A Novel Microbial Dysbiosis Index and Intestinal Microbiota-Associated Markers as Tools of Precision Medicine in Inflammatory Bowel Disease Paediatric Patients.

Recent evidence indicates that the gut microbiota (GM) has a significant impact on the inflammatory bowel disease (IBD) progression. Our aim was to investigate the GM profiles, the Microbial Dysbiosis Index (MDI) and the intestinal microbiota-associated markers in relation to IBD clinical characteristics and disease state. We performed 16S rRNA metataxonomy on both stools and ileal biopsies, metabolic dysbiosis tests on urine and intestinal permeability and mucosal immunity activation tests on the stools of 35 IBD paediatric patients. On the GM profile, we assigned the MDI to each patient. In the statistical analyses, the MDI was correlated with clinical parameters and intestinal microbial-associated markers. In IBD patients with high MDI, Gemellaceae and Enterobacteriaceae were increased in stools, and Fusobacterium, Haemophilus and Veillonella were increased in ileal biopsies. Ruminococcaceae and WAL_1855D were enriched in active disease condition; the last one was also positively correlated to MDI. Furthermore, the MDI results correlated with PUCAI and Matts scores in ulcerative colitis patients (UC). Finally, in our patients, we detected metabolic dysbiosis, intestinal permeability and mucosal immunity activation. In conclusion, the MDI showed a strong association with both severity and activity of IBD and a positive correlation with clinical scores, especially in UC. Thus, this evidence could be a useful tool for the diagnosis and prognosis of IBD.

Clinical Characteristics and Etiology of Terminal Ileum Ulcers: A Retrospective Study.

Terminal ileal ulcers can have various etiologies, including Crohn's disease (CD), infections, and medication-related causes. This study aims to investigate the incidence of terminal ileal ulcers detected during colonoscopies, explore their underlying causes, and analyze their clinical, endoscopic, and histopathological characteristics. Additionally, the study aims to identify predictive factors that indicate the need for follow-up. Medical records of all patients who underwent colonoscopies, between 2009 and 2019 were retrospectively reviewed. Patients with terminal ileal ulcers, with or without ileocecal valve involvement, were included in the study. Demographic information, medication usage, symptoms, colonoscopy findings, and histopathological data of these patients were analyzed. A total of 398 patients were included in the study. Histopathological examination revealed that 243 patients (61%) had active ileitis, and 69 patients (17.4%) had chronic active ileitis. The final diagnoses for ulcers were: nonspecific ulcers in 212 patients (53.3%), CD in 66 patients (16.6%), and non-steroidal anti-inflammatory drug-induced ulcers in 58 patients (14.6%). In the multivariate analysis, the parameters predicting CD included the presence of 10 or more ulcers (odds ratio (OR) = 7.305), deep ulcers (OR = 7.431), and edematous surrounding tissue (OR = 5.174), all of which were statistically significant (P < .001). Upon final evaluation, only 66 patients (16.6%) were diagnosed with CD, while 212 patients (53.3%) had nonspecific ulcers. The majority of patients with healed ulcers exhibited pathological findings consistent with active ileitis. Therefore, it can be concluded that not all terminal ileal ulcers are indicative of CD. In those cases with active ileitis, repetitive colonoscopies should be reconsidered.

Identification and multimodal characterization of a specialized epithelial cell type associated with Crohn's disease.

Crohn's disease (CD) is a complex chronic inflammatory disorder with both gastrointestinal and extra-intestinal manifestations associated immune dysregulation. Analyzing 202,359 cells from 170 specimens across 83 patients, we identify a distinct epithelial cell type in both terminal ileum and ascending colon (hereon as 'LND') with high expression of LCN2, NOS2, and DUOX2 and genes related to antimicrobial response and immunoregulation. LND cells, confirmed by in-situ RNA and protein imaging, are rare in non-IBD controls but expand in active CD, and actively interact with immune cells and specifically express IBD/CD susceptibility genes, suggesting a possible function in CD immunopathogenesis. Furthermore, we discover early and late LND subpopulations with different origins and developmental potential. A higher ratio of late-to-early LND cells correlates with better response to anti-TNF treatment. Our findings thus suggest a potential pathogenic role for LND cells in both Crohn's ileitis and colitis.

Quercetin and ibuprofen combination displayed anti-inflammatory effects and also extenuates the enteric neurons damage of arthritic rats.

