Obesity, visceral fat and Crohn's disease

Integrative multi-omics analysis of Crohn's disease and metabolic syndrome: Unveiling the underlying molecular mechanisms of comorbidity

OBJECTIVES

The focus of this study is on identifying a potential association between Crohn's disease (CD), a chronic inflammatory bowel condition, and metabolic syndrome (Mets), characterized by a cluster of metabolic abnormalities, including high blood pressure, abnormal lipid levels, and overweight. While the link between CD and MetS has been suggested in the medical community, the underlying molecular mechanisms remain largely unexplored.

METHODS

Using microarray data from the Gene Expression Omnibus (GEO) database, we conducted a differential gene expression analysis and applied Weighted Gene Co-expression Network Analysis (WGCNA) to identify genes shared between CD and MetS. To further elucidate the functions of these shared genes, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses and constructed protein-protein interaction (PPI) networks. For key gene screening, we used Random Forest and Least Absolute Shrinkage and Selection Operator (LASSO) regression and constructed a diagnostic prediction model with the Extreme Gradient Boosting (XGBoost) algorithm. Additionally, CIBERSORT and Gene Set Variation Analysis (GSVA) were employed to examine the relationships between these genes and immune cell infiltration, as well as metabolic pathways. Mendelian randomization and colocalization analyses were also conducted to explore causal links between genes and disease. Lastly, single-cell RNA sequencing (scRNA-seq) was used to validate the functionality of these key genes.

RESULTS

Through the use of the limma R package and WGCNA, we identified 1767 co-expressed genes common to both CD and MetS, which are notably enriched in pathways related to immune responses and metabolic regulation. After thorough analysis, 34 key genes were highlighted, demonstrating their potential utility in prognostic models. These genes were closely linked to tissue immune responses and metabolic functions. Subsequent scRNA-seq analysis confirmed the strong diagnostic potential of PIM2 and PBX2, with especially prominent expression in T and B cells.

CONCLUSION

This study identifies shared regulatory genes between CD and MetS, advancing the development of precise diagnostic tools. In particular, PIM2 and PBX2 were found to be positively associated with hypoxia and hemoglobin metabolism pathways, suggesting their involvement in the modulation of cellular processes. These findings improve our understanding of the molecular mechanisms underlying the comorbidity of CD and MetS, offering novel targets for integrated therapeutic interventions.

Bariatric Surgery Outcomes in Patients with Inflammatory Bowel Disease in the United States: An Analysis of the Nationwide Readmissions Database

PURPOSE

Bariatric surgery has been reported to produce durable weight loss in the management of obesity; sleeve gastrectomy (SG) is the most common bariatric procedure. Obesity is a common comorbidity of inflammatory bowel disease (IBD), and the impact of IBD on short-term SG outcomes has not been widely reported. This study assessed whether IBD was associated with adverse post-SG outcomes.

MATERIALS AND METHODS

Hospitalizations of patients undergoing SG in the United States were identified using the 2010-2020 Nationwide Readmissions Database (NRD) and stratified by IBD diagnosis. The SG cohort was propensity-matched based on age, biological sex, body mass index (BMI), comorbid diabetes, hypertension, depression, chronic obstructive pulmonary disease, and discharge in quarter four. Primary aims were to compare in-hospital mortality, post-operative complications, and all-cause 90-day readmission between patients with and without IBD. Secondary outcomes were length of stay (LOS) and total hospital cost.

RESULTS

A total of 2030 hospitalizations were matched. The odds of complication were 48% higher for hospitalizations of patients with IBD (11.1% vs. 7.8%; aOR 1.48, aOR 95% CI 1.10-2.00, p = .009). The most common complication was nausea (4.9% vs. 3.7%, p = .187). No statistically significant difference was observed for all-cause 90-day readmissions, LOS, or hospital cost.

CONCLUSION

Hospitalizations of patients with IBD who underwent SG experienced significantly higher post-operative complication rates. However, the similar lengths of stay and readmission rates compared to propensity-matched SG hospitalizations without IBD suggest many complications were minor. SG remains a safe weight loss procedure for patients suffering from IBD and obesity.

Circulatory resistin levels in inflammatory bowel disease: a systematic review and meta-analysis

BACKGROUND

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is a chronic relapsing-remitting systemic disease of the gastrointestinal tract with rising incidence. Studies have shown that adipocytes play a crucial role in patients with IBD by actively participating in systemic immune responses. The present study was designed to investigate the correlation between the circulatory levels of resistin, as an adipokine, and active and remission phases of IBD in comparison with healthy controls.

METHODS

Relevant articles were retrieved from PubMed, Embase, the Web of Science, and Scopus from inception until June 2023. Estimation of the standardized mean difference (SMD) and 95% confidence interval (CI) for comparison of plasma/serum resistin levels between IBD patients, patients in remission, and healthy controls were conducted through random-effect meta-analysis.

RESULTS

A total of 19 studies were included, assessing 1836 cases. Meta-analysis indicated that generally, serum/plasma resistin levels were higher in IBD patients in comparison with healthy controls (SMD 1.33, 95% CI 0.58 to 2.08, p-value < 0.01). This was true for each of the UC and CD separate analyses, as well. Moreover, it was shown that higher serum/plasma resistin levels were detected in the active phase of IBD than in the remission phase (SMD 1.04, 95% CI 0.65 to 1.42, p-value = 0.01). Finally, higher serum/plasma resistin levels were found in the remission phase compared to healthy controls (SMD 0.60, 95% CI 0.15 to 1.06, p-value < 0.01).

CONCLUSION

The results of this systematic review and meta-analysis support the conclusion that circulating resistin levels are increased in IBD (both UC and CD). Also, higher resistin levels were recorded in the remission phase of IBD in comparison with healthy controls. This indicates that further studies may provide valuable insights into the role of resistin in the pathogenesis of IBD.

