAI) of ≥ 5 and endoscopic activity, while remission was based on SCCAI < 4 and a normal fecal calprotectin. A questionnaire evaluating recent infections, stress, drug intake (antibiotics, pain medication), adherence to therapy, and use of complementary and alternative therapy (CAM) was administered.ResultsWe included 84 patients (51 with flare and 33 in remission) with a median age of 38 years, of whom 47 (55.9%) were males. The two groups were similar for baseline parameters, including age (38, 23–50 and 38, 25.5–48.5 years), male gender (52.9% and 60.6%), extent of disease, extraintestinal manifestations (21.6% and 12.1%), use of 5-aminosalicylates (76.5% and 90.9%). The thiopurine use was lower in those having a flare (15.7% and 36.4%). Amongst the predictors of flare, the recent infections (39.2% and 30.3%), recent travel (31.4 and 27.3%), eating outside food (47.1% and 39.4%), consumption of milk products (88.2% and 75.8%), use of pain medication (43.1% and 33.3%) and recent stress (62.7% and 60.6%) were similar between cases and controls. The rates of antibiotic use (29.4% and 6.1%), lack of adherence (50.9% and 15.2%), and intake of CAM (70.6% and 33.3%) were higher in those with flare. Patients attributed a lack of adherence to the cost of therapy, presumed cure (due to lack of symptoms), and fear of adverse effects.ConclusionLack of adherence to inflammatory bowel disease therapies and recent CAM and antibiotic intake was higher in patients with flares of UC. The study makes ground for educational intervention(s) promoting knowledge and adherence to IBD therapies.

Plasminogen Activator Inhibitor 1 Is a Novel Faecal Biomarker for Monitoring Disease Activity and Therapeutic Response in Inflammatory Bowel Diseases.

Crohn's disease [CD] and ulcerative colitis [UC] require lifelong treatment and patient monitoring. Current biomarkers have several limitations; therefore, there is an unmet need to identify novel biomarkers in inflammatory bowel disease [IBD]. Previously, the role of plasminogen activator inhibitor 1 [PAI-1] was established in the pathogenesis of IBD and suggested as a potential biomarker. Therefore, we aimed to comprehensively analyse the selectivity of PAI-1 in IBD, its correlation with disease activity, and its potential to predict therapeutic response. Blood, colon biopsy, organoid cultures [OC], and faecal samples were used from active and inactive IBD patients and control subjects. Serpin E1 gene expressions and PAI-1 protein levels and localisation in serum, biopsy, and faecal samples were evaluated by qRT-PCR, ELISA, and immunostaining, respectively. The study population comprised 132 IBD patients [56 CD and 76 UC] and 40 non-IBD patients. We demonstrated that the serum, mucosal, and faecal PAI-1 concentrations are elevated in IBD patients, showing clinical and endoscopic activity. In responders [decrease of eMayo ≥3 in UC; or SES-CD 50% in CD], the initial PAI-1 level decreased significantly upon successful therapy. OCs derived from active IBD patients produced higher concentrations of PAI-1 than the controls, suggesting that epithelial cells could be a source of PAI-1. Moreover, faecal PAI-1 selectively increases in active IBD but not in other organic gastrointestinal diseases. The serum, mucosal, and faecal PAI-1 concentration correlates with disease activity and therapeutic response in IBD, suggesting that PAI-1 could be used as a novel, non-invasive, disease-specific, faecal biomarker in patient follow-up.

Focal Active Colitis: What Are Its Clinical Implications? A Narrative Review.

Focal active colitis (FAC) is described as a histolopathological term indicating the isolated finding of focal neutrophil infiltration in the colonic crypts. Currently, there exist numerous debates regarding the clinical significance of diagnosing FAC, which may or may not have clinical relevance as it is frequently detected in colorectal biopsies without any other microscopic abnormalities. The objective of this narrative review is to provide an overview of the available evidence concerning the clinical implications of FAC, both in the adult population (among five studies available in the scientific literature) and in the pediatric context (based on two available studies).

High prevalence of Mucosa-Associated extended-spectrum β-Lactamase-producing Escherichia coli and Klebsiella pneumoniae among Iranain patients with inflammatory bowel disease (IBD)

BackgroundSeveral pieces of evidence suggest that certain pathobionts belonging to Enterobacterales are associated with the development and progression of inflammatory bowel diseases (IBD). Extended-spectrum β-lactamases (ESBLs) ESBLs are frequently found in the Enterobacterales members, particularly in Escherichia coli and Klebsiella spp., and might trigger antibiotic-induced perturbations of the intestinal microbiota and led to more severe disease activity in IBD. Therefore, the severity of IBD could be influenced by ESBL-producing Enterobacterales, and hence, this study aimed to investigate the presence of ESBLs and carbapenemases among mucosa-associated E. coli and Klebsiella pneumoniae isolated from colonic biopsies of Iranian patients with IBD.MethodsIn this cross-sectional study, E. coli and K. pneumoniae were isolated from inflamed ileum and/or colon tissue of patients with IBD, including Ulcerative colitis (UC) and Crohn’s disease (CD), during colonoscopy. Demographic data and clinical characteristics were recorded, and UC and CD disease activity and extent were evaluated according to the full Mayo score and Crohn’s disease activity index (CDAI), respectively. Phenotypic and molecular detection of ESBL- and carbapenemase-producing E. coli and Klebsiella pneumoniae were carried out. Disease activity and other clinical and microbial features were compared in patients with and without gut colonization with ESBL producers.ResultsA total of 83 IBD patients, including 67 UC and 16 CD, were enrolled in the initial analysis. Intestinal colonization with ESBL-producing E. coli and/or Klebsiella pneumoniae was found in 37 (55.2%) of UC and 9 (56.2%) of DC patients – mostly harbored E. coli containing the blaCTX−M and blaTEM genes. UC patients with intestinal colonization with ESBL-producers had more severe disease compared with patients without colonization. Moreover, 10.2% of tested E. coli and 34.8% of K. pneumoniea were recognized as potential carbapenemase producers.ConclusionIntestinal colonization with ESBL producers could arise disease activity in IBD patients. Further large-scale case-control studies should be performed to investigate the possible confounding factors that could contribute to this outcome.

