Translocation of Viable Gut Microbiota to Mesenteric Adipose Drives Formation of Creeping Fat in Humans

Surgical treatment of inflammatory bowel disease: From the gastroenterologist’s stand-point

Treatment of ulcerative colitis (UC) and Crohn’s disease (CD) represents, in the majority of cases, a real challenge to the gastroenterologist’s abilities and skills as well as a clinical test concerning his/her levels of medical knowledge and experience. During the last two decades, our pharmaceutical arsenal was significantly strengthened, especially after the introduction of the so-called biological agents, drugs which to a large extent not only improved the results of conservative treatment but also changed the natural history of the disease. However, colectomy is still necessary for some patients with severe UC although smaller compared to the past, precisely because of the improvements achieved in the available conservative treatment. Nevertheless, surgeries to treat colon dysplasia and cancer are increasing to some extent. At the same time, satisfactory improvements in surgical techniques, the pre-and post-operative care of patients, as well as the selection of the appropriate time for performing the surgery have been noticed. Regarding patients with CD, the improvement of conservative treatment did not significantly change the need for surgical treatment since two-thirds of patients need to undergo surgery at some point in the course of their disease. On the other hand, the outcome of the operation has improved through good preoperative care as well as the wide application of more conservative surgical techniques aimed at keeping as much of the bowel in situ as possible. This article discusses the indications for surgical management of UC patients from the gastroenterologist’s point of view, the results of the emerging new techniques such as transanal surgery and robotics, as well as alternative operations to the classic ileo-anal-pouch anastomosis. The author also discusses the basic principles of surgical management of patients with CD based on the results of the relevant literature. The self-evident is emphasized, that is, to achieve an excellent therapeutic result in patients with severe inflammatory bowel disease in today’s era; the close cooperation of gastroenterologists with surgeons, pathologists, imaging, and nutritionists is of paramount importance.

Adipose tissue as a linchpin of organismal ageing

Ageing is a conserved biological process, modulated by intrinsic and extrinsic factors, that leads to changes in life expectancy. In humans, ageing is characterized by greatly increased prevalence of cardiometabolic disease, type 2 diabetes and disorders associated with impaired immune surveillance. Adipose tissue displays species-conserved, temporal changes with ageing, including redistribution from peripheral to central depots, loss of thermogenic capacity and expansion within the bone marrow. Adipose tissue is localized to discrete depots, and also diffusely distributed within multiple organs and tissues in direct proximity to specialized cells. Thus, through their potent endocrine properties, adipocytes are capable of modulating tissue and organ function throughout the body. In addition to adipocytes, multipotent progenitor/stem cells in adipose tissue play a crucial role in maintenance and repair of tissues throughout the lifetime. Adipose tissue may therefore be a central driver for organismal ageing and age-associated diseases. Here we review the features of adipose tissue during ageing, and discuss potential mechanisms by which these changes affect whole-body metabolism, immunity and longevity. We also explore the potential of adipose tissue-targeted therapies to ameliorate age-associated disease burdens.

Gut symbionts alleviate MASH through a secondary bile acid biosynthetic pathway

The gut microbiota has been found to play an important role in the progression of metabolic dysfunction-associated steatohepatitis (MASH), but the mechanisms have not been established. Here, by developing a click-chemistry-based enrichment strategy, we identified several microbial-derived bile acids, including the previously uncharacterized 3-succinylated cholic acid (3-sucCA), which is negatively correlated with liver damage in patients with liver-tissue-biopsy-proven metabolic dysfunction-associated fatty liver disease (MAFLD). By screening human bacterial isolates, we identified Bacteroides uniformis strains as effective producers of 3-sucCA both in vitro and in vivo. By activity-based protein purification and identification, we identified an enzyme annotated as β-lactamase in B. uniformis responsible for 3-sucCA biosynthesis. Furthermore, we found that 3-sucCA is a lumen-restricted metabolite and alleviates MASH by promoting the growth of Akkermansia muciniphila. Together, our data offer new insights into the gut microbiota-liver axis that may be leveraged to augment the management of MASH.

Spatial features of skip lesions in Crohn's disease

Skip lesions are an enigmatic spatial feature characterizing Crohn's disease (CD). They comprise inflamed and adjacent non-inflamed tissue sections with a clear demarcation. Currently, spatial features of the human gastrointestinal (GI) system lack clarity regarding the organization of microbes, mucus, tissue, and host cells during inflammation. New technologies with multiplexing abilities and innovative approaches provide ways of examining the spatial organization of inflamed and non-inflamed tissues in CD, which may open new avenues for diagnosis, prognosis, and treatment. In this review, we present evidence of the relevance of spatial context in patients with CD and the methods and ideas recently published in studies of spatiality during inflammation. With this review, we aim to provide inspiration for further research to address existing gaps.

The Expanding Problem of Regional Adiposity: Revisiting a 1985 Diabetes Classic by Ohlson et al

Body fat distribution is a predictor of metabolic health in obesity. In this Classics in Diabetes article, we revisit a 1985 Diabetes article by Swedish investigators Ohlson et al. This work was one of the first prospective population-based studies that established a relationship between abdominal adiposity and the risk for developing diabetes. Here, we discuss evolving concepts regarding the link between regional adiposity and diabetes and other chronic disorders. Moreover, we highlight fundamental questions that remain unresolved.

Mesenteric-based surgery for Crohn's disease: evidence and perspectives

Postoperative anastomotic recurrence of Crohn's disease is challenging and can lead to symptom recurrence and further surgery. The mesenteric pole of the intestine is the initial site of macroscopic anastomotic recurrence, and the mesentery may play an important role in recurrence after surgical resection. Therefore, "mesenteric-based surgery" has gained increasing attention by clinicians. However, the role of mesentery in the postoperative recurrence remains controversial. This review will examine mesenteric changes in Crohn's disease, proposed roles for mesentery in disease progression, and the potential for mesenteric-based surgery in the surgical management of Crohn disease.

Safety & feasibility of targeted mesenteric approaches with Kono-S anastomosis and extended mesenteric excision in ileocolic resection and anastomosis in Crohn's disease

BACKGROUND

The mesentery has recently been implicated in the pathophysiology of Crohn's disease (CD), and several techniques have been developed to target the mesentery to reduce its influence on recurrence. We aimed to describe short-term safety and feasibility after these approaches.

METHODS

This is a comparative, retrospective, single-center cohort study of consecutive CD patients undergoing primary or redo ileocolic resection from 2015 to 2022 with Kono-S anastomosis (KSA), extended mesenteric excision (EME) only, or both: mesenteric excision and exclusion (MEE).

RESULTS

186 patients underwent KSA (n ​= ​74), EME (n ​= ​66), or MEE (n ​= ​46). The groups had comparable baseline characteristics. The MEE group operative time was longer (median: 187 vs. KSA 170, EME 152 ​min, p ​< ​0.01). Postoperatively, the groups had similar lengths of stay (median 4 days), readmissions (9.1 ​%), major postoperative complications (6.5 ​%), and anastomotic leaks (1.1 ​%).

CONCLUSION

Targeting the mesentery with novel surgical approaches for ileocolic Crohn's disease was safe and feasible for short-term follow-up.

Recurrent Crohn's disease

Although surgical management of the ileocolic segment in pediatric Crohn's disease is not curative, the main goal of therapy is to allow for growth, adequate nutrition, and age-appropriate development. Recurrent disease at the site of anastomosis presents as a major morbidity. Several factors have been implicated in the development of surgical recurrence though data in the literature is scarce. This review explores the epidemiology of recurrent ileocolic disease following primary surgery, indications for surgical intervention, and techniques reported in the literature. Pediatric data is scarce, and therefore, much of it is extrapolated from adult literature.

Preventing fibrosis in IBD: update on immune pathways and clinical strategies

INTRODUCTION

Intestinal fibrosis is a common and serious complication of inflammatory bowel diseases (IBD) driving stricture formation in Crohn's disease patients and leading to submucosal damage in ulcerative colitis. Recent studies provided novel insights into the role of immune and nonimmune components in the pathogenesis of intestinal fibrosis. Those new findings may accelerate the development of anti-fibrotic treatment in IBD patients.

AREAS COVERED

This review is designed to cover the recent progress in mechanistic research and therapeutic developments on intestinal fibrosis in IBD patients, including new cell clusters, cytokines, proteins, microbiota, creeping fat, and anti-fibrotic therapies.

EXPERT OPINION

Due to the previously existing major obstacle of missing consensus on stricture definitions and the absence of clinical trial endpoints, testing of drugs with an anti-fibrotic mechanism is just starting in stricturing Crohn's disease (CD). A biomarker to stratify CD patients at diagnosis without any complications into at-risk populations for future strictures would be highly desirable. Further investigations are needed to identify novel mechanisms of fibrogenesis in the intestine that are targetable and ideally gut specific.

