Johannes Reiner

The current standard of care for the definitive surgical treatment of complicative ulcerative colitis is a continence-preserving proctocolectomy with the creation of an ileal pouch anal anastomosis. In addition to structural and functional disorders, pouchitis of the J-pouch is a common phenomenon, typically well responsive to antimicrobial therapy. However, sometimes chronic antibiotic-refractory pouchitis occurs, most often due to not completely understood multifactorial pathomechanisms. While high-quality evidence is available only for anti-integrin therapy, the role of advanced therapy, i.e., cytokine-antibodies or small molecules in the treatment of chronic antibiotic-refractory pouchitis (CARP), is emerging.This case demonstrates a successful induction treatment of CARP with the novel p19-selective IL-23-targeted antibody mirikizumab.

Ileocecal resection (ICR) is frequently performed in Crohn’s disease (CD). NOD2 mutations are risk factors for CD. Nod2 knockout (ko) mice show impaired anastomotic healing after extended ICR. We further investigated the role of NOD2 after limited ICR. C57B16/J (wt) and Nod2 ko littermates underwent limited ICR including 1–2 cm terminal ileum and were randomly assigned to vehicle or MDP treatment. Bursting pressure was measured on POD 5, and the anastomosis was analyzed for matrix turn-over and granulation tissue. Wound fibroblasts from subcutaneously implanted sponges were used for comparison. The M1/M2 macrophage plasma cytokines were analyzed. Mortality was not different between groups. Bursting pressure was significantly decreased in ko mice. This was associated with less granulation tissue but was not affected by MDP. However, anastomotic leak (AL) rate tended to be lower in MDP-treated ko mice (29% vs. 11%, p = 0.07). mRNA expression of collagen-1α (col1 α), collagen-3α (col3 α), matrix metalloproteinase (mmp)2 and mmp9 was increased in ko mice, indicating increased matrix turn-over, specifically in the anastomosis. Systemic TNF-α expression was significantly lower in ko mice. Ileocolonic healing is impaired in Nod2 ko mice after limited ICR by local mechanisms maybe including local dysbiosis.

Short bowel syndrome can occur after extensive intestinal resection, causing intestinal insufficiency or intestinal failure, which requires long‐term parenteral nutrition. Glucagon‐like peptide‐2 (GLP‐2) pharmacotherapy is now clinically used to reduce the disease burden of intestinal failure. However, many patients still cannot be weaned off from parenteral nutrition completely. The novel dual GLP‐1 and GLP‐2 receptor agonist dapiglutide has previously been shown to be highly effective in a preclinical murine short bowel model. Here, we studied the effects of dapiglutide on intestinal epithelial barrier function. In the jejunum, dapiglutide increased claudin‐7 expression and tightened the paracellular tight junction leak pathway. At the same time, dapiglutide promoted paracellular tight junction cation size selectivity in the jejunum. This was paralleled by extension of the cation selective tight junction proteins claudin‐2 and claudin‐10b and preserved claudin‐15 expression and localization along the crypt–villus axis in the jejunum. In the colon, no barrier effects from dapiglutide were observed. In the colon, dapiglutide attenuated the short bowel–associated, compensatorily increased epithelial sodium channel activity, likely secondary, by improved volume status. Future studies are needed to address the intestinal adaptation of the colon.