Role of Serum Interleukin-6, Interleukin-1β and Interleukin-10 in Assessment of Disease Activity and Nutritional Status in Patients with Inflammatory Bowel Disease.

Inflammatory bowel diseases (IBD) are characterised by multifactorial and chronic inflammation. Much attention has been paid to immune dysfunction in inflammatory bowel diseases. The aim of this study was to assess the usefulness of serum IL-6, IL-1β and IL-10 in determining the activity and nutritional status in IBD patients. The case-control study was carried out on 82 patients with IBD; the control group consisted of 25 clinically healthy subjects. The serum concentrations of IL-6, IL-1 β and IL-10 were determined by the quantitative sandwich enzyme-linked immunosorbent assay. There were no significant differences in IL-6 and IL-1β levels in UC and CD patients according to disease activity as assessed by the Montreal classification, Partial Mayo Score and CDAI. Significantly higher IL-6 levels were found in patients with low body fat in comparison to patients with normal body fat. Furthermore, significantly higher mean IL-6 levels were observed in patients with excess body fat in comparison to patients with normal body fat, and also in comparison to patients with deficient body fat. IL-6 and IL-1β may provide extra information regarding the nutritional status of IBD patients. IL-10 can be considered a non-invasive biomarker of IBD activity.

Diabetes exacerbates inflammatory bowel disease in mice with diet-induced obesity.

The increased prevalence of inflammatory bowel disease (IBD) among patients with obesity and type 2 diabetes suggests a causal link between these diseases, potentially involving the effect of hyperglycemia to disrupt intestinal barrier integrity. To investigate whether the deleterious impact of diabetes on the intestinal barrier is associated with increased IBD severity in a murine model of colitis in mice with and without diet-induced obesity. Mice were fed chow or a high-fat diet and subsequently received streptozotocin to induce diabetic-range hyperglycemia. Six weeks later, dextran sodium sulfate was given to induce colitis. In select experiments, a subset of diabetic mice was treated with the antidiabetic drug dapagliflozin prior to colitis onset. Endpoints included both clinical and histological measures of colitis activity as well as histochemical markers of colonic epithelial barrier integrity. In mice given a high-fat diet, but not chow-fed animals, diabetes was associated with significantly increased clinical colitis activity and histopathologic markers of disease severity. Diabetes was also associated with a decrease in key components that regulate colonic epithelial barrier integrity (colonic mucin layer content and epithelial tight junction proteins) in diet-induced obese mice. Each of these effects of diabetes in diet-induced obese mice was ameliorated by restoring normoglycemia. In obese mice, diabetes worsened clinical and pathologic outcomes of colitis via mechanisms that are reversible with treatment of hyperglycemia. Hyperglycemia-induced intestinal barrier dysfunction offers a plausible mechanism linking diabetes to increased colitis severity. These findings suggest that effective diabetes management may decrease the clinical severity of IBD.

ALDH1A Inhibition Suppresses Colitis and Alters α4β7 Integrin Expression on Activated T Cells in Mdr1a-/- Mice.

There are limited pharmacological treatment options for inflammatory bowel disease (IBD), and some of these options are expensive and administered by injection or infusion. Thus, new cheaper and easier (oral) treatment options are needed. ALDH1A enzymes produce retinoic acid that can affect intestinal diseases such as IBD by regulating immune cells in the gut. We previously demonstrated that an orally deliverable ALDH1A inhibitor, WIN 18,466, can suppress colitis in an acute mouse model of IBD. Here, we tested the efficacy of ALDH1A inhibition in a chronic mouse model of IBD. Mdr1a-/- mice were treated with a diet containing WIN 18,446 starting 1 week prior to inducing colitis by H. bilis inoculation. Treatment was continued until the study end point and colitis was monitored based on clinical symptoms and confirmed by histological analysis. Immune cell phenotypes in colon-draining lymph nodes (cMLN) were analyzed. WIN 18,446 treatment reduced clinical symptoms and improved histopathologic colitis scores. This was associated with decreased expression of the gut homing integrin, α4β7, on T cells in cMLN; increased expression of CD103, a protein associated with tissue-resident memory T cells; and changes in dendritic cells, plasmacytoid dendritic cells and B cells in inhibitor-treated mice. ALDH1A inhibition broadly influences immune cells during colitis and is a potential new target for IBD treatment. Future studies will be needed to determine the efficacy of ALDH1A inhibition on active colitis and to evaluate its relative efficacy in comparison to approved drugs.