Nutritional Risk and Sarcopenia Features in Patients with Crohn's Disease: Relation to Body Composition, Physical Performance, Nutritional Questionnaires and Biomarkers

Patients with Crohn's disease (CD) face malnutrition risk, which, combined with inflammation, can lead to sarcopenia, associated with a worse prognosis. The purpose of the present study was to assess malnutrition and sarcopenia in patients with CD. Fifty-three patients (26 women) participated (38.1 ± 10.9 years, 79% in remission). Body composition, physical performance, nutritional questionnaires, and biomarkers were performed. Malnutrition was screened with the Mini Nutritional Assessment (MNA) and the Malnutrition Inflammation Risk Tool (MIRT) and was assessed with the Global Leadership Initiative on Malnutrition (GLIM) tool using etiologic along with three different phenotypic criteria: low Body Mass Index (BMI), low Calf Circumference (CC), and low Fat-Free Mass Index (FFMI). To find cases and evaluate sarcopenia, the Sarcopenia Questionnaire (SARC-F) and European Working Group on Sarcopenia2 (EWGSOP2) criteria were used. Malnutrition rates were 11.3% (n = 6), 7.5% (n = 4), and 5.6% (n = 3) based on low FFMI, CC, and BMI, correspondingly. Four (7%) patients had low Hand-Grip Strength (HGS), n = 8 (14.8%) had low Appendicular Lean Mass (ALM), and n = 3 (5.6%) had low gait speed. No-one had sarcopenia. A high albumin and triceps skinfold pattern, identified by principal component analysis, was related to reduced C-Reactive Protein (CRP) levels (B = -0.180, SE = 0.085, p = 0.045). In conclusion, based on the studied anthropometric, nutritional, and functional variables, CD patients were not diagnosed with sarcopenia in the present study. Body composition patterns were related to the inflammatory burden, underlying the interplay of inflammation and malnutrition, even in remission states. Further studies on older populations and during disease exacerbation are necessary to explore the potential link between CD, inflammation, and sarcopenia.

Systematic review: Outcomes of bariatric surgery in patients with inflammatory bowel disease and de-novo IBD development after bariatric surgery

A large proportion of patients diagnosed with inflammatory bowel disease are obese. Outcomes of bariatric surgery in patients with IBD and on IBD disease course itself is not clear. Furthermore, there is some evidence that bariatric surgery can precipitate the development of de-novo IBD. Thus, the aim of this systematic review was to summarise the evidence from the literature surrounding these questions. A comprehensive literature review was conducted based on the preferred reporting items for systematic reviews and meta-analysis guidelines (PRISMA). PUBMED, and MEDLINE databases was searched using a combination of keywords and MeSH terms including "gastric bypass", "sleeve gastrectomy", "Roux-en-Y", "Duodenal switch", "RYGB", "bariatric surgery" and "inflammatory bowel disease", "Crohn's disease" ,"Ulcerative colitis". Studies published up to March 2020 were included in this analysis. 22 studies met the inclusion criteria. Studies revealed that bariatric surgery is safe and effective for patients with IBD and resulted in significant weight loss at both the 6-month and 12-month time points. Furthermore, multiple studies reported de-novo IBD development following bariatric surgery in a selection of patients.

Measurement of the stiffness of the normal terminal ileum mesentery using shear-wave elastography

OBJECTIVE

To investigate the feasibility of using shear-wave elastography (SWE) to measure the stiffness of the normal terminal ileum mesentery, and to establish its normal reference range.

METHODS

Ninety-five normal subjects and 22 patients with mesentery-related disease were included. The average Young's modulus of the normal terminal ileal mesentery was measured by SWE ultrasound. The thickness and the extent to which mesenteric fat extended around the intestinal circumference of the normal terminal ileum were also recorded. The normal reference range was established and the SWE values of normal and diseased subjects were compared.

RESULTS

Transabdominal SWE examination of the terminal ileum mesentery was successfully performed on 91 subjects (95.8 %). The mean extent range, thickness, and SWE value of the normal terminal ileum mesentery were 1/4 (1/5-1/3), 6.8 ± 2.4 mm, and 4.3 ± 2.1 kPa, respectively. These parameters did not differ significantly between genders, and across age and body mass index groups (all P > 0.05). The intra- and inter-operator consistencies were excellent for the replicated SWE measurements (0.801 [95 % confidence interval: 0.560-0.916] and 0.751 (95 % confidence interval: 0.388-0.900], respectively). The mean mesenteric elasticity in diseased subjects was 21.9 ± 10.7 kPa, which was significantly higher than that in normal subjects (P < 0.001). The cut-off value for mesenteric elasticity was 9.3 kPa, with a sensitivity of 90 % and a specificity of 100 % (P < 0.001).

CONCLUSION

SWE can be used to reliably evaluate the stiffness of the terminal ileum mesentery in normal subjects.

Correlation between magnetic resonance enterography and ileo-colonoscopy for assessment of disease activity in terminal ileal Crohn's disease

BACKGROUND

Magnetic resonance enterography (MRE) has emerged as a novel tool for the assessment of disease activity in Crohn's disease (CD). Real world data from Indian subcontinent on performance of MRE in terminal ileal CD are lacking.

METHODS

Retrospective analysis of patients with terminal ileal CD who underwent both ileo-colonoscopy and MRE was performed. Ileo-colonoscopy was considered the gold standard for assessment of disease activity. On ileo-colonoscopy, a simple endoscopic score for Crohn's disease (SES-CD) ≥2 was considered active disease; presence of ulcers indicated severe disease. MRE scoring of the disease activity was performed using magnetic resonance index of activity (MARIA) and simplified MARIA (MARIAs). The measure of agreement between ileo-colonoscopy and MRE and comparison of MARIA and MARIAs for assessment of disease activity and sensitivity of MRE to detect mucosal ulcerations were calculated.