This study aimed to investigate the antioxidant and anti-inflammatory properties of quercetin on the cellular components of the Enteric Nervous System in the ileum of rats with arthritis. Rats were distributed into five groups: control (C), arthritic (AIA), arthritic treated with ibuprofen (AI), arthritic treated with quercetin (AQ) and arthritic treated with both ibuprofen and quercetin (AIQ). The ileum was processed for immunohistochemical techniques for HuC/D, calcitonin gene-related peptide, and vasoactive intestinal polypeptide. Measurements in histological sections, chemiluminescence assays, and total antioxidant capacity were also performed. Rheumatoid arthritis resulted in a decrease in neuronal density, yet neuroplasticity mechanisms were evident through observed changes in varicosities size and neuronal area compared to the control group. Reduced paw edema and neuroprotective effects were predominantly noted in both plexuses, as evidenced by the increased density preservation of HuC/D-IR neurons in the AIQ group. The increase of lipoperoxidation levels and paw edema volume in the AQ group was observed compared to the arthritic, whereas the AIQ group mainly showed similar results to those observed in the control. The enteropathy associated with arthritis proved to be significant in the field of gastroenterology, and the combination of quercetin and ibuprofen demonstrated promising anti-inflammatory and neuroprotective effects.

Chronic abdominal distention caused by diffuse nodular ileal and mesenteric lipomatosis: A case report.

RATIONALE: Diffuse intestinal and mesenteric lipomatosis is a rare condition characterized by the overgrowth of adipose tissue in the intestines and mesentery. This case report aims to highlight the rare occurrence of chronic abdominal distention caused by this disease and its unique invasion into the muscle layer, which has not been previously reported. PATIENT CONCERNS: A 36-year-old woman with a 7-year history of abdominal distension was admitted to our hospital's Department of Gastrointestinal Surgery. DIAGNOSE: Abdominal and pelvic computed tomography revealed diffuse small intestinal lipomatosis. INTERVENTIONS: The patient underwent surgery. We performed an open-field ilectomy involving removal of all lipomatous intestines (250 cm). OUTCOMES: During the surgery, diffuse nodular ileal and mesenteric lipomatosis was confirmed, characterized by the presence of multiple nodular lipomas within the submucosal and muscular layers. The surgical intervention involved the resection of 250 cm of the affected ileum, followed by jejunoileal anastomosis. Postoperative pathology confirmed the diagnosis, with lesions observed in both the submucosa and muscle layers. The patient showed significant improvement in symptoms, with normal intestinal function and weight gain observed over a 10-month follow-up period, and no signs of recurrence. LESSONS: Diffuse intestinal and mesenteric lipomatosis can lead to long-term abdominal distension. Additionally, it may be involved in the muscle layer of the intestinal wall. Surgery is the primary treatment option for symptomatic intestinal lipomatosis.

Intestinal duplication in a miniature Schnauzer dog.

A 9-week-old miniature Schnauzer dog was brought to a veterinary clinic because of an acute onset of vomiting. A 2 to 3-centimeter, round, firm structure in the mid-abdomen was palpated with a repeatable pain response. An exploratory laparotomy revealed a grossly cystic-appearing mass on the distal ileum. Resection and anastomosis were conducted. The histopathology report concluded the structure was an intestinal duplication, a rare congenital abnormality, with the structure sharing an outer muscular layer with the normal intestine. The resection was considered completely excised. The puppy recovered well and was clinically normal on follow-up examinations. The findings from this case suggest congenital abnormalities should always be included on a differential diagnosis list for all young animals, regardless of the presenting complaint.

Duplication intestinale chez un Schnauzer miniatureUn Schnauzer miniature âgé de 9 semaines a été présenté à une clinique vétérinaire pour cause d'apparition de vomissements aigus. Une structure ferme et ronde, de 2 à 3 cm de diamètre au milieu de l'abdomen était palpée avec une réponse à la douleur répétée. Une laparotomie exploratoire a révélé la présence d'une masse d'apparence kystique sur l'iléon distal. Une résection et une anastomose ont été effectuées. Le rapport d'histopathologie concluait que la structure était une duplication intestinale, une anomalie congénitale rare, et que la structure partageait une couche musculaire externe avec l'intestin normal. La résection a été considérée comme complètement excisée. Le chiot a bien récupéré et était cliniquement normal lors des examens de suivi. Les trouvailles dans le cas présent suggèrent que les anomalies congénitales devraient toujours être incluses dans la liste des diagnostics différentiels pour les jeunes animaux, indépendamment de la raison pour la consultation.(Traduit par Dr Serge Messier).