Inflammation and bacteriophages affect DNA inversion states and functionality of the gut microbiota

Reversible genomic DNA inversions control the expression of numerous gut bacterial molecules, but how this impacts disease remains uncertain. By analyzing metagenomic samples from inflammatory bowel disease (IBD) cohorts, we identified multiple invertible regions where a particular orientation correlated with disease. These include the promoter of polysaccharide A (PSA) of Bacteroides fragilis, which induces regulatory T cells (Tregs) and ameliorates experimental colitis. The PSA promoter was mostly oriented "OFF" in IBD patients, which correlated with increased B. fragilis-associated bacteriophages. Similarly, in mice colonized with a healthy human microbiota and B. fragilis, induction of colitis caused a decline of PSA in the "ON" orientation that reversed as inflammation resolved. Monocolonization of mice with B. fragilis revealed that bacteriophage infection increased the frequency of PSA in the "OFF" orientation, causing reduced PSA expression and decreased Treg cells. Altogether, we reveal dynamic bacterial phase variations driven by bacteriophages and host inflammation, signifying bacterial functional plasticity during disease.

Efficacy and safety of gut microbiota-based therapies in autoimmune and rheumatic diseases: a systematic review and meta-analysis of 80 randomized controlled trials

BACKGROUND

Previous randomized controlled trials (RCTs) suggested that gut microbiota-based therapies may be effective in treating autoimmune diseases, but a systematic summary is lacking.

METHODS

Pubmed, EMbase, Sinomed, and other databases were searched for RCTs related to the treatment of autoimmune diseases with probiotics from inception to June 2022. RevMan 5.4 software was used for meta-analysis after 2 investigators independently screened literature, extracted data, and assessed the risk of bias of included studies.

RESULTS

A total of 80 RCTs and 14 types of autoimmune disease [celiac sprue, SLE, and lupus nephritis (LN), RA, juvenile idiopathic arthritis (JIA), spondyloarthritis, psoriasis, fibromyalgia syndrome, MS, systemic sclerosis, type 1 diabetes mellitus (T1DM), oral lichen planus (OLP), Crohn's disease, ulcerative colitis] were included. The results showed that gut microbiota-based therapies may improve the symptoms and/or inflammatory factor of celiac sprue, SLE and LN, JIA, psoriasis, PSS, MS, systemic sclerosis, Crohn's disease, and ulcerative colitis. However, gut microbiota-based therapies may not improve the symptoms and/or inflammatory factor of spondyloarthritis and RA. Gut microbiota-based therapies may relieve the pain of fibromyalgia syndrome, but the effect on fibromyalgia impact questionnaire score is not significant. Gut microbiota-based therapies may improve HbA1c in T1DM, but its effect on total insulin requirement does not seem to be significant. These RCTs showed that probiotics did not increase the incidence of adverse events.

CONCLUSIONS

Gut microbiota-based therapies may improve several autoimmune diseases (celiac sprue, SLE and LN, JIA, psoriasis, fibromyalgia syndrome, PSS, MS, T1DM, Crohn's disease, and ulcerative colitis).

Metabolic network of the gut microbiota in inflammatory bowel disease

Gut dysbiosis is closely linked to the pathogenesis of inflammatory bowel disease (IBD). Emerging studies highlight the relationship between host metabolism and the modulation of gut microbiota composition through regulating the luminal microenvironment. In IBD, various disease-associated factors contribute to the significant perturbation of host metabolism. Such disturbance catalyzes the selective proliferation of specific microbial populations, particularly pathobionts such as adherent invasive Escherichia coli and oral-derived bacteria. Pathobionts employ various strategies to adapt better to the disease-associated luminal environments. In addition to the host-microbe interaction, recent studies demonstrate that the metabolic network between commensal symbionts and pathobionts facilitates the expansion of pathobionts in the inflamed gut. Understanding the metabolic network among the host, commensal symbionts, and pathobionts provides new insights into the pathogenesis of IBD and novel avenues for treating IBD.

Relationship between SIRI and android and gynoid fat related to obesity and cardiovascular risk: a cross-sectional study of NHANES 2017-2018

OBJECTIVE

Inflammation has a crucial role in several metabolic diseases, such as obesity. The author aimed to investigate the relationship between the system inflammation response index (SIRI) and android fat composition and distribution.

METHODS

Data for individuals aged 8-59 years, SIRI, android percent fat, and android-to-gynoid ratio from the 2017 to 2018 National Health and Nutrition Examination Survey were used. Weighted multiple linear regression and smooth curve fitting were used to test for linear and nonlinear associations. Additional subgroup analyses were performed. Threshold effect analysis was performed using a two-linear regression model.

RESULTS

Multiple linear regression showed a positive correlation between SIRI and android percent fat (β 0.92, 95% confidence interval [CI] 0.25-1.59) and between SIRI and the android-to-gynoid ratio (β 0.01, 95% CI 0.00-0.03) in 3783 Americans aged 8-59 years. The results showed that the effect of factors, other than smoking status, on the relationship between SIRI and android percent fat and android-to-gynoid ratio was not significant. There was a nonlinear relationship between SIRI and both android percent fat and android-to-gynoid ratio.

CONCLUSIONS

Elevated SIRI levels were associated with an increased android percent fat and android-to-gynoid ratio. Larger prospective studies are needed to validate the findings.

Computed tomography-based body composition parameters can predict short-term prognosis in ulcerative colitis patients

OBJECTIVES

Emerging evidence suggests a potential relationship between body composition and short-term prognosis of ulcerative colitis (UC). Early and accurate assessment of rapid remission based on conventional therapy via abdominal computed tomography (CT) images has rarely been investigated. This study aimed to build a prediction model using CT-based body composition parameters for UC risk stratification.

METHODS

In total, 138 patients with abdominal CT images were enrolled. Eleven quantitative parameters related to body composition involving skeletal muscle mass, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) were measured and calculated using a semi-automated segmentation method. A prediction model was established with significant parameters using a multivariable logistic regression. The receiver operating characteristic (ROC) curve was plotted to evaluate prediction performance. Subgroup analyses were implemented to evaluate the diagnostic efficiency of the prediction model between different disease locations, centers, and CT scanners. The Delong test was used for statistical comparison of ROC curves.

RESULTS

VAT density, SAT density, gender, and visceral obesity were significantly statistically different between remission and invalidation groups (all p < 0.05). The accuracy, sensitivity, specificity, and area under the ROC curve (AUC) of the prediction model were 82.61%, 95.45%, 69.89%, and 0.855 (0.792-0.917), respectively. The positive predictive value and negative predictive value were 70.79% and 93.88%, respectively. No significant differences in the AUC of the prediction model were found in different subgroups (all p > 0.05).

CONCLUSIONS

The predicting model constructed with CT-based body composition parameters is a potential non-invasive approach for short-term prognosis identification and risk stratification. Additionally, VAT density was an independent predictor for escalating therapeutic regimens in UC cohorts.

CRITICAL RELEVANCE STATEMENT

The CT images were used for evaluating body composition and risk stratification of ulcerative colitis patients, and a potential non-invasive prediction model was constructed to identify non-responders with conventional therapy for making therapeutic regimens timely and accurately.

KEY POINTS

• CT-based prediction models help divide patients into invalidation and remission groups in UC. • Results of the subgroup analysis confirmed the stability of the prediction model with a high AUC (all > 0.820). • The visceral adipose tissue density was an independent predictor of bad short-term prognosis in UC.

Transcriptomic Profiling and Cellular Composition of Creeping Fat in Crohn's disease

BACKGROUND AND AIMS

Creeping fat [CF] is a poorly understood feature of Crohn's disease [CD], characterized by the wrapping of mesenteric adipose tissue [MAT] around the inflamed intestine. The aim of this study was to investigate the transcriptional profile and compositional features of CF.

METHODS

We collected 59 MAT samples: 23 paired samples from patients with CD (CF [CD-CF] and MAT around the uninflamed intestine [CD-MAT]) and 13 MAT samples from non-CD patients [Con-MAT]. Differentially expressed gene [DEG], functional pathway, cell deconvolution, and gene co-expression network analyses were performed.

RESULTS

By comparing three different MAT samples, we identified a total of 529 DEGs [|log2FoldChange| > 1.5; false discovery rate < 0.05]. Of these, 323 genes showed an incremental pattern from Con-MAT to CD-MAT, and to CD-CF, while 105 genes displayed a decremental pattern. Genes with an incremental pattern were related to immune cell responses, including B- and T-cell activation, while genes with a decremental pattern were involved in cell trafficking and migration. Cell deconvolution analysis revealed significant changes in cellular composition between the CD-CF and Con-MAT groups, with increased proportions of B-cells/plasma cells [p = 1.16 × 10-4], T-cells [p = 3.66 × 10-3], and mononuclear phagocytes [p = 3.53 × 10-2] in the CD-CF group. In contrast, only the B-cell/plasma cell component showed a significant increase [p = 1.62 × 10-2] in the CD-MAT group compared to Con-MAT.