RESULTS

Seventy patients with terminal ileal CD (mean age 40.74±15.56 years; 71.4% males [n=50]) were evaluated. The sensitivities of MARIA and MARIAs scores to detect active disease were 0.76 and 0.84, respectively. The area under the receiver operating characteristic curve (AUROC) for detecting severe disease was 0.836 (p<0.0001) for MARIA and 0.861 (p<0.0001) for MARIAs. For mild active disease, there was no agreement between SES-CD and MARIA or MARIAs; however, for severe disease, the agreement was fair and moderate for MARIA and MARIAs, respectively. MARIA and MARIAs were comparable for identification of active and severe disease (κ 0.759, p<0.0001 and κ 0.840, p<0.0001, respectively). MRE was 68.18% sensitive to detect mucosal ulcers.

CONCLUSION

MRE is a reliable and sensitive tool for detection of endoscopically severe, but not mild, terminal ileal CD.

Systematic review and meta-analysis: association between obesity/overweight and surgical complications in IBD

PURPOSE

While the prevalence of obesity in inflammatory bowel disease (IBD) patients is rapidly increasing, it is unclear whether obesity affects surgical outcomes in this population. This meta-analysis aims to assess the impact of obesity/overweight on patients undergoing surgery for IBD.

METHODS

Databases (PubMed, Web of Science, Cochrane Library, and Springer) were searched through September 2021. The meta-analysis included patients with surgically treated IBD to investigate the impact of obesity/overweight on this population. Primary outcomes included overall complications, infectious complications, noninfectious complications, and conversion to laparotomy.

RESULTS

Fifteen studies totaling 12,622 IBD patients were enrolled. Compared with nonobese (including overweight) patients, obese IBD patients have increased the risk in terms of overall complications (OR = 1.45, p < 0.001), infectious complications (OR = 1.48, p = 0.003) (especially wound complications), as well as conversion to laparotomy (OR = 1.90, p < 0.001). Among the noninfectious complications, only the incidence of visceral injury (OR = 2.36, p = 0.05) had significantly increased. Compared with non-overweight patients, the risk of developing wound complications (OR = 1.65, p = 0.01) and sepsis (OR = 1.73, p = 0.007) were increased in overweight patients, but the rates of overall complications (OR = 1.04, p = 0.81), infectious complications (OR = 1.31, p = 0.07), and conversion to laparotomy (OR = 1.33, p = 0.08) associated with body mass index (BMI) were not significantly different.

CONCLUSION

Obesity is a risk factor for surgical complications in IBD patients, mainly reflected in infectious complications. Moreover, obese patients seem to have a more common chance of developing surgical complications than overweight patients.

Prehabilitation prior to intestinal resection in Crohn's disease patients: An opinion review

Patients with Crohn's disease (CD) are at a considerable risk for intestinal surgery. Approximately 25% of patients with CD will undergo an intestinal resection within 10 years of diagnosis. Postoperative complications after CD surgery have been reported in 20%-47% of the patients. Both general and CD-related risk factors are associated with postoperative complications, and comprise non-modifiable (e.g., age) and potentially modifiable risk factors (e.g., malnutrition). Prehabilitation focuses on the preoperative period with strategies designed to optimize modifiable risk factors concerning the physical and mental condition of the individual patient. The aim of prehabilitation is to enhance postoperative recovery and return to or even improve preoperative functional capacity. Preoperative improvement of nutritional status, physical fitness, cessation of smoking, psychological support, and critical revision of preoperative use of CD medication are important strategies. Studies of the effect on postoperative outcome in CD patients are scarce, and guidelines lack recommendations on tailored management. In this opinion review, we review the current evidence on the impact of screening and management of nutritional status, physical fitness, CD medication and laboratory values on the postoperative course following an intestinal resection in CD patients. In addition, we aim to provide guidance for individualized multimodal prehabilitation in clinical practice concerning these modifiable factors.

Insights on the Gut-Mesentery-Lung Axis in Pulmonary Arterial Hypertension: A Poorly Investigated Crossroad

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by the hyperproliferation of vascular cells, including smooth muscle and endothelial cells. Hyperproliferative cells eventually obstruct the lung vasculature, leading to irreversible lesions that collectively drive pulmonary pressure to life-threatening levels. Although the primary cause of PAH is not fully understood, several studies have indicated it results from chronic pulmonary inflammation, such as observed in response to pathogens' infection. Curiously, infection by the intravascular parasite Schistosoma mansoni recapitulates several aspects of the widespread pulmonary inflammation that leads to development of chronic PAH. Globally, >200 million people are currently infected by Schistosoma spp., with about 5% developing PAH (Sch-PAH) in response to the parasite egg-induced obliteration and remodeling of the lung vasculature. Before their settling into the lungs, Schistosoma eggs are released inside the mesenteric veins, where they either cross the intestinal wall and disturb the gut microbiome or migrate to other organs, including the lungs and liver, increasing pressure. Spontaneous or surgical liver bypass via collateral circulation alleviates the pressure in the portal system; however, it also allows the translocation of pathogens, toxins, and antigens into the lungs, ultimately causing PAH. This brief review provides an overview of the gut-mesentery-lung axis during PAH, with a particular focus on Sch-PAH, and attempts to delineate the mechanism by which pathogen translocation might contribute to the onset of chronic pulmonary vascular diseases.

The exercise-induced inflammatory response in inflammatory bowel disease: A systematic review and meta-analysis

BACKGROUND

This study investigated selected inflammatory responses to acute and chronic exercise in individuals with inflammatory bowel disease (IBD).

METHODS

A systematic review and meta-analysis was conducted on all relevant exercise-based intervention publications with IBD participants. The study included articles that utilised a broad range of acute and chronic exercise interventions, with inflammatory biomarkers measured and symptoms documented, both pre- and post-exercise for those with IBD. The search was limited to studies published in English, the use of human participants, and primary studies, with no restrictions on date of publication or participant's age. Articles were retrieved through the electronic databases: PubMed, SPORTDiscus, and Scopus. This study adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines.