Fibrosis-Related microRNAs in Crohn's Disease with Fibrostenosis and Inflammatory Stenosis.

Crohn's disease (CD) is frequently complicated by strictures that can be either inflammatory or fibrostenotic. This distinction is important for deciding the best treatment course, but it can be difficult to determine clinically, sometimes even by advanced imaging techniques. We performed miRNA PCR panel screening on pooled samples of ileum with CD fibrostenosis or inflammatory stenosis. Eight miRNAs with profibrotic (miR-93-5p, miR-376c-3p and miR-424-5p), or fibroprotective (miR-133a-3p, miR-133b, miR-193a-5p, miR-335-5p and miR-378a-3p) functions described in the literature were selected for validation on 20 samples each of CD with fibrostenosis or inflammatory stenosis, with a separate sampling of the submucosa and subserosa. The results showed significant differences between the groups in subserosal samples, with upregulation of profibrotic miRNAs and downregulation of fibroprotective miRNAs in fibrostenosis compared to inflammatory stenosis. Only miR-424-5p showed a significant difference in the submucosa. There were significant differences in miRNA expression between subserosa and submucosa. Our results provide further evidence that the major differences between fibrostenosis and inflammatory stenosis are located in the subserosa, which is inaccessible to endoscopic sampling, highlighting the need for cross-sectional imaging or serological markers. We identify several miRNAs previously not connected to fibrosis in CD, which could potentially serve as biomarkers of fibrostenosis.

Polypoid heterotopic gastric mucosa: in terminal ileum causing extensive lower gastrointestinal bleeding without Meckel's diverticulum: a case report.

BACKGROUND: Heterotopic gastric mucosa (HGM) can be located in various parts of the gastrointestinal tract. As a rare anomaly in the small intestine, it can become complicated by intussusception, obstruction, gastrointestinal bleeding, and even peritonitis, leading to death. CASE PRESENTATION: This case report focuses on a 12-year-old Middle Eastern boy who presented with hematochezia and abdominal pain for a couple of days. A tagged Red blood cell (RBC) scan and Technetium scan revealed gastrointestinal bleeding at the lower abdomen, highly suggestive of the diagnosis of Meckel's diverticulum. Subsequently, exploratory laparotomy revealed contiguous and scattered mucosal lesions with multiple polyps of various sizes in the terminal ileum. Meckel's diverticulum was absent, and the patient was treated with resection and primary anastomosis. The resected tissue revealed extensive ectopic gastric mucosa and polypoid tissues. The patient recovered uneventfully and was discharged four days after the surgery. The symptoms did not recur within six months after his surgery. CONCLUSION: Our case demonstrated that despite the rarity of multiple polypoid gastric heterotopias in the terminal ileum, it should be considered as one of the differential diagnoses of gastrointestinal tract bleeding.

Identifying the importance of PCK1 in maintaining ileal epithelial barrier integrity in Crohn's disease.

BACKGROUND: Crohn's disease (CD) is marked by disruption of intestinal epithelial barrier, with unclear underlying molecular mechanisms. This study aimed to investigate key genes regulating the intestinal barrier in CD patients. METHODS: Differential gene expression analysis and gene set enrichment analysis were conducted to identify potential key genes involved in CD within the GEO database. Single-cell RNA sequencing from ileum samples in GSE134809 of 59,831 inflamed and uninflamed cells from 11 CD patients and microarray data from ileal tissues in GSE69762 (3 controls and 4 CD patients) and GSE75214 (11 controls and 51 CD patients) with GSE179285 (49 uninflamed and 33 inflamed from CD patients) as the validation set. Protein-protein interaction and logistic regression analyses identified key downregulated genes in CD. A key gene was then investigated through immunohistochemistry of ileal tissues from 5 CD patients and in the Caco-2 cell line with RNA interference and treatment with IFN-γ and TNF-α to stimulate inflammation. RESULTS: Single-cell RNA-seq identified 33 genes and microarray identified 167 genes with significant downregulation in inflamed CD samples. PCK1 was identified and validated as one of the most promising candidate genes. Reduced PCK1 expression was evident in inflamed ileal tissues. In vitro, knockdown of PCK1 resulted in decreased cell viability, increased apoptosis, and reduced nectin-2 production, while combination of IFN-γ and TNF-α significantly reduced PCK1. CONCLUSIONS: PCK1 is downregulated in inflamed ileal tissues of CD patients and may be a key factor in maintaining epithelial integrity during inflammation in Crohn's disease.