CONCLUSION

The distinct transcriptional profiles and altered cellular components of each MAT found in our study provide insight into the mechanisms behind CF and highlight its possible role in the pathogenesis of CD.

Integrated meta-omics reveals the regulatory landscape involved in lipid metabolism between pig breeds

BACKGROUND

Domesticated pigs serve as an ideal animal model for biomedical research and also provide the majority of meat for human consumption in China. Porcine intramuscular fat content associates with human health and diseases and is essential in pork quality. The molecular mechanisms controlling lipid metabolism and intramuscular fat accretion across tissues in pigs, and how these changes in response to pig breeds, remain largely unknown.

RESULTS

We surveyed the tissue-resident cell types of the porcine jejunum, colon, liver, and longissimus dorsi muscle between Lantang and Landrace breeds by single-cell RNA sequencing. Combining lipidomics and metagenomics approaches, we also characterized gene signatures and determined key discriminating markers of lipid digestibility, absorption, conversion, and deposition across tissues in two pig breeds. In Landrace, lean-meat swine mainly exhibited breed-specific advantages in lipid absorption and oxidation for energy supply in small and large intestinal epitheliums, nascent high-density lipoprotein synthesis for reverse cholesterol transport in enterocytes and hepatocytes, bile acid formation, and secretion for fat emulsification in hepatocytes, as well as intestinal-microbiota gene expression involved in lipid accumulation product. In Lantang, obese-meat swine showed a higher synthesis capacity of chylomicrons responsible for high serum triacylglycerol levels in small intestinal epitheliums, the predominant characteristics of lipid absorption in muscle tissue, and greater intramuscular adipcytogenesis potentials from muscular fibro-adipogenic progenitor subpopulation.

CONCLUSIONS

The findings enhanced our understanding of the cellular biology of lipid metabolism and opened new avenues to improve animal production and human diseases. Video Abstract.

Christensenella minuta interacts with multiple gut bacteria

Introduction

Gut microbes form complex networks that significantly influence host health and disease treatment. Interventions with the probiotic bacteria on the gut microbiota have been demonstrated to improve host well-being. As a representative of next-generation probiotics, Christensenella minuta (C. minuta) plays a critical role in regulating energy balance and metabolic homeostasis in human bodies, showing potential in treating metabolic disorders and reducing inflammation. However, interactions of C. minuta with the members of the networked gut microbiota have rarely been explored.

Methods

In this study, we investigated the impact of C. minuta on fecal microbiota via metagenomic sequencing, focusing on retrieving bacterial strains and coculture assays of C. minuta with associated microbial partners.

Results

Our results showed that C. minuta intervention significantly reduced the diversity of fecal microorganisms, but specifically enhanced some groups of bacteria, such as Lactobacillaceae. C. minuta selectively enriched bacterial pathways that compensated for its metabolic defects on vitamin B1, B12, serine, and glutamate synthesis. Meanwhile, C. minuta cross-feeds Faecalibacterium prausnitzii and other bacteria via the production of arginine, branched-chain amino acids, fumaric acids and short-chain fatty acids (SCFAs), such as acetic. Both metagenomic data analysis and culture experiments revealed that C. minuta negatively correlated with Klebsiella pneumoniae and 14 other bacterial taxa, while positively correlated with F. prausnitzii. Our results advance our comprehension of C. minuta's in modulating the gut microbial network.

Conclusions

C. minuta disrupts the composition of the fecal microbiota. This disturbance is manifested through cross-feeding, nutritional competition, and supplementation of its own metabolic deficiencies, resulting in the specific enrichment or inhibition of the growth of certain bacteria. This study will shed light on the application of C. minuta as a probiotic for effective interventions on gut microbiomes and improvement of host health.

Mucosal host-microbe interactions associate with clinical phenotypes in inflammatory bowel disease

Disrupted host-microbe interactions at the mucosal level are key to the pathophysiology of IBD. This study aimed to comprehensively examine crosstalk between mucosal gene expression and microbiota in patients with IBD. To study tissue-specific interactions, we perform transcriptomic (RNA-seq) and microbial (16S-rRNA-seq) profiling of 697 intestinal biopsies (645 derived from 335 patients with IBD and 52 from 16 non-IBD controls). Mucosal gene expression patterns in IBD are mainly determined by tissue location and inflammation, whereas the mucosal microbiota composition shows a high degree of individual specificity. Analysis of transcript-bacteria interactions identifies six distinct groups of inflammation-related pathways that are associated with intestinal microbiota (adjusted P < 0.05). An increased abundance of Bifidobacterium is associated with higher expression of genes involved in fatty acid metabolism, while Bacteroides correlates with increased metallothionein signaling. In patients with fibrostenosis, a transcriptional network dominated by immunoregulatory genes is associated with Lachnoclostridium bacteria in non-stenotic tissue (adjusted P < 0.05), while being absent in CD without fibrostenosis. In patients using TNF-α-antagonists, a transcriptional network dominated by fatty acid metabolism genes is linked to Ruminococcaceae (adjusted P < 0.05). Mucosal microbiota composition correlates with enrichment of intestinal epithelial cells, macrophages, and NK-cells. Overall, these data demonstrate the presence of context-specific mucosal host-microbe interactions in IBD, revealing significantly altered inflammation-associated gene-taxa modules, particularly in patients with fibrostenotic CD and patients using TNF-α-antagonists. This study provides compelling insights into host-microbe interactions that may guide microbiota-directed precision medicine and fuels the rationale for microbiota-targeted therapeutics as a strategy to alter disease course in IBD.

MUC17 is an essential small intestinal glycocalyx component that is disrupted in Crohn's disease

Crohn's disease (CD) is the chronic inflammation of the ileum and colon triggered by bacteria, but insights into molecular perturbations at the bacteria-epithelium interface are limited. We report that membrane mucin MUC17 protects small intestinal enterocytes against commensal and pathogenic bacteria. In non-inflamed CD ileum, reduced MUC17 levels correlated with a compromised glycocalyx, allowing bacterial contact with enterocytes. Muc17 deletion in mice rendered the small intestine prone to atypical infection while maintaining resistance to colitis. The loss of Muc17 resulted in spontaneous deterioration of epithelial homeostasis and extra-intestinal translocation of bacteria. Finally, Muc17-deficient mice harbored specific small intestinal bacterial taxa observed in CD. Our findings highlight MUC17 as an essential line of defense in the small intestine with relevance for early epithelial defects in CD.

CT enterography-based radiomics combined with body composition to predict infliximab treatment failure in Crohn's disease

PURPOSE

Accurately predicting the treatment response in patients with Crohn's disease (CD) receiving infliximab therapy is crucial for clinical decision-making. We aimed to construct a prediction model incorporating radiomics and body composition features derived from computed tomography (CT) enterography for identifying individuals at high risk for infliximab treatment failure.

METHODS

This retrospective study included 137 patients with CD between 2015 and 2021, who were divided into a training cohort and a validation cohort with a ratio of 7:3. Patients underwent CT enterography examinations within 1 month before infliximab initiation. Radiomic features of the intestinal segments involved were extracted, and body composition features were measured at the level of the L3 lumbar vertebra. A model that combined radiomics with body composition was constructed. The primary outcome was the occurrence of infliximab treatment failure within 1 year. The model performance was evaluated using discrimination, calibration, and decision curves.

RESULTS

Fifty-two patients (38.0%) showed infliximab treatment failure. Eight significant radiomic features were used to develop the radiomics model. The model incorporating radiomics model score, skeletal muscle index (SMI), and creeping fat showed good discrimination for predicting infliximab treatment failure, with an area under the curve (AUC) of 0.88 (95% CI 0.81, 0.95) in the training cohort and 0.83 (95% CI 0.66, 1.00) in the validation cohort. The favorable clinical application was observed using decision curve analysis.

CONCLUSIONS

We constructed a comprehensive model incorporating radiomics and muscle volume, which could potentially be used to facilitate the individualized prediction of infliximab treatment response in patients with CD.

B cell-mediated CD4 T-cell costimulation via CD86 exacerbates pro-inflammatory cytokine production during autoimmune intestinal inflammation

Dysregulated B cell responses have been described in inflammatory bowel disease (IBD) patients; however, the role of B cells in IBD pathology remained incompletely understood. We here provide evidence for the detrimental role of activated B cells during the onset of autoimmune intestinal inflammation. Using Wiskott-Aldrich Syndrome interacting protein deficient (Wipf1-/-) mice as a mouse model of chronic colitis, we identified clusters of differentiation (CD)86 expression on activated B cells as a crucial factor exacerbating pro-inflammatory cytokine production of intestinal CD4 T cells. Depleting B cells through anti-CD20 antibody treatment or blocking costimulatory signals mediated by CD86 through cytotoxic T lymphocyte antigen-4-immunoglobulin (CTLA-4-Ig) diminished intestinal inflammation in our mouse model of chronic IBD at the onset of disease. This was due to a reduction in aberrant humoral immune responses and reduced CD4 T cell pro-inflammatory cytokine production, especially interferon-g (IFN-g) and granulocyte-macrophage colony-stimulating factor (GM-CSF). Interestingly, in addition to B cells isolated from the inflamed colon of Wipf1-/- mice, we also found CD86 mRNA and protein expression upregulated on activated B cells isolated from inflamed tissue of human patients with IBD. B cell activation and CD86 expression were boosted by soluble CD40L in vitro, which we found in the serum of mice and human patients with IBD. In summary, our data provides detailed insight into the contribution of B cells to intestinal inflammation, with implications for the treatment of IBD.