RESULTS

Six inflammatory markers were included in the meta-analysis which consisted of five studies. Exercise interventions resulted in no significant difference in IL-6 (SMD = -0.09; 95% CI = -0.49, 0.30; P = 0.64), TNF-α (SMD = 0.08; 95% CI = -0.31, 0.48; P = 0.68), CRP (SMD = -0.04; 95% CI = -0.58, 0.50; P = 0.89), IL-17 (SMD = 0.15; 95% CI = -0.45, 0.76; P = 0.62), leukocytes (SMD = 0.40; 95% CI = -0.53, 1.33; P = 0.40) or lymphocytes (SMD = 0.32; 95% CI = -0.33, 0.97; P = 0.33), thus, indicating exercise may have no effect on inflammatory markers in IBD. Bowel symptoms improved following regular moderate exercise that incorporated stress management.

CONCLUSION

Heterogeneity among the identified literature may have led to exercise interventions being ineffective in reducing inflammation. Although the limited number of eligible studies may reduce the reliability of results, it emphasises the need for additional research in this domain. Importantly, no adverse symptomatic responses to exercise indicate that exercise is safe for IBD patients.

The Role of Gut Microbiota and Metabolites in Obesity-Associated Chronic Gastrointestinal Disorders

The gut microbiota is a complex community of microorganisms that has become a new focus of attention due to its association with numerous human diseases. Research over the last few decades has shown that the gut microbiota plays a considerable role in regulating intestinal homeostasis, and disruption to the microbial community has been linked to chronic disease conditions such as inflammatory bowel disease (IBD), colorectal cancer (CRC), and obesity. Obesity has become a global pandemic, and its prevalence is increasing worldwide mostly in Western countries due to a sedentary lifestyle and consumption of high-fat/high-sugar diets. Obesity-mediated gut microbiota alterations have been associated with the development of IBD and IBD-induced CRC. This review highlights how obesity-associated dysbiosis can lead to the pathogenesis of IBD and CRC with a special focus on mechanisms of altered absorption of short-chain fatty acids (SCFAs).

Ulcerative colitis immune cell landscapes and differentially expressed gene signatures determine novel regulators and predict clinical response to biologic therapy

The heterogeneous pathobiology underlying Ulcerative Colitis (UC) is not fully understood. Using publicly available transcriptomes from adult UC patients, we identified the immune cell landscape, molecular pathways, and differentially expressed genes (DEGs) across patient cohorts and their association with treatment outcomes. The global immune cell landscape of UC tissue included increased neutrophils, T CD4 memory activated cells, active dendritic cells (DC), and M0 macrophages, as well as reduced trends in T CD8, Tregs, B memory, resting DC, and M2 macrophages. Pathway analysis of DEGs across UC cohorts demonstrated activated bacterial, inflammatory, growth, and cellular signaling. We identified a specific transcriptional signature of one hundred DEGs (UC100) that distinctly separated UC inflamed from uninflamed transcriptomes. Several UC100 DEGs, with unidentified roles in UC, were validated in primary tissue. Additionally, non-responders to anti-TNFα and anti-α4β7 therapy displayed distinct profiles of immune cells and pathways pertaining to inflammation, growth, and metabolism. We identified twenty resistant DEGs in UC non-responders to both therapies of which four had significant predictive power to treatment outcome. We demonstrated the global immune landscape and pathways in UC tissue, highlighting a unique UC signature across cohorts and a UC resistant signature with predictive performance to biologic therapy outcome.

Role of Adipose Tissue in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs), chronic inflammatory disorders affecting the gastrointestinal tract, include Crohn's disease and ulcerative colitis. There are increasing clinical and experimental data showing that obesity, especially visceral adiposity, plays a substantial role in the pathogenesis of IBD. Obesity seems to be an important risk factor also for IBD disease severity and clinical outcomes. Visceral adipose tissue is an active multifunctional metabolic organ involved in lipid storage and immunological and endocrine activity. Bowel inflammation penetrates the surrounding adipose tissue along the mesentery. Mesenteric fat serves as a barrier to inflammation and controls immune responses to the translocation of gut bacteria. At the same time, mesenteric adipose tissue may be the principal source of cytokines and adipokines responsible for inflammatory processes associated with IBD. This review is particularly focusing on the potential role of adipokines in IBD pathogenesis and their possible use as promising therapeutic targets.

Potential of Nutraceutical Supplementation in the Modulation of White and Brown Fat Tissues in Obesity-Associated Disorders: Role of Inflammatory Signalling

The high incidence of obesity is associated with an increasing risk of several chronic diseases such as cardiovascular disease, type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). Sustained obesity is characterized by a chronic and unsolved inflammation of adipose tissue, which leads to a greater expression of proinflammatory adipokines, excessive lipid storage and adipogenesis. The purpose of this review is to clarify how inflammatory mediators act during adipose tissue dysfunction in the development of insulin resistance and all obesity-associated diseases. In particular, we focused our attention on the role of inflammatory signaling in brown adipose tissue (BAT) thermogenic activity and the browning of white adipose tissue (WAT), which represent a relevant component of adipose alterations during obesity. Furthermore, we reported the most recent evidence in the literature on nutraceutical supplementation in the management of the adipose inflammatory state, and in particular on their potential effect on common inflammatory mediators and pathways, responsible for WAT and BAT dysfunction. Although further research is needed to demonstrate that targeting pro-inflammatory mediators improves adipose tissue dysfunction and activates thermogenesis in BAT and WAT browning during obesity, polyphenols supplementation could represent an innovative therapeutic strategy to prevent progression of obesity and obesity-related metabolic diseases.

The impact of obesity on hospitalized patients with ulcerative colitis

Background

Obesity is the fifth leading risk factor for mortality in the world and it has increased among patients with ulcerative colitis in recent years. We examined the impact of obesity on the hospitalized patients admitted primarily with a diagnosis of ulcerative colitis.

Methods

We used the National Inpatient Sample data for the year 2016 to identify patients with ulcerative colitis and compared obese and non-obese patients in terms of length of hospital stay, total charges, and mortality. We used multiple imputations to estimate missing values and survey analysis to estimate the outcomes, and we adjusted for confounders by implementing the inverse probability of treatment weighting using propensity score.