Effect of mesenteric sparing or extended resection in primary ileocolic resection for Crohn's disease on postoperative endoscopic recurrence (SPICY): an international, randomised controlled trial.

BACKGROUND: Retrospective research suggests that excision of the affected mesentery can improve outcomes after an ileocoecal resection in Crohn's disease. However, prospective data from randomised controlled trials are scarce. We aimed to compare rates of postoperative recurrence in patients with Crohn's disease who underwent extended mesenteric resection. METHODS: This international, randomised controlled trial was done in six hospitals and tertiary care centres in the Netherlands and Italy. Eligible patients were aged 16 years or older and had Crohn's disease that was previously confirmed by endoscopy in the terminal ileum or ileocolic region (L1 or L3 disease), with an imaging update in the past 3 months (ultrasound, MRI, or CT enterography). Eligible patients were scheduled to undergo primary ileocolic resection with ileocolic anastomosis. Enrolled patients were assigned by use of simple random allocation (1:1) to either extended mesenteric resection (intervention) or conventional mesenteric sparing resection (control). The primary endpoint was endoscopic recurrence 6 months after surgery. Analyses were done in all patients with primary endpoint data, excluding those who had no anastomosis, a postoperative diagnosis other than Crohn's disease, or withdrew consent. This trial was registered with ClinicalTrials.gov, NCT04538638. FINDINGS: Between Feb 19, 2020, and April 24, 2023, we assessed 217 patients for eligibility. 78 patients were excluded due to failure to meet the inclusion criteria or refusal to participate. 139 patients were enrolled and randomly assigned to either extended mesenteric resection (n=71) or mesenteric sparing resection (n=68). All 139 patients underwent surgery. Six patients were excluded after random assignment due to withdrawal of consent (n=2), postoperative diagnosis other than Crohn's disease (n=2) and no anastomosis performed (in case of a stoma; n=2). Two patients were lost to follow-up, and two more patients deviated from the protocol by undergoing investigations other than endoscopy 6 months after. 133 patients were included in the baseline analysis (67 in the extended resection group and 66 in the sparing resection group) of whom 57 (43%) were male. Baseline characteristics were similar between the groups, and median patient age was 36 years (IQR 25-54). 131 patients were analysed for the primary outcome. There was no difference between groups in the rate of endoscopic recurrence at 6 months after surgery (28 [42%] of 66 patients in the extended mesenteric resection group vs 28 [43%] of 65 patients in the mesenteric sparing resection group, relative risk 0·985, 95% CI 0·663-1·464; p=1·0). Five (8%) of 66 patients in the extended mesenteric resection group had anastomotic leakage within the 30 days after surgery, as did one (2%) of 65 in the mesenteric sparing group. Postoperative complications of Clavien-Dindo grade IIIa or higher were reported in seven (11%) patients in the mesenteric resection group and five (8%) in the mesenteric sparing group. INTERPRETATION: Extended mesenteric resection was not superior to conventional resection with regard to endoscopic Crohn's disease recurrence. These data support the guideline-recommended mesenteric sparing approach. FUNDING: Topconsortia voor Kennis en Innovatie-Topsector Life Sciences & Health.

Exploring the Effects of an Alfalfa Leaf-Derived Adsorbent on Microbial Community, Ileal Morphology, Barrier Function, and Immunity in Turkey Poults during Chronic Aflatoxin B1 Exposure.