Residual abnormalities on CTE predict adverse outcomes in Crohn's disease with endoscopic healing

BACKGROUND

Residual abnormalities on computed tomography enterography (CTE) in Crohn's disease (CD) with endoscopic healing (EH) may have prognostic implications and affect therapeutic strategy.

METHODS

CD patients with EH who underwent CTE between March 2015 and June 2022 were enrolled. CTE findings of the terminal ileum and the most severe segment of colon at the time of EH were assessed respectively for each patient. Cox regression analysis and Kaplan-Meier curves were used to evaluate the association between residual abnormalities and adverse outcomes.

RESULTS

A total of 140 patients (217 digestive segments) were included. Mesenteric edema (hazard ratio [HR] = 3.61, 95% CI = 1.81-7.20, P<0.001), fibrofatty proliferation (HR = 3.40, 95% CI = 1.97-5.85, P<0.001) and active small bowel inflammation (HR = 2.74, 95% CI = 1.59-4.71, P<0.001) were risk factors for clinical relapse. Furthermore, we built a scoring system using the three parameters. Radiologic score ≥ 1 was the best threshold to predict clinical relapse (HR = 4.56, 95% CI = 2.54-8.19, P<0.001) and it was validated in different outcomes.

CONCLUSION

The scoring system based on three residual abnormalities on CTE can predict adverse outcomes in CD patients with EH.

Causal relationship between gut microbiota and hidradenitis suppurativa: a two-sample Mendelian randomization study

Background

Accumulating evidence suggests that alterations in gut microbiota composition are associated with the hidradenitis suppurativa (HS). However, the causal association between gut microbiota and HS remain undetermined.

Methods

We performed a bidirectional two-sample Mendelian randomization (MR) analysis using genome-wide association study summary data of gut microbiota and hidradenitis suppurativa from the MiBioGen consortium which concluded 18,340 individuals analyzed by the MiBioGen Consortium, comprising 211 gut microbiota. HS data were acquired from strictly defined HS data collected by FinnGenbiobank analysis, which included 211,548 European ancestors (409 HS patients, 211,139 controls). The inverse variance weighted method (IVW), weighted median (WME), simple model, weighted model, weighted median, and MR-Egger were used to determine the changes of HS pathogenic bacterial taxa, followed by sensitivity analysis including horizontal pleiotropy analysis. The MR Steiger test evaluated the strength of a causal association and the leave-one-out method assessed the reliability of the results. Additionally, a reverse MR analysis was carried out to seek for possible reverse causality.

Results

By combining the findings of all the MR steps, we identified four causal bacterial taxa, namely, Family XI, Porphyromonadaceae, Clostridium innocuum group and Lachnospira. The risk of HS might be positively associated with a high relative abundance of Clostridium innocuum group (Odds ratio, OR 2.17, p = 0.00038) and Lachnospira (OR 2.45, p = 0.017) but negatively associated with Family XI (OR 0.67, p = 0.049) and Porphyromonadaceae (OR 0.29, p = 0.014). There were no noticeable outliers, horizontal pleiotropy, or heterogeneity. Furthermore, there was no proof of reverse causation found in the reverse MR study.

Conclusion

This study indicates that Clostridium innocuum group and Lachnospira might have anti-protective effect on HS, whereas Family XI and Porphyromonadaceae might have a protective effect on HS. Our study reveals that there exists a beneficial or detrimental causal effect of gut microbiota composition on HS and offers potentially beneficial methods for therapy and avoidance of HS.

Ultrasound in Pediatric Inflammatory Bowel Disease-A Review of the State of the Art and Future Perspectives

Inflammatory bowel disease (IBD) comprises a group of relapsing, chronic diseases of the gastrointestinal tract that, in addition to adults, can affect children and adolescents. To detect relapses of inflammation, these patients require close observation, frequent follow-up, and therapeutic adjustments. While reference standard diagnostics include anamnestic factors, laboratory and stool sample assessment, performing specific imaging in children and adolescents is much more challenging than in adults. Endoscopic and classic cross-sectional imaging modalities may be invasive and often require sedation for younger patients. For this reason, intestinal ultrasound (IUS) is becoming increasingly important for the non-invasive assessment of the intestine and its inflammatory affection. In this review, we would like to shed light on the current state of the art and provide an outlook on developments in this field that could potentially spare these patients more invasive follow-up procedures.

Gut ribotoxic stress responses facilitate dyslipidemia via metabolic reprogramming: an environmental health prediction

Rationale: The gut and its accessory organ, the liver, are crucial determinants of metabolic homeostasis via the regulation of circulating lipids for cardiovascular health. In response to environmental insults, cells undergo diverse adaptation or pathophysiological processes via stress-responsive eukaryotic initiation factor 2 alpha (eIF2α) kinase signaling and subsequent cellular reprogramming. We noted that patients with inflammatory gut distress display enhanced levels of ribosomal stress-responsive eIF2α kinase, which is notably associated with lipid metabolic process genes. Based on an assumption that eukaryotic ribosomes are a promising stress-responsive module for molecular reprogramming, chemical ribosome-inactivating stressors (RIS) were assessed for their involvement in enterohepatic lipid regulation. Methods: Experimental assessment was based on prediction using the clinical transcriptome and single-cell RNA-sequencing analysis of inflammatory bowel diseases and obesity. The prediction was verified using RIS exposure models of mice, gut organoids, and intestinal cells. The lipidomic profiling was performed to address RIS-induced intracellular fat alterations. Biochemical processes of the mechanisms were evaluated using RT-PCR, western blot analysis, luciferase reporter assays, and confocal microscopy of genetically ablated or chemically inhibited mice, organoids, and cells. Results: Chemical RIS including deoxynivalenol promoted enterohepatic lipid sequestration while lowering blood LDL cholesterol in normal and diet-induced obese mice. Although ribosomal stress caused extensive alterations in cellular lipids and metabolic genes, the cholesterol import-associated pathway was notably modulated. In particular, ribosomal stress enhanced gut levels of the low-density lipoprotein receptor (LDLR) via both transcriptional and post-transcriptional regulation. Subsequently, LDLR facilitated enterohepatic cholesterol accumulation, leading to dyslipidemia in response to ribosomal stress. Moreover, genetic features of stress-responsive LDLR modulators were consistently proven in the inflammation- and obesity-associated gut model. Conclusion: The elucidated ribosome-linked gut lipid regulation provides predictive insights into stress-responsive metabolic rewiring in chronic human diseases as an environmental health prediction.

Causal relationship between the gut microbiome and basal cell carcinoma, melanoma skin cancer, ease of skin tanning: evidence from three two-sample mendelian randomisation studies

Objectives

The present study used publicly available genome-wide association study (GWAS) summary data to perform three two-sample Mendelian randomization (MR) studies, aiming to examine the causal links between gut microbiome and BCC, melanoma skin cancer, ease of skin tanning.

Methods

SNPs associated with exposures to basal cell carcinoma, melanoma skin cancer and ease of skin tanning from the genome-wide association study data of UK Biobank and MRC-IEU (MRC Integrative Epidemiology Unit), and the meta-analysis data from Biobank and MRC-IEU were used as instrumental variables (IVs). The casual estimates were assessed with a two-sample Mendelian randomisation test using the inverse-variance-weighted (IVW) method, Wald ratio, MR-Egger method, maximum likelihood, weighted median, simple mode, and weighted mode.

Results

After the application of MR analysis, diffirent effects of multiple groups of gut microbiota was observed for BCC, melanoma skin cancer and ease of skin tanning. The relationships between the gut microbiome and BCC, melanoma skin cancer, ease of skin tanning were supported by a suite of sensitivity analyses, with no statistical evidence of instrument heterogeneity or horizontal pleiotropy. Further investigation is required to explore the relationship between between the gut microbiome and BCC, melanoma skin cancer, ease of skin tanning.

Conclusion

Our study initially identified potential causal roles between the gut microbiome and BCC, melanoma skin cancer, ease of skin tanning, and highlighted the role of gut microbiome in the progression of basal cell carcinoma, melanoma skin cancer, ease of skin tanning.