Results

A total of 61,075 admissions with ulcerative colitis were identified. Among these, 6020 were diagnosed with obesity. Baseline hospital and patient characteristics between the 2 groups were notable for differences in age and sex. Patients with obesity were found to have a mean hospital stay longer by 0.57 days (95% confidence interval [CI] 0.22-0.93; P=0.002) and charges $6341.71 higher (95%CI 2499.72-10,183.71; P=0.001) compared to non-obese patients. There was no difference in hospital mortality, with an odds ratio of 0.28 (95%CI 0.04-2.05; P=0.212).

Conclusion

In a comprehensive review of inpatient admissions in 2016, primarily for ulcerative colitis, obesity was associated with a longer hospital stay and higher total charges per admission after balancing of confounders.

Autophagy and proinflammatory cytokine expression in the intestinal mucosa and mesenteric fat tissue of patients with Crohn's disease

Background Recently, mesenteric fat has been proposed to play a role in the pathophysiol- ogy of Crohn's disease (CD), as fat hypertrophy is detected close to the affected intestinal area; however, there are few studies regarding autophagy and creeping fat tissue in CD.

Objective Evaluate autophagy-related proteins and proinflammatory cytokines in intestinal mucosa and mesenteric fat in patients with CD and controls.

Patients and methods Ten patients with CD, eight with non-inflammatory disease who underwent surgery, and eight with normal ileocolonoscopy were studied. The expression of LC3-II, TNF-α and IL-23 was determined by immunoblot of protein extracts. In addition, total RNA of LC3 and Atg16-L1 were determined using RT-PCR.

Results The expression of LC3-II was significantly lower in the mesenteric tissue of CD when compared to controls (p < 0.05). In contrast, the intestinal mucosa of the CD group had higher levels of LC3-II (p < 0.05). However, mRNA expression of autophagy-related pro- teins was similar when compared to mesenteric fat groups. TNF-α and IL-23 expressions were higher in intestinal mucosa of CD than in control (p < 0.05).

Conclusion These findings suggest a defect in the autophagic activity of the creeping fat tissue in CD, which could be involved with the maintenance of the inflammatory process in the intestinal mucosa.

Safety and Efficacy of Bariatric Surgery in Inflammatory Bowel Disease Patients: a Systematic Review and Meta-analysis

BACKGROUND

The safety and efficacy of bariatric surgery in inflammatory bowel disease (IBD) patients is poorly understood. We conducted a systematic review and meta-analysis studying safety and efficacy of bariatric surgery in IBD patients as well as the impact of bariatric surgery on IBD course.

METHODS

We conducted a comprehensive search of multiple databases (through September 2019) to identify studies that reported outcome of bariatric surgery in IBD patients. Outcomes assessed included the pooled rate of adverse events, change in medications after bariatric surgery, and 12-month excess weight loss (EWL) and body mass index (BMI) reduction after bariatric surgery.

RESULTS

A total of 10 studies were included in final analysis. The pooled rate of early and late adverse events was 15.9% (95% CI, 9.3-25.9) and 16.9% (95% CI, 12.1-23.1), respectively. The rate of adverse events in Roux-en-Y gastric bypass was 45.6% (95% CI, 21.9-71.4) compared with 21.6% (95% CI, 11.1-38) in sleeve gastrectomy (p = 0.11). The pooled rate of 12-month EWL and BMI reduction after surgery was 66.1% (95% CI, 59.8-72.3%) and 13.7 kg/m² (95% CI, 12.5-14.9), respectively. The pooled rate of decrease, increase, and no change of IBD medications were 45.6% (95% CI, 23.8-69.2), 11% (95% CI, 6.3-18.4), and 57.6% (95% CI, 39.2-74.1), respectively.

CONCLUSIONS

Bariatric surgery has acceptable safety and efficacy profile in IBD patients. Nearly half of patients had decrease in their IBD medications after bariatric surgery, and only 10% experienced therapeutic escalation following bariatric surgery. Sleeve gastrectomy may be the preferred procedure in this population.

Relationship of mesenteric panniculitis with visceral and subcutaneous adipose tissue

Background/aim

Mesenteric panniculitis (MP) is an idiopathic benign disease characterized by fat necrosis, chronic inflammation, and fibrosis. The relationship between obesity and chronic low-grade inflammation has been reported. This study investigated the relationship of MP diagnosed using multidetector computed tomography (MDCT) with visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas.

Materials and methods

We retrospectively enrolled 104 patients with no radiological findings other than MP. Additionally, 76 individuals without any indicative radiological findings were included as controls. VAT and SAT were separately calculated (cm2) using a 3-dimensional workstation. The abdominal circumference was measured (cm).

Results

The mean abdominal circumference was 99.9 ± 7.9 cm, SAT was 195.3 ± 89.1 cm2, and VAT was 203.9 ± 72.8 cm2 in the MP group. The abdominal circumference, VAT, and SAT were significantly higher in the MP group than in the control group (P < 0.001). According to the receiver operating characteristic (ROC) analysis, cut-off level VAT and SAT were 167.5 cm2 (sensitivity 71%, specificity 69%) and 117.5 cm2 (sensitivity 78%, specificity 51 %), respectively.

Conclusion

Increased VAT and SAT were associated with MP, suggesting their role in the etiology of MP.

Whole transcriptional analysis identifies markers of B, T and plasma cell signaling pathways in the mesenteric adipose tissue associated with Crohn's disease

Background

Crohn’s disease (CD) is a multifactorial disease characterized by chronic intestinal inflammation. The increased visceral adiposity near the affected intestinal area, of which mesenteric adipose tissue (MAT) is the main component, is a feature of CD. Both protective and pathological roles have been attributed to this disease-associated tissue in CD. To understand the contribution of MAT to CD pathophysiology, a molecular and cellular signature of disease-associated MAT in CD patients was provided.