This article follows-up on our recently published work, which evaluated the impact of the addition of an alfalfa leaf-derived adsorbent in the aflatoxin B1 (AFB1)-contaminated diet in regard to the production parameters, blood cell count, serum biochemistry, liver enzymes, and liver histology of turkey poults. This paper presents complementary results on microbial community, ileal morphology, barrier function, and immunity. For this purpose, 350 1-day-old female turkey poults were randomly distributed into five groups: (1) Control, AFB1-free diet; (2) AF, AFB1-contaminated diet at 250 ng/g; (3) alfalfa, AFB1-free diet + 0.5% (w/w) adsorbent; (4) alfalfa + AF, AFB1-contaminated diet at 250 ng/g + 0.5% (w/w) adsorbent; and (5) YCW + AF, AFB1-contaminated diet at 250 ng/g + 0.5% (w/w) commercial yeast cell wall-based adsorbent (reference group). In general, in the AF group, the growth of opportunistic pathogens was promoted, which lead to gut dysbacteriosis, mainly influenced by Streptococcus lutetiensis. Conversely, a significant increase in beneficial bacteria (Faecalibacterium and Coprococcus catus) was promoted by the addition of the plant-based adsorbent. Moreover, the AF group had the lowest villus height and a compromised barrier function, as evidenced by a significant (p < 0.05) increase in fluorescein isothiocyanate dextran (FITC-d), but these negative effects were almost reversed by the addition of the alfalfa adsorbent. Furthermore, the AF + YCW and alfalfa + AF groups exhibited a significant increase in the cutaneous basophil hypersensitivity response compared to the rest of the experimental groups. Taken together, these results pointed out that the alfalfa counteracts the adverse effects of AFB1 in poults, facilitating the colonization of beneficial bacteria and improving the barrier function of the turkey poults.

Intercellular interaction between FAP+ fibroblasts and CD150+ inflammatory monocytes mediates fibrostenosis in Crohn's disease.

Crohn's disease (CD) is marked by recurring intestinal inflammation and tissue injury, often resulting in fibrostenosis and bowel obstruction, necessitating surgical intervention with high recurrence rates. To elucidate the mechanisms underlying fibrostenosis in CD, we analyzed the transcriptome of cells isolated from the transmural ileum of patients with CD, including a trio of lesions from each patient: non-affected, inflamed, and stenotic ileum samples, and compared them with samples from patients without CD. Our computational analysis revealed that profibrotic signals from a subset of monocyte-derived cells expressing CD150 induced a disease-specific fibroblast population, resulting in chronic inflammation and tissue fibrosis. The transcription factor TWIST1 was identified as a key modulator of fibroblast activation and extracellular matrix (ECM) deposition. Genetic and pharmacological inhibition of TWIST1 prevents fibroblast activation, reducing ECM production and collagen deposition. Our findings suggest that the myeloid-stromal axis may offer a promising therapeutic target to prevent fibrostenosis in CD.

TWIST1+FAP+ fibroblasts in the pathogenesis of intestinal fibrosis in Crohn's disease.

Intestinal fibrosis, a severe complication of Crohn's disease (CD), is characterized by excessive extracellular matrix (ECM) deposition and induces intestinal strictures, but there are no effective antifibrosis drugs available for clinical application. We performed single-cell RNA sequencing (scRNA-Seq) of fibrotic and nonfibrotic ileal tissues from patients with CD with intestinal obstruction. Analysis revealed mesenchymal stromal cells (MSCs) as the major producers of ECM and the increased infiltration of its subset FAP+ fibroblasts in fibrotic sites, which was confirmed by immunofluorescence and flow cytometry. Single-cell transcriptomic profiling of chronic dextran sulfate sodium salt murine colitis model revealed that CD81+Pi16- fibroblasts exhibited transcriptomic and functional similarities to human FAP+ fibroblasts. Consistently, FAP+ fibroblasts were identified as the key subtype with the highest level of ECM production in fibrotic intestines. Furthermore, specific knockout or pharmacological inhibition of TWIST1, which was highly expressed by FAP+ fibroblasts, could significantly ameliorate fibrosis in mice. In addition, TWIST1 expression was induced by CXCL9+ macrophages enriched in fibrotic tissues via IL-1ß and TGF-ß signal. These findings suggest the inhibition of TWIST1 as a promising strategy for CD fibrosis treatment.

The potential therapeutic effects of exosomes derived from bone marrow mesenchymal stem cells on ileum injury of a rat sepsis model (histological and immunohistochemical study).