Longitudinal dynamics of gut bacteriome and mycobiome interactions pre- and post-visceral surgery in Crohn's disease

Introduction

Alterations of the gut microbiome are involved in the pathogenesis of Crohn's disease (CD). The role of fungi in this context is unclear. This study aimed to determine postoperative changes in the bacterial and fungal gut communities of CD patients undergoing intestinal resection, and to evaluate interactions between the bacteriome and mycobiome and their impact on the patients' outcome.

Methods

We report a subgroup analysis of a prospective cohort study, focusing on 10 CD patients whose fecal samples were collected for bacterial 16S rRNA and fungal ITS2 genes next-generation sequencing the day before surgery and on the 5th or 6th postoperative day.

Results

No significant differences in bacterial and fungal diversity were observed between preoperative and postoperative stool samples. By in-depth analysis, significant postoperative abundance changes of bacteria and fungi and 17 interkingdom correlations were detected. Network analysis identified 13 microbial clusters in the perioperative gut communities, revealing symbiotic and competitive interactions. Relevant factors were gender, age, BMI, lifestyle habits (smoking, alcohol consumption) and surgical technique. Postoperative abundance changes and identified clusters were associated with clinical outcomes (length of hospital stay, complications) and levels of inflammatory markers.

Conclusions

Our findings highlight the importance of dissecting the interactions of gut bacterial and fungal communities in CD patients and their potential influence on postoperative and disease outcomes.

Pathobionts in Inflammatory Bowel Disease: Origins, Underlying Mechanisms, and Implications for Clinical Care

The gut microbiota plays a significant role in the pathogenesis of both forms of inflammatory bowel disease (IBD), namely, Crohn's disease (CD) and ulcerative colitis (UC). Although evidence suggests dysbiosis and loss of beneficial microbial species can exacerbate IBD, many new studies have identified microbes with pathogenic qualities, termed "pathobionts," within the intestines of patients with IBD. The concept of pathobionts initiating or driving the chronicity of IBD has largely focused on the putative aggravating role that adherent invasive Escherichia coli may play in CD. However, recent studies have identified additional bacterial and fungal pathobionts in patients with CD and UC. This review will highlight the characteristics of these pathobionts and their implications for IBD treatment. Beyond exploring the origins of pathobionts, we discuss those associated with specific clinical features and the potential mechanisms involved, such as creeping fat (Clostridium innocuum) and impaired wound healing (Debaryomyces hansenii) in patients with CD as well as the increased fecal proteolytic activity (Bacteroides vulgatus) seen as a biomarker for UC severity. Finally, we examine the potential impact of pathobionts on current IBD therapies, and several new approaches to target pathobionts currently in the early stages of development. Despite recognizing that pathobionts likely contribute to the pathogenesis of IBD, more work is needed to define their modes of action. Determining whether causal relationships exist between pathobionts and specific disease characteristics could pave the way for improved care for patients, particularly for those not responding to current IBD therapies.

Precocious infant fecal microbiome promotes enterocyte barrier dysfuction, altered neuroendocrine signaling and associates with increased childhood obesity risk

Early life gut microbiome composition has been correlated with childhood obesity, though microbial functional contributions to disease origins remain unclear. Here, using an infant birth cohort (n = 349) we identify a distinct fecal microbiota composition in 1-month-old infants with the lowest rate of exclusive breastfeeding, that relates with higher relative risk for obesity and overweight phenotypes at two years. Higher-risk infant fecal microbiomes exhibited accelerated taxonomic and functional maturation and broad-ranging metabolic reprogramming, including reduced concentrations of neuro-endocrine signals. In vitro, exposure of enterocytes to fecal extracts from higher-risk infants led to upregulation of genes associated with obesity and with expansion of nutrient sensing enteroendocrine progenitor cells. Fecal extracts from higher-risk infants also promoted enterocyte barrier dysfunction. These data implicate dysregulation of infant microbiome functional development, and more specifically promotion of enteroendocrine signaling and epithelial barrier impairment in the early-life developmental origins of childhood obesity.

The Impact of Obesity on Inflammatory Bowel Disease

Obesity is prevalent in the inflammatory bowel disease (IBD) population, particularly in newly developed countries where both IBD and obesity in the general population are on the rise. The role of obesity in the pathogenesis of IBD was entertained but results from available studies are conflicting. It does, however, appear to negatively influence disease course whilst impacting on our medical and surgical therapies. The pro-inflammatory profile of the visceral adipose tissue might play a role in the pathogenesis and course of Crohn's Disease (CD). Interestingly, isolating the mesentery from the surgical anastomosis using a KONO-S technique significantly decreases anastomotic recurrence rate. Anti-obesity therapy is not widely used in IBD but was suggested as an adjunctive therapy in those patients. In this review, we aimed to highlight the epidemiology of obesity in IBD and to describe its influence on disease course and outcomes.

Creeping fat exhibits distinct Inflammation-specific adipogenic preadipocytes in Crohn's disease

Creeping fat (CrF) is an extraintestinal manifestation observed in patients with Crohn's disease (CD). It is characterized by the accumulation of mesenteric adipose tissue (MAT) that wraps around the intestinal wall. Although the role of CrF in CD is still debated, multiple studies have highlighted a correlation between CrF and inflammation, as well as fibrostenosais of the intestine, which contributes to the worsening of CD symptoms. However, the mechanism underlying the potential role of CrF in the development of Crohn's fibrosis remains an enigma. This study aimed to analyze CrF comprehensively using single-cell RNA sequencing analysis. The data was compared with transcriptomic data from adipose tissue in other disease conditions, such as ulcerative colitis, lymphedema, and obesity. Our analysis classified two lineages of preadipocyte (PAC) clusters responsible for adipogenesis and fibrosis in CrF. Committed PACs in CrF showed increased cytokine expression in response to bacterial stimuli, potentially worsening inflammation in patients with CD. We also observed an increase in fibrotic activity in PAC clusters in CrF. Co-analyzing the data from patients with lymphedema, we found that pro-fibrotic PACs featured upregulated pentraxin-3 expression, suggesting a potential target for the treatment of fibrosis in CrF. Furthermore, PACs in CrF exhibited a distinct increase in cell-to-cell communication via cytokines related to inflammation and fibrosis, such as CCL, LIGHT, PDGF, MIF, and SEMA3. Interestingly, these interactions also increased in PACs of the lymphedema, whereas the increased MIF signal of PACs was found to be a distinct characteristic of CrF. In immune cell clusters in CrF, we observed high immune activity of pro-inflammatory macrophages, antigen-presenting macrophages, B cells, and IgG+ plasma cells. Finally, we have demonstrated elevated IgG+ plasma cell infiltration and increased pentraxin-3 protein levels in the fibrotic regions of CrF in CD patients when compared to MAT from both UC patients and healthy individuals. These findings provide new insights into the transcriptomic features related to the inflammation of cells in CrF and suggest potential targets for attenuating fibrosis in CD.

Metagenomics study on taxonomic and functional change of gut microbiota in patients with obesity with PCOS treated with exenatide combination with metformin or metformin alone

OBJECTIVE

To investigate the effect of exenatide treatment on the composition of intestinal flora and metabolic pathways in patients with obesity with polycystic ovary syndrome.

METHODS

Patients with obesity with polycystic ovary syndrome (PCOS) were distributed to two groups: one received exenatide combined with metformin (COM group, n = 14) and the other used metformin alone (MF group, n = 15). Fresh fecal specimens from the participants, including 29 patients with obesity with PCOS and 6 healthy controls, were collected for metagenomic sequencing. The effect of exenatide combination with metformin or metformin alone on the composition and function of intestinal flora in patients with obesity with PCOS were compared by bioinformatics analysis.

RESULTS

The level of BMI, TT, HbA1c, and HDL-c was significantly improved in both groups. The MF and COM groups were abundant in Firmicutes, Bacteroidetes, Uroviricota, Actinobacteria, and Proteobacteria. Abundance of Bacteroidetes, Proteobacteria, Hungatella, and certain probiotics like Phocaeicola and Anaerobutyricum significantly increased in both groups after treatment. Enriched microbial species in the MF and COM group were different. Clostridium, Fusobacterium, and Oxalobacter were the main bacteria in the post-MF group, while Lactococcus_garvieae, Clostridium_perfringens, and Coprococcus_sp_AF16_5 were the main bacteria in the post-COM group. The post-COM group had more probiotic species including Bifidobacterium, Prevotella, and Anaerobutyricum after treatment.

CONCLUSION

Both exenatide combined with metformin and metformin monotherapy can improve metabolic and endocrine markers, and the diversity and abundance of gut microbiota in patients with obesity with PCOS. The effects of the combination and monotherapy agents on intestinal flora were consistent to some extent but also unique respectively.