Methods

We performed an observational study with whole transcriptional analysis by RNA sequencing (RNA-seq) of MAT and ileal mucosa from CD patients with active disease and controls. qPCR and immunohistology were performed for validation analysis.

Results

RNA-seq identified 17 significantly regulated genes (|FC| > 1.5; FDR < 0.05) in CD-MAT compared to non-IBD controls, with a marked upregulation of plasma cell genes (i.e., IGLL5, MZB1, CD79A, POU2AF1, FCRL5, JCHAIN, DERL3, SDC1, PIM2). A less strict statistical cutoff value (|FC| > 1.5, nominal p ≤ 0.05) yielded a larger list of 651 genes in CD-MAT compared to controls. CD ileum showed the significant regulation compared to control ileum of 849 genes (|FC| > 1.5; FDR < 0.05) or 2654 genes (|FC| > 1.5, nominal p ≤ 0.05). Ingenuity Pathway Analysis revealed the significant regulation of pathways related to T- and B cell functionality in the MAT of CD patients. Despite the differences between the MAT and ileal signatures of CD patients, we identified a subset of 204 genes significantly modulated in both tissues compared to controls. This common signature included genes related to the plasma cell signature. Genes such as S100A8, S100A9 (calprotectin) and IL1B, which are associated with acute inflammatory response, were exclusively regulated in the ileal mucosa of CD disease. In contrast, some genes encoding for lymphocyte receptors such as MS4A1, CD3D and CD79A were exclusively regulated in CD-MAT, exhibiting a different pattern of immune cell activation compared to the ileal mucosa in CD patients. qPCR and immunohistology confirmed the presence of large infiltrates of CD3⁺ CD20⁺ lymphocytes and CD138⁺ plasma cells in CD-MAT.

Conclusion

Our data strongly supports the role of CD-associated MAT as a site for T-, B- and plasma cell activation, and suggests that it could also act as a reservoir of memory immune responses.

Serum Polyunsaturated Fatty Acids Correlate with Serum Cytokines and Clinical Disease Activity in Crohn's Disease

Crohn's disease (CD) has been associated with an increased consumption of n-6 polyunsaturated fatty acid (PUFA), while greater intake of n-3 PUFA has been associated with a reduced risk. We sought to investigate serum fatty acid composition in CD, and associations of fatty acids with disease activity, cytokines, and adipokines. Serum was prospectively collected from 116 CD subjects and 27 non-IBD controls. Clinical disease activity was assessed by the Harvey Bradshaw Index (HBI). Serum fatty acids were measured by gas chromatography. Serum cytokines and adipokines were measured by Luminex assay. Dietary histories were obtained from a subset of patients. Nine serum cytokines and adipokines were increased in CD versus controls. CD subjects had increased percentage serum monounsaturated fatty acids (MUFA), dihomo-gamma linolenic acid (DGLA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and oleic acid, but decreased arachidonic acid (AA) versus controls. The % total n-3 fatty acids and % EPA directly correlated with pro-inflammatory cytokine levels and HBI, whereas the % total n-6 fatty acids were inversely correlated with pro-inflammatory cytokine levels and HBI. CD subjects had increased caloric intake versus controls, but no alterations in total fat or PUFA intake. We found differences in serum fatty acids, most notably PUFA, in CD that correlated both with clinical disease activity and inflammatory cytokines. Our findings indicate that altered fatty acid metabolism or utilization is present in CD and is related to disease activity.

Mesenteric Adipose Tissue Alterations in Crohn's Disease Are Associated With the Lymphatic System

BACKGROUND

Mesenteric fat wrapping and thickening are typical characteristics of Crohn's disease (CD). The purpose of this study was to explore the cause of mesenteric adipose hypertrophy and analyze the role of lymphatic vessels in mesenteric adipose tissue in CD.

METHODS

Twenty-three CD patients who underwent ileocolonic resection were included. In CD patients, specimens were obtained from hypertrophic mesenteric adipose tissue (htMAT) next to the diseased ileum. The mesenteric lymphatic vessels in mesenteric adipose tissue were separated under stereoscope microscope. Transmission electron microscopy and immunofluorescence were used to observe the structure of mesenteric lymphatic vessels. The NF-κB signaling pathway in mesenteric adipose tissue was detected in CD specimens using Western blotting.

RESULTS

Electron microscopy showed that the structure of mesenteric lymphatic vessel was discontinuous, and the microstructure of lymphatic endothelial cells appeared ruptured and incomplete. Through an immunofluorescence technique, we found that the surface of lymphatic endothelial cells lacked tight junction protein staining in CD. Also, the expression of claudin-1, occludin, and ZO-1 in the mesenteric lymphatic vessel of htMAT was significantly lower than that of control. These results indicated that the structure of the mesenteric lymphatic vessel in htMAT was mispatterned and ruptured, which could lead to lymph leakage. Leaky lymph factors could stimulate adipose tissue to proliferate. Antigens that leaked into the mesenteric adipose tissue could effectively elicit an immune response. The levels of cytokines (TNF-a, IL-1β, IL-6) was increased in the htMAT of CD patients by activated NF-κB signaling pathway.

CONCLUSIONS

Our findings demonstrated that the hypertrophy of mesenteric adipose tissue may result from mispatterned and ruptured lymphatic vessels. Alteration of mesenteric adipose tissue was associated with activated NF-κB signaling pathway. This study enhances support for elucidating the importance of mesenteric lymphatic vessels and adipose tissue in CD.

VISCERAL FAT IS INCREASED IN INDIVIDUALS WITH CROHN'S DISEASE: A COMPARATIVE ANALYSIS WITH HEALTHY CONTROLS

BACKGROUND

It is known that obesity is associated with a chronic inflammatory state, but few studies have evaluated visceral fat (VF) content and its role in individuals with Crohn's disease (CD).

OBJETIVE

To compare the nutritional status, body composition and proportion of VF between CD individuals and healthy volunteers.