Background: Extensive intestinal resection may lead to short bowel (SB) syndrome, resulting in intestinal insufficiency or intestinal failure (IF). Intestinal insufficiency and IF involve deficiency of the proglucagon‐derived hormones glucagon‐like peptide‐1 (GLP‐1) and GLP‐2. Two major problems of SB are epithelial surface loss and accelerated transit. Standard treatment now targets intestinal adaptation with a GLP‐2 analogue to enlarge absorptive surface area. It is possible that additional benefit can be gained from a combination of GLP‐1 and GLP‐2 activity, with the aim to enlarge intestinal surface area and slow intestinal transit.Methods: The GLP‐1– and GLP‐2–specific effects of the novel dual GLP‐1 receptor (GLP‐1R) and GLP‐2 receptor (GLP‐2R) agonist dapiglutide (rINN) were characterized in rodents. Furthermore, in a murine SB model of intestinal insufficiency with 40% ileocecal resection, the influence of dapiglutide on intestinal growth, body weight, food intake, volume status, and stool water content was tested against vehicle and sham‐operated male mice.Results: Dapiglutide significantly improves oral glucose tolerance, reduces intestinal transit time, and promotes intestinal growth. In the SB mouse model, dapiglutide promotes body weight recovery, despite unchanged intake of liquid diet. Dapiglutide promotes significant intestinal growth, as indicated by significantly increased villus height as well as intestinal length. Furthermore, dapiglutide reduces stool water losses, resulting in reduced plasma aldosterone.Conclusion: Dapiglutide possesses specific and potent GLP‐1R and GLP‐2R agonist effects in rodents. In the murine SB model, combined unimolecular GLP‐1R and GLP‐2R stimulation with dapiglutide potently attenuates intestinal insufficiency and potentially also IF.

Intestinal failure (IF) requires parenteral support (PS) substituting energy, water, and electrolytes to compensate intestinal losses and replenish deficits. Convalescence, adaptation, and reconstructive surgery facilitate PS reduction. We analyzed the effect of changes of PS on body mass index (BMI) in early adult IF. Energy, volume, and sodium content of PS and BMI were collected at the initial contact (FIRST), the time of maximal PS and BMI (MAX) and the last contact (LAST). Patients were categorized based on functional anatomy: small bowel enterostomy—group 1, jejuno-colic anastomosis—group 2. Analysis of variance was used to test the relative impact of changes in energy, volume, or sodium. Total of 50 patients were followed for 596 days. Although energy, volume, and sodium support were already high at FIRST, we increased PS to MAX, which was accompanied by a significant BMI increase. Thereafter PS could be reduced significantly, leading to a small BMI decrease in group 1, but not in group 2. Increased sodium support had a stronger impact on BMI than energy or volume. Total of 13 patients were weaned. Dynamic PS adjustments are required in the early phase of adult IF. Vigorous sodium support acts as an independent factor.

Background In short bowel syndrome, epithelial surface loss results in impaired nutrient absorption and may lead to intestinal insufficiency or intestinal failure. Nucleotide oligomerization domain 2 (Nod2) dysfunction predisposes to the development of intestinal failure after intestinal resection and is associated with intestinal barrier defects. Epithelial barrier function is crucial for intestinal absorption and for intestinal adaptation in the short bowel situation. Aims The aim of the study was to characterize the effects of the GLP-2 analogue Teduglutide in the small intestine in the presence and absence of Nod2 in a mouse model of short bowel syndrome. Methods Mice underwent 40% ICR and were thereafter treated with Teduglutide versus vehicle injections. Survival, body weight, stool water, and sodium content and plasma aldosterone concentrations were determined. Intestinal and kidney tissue was examined with light and fluorescence microscopy, Ussing chamber studies and quantitative PCR in wild type and transgenic mice. Results Teduglutide reduced intestinal failure incidence in Nod2 k.o. mice. In wt mice, Teduglutide attenuated intestinal insufficiency as indicated by reduced body weight loss and lower plasma aldosterone concentrations, lower stool water content, and lower stool sodium losses. Teduglutide treatment was associated with enhanced epithelial paracellular pore function and enhanced claudin-10 expression in tight junctions in the villus tips, where it colocalized with sodium–glucose cotransporter 1 (SGLT-1), which mediates Na-coupled glucose transport. Conclusions In the SBS situation, Teduglutide not only maximizes small intestinal mucosal hypertrophy but also partially restores small intestinal epithelial function through an altered distribution of claudin-10, facilitating sodium recirculation for Na-coupled glucose transport and water absorption.

Short bowel syndrome results from extensive small bowel resection and induces adaptation of the remaining intestine. Ileocecal resection (ICR) is the most frequent situation in humans. Villus hypertrophy is one hallmark of mucosal adaptation, but the functional mechanisms of mucosal adaptation are incompletely understood.