Clostridium innocuum, an emerging pathogen that induces lipid raft-mediated cytotoxicity

Clostridium innocuum is an emerging spore-forming anaerobe that is often observed in Clostridioides difficile-associated inflammatory bowel disease (IBD) exacerbations. Unlike C. difficile, C. innocuum neither produces toxins nor possesses toxin-encoding genetic loci, but is commonly found in both intestinal and extra-intestinal infections. Membrane lipid rafts are composed of dynamic assemblies of cholesterol and sphingolipids, allowing bacteria to gain access to cells. However, the direct interaction between C. innocuum and lipid rafts that confers bacteria the ability to disrupt the intestinal barrier and induce pathogenesis remains unclear. In this study, we investigated the associations among nucleotide-binding oligomerization domain containing 2 (NOD2), lipid rafts, and cytotoxicity in C. innocuum-infected gut epithelial cells. Our results revealed that lipid rafts were involved in C. innocuum-induced NOD2 expression and nuclear factor (NF)-κB activation, triggering an inflammatory response. Reducing cholesterol by simvastatin significantly dampened C. innocuum-induced cell death, indicating that the C. innocuum-induced pathogenicity of cells was lipid raft-dependent. These results demonstrate that NOD2 mobilization into membrane rafts in response to C. innocuum-induced cytotoxicity results in aggravated pathogenicity.

Translocation of gut microbes to epididymal white adipose tissue drives lipid metabolism disorder under heat stress

Heat stress induces multi-organ damage and serious physiological dysfunction in mammals, and gut bacteria may translocate to extra-intestinal tissues under heat stress pathology. However, whether gut bacteria translocate to the key metabolic organs and impair function as a result of heat stress remains unknown. Using a heat stress-induced mouse model, heat stress inhibited epididymal white adipose tissue (eWAT) expansion and induced lipid metabolic disorder but did not damage other organs, such as the heart, liver, spleen, or muscle. Microbial profiling analysis revealed that heat stress shifted the bacterial community in the cecum and eWAT but not in the inguinal white adipose tissue, blood, heart, liver, spleen, or muscle. Notably, gut-vascular barrier function was impaired, and the levels of some bacteria, particularly Lactobacillus, were higher in the eWAT, as confirmed by catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH) staining when mice were under heat stress. Moreover, integrated multi-omics analysis showed that the eWAT microbiota was associated with host lipid metabolism, and the expression of genes involved in the lipid metabolism in eWAT was upregulated under heat stress. A follow-up microbial supplementation study after introducing Lactobacillus plantarum to heat-stressed mice revealed that the probiotic ameliorated heat stress-induced loss of eWAT and dyslipidemia and reduced gut bacterial translocation to the eWAT by improving gut barrier function. Overall, our findings suggest that gut bacteria, particularly Lactobacillus spp., play a crucial role in heat stress-induced lipid metabolism disorder and that there is therapeutic potential for using probiotics, such as Lactobacillus plantarum.

Identification of a Novel Long Non-Coding RNA G8110 That Modulates Porcine Adipogenic Differentiation and Inflammatory Responses

Long non-coding RNAs (lncRNAs) have been extensively studied, and their crucial roles in adipogenesis, lipid metabolism, and gene expression have been revealed. However, the exact regulatory or other mechanisms by which lncRNAs influence the functioning of mesenteric adipose tissue (MAT) remain largely unknown. In this paper, we report the identification of a new lncRNA, named G8110, from the MAT of Bama pigs. The coordinated expression levels of lncRNA G8110 and NFE2L1 were significantly decreased in the MAT of obese Bama pigs compared with those in the MAT of lean pigs. Using a bone mesenchymal stem cell adipogenic differentiation model, we found that lncRNA G8110 played a role in adipocyte differentiation by positively regulating NFE2L1. We also found that lncRNA G8110 inhibited the formation of intracellular lipid synthesis, promoted lipid metabolism, and inhibited the expression of inflammatory cytokines. Our findings regarding lipid synthesis may further promote the role of lncRNAs in driving adipose tissue remodeling and maintaining metabolic health.

Results of the Eighth Scientific Workshop of ECCO: Pathophysiology and Risk Factors of Postoperative Crohn's Disease Recurrence after an Ileocolonic Resection

Postoperative recurrence [POR] after an ileocolonic resection with ileocolonic anastomosis is frequently encountered in patients with Crohn's disease. The 8th Scientific Workshop of ECCO reviewed the available evidence on the pathophysiology and risk factors for POR. In this paper, we discuss published data on the role of the microbiome, the mesentery, the immune system and the genetic background. In addition to investigating the causative mechanisms of POR, identification of risk factors is essential to tailor preventive strategies. Potential clinical, surgical and histological risk factors are presented along with their limitations. Emphasis is placed on unanswered research questions, guiding prevention of POR based on individual patient profiles.

Creeping Fat in the Pathogenesis of Crohn's Disease: An Orchestrator or a Silent Bystander?

Although the phenomenon of hypertrophied adipose tissue surrounding inflamed bowel segments in Crohn's disease has been described since 1932, the mechanisms mediating the creeping fat formation and its role in the pathogenesis of the disease have not been fully unraveled. Recent advances demonstrating the multiple actions of adipose tissue beyond energy storage have brought creeping fat to the forefront of scientific research. In Crohn's disease, dysbiosis and transmural injury compromise the integrity of the intestinal barrier, resulting in an excessive influx of intraluminal microbiota and xenobiotics. The gut and peri-intestinal fat are in close anatomic relationship, implying a direct reciprocal immunologic relationship, whereas adipocytes are equipped with an arsenal of innate immunity sensors that respond to invading stimuli. As a result, adipocytes and their progenitor cells undergo profound immunophenotypic changes, leading to adipose tissue remodeling and eventual formation of creeping fat. Indeed, creeping fat is an immunologically active organ that synthesizes various pro- and anti-inflammatory cytokines, profibrotic mediators, and adipokines that serve as paracrine/autocrine signals and regulate immune responses. Therefore, creeping fat appears to be involved in inflammatory signaling, which explains why it has been associated with a higher severity or complicated phenotype of Crohn's disease. Interestingly, there is growing evidence for an alternative immunomodulatory function of creeping fat as a second barrier that prevents an abnormal systemic inflammatory response at the expense of an increasingly proliferating profibrotic environment. Further studies are needed to clarify how this modified adipose tissue exerts its antithetic effect during the course of Crohn's disease.

Microbiota DNA Translocation Into Mesentery Lymph Nodes Is Associated With Early Development of Pouchitis After IPAA for Ulcerative Colitis

BACKGROUND

The role of bacterial translocation in Crohn's disease has been extensively studied. However, data regarding bacterial translocation into the mesentery in patients with ulcerative colitis were scarce.

OBJECTIVE

This study aimed to explore the relationship between bacterial translocation and postoperative outcome by comparing the microbiome profile of different anatomical sites in patients with ulcerative colitis who underwent proctocolectomy and IPAA.

DESIGN

A prospective study.

SETTING

This study was conducted at the Jinling Hospital from August 2017 to May 2018.

PATIENTS

Samples of 27 patients with ulcerative colitis who had IPAA and 15 healthy controls who underwent routine colonoscopy were collected.

MAIN OUTCOME MEASURES

The microbiome profile of different tissue sites and short- and long-term outcomes after IPAA in patients with ulcerative colitis.

RESULTS

Bacterial DNA was detected in mesenteric lymph nodes of 51.9% of patients with ulcerative colitis (14/27) and in mesenteric adipose tissue of 66.7% of patients (18/27). The microbiome in mesenteric lymph nodes and mesenteric adipose tissue resembled the mucosal microbiome to a greater extent than the fecal microbiome. Positive bacterial DNA in mesenteric lymph nodes (8/14 vs 0/13; p = 0.002) was associated with pouchitis within 12 months after IPAA, whereas Bray-Curtis distance in mesenteric lymph nodes was significantly different between patients with pouchitis and without ( p = 0.009).

LIMITATIONS

This study was limited by its small sample size and lacked situ experiment to confirm the true bacterial translation.

CONCLUSIONS

Bacterial translocation was highly prevalent in patients with ulcerative colitis. The translocated bacteria DNA in mesenteric adipose tissue and mesenteric lymph nodes was highly correlated and more likely to originate from mucosal than fecal microbiome. Also, the extent of bacterial translocation and translocation of certain bacteria might be associated with the early development of pouchitis after IPAA. This might represent an unprecedented technique to predict pouchitis using mesenteric lymph node bacterial profiles. See Video Abstract at http://links.lww.com/DCR/C119 .