METHODS

Cross-sectional study that enrolled individuals with Crohn's disease and healthy controls. The stratification according to nutritional status was carried out by means of BMI. The percentage of body fat percentage (%BF) and VF were estimated by means of DEXA. VF proportion was evaluated by means of the VF/BMI and VF/%BF ratios.

RESULTS

A total of 78 individuals were included. The control group was comprised of 28 healthy subjects aged 35.39±10 years old (60.7% women); mean BMI=23.94±3.34 kg/m2; mean VF=511.82±448.68 g; mean CRP=0.81±1.78 ng/mL. The CD group was comprised of 50 patients; 11 (22%) were underweight (BMI=18.20±1.97 kg/ m2; %BF=24.46±10.01; VF=217.18±218.95 g; CRP=4.12±4.84 ng/mL); 18 (36%) presented normal weight (BMI=22.43±1.48 kg/m2; %BF=30.92±6.63; VF=542.00±425.47 g and CRP=4.40±1.78 ng/mL); 21 (42%) were overweight or obese (BMI=29.48±3.78 kg/m2; %BF=39.91±7.33; VF=1525.23±672.7 g and CRP=1.33±2.06 ng/mL). The VF/BMI ratio was higher in the CD group when compared to controls (32.41±24.63 vs 20.01±16.23 g per BMI point; P=0.02). Likewise, the VF/%BF was also higher in the CD group (35.21±23.33 vs 15.60±12.55 g per percentage point; P<0.001).

CONCLUSION

Among individuals with Crohn's disease, BMI presents a direct correlation with visceral fat content. These results indicate the presence of an adiposopathy in Crohn's disease subjects, which is evidenced by a higher visceral fat.

Kejadian Obesitas, Obesitas Sentral, dan Kelebihan Lemak Viseral pada Lansia Wanita

Background: Obesity, central obesity, and visceral fat is an excessive fat that can release various types of diseases such as cardiovascular disease, stroke and can increase the risk of bone damage in the elderly. Objectives: The purpose of this study was to analyze the risk factors of obesity, central obesity, and visceral fat in elderly women. Methods:This was an observational analytic study with cross sectional design. The samples of the study were 81 elderly women registered as member of Posyandu Lansia in the working area of Puskesmas Jagir, Wonokromo, Surabaya. The data collected using 3 times 24-hour food recall, anthropometry (body weight, body height, and waist circumference), visceral fat using Bio Impedance Analysis (BIA), and questionnaire related to subject’s characteristic. The data were analyzed using logistic regression analysis. Results: The results showed that the mean age of the subjects were 67.12±5.97 years old. Most of the subjects have low education (71.6%) and 87.7% of subjects didn’t work. The mean value of daily energy intake was 1074.31±298.67 kcal.  There were 34.6% obese subjects, only 17.3% subjects didn’t experience central obesity, and 28.4% of subjects had excess body visceral fat. The statistical test showed significant correlation between age with obesi (p-value=0.042), age with central obesity (p-value=0.009) but age with visceral fat had no significant correlation (p-value=0.163). Daily food intake, education, and occupation did not show significant correlation with obesity, central obesity, or visceral fat (p-value>0.05).  Conclusions: The risk for obesity and central obesity was decreased with aging in elderly but not with visceral fat.ABSTRAKLatar Belakang: Obesitas, obesitas sentral, dan lemak viseral merupakan penumpukan lemak tubuh yang berlebihan dan berisiko untuk menimbulkan berbagai penyakit degeneratif seperti jantung iskemi dan stroke serta dapat meningkatkan risiko kerusakan tulang pada lansia.  Tujuan: Tujuan dari penelitian ini adalah untuk menganalisis faktor risiko obesitas, obesitas sentral, dan kelebihan lemak viseral pada lansia wanita.Metode: Penelitian ini menggunakan desain studi cross sectional dengan pendekatan kuantitatif.  Sampel dari penelitian ini adalah 81 lansia wanita yang menjadi anggota posyandu lansia di wilayah kerja Puskesmas Jagir, Wonokromo, Surabaya. Pengumpulan data menggunakan food recall 3 x 24 jam, antropometri (berat badan, tinggi badan, dan lingkar perut), lemak viseral menggunakan Bio Impedance Analysis (BIA), serta kuesioner terkait data diri subjek. Data dianalisis dengan menggunakan analisis regresi logistik.Hasil: Hasil penelitian menujukkan rata-rata usia subjek adalah 67,12±5,97. Sebagian besar subjek memiliki riwayat pendidikan rendah (71,6%) dan sebanyak 87,7% subjek tidak bekerja. Rata-rata asupan zat gizi subjek lebih rendah jika dibandingkan dengan Angka Kecukupan Gizi (AKG). Sebanyak 34,6% subjek mengalami obesitas; angka kejadian obesitas sentral yaitu 17,3%; dan 28,4% subjek memiliki lemak viseral tubuh berlebih. Uji statistik menunjukkan hubungan signifikan antara usia dengan obesitas (p-value = 0,042), usia dengan obesitas sentral (p-value = 0,009) tetapi usia dengan lemak viseral tidak memiliki hubungan signifikan (p-value = 0,163). Asupan makanan harian, pendidikan, dan pekerjaan tidak  menunjukkan hubungan signifikan dengan obesitas, obesitas sentral, maupun lemak viseral (p-value > 0,05).Kesimpulan: Pada lansia, risiko mengalami obesitas maupun obesitas sentral semakin menurun seiring dengan bertambahnya usia. Lemak viseral tidak berhubungan dengan usia.