Sepsis denotes a serious high mortality concern. The study was designed to evaluate the effect of mesenchymal stem cell exosomes (MSC-exosomes) on the evolution of the animal model of sepsis. In this study, 36 rats were distributed into three groups, (I) controls, (II) LPS-treated, and (III) LPS+MSC-EVs. Sepsis was simulated by administering E. coli-LPS to the laboratory animals. Group III was given MSC-exosomes four hours after the LPS injection. Forty-eight hours later rats were sacrificed. Ileum samples were excised, and processed for the histological assessment, immunohistochemical identification of CD44, and inducible nitric oxide synthase (iNOS). Ileum homogenate was used to estimate tumor necrosis factor α (TNF α) besides Cyclooxygenase-2 (COX 2). PCR was used for the detection of interleukin 1α (IL­1α), and interleukin 17 (IL­17). Statistical and morphometrical analysis was done. The LPS-treated group showed increased TNF-α, IL­1α, IL­17, and decreased COX 2. LPS administration led to cytoplasmic vacuolization of enterocytes, an increase in the vasculature, and cellular infiltrations invaded the lamina propria. There was a significant rise in goblet cells and the proportion of collagen fibers. Ultrastructurally, the enterocytes displayed nuclear irregularity, rough endoplasmic reticulum (rER) dilatation, and increased mitochondria number. Sepsis induces a significant increase in iNOS and a decrease in CD44 immune expressions. LPS+MSC-EVs group restored normal ileum structure and revealed a significant elevation in CD44 and a reduction in iNOS immunoreactions. LPS-sepsis induced an obvious ileum inflammatory deterioration ameliorated by MSC-exosomes, mostly through their antioxidant, anti-inflammatory, and anti-apoptotic properties.

The effect of ileal resection length on postoperative complications and prognosis in right colon cancer.

BACKGROUND: There is a lack of literature on the length of the terminal ileum to be resected in right hemicolectomy for colon cancer. Therefore, we aimed to determine the mean ileal loop length and the effect of this variation on postoperative complications and long-term oncological outcomes in patients who underwent right hemicolectomy. METHODS: Right hemicolectomy surgeries performed for colon cancer in a tertiary care hospital between January 2011 and December 2018 were retrospectively analyzed from a prospective database. Two patient groups were established based on the mean length of the resected ileum above and below 7 cm. The two groups were compared for clinicopathological data, postoperative complications, mortality, long-term overall survival (OS) and disease-free survival (DFS). The factors contributing to OS and DFS were analyzed. RESULTS: The study included 217 patients. Body mass index (BMI) values were significantly higher in the ileum resection length > 7 cm group (p = 0.009). Pathological N stage, tumor diameter, and number of metastatic lymph nodes were significantly higher in the ileum resection length > 7 cm group (p = 0.001, p = 0.001, and p = 0.026, respectively). There was no significant difference for postoperative complication and mortality rates between the two groups. The mean follow-up period was 61.2 months (2-120) in all patients. The total number of deaths was 29 (11.7%) while the 60-month OS was 83.5% and 50-month DFS was 81.8%. There was no significant difference between the groups in terms of OS and DFS rates (p > 0.05). CONCLUSIONS: Excessive resection of the distal ileum in right hemicolectomy does not provide any benefit in terms of prognosis and complications.The ileum resection length and values close to it in our study appear to be sufficient.

Chronic skin damage induces small intestinal damage via IL-13-induced apoptosis.

The gut-skin axis has recently been widely recognized, and both the gut and skin have been found to affect each other through a bidirectional connection; however, the precise mechanisms remain to be elucidated. Therefore, we aimed to investigate the effects of chronic skin damage (CSD) on mouse intestines. Following the CSD model, 4% sodium dodecyl sulfate was applied to the back-shaved murine skin six times for 2 weeks after tape stripping. The small and large intestines were analyzed histologically and immunologically, respectively. Intestinal permeability was measured using fluorescein isothiocyanate-conjugated-dextran. The role of interleukin-13 (IL-13) in the ileum was investigated using an anti-IL-13 antibody. Apoptotic intestinal cells were analyzed using TUNEL staining. Villus atrophy was observed in the small intestine in the CSD model, along with increased permeability. Mast cells, but not T cells, eosinophils, or innate lymph cell-2, were increased in the intestinal mucosa. However, no significant changes were observed in the large intestine. mRNA expression of IL-13 was increased only in the ileum of the CSD model. Apoptotic intestinal epithelial cells were significantly increased in the ileum of the CSD model. Administration of an anti-IL-13 antibody ameliorated the intestinal damage caused by CSD, along with decreased apoptotic cells and mast cell infiltration. Skin damage causes morphological changes in the small intestine, accompanied by increased intestinal permeability, possibly through the IL-13-induced apoptosis of mast cells in the epithelium. Surfactant-mediated mechanical skin damage can cause a leaky gut.