LA TRANSLOCACIN DEL ADN DE LA MICROBIOTA EN LOS GANGLIOS LINFTICOS DEL MESENTERIO SE ASOCIA CON EL DESARROLLO TEMPRANO DE POUCHITIS DESPUS DE IPAA PARA LA COLITIS ULCEROSA

ANTECEDENTES:El papel de la translocación bacteriana en la enfermedad de Crohn se ha estudiado ampliamente en los últimos años. Sin embargo, los datos sobre la translocación bacteriana en el mesenterio en pacientes con colitis ulcerosa fueron escasos.OBJETIVO:El objetivo de este estudio fue explorar la relación entre la translocación bacteriana y el resultado postoperatorio comparando el perfil del microbioma de diferentes sitios anatómicos en pacientes con colitis ulcerosa que se sometieron a proctocolectomía y anastomosis ileoanal con bolsa.DISEÑO:Estudio prospectivo.AJUSTE:Este estudio se realizó en el Hospital Jinling desde agosto de 2017 hasta mayo de 2018.PACIENTES:Se recogieron muestras de 27 pacientes con colitis ulcerosa que tenían anastomosis de bolsa ileoanal y 15 controles sanos que se sometieron a una colonoscopia de rutina.PRINCIPALES MEDIDAS DE RESULTADO:El perfil del microbioma de diferentes sitios de tejido y los resultados a corto y largo plazo después de la anastomosis ileoanal con bolsa en pacientes con colitis ulcerosa.RESULTADOS:Se detectó ADN bacteriano en los ganglios linfáticos mesentéricos del 51,9 % (14/27) de los pacientes con colitis ulcerosa y en el tejido adiposo mesentérico del 66,7 % (18/27) de los pacientes, respectivamente. El microbioma en los ganglios linfáticos mesentéricos y el tejido adiposo mesentérico se parecía más al microbioma de la mucosa que al microbioma fecal. El ADN bacteriano translocado en los ganglios linfáticos mesentéricos y el tejido adiposo mesentérico estaban altamente correlacionados. El ADN bacteriano positivo en los ganglios linfáticos mesentéricos (8/14 frente a 0/13, p = 0,002) se asoció con reservoritis dentro de los 12 meses posteriores a la anastomosis ileoanal con reservorio, mientras que la distancia de Bray-Curtis en los ganglios linfáticos mesentéricos fue significativamente diferente entre reservoritis y no reservorios. -pacientes con reservorio (p = 0,009). Ruminococcus, Bacteroides y Clostridiales se encontraron exclusivamente en los ganglios linfáticos mesentéricos de pacientes con reservoritis.LIMITACIÓN:Este estudio estuvo limitado por el pequeño tamaño de la muestra y la falta de un experimento in situ para confirmar la verdadera traducción bacteriana.CONCLUSIÓN:La translocación bacteriana fue altamente prevalente en pacientes con colitis ulcerosa. El ADN bacteriano translocado en el tejido adiposo mesentérico y los ganglios linfáticos mesentéricos estaba altamente correlacionado y era más probable que se originara en el microbioma de la mucosa que en el fecal. Además, la extensión de la translocación bacteriana y la translocación de ciertas bacterias podría estar asociada con el desarrollo temprano de reservoritis después de la anastomosis del reservorio ileoanal. Esto podría representar una técnica sin precedentes para predecir la reservoritis utilizando perfiles bacterianos de los ganglios linfáticos mesentéricos. Consulte Video Resumen en. http://links.lww.com/DCR/C119(Traducción-Dr. Felipe Bellolio ).

Appearance of the Bowel and Mesentery During Surgery Is Not Predictive of Postoperative Recurrence After Ileocecal Resection for Crohn's Disease: A Prospective Monocentric Study

BACKGROUND

Very few risk factors for postoperative recurrence (POR) of Crohn's Disease (CD) after ileocecal resection have been identified. The aim of the present study was to verify the association between an a priori defined list of intraoperative macroscopic findings and POR.

METHODS

This was a prospective observational study including patients undergoing primary ileocecal resection for CD. Four intraoperative factors were independently evaluated by 2 surgeons: length of resected ileum, mesentery thickness, presence of areas of serosal fat infiltration, or abnormal serosal vasodilation on normal bowel proximal to the resected bowel. The primary end point was early endoscopic POR at month 6 and defined as modified Rutgeerts score ≥i2b. Secondary end points were clinical and surgical recurrence.

RESULTS

Between September 2020 and November 2022, 83 consecutive patients were included. Early endoscopic recurrence occurred in 45 of 76 patients (59.2%). Clinical and biochemical recurrence occurred in 17.3% (95% confidence interval, [CI], 10.4%-28.0%) and 14.6% of the patients after 12 months. The risk of developing endoscopic and clinical recurrence was 1.127 (95% CI, 0.448;2.834, P = .799) and 0.896 (95% CI, 0.324-2.478, P = .832) when serosal fat infiltration was observed, and 1.388 (95% CI, 0.554-3.476, P = .484), and 1.153 (95% CI, 0.417;3.187, P = .783) when abnormal serosal vasodilation was observed. Similarly, length of the resected bowel and mesentery thickness showed no association with POR. A subgroup analysis on patients who received no postoperative medical prophylaxis did not identify any risk factor for endoscopic POR.

CONCLUSIONS

The macroscopic appearance of the bowel and associated mesentery during surgery does not seem to be predictive of POR after ileocecal resection for CD.

Higher Intra-Abdominal Visceral Adipose Tissue Mass Is Associated With Lower Rates of Clinical and Endoscopic Remission in Patients With Inflammatory Bowel Diseases Initiating Biologic Therapy: Results of the Constellation Study

BACKGROUND & AIMS

We sought to assess the association between intra-abdominal visceral adipose tissue (IA-VAT) and response to 3 different biologic drugs in patients with inflammatory bowel disease (IBD) and to investigate its effects on inflammatory cytokine expression, pharmacokinetics, and intestinal microbiota.

METHODS

We prospectively enrolled subjects with active IBD initiating infliximab, vedolizumab, or ustekinumab and a healthy control group. Baseline body composition (including IA-VAT as percent of total body mass [IA-VAT%]) was measured using GE iDXA scan. Primary outcome was corticosteroid- free deep remission at weeks 14-16, defined as Harvey Bradshaw Index <5 for Crohn's disease and partial Mayo score <2 for ulcerative colitis, with a normal C-reactive protein and fecal calprotectin. Secondary outcomes were corticosteroid-free deep remission and endoscopic remission (Endoscopic Mayo Score ≤1 in ulcerative colitis or Simple Endoscopic Score for Crohn's disease ≤2) at weeks 30-46.

RESULTS

A total of 141 patients with IBD and 51 healthy controls were included. No differences in body composition parameters were seen between the IBD and healthy control cohorts. Patients with higher IA-VAT% were less likely to achieve corticosteroid-free deep remission (P < .001) or endoscopic remission (P = .02) vs those with lower IA-VAT%. Furthermore, nonresponders with high IA-VAT% had significantly higher serum interleukin-6 and tumor necrosis factor at baseline compared with responders and patients with low IA-VAT%. Drug pharmacokinetic properties and microbiota diversity were similar when comparing high and low IA-VAT% groups.

CONCLUSIONS

Higher IA-VAT% was independently associated with worse outcomes. This association could be driven at least partially by discrete differences in inflammatory cytokine expression.

Bacteremia due to Clostridium innocuum: Analysis of four cases and literature review

Clostridium innocuum is a Gram-positive anaerobic spore-forming bacillus that has been identified as part of the normal intestinal microbiota. This bacterium has been rarely associated with human infections, and only few severe infections have been reported until now. In this work, we report on four patients with bacteremia due to C. innocuum, which were well identified by MALDI-TOF MS. Moreover, a review of the previous published cases of bacteremia due to this anaerobic bacterium has been performed.

Visceral adipose microbial and inflammatory signatures in metabolically healthy and unhealthy nonhuman primates

OBJECTIVE

Obesity is a key risk factor for metabolic syndrome (MetS); however, >10% of lean individuals meet MetS criteria. Visceral adipose tissue (VAT) disproportionately contributes to inflammation and insulin resistance compared with subcutaneous fat depots. The primary aim of this study was to profile tissue microbiome components in VAT over a wide range of metabolic statuses in a highly clinically relevant model.

METHODS

VAT was profiled from nonhuman primates that naturally demonstrate four distinct health phenotypes despite consuming a healthy diet, namely metabolically healthy lean and obese and metabolically unhealthy lean and obese.

RESULTS

VAT biopsied from unhealthy lean and obese nonhuman primates demonstrated upregulation of immune signaling pathways, a tissue microbiome enriched in gram-negative bacteria including Pseudomonas, and deficiencies in anti-inflammatory adipose tissue M2 macrophages. VAT microbiomes were distinct from fecal microbiomes, and fecal microbiomes did not differ by metabolic health group, which was in contrast to the VAT bacterial communities.

CONCLUSIONS

Immune activation with gram-negative VAT microbial communities is a consistent feature in elevated MetS risk in both lean and obesity states.

Recent insights of obesity-induced gut and adipose tissue dysbiosis in type 2 diabetes

An imbalance in microbial homeostasis, referred to as dysbiosis, is critically associated with the progression of obesity-induced metabolic disorders including type 2 diabetes (T2D). Alteration in gut microbial diversity and the abundance of pathogenic bacteria disrupt metabolic homeostasis and potentiate chronic inflammation, due to intestinal leakage or release of a diverse range of microbial metabolites. The obesity-associated shifts in gut microbial diversity worsen the triglyceride and cholesterol level that regulates adipogenesis, lipolysis, and fatty acid oxidation. Moreover, an intricate interaction of the gut-brain axis coupled with the altered microbiome profile and microbiome-derived metabolites disrupt bidirectional communication for instigating insulin resistance. Furthermore, a distinct microbial community within visceral adipose tissue is associated with its dysfunction in obese T2D individuals. The specific bacterial signature was found in the mesenteric adipose tissue of T2D patients. Recently, it has been shown that in Crohn's disease, the gut-derived bacterium Clostridium innocuum translocated to the mesenteric adipose tissue and modulates its function by inducing M2 macrophage polarization, increasing adipogenesis, and promoting microbial surveillance. Considering these facts, modulation of microbiota in the gut and adipose tissue could serve as one of the contemporary approaches to manage T2D by using prebiotics, probiotics, or faecal microbial transplantation. Altogether, this review consolidates the current knowledge on gut and adipose tissue dysbiosis and its role in the development and progression of obesity-induced T2D. It emphasizes the significance of the gut microbiota and its metabolites as well as the alteration of adipose tissue microbiome profile for promoting adipose tissue dysfunction, and identifying novel therapeutic strategies, providing valuable insights and directions for future research and potential clinical interventions.

A CCL2+DPP4+ subset of mesenchymal stem cells expedites aberrant formation of creeping fat in humans

Creeping fat is a typical feature of Crohn's disease. It refers to the expansion of mesenteric adipose tissue around inflamed and fibrotic intestines and is associated with stricture formation and intestinal obstruction. In this study, we characterize creeping fat as pro-adipogenic and pro-fibrotic. Lipidomics analysis of Crohn's disease patients (sixteen males, six females) and healthy controls (five males, ten females) reveals abnormal lipid metabolism in creeping fat. Through scRNA-seq analysis on mesenteric adipose tissue from patients (five males, one female) and healthy controls (two females), we identify a CCL2+DPP4+ subset of mesenchymal stem cells that expands in creeping fat and expedites adipogenic differentiation into dystrophic adipocytes in response to CCL20+CD14+ monocytes and IL-6, leading to the formation of creeping fat. Ex vivo experiments (tissues from five males, one female) confirm that both CCL20+CD14+ monocytes and IL-6 activate DPP4+ mesenchymal stem cells towards a pro-adipogenic phenotype. This study provides a comprehensive investigation of creeping fat formation and offers a conceptual framework for discovering therapeutic targets for treatment of Crohn's disease.

Viscoelastic properties of small bowel mesentery at MR elastography in Crohn's disease: a prospective cross-sectional exploratory study

BACKGROUND

Creeping fat is a pathological feature of small bowel Crohn's disease (CD), with literature suggesting that bowel resection with extended mesenteric resection is related to less postoperative recurrences. Conventional imaging is unable to accurately quantify the disease involvement (i.e., fibrosis) of creeping fat. Quantification of disease involvement could be useful in decision-making for additional extended mesenteric resection. We investigated the feasibility of magnetic resonance elastography (MRE) of the mesentery and if MRE is capable to detect fibrotic disease involvement of mesentery in active CD.

METHODS

Multifrequency MRE yielded spatial stiffness (shear wave speed, SWS, |G*|) and fluidity maps (φ). Viscoelastic properties of seven CD patients' mesentery were compared to age- and sex-matched healthy volunteers (HV) (Mann-Whitney U-test). Within CD patients, the affected and "presumably" unaffected mesentery were compared (Wilcoxon-signed rank test). Repeatability was tested in 15 HVs (Bland-Altman analysis, coefficient of variation [CoV]). Spearman rank correlations were used to investigate the relation between microscopically scored amount of mesenteric fibrosis and viscoelastic parameters.

RESULTS

SWS, |G*|, and φ of affected mesentery in CD were higher compared to HV (p = 0.017, p = 0.001, p = 0.017). Strong correlations were found between percentage of area of mesenteric fibrosis and SWS and |G*| (p < 0.010). No differences were found within CD between affected and presumably unaffected mesentery. Repeatability of SWS showed 95% limits of agreement of (-0.09, 0.13 m/s) and within-subject CoV of 5.3%.

CONCLUSION

MRE may have the potential to measure fibrotic disease involvement of the mesentery in CD, possibly guiding clinical decision-making with respect to extended mesenteric resection.

TRIAL REGISTRATION

Dutch trial register, NL9105 , registered 7 December 2020.

RELEVANCE STATEMENT

MRE may have the potential to measure the amount of mesenteric fibrosis of the affected mesenteric fat in active Crohn's disease, giving more insight into disease progression and could potentially play a role in clinical decision-making for extended mesenteric resection.

KEY POINTS

• MRE of the mesentery in patients with active CD is feasible. • Fluidity and stiffness of the mesentery increase in active CD, while stiffness correlates with the histopathological amount of mesenteric fibrosis. • MRE provides biomarkers to quantify mesenteric disease activity in active CD.

Development and validation of multiparametric models based on computed tomography enterography to determine endoscopic activity and surgical risk in patients with Crohn's disease: A multi-center study

Objective

To develop novel multiparametric models based on computed tomography enterography (CTE) scores to identify endoscopic activity and surgical risk in patients with Crohn's disease (CD).

Methods

We analyzed 171 patients from 3 hospitals. Correlations between CTE outcomes and endoscopic scores were assessed using Spearman's rank correlation analysis. Predictive models for moderate to severe CD were developed, and receiver operating characteristic (ROC) curves were constructed to determine the area under the ROC curve (AUC). A combined nomogram based on CTE scores and clinical variables was also developed for predicting moderate to severe CD and surgery.

Results

CTE scores were significantly correlated with endoscopy scores at the segment level. The global CTE score was an independent predictor of severe (HR = 1.231, 95% CI: 1.048-1.446, p = 0.012) and moderate-to-severe Simplified Endoscopic Scores for Crohn's Disease (SES-CD) (HR = 1.202, 95% CI: 1.090-1.325, p < 0.001). The nomogram integrating CTE and clinical data predicted moderate to severe SES-CD and severe SES-CD scores in the validation cohort with AUCs of 0.837 and 0.807, respectively. The CTE score (HR = 1.18; 95% CI: 1.103-1.262; p = 0.001) and SES-CD score (HR = 3.125, 95% CI: 1.542-6.33; p = 0.001) were independent prognostic factors for surgery-free survival. A prognostic nomogram incorporating CTE scores, SES-CD and C-reactive protein (CRP) accurately predicted the risk of surgery in patients with CD.

Conclusion

The newly developed CTE score and multiparametric models displayed high accuracy in predicting moderate to severe CD and surgical risk for CD patients.

Effect of anastomotic configuration on Crohn's disease recurrence after primary ileocolic resection: a comparative monocentric study of end-to-end versus side-to-side anastomosis

There is ongoing debate whether the type of anastomosis following intestinal resection for Crohn's disease (CD) can impact on complications and postoperative recurrence. The aim of the present study is to describe the outcomes of side-to-side (S-S) vs end-to-end (E-E) anastomosis after ileocecal resection for CD. A retrospective comparative study was conducted in consecutive CD patients who underwent primary ileocecal resection between 2005 and 2013. All patients underwent colonoscopy 6 months postoperatively to assess endoscopic recurrence, defined as Rutgeerts' score (RS) ≥ i2. Surgical recurrence implied reoperation due to CD activity at the anastomotic site. Modified surgical recurrence was defined as the need for reoperation or balloon-dilation. Perioperative factors related to recurrence were evaluated. Of the 127 patients included, 51 (40.2%) received an E-E anastomosis. Median follow-up was longer in the E-E group (8.62 vs 13.68 years). Apart from the microscopic resection margins, patient, disease and surgical characteristics were similar between both groups. Anastomotic complications were comparable (S-S 5.3% vs E-E 5.8%, p = 1.00)0. Postoperatively, biologicals were used in 55.3% and 62.7% (p = 0.47) in S-S and E-E patients, respectively. Endoscopic recurrence did not differ between S-S and E-E patients (78.9 vs 72.9%, p = 0.37), with no significant difference in RS values between both groups (p = 0.87). Throughout follow-up, a higher surgical (p = 0.04) and modified surgical recurrence (p = 0.002) rate was observed in the E-E anastomosis group. Type of anastomosis was an independent risk factor for modified surgical recurrence. The type of anastomosis did not influence endoscopic recurrence and immediate postoperative disease complications. However, the wide diameter and the morphologic characteristic of the stapled S-S anastomosis resulted in a significant reduced risk for surgical and endoscopic reintervention on the long term.