Visceral fat area measured with computed tomography does not predict postoperative course in Crohn´s disease patients

The role of visceral fat measured by computer tomography is yet not well defined in patients with Crohn's disease. Therefore, the present study was designed to assess the impact of visceral fat area on postoperative short-term outcome and surgical characteristics. We analyzed 95 patients, who underwent intestinal resection for symptomatic Crohn's disease at an academic tertiary referral center between 2003 and 2008. Visceral fat area was measured on preoperative computed tomography scans. Postoperative morbidity was graded according to the Clavien-Dindo classification. Visceral fat area was correlated with baseline characteristics, disease phenotype and 30-day morbidity. Body mass index and age were significantly associated with a higher visceral fat area (p = 0.001). Overall 19 (20.0%) postoperative complications were observed, of whom 7 (7.4%) patients required surgical re-intervention. No significant difference was found with regard to visceral fat area between patients with an uneventful and eventful postoperative course (no complications: median visceral fat area 52.0 cm² SD 59.7, complications: 41.3 cm² SD 42.8; p = 0.465). In contrast to current literature, we cannot support the role of visceral fat area for predicting postoperative course in Crohn's disease. In addition, no correlation of the visceral fat area and disease behavior was detected.

An automated identification and analysis of ontological terms in gastrointestinal diseases and nutrition-related literature provides useful insights

With an unprecedented growth in the biomedical literature, keeping up to date with the new developments presents an immense challenge. Publications are often studied in isolation of the established literature, with interpretation being subjective and often introducing human bias. With ontology-driven annotation of biomedical data gaining popularity in recent years and online databases offering metatags with rich textual information, it is now possible to automatically text-mine ontological terms and complement the laborious task of manual management, interpretation, and analysis of the accumulated literature with downstream statistical analysis. In this paper, we have formulated an automated workflow through which we have identified ontological information, including nutrition-related terms in PubMed abstracts (from 1991 to 2016) for two main types of Inflammatory Bowel Diseases: Crohn’s Disease and Ulcerative Colitis; and two other gastrointestinal (GI) diseases, namely, Coeliac Disease and Irritable Bowel Syndrome. Our analysis reveals unique clustering patterns as well as spatial and temporal trends inherent to the considered GI diseases in terms of literature that has been accumulated so far. Although automated interpretation cannot replace human judgement, the developed workflow shows promising results and can be a useful tool in systematic literature reviews. The workflow is available at https://github.com/KociOrges/pytag.

Prior Repeated Stress Attenuates Cold-Induced Immunomodulation Associated with "Browning" in Mesenteric Fat of Rats

Continuous exposure to cold leads to activation of adaptive thermogenesis in brown adipose tissue but also to induction of brown/beige cell phenotype in white adipose tissue. The aim of this work was to investigate whether prior exposure to immobilization (IMO) stress may affect immune response associated with adipocyte "browning" in mesenteric adipose tissue (mWAT). In the first experiment, Sprague-Dawley rats were exposed to acute (3 h) or prolonged (7 days) cold exposure (4 ± 1 °C). 7-day cold stimulated gene expression of uncoupling protein 1 and other "browning"-associated factors. In the second experiment, rats were immobilized for 7 days (2 h daily) followed by exposure to continuous cold for 1 or 7 days. Prior IMO exaggerated cold-induced sympathetic response manifested by elevated tyrosine hydroxylase (TH) protein and norepinephrine in mWAT. Induction of non-sympathetic catecholamine production demonstrated by elevated TH and PNMT (phenylethanolamine N-methyltransferase) mRNAs was observed after 7-day cold; however, prior IMO attenuated this response. 7-day cold-induced gene expression of anti-inflammatory mediators (IL-4, IL-13, IL-10, adiponectin), markers of M2 macrophages (Arg1, Retnlα), and eosinophil-associated molecules (eotaxin, IL-5), while inhibited expression of pro-inflammatory cytokines (IFNγ, IL-1b, IL-6, IL-17) and monocytes (MCP-1, Ly6C). This immune response was accompanied by elevated expression of uncoupling protein-1 and other thermogenic factors. Rats exposed to prior IMO exhibited inhibition of cold-induced immune and "browning"-related expression pattern. Overall, we demonstrated that 7-day cold-induced browning"-associated changes in rat mWAT, while prior history of repeated stress prevented this response.

Obesity/Bariatric Surgery and Crohn's Disease

BACKGROUND

Crohn's disease (CD) following bariatric surgery has been previously described. It is not clear whether the clinical entity is due to rapid metabolism of fat, change in the bacterial milieu of the bowel, the loss of defense mechanisms of the stomach, or even a coincidence.

OBJECTIVES

To present observations which might serve to sort out these various etiologies.

DESIGN

We present 5 cases of colitis, ileocolitis or enteritis, some with fistula formation, with clinical onset following bariatric surgery and add these to the 7 cases previously identified as CD reported elsewhere. We provide the clinical features of these 12 cases to reconcile with causative mechanisms.

LIMITATIONS

It remains possible that the onset of CD (or other inflammatory bowel disease) precedes the bariatric surgery which then accelerates the clinical manifestations described. Furthermore, without controls the association could remain a coincidence.

CONCLUSIONS

We review the evidence for release of proinflammatory cells and cytokines contained in fat following the bariatric surgery, and also consider the roles that the surgical resection of stomach and shortening of the bowel may also bring about this syndrome. The earlier onset is more likely due to surgical loss of defenses of the stomach and the later onset to a metabolic alteration of the presurgical obesity, involving fat metabolism, and/or the microbiome. The role of characteristic creeping fat of CD is also addressed.

Outcomes of Bariatric Surgery in Patients with Inflammatory Bowel Disease

BACKGROUND

Obesity has become prevalent in patients with inflammatory bowel disease (IBD). Bariatric surgery can be considered to be contraindicated in IBD patients. We aimed to evaluate feasibility, safety, and efficacy of bariatric surgery in IBD patients.

METHODS

We retrospectively identified all morbidly obese patients with a known diagnosis of IBD, who underwent bariatric surgery between January 2005 and December 2012. Postoperative outcomes and status of IBD in patients on maintenance therapy for their disease were assessed.

RESULTS

We identified 20 IBD patients including 13 ulcerative colitis (UC) and 7 Crohn's disease (CD) patients with a mean age of 54.0 ± 10.5 years, BMI of 50.1 ± 9.0 kg/m(2), and duration of IBD of 11.3 ± 5.2 years. Eleven patients were on medication for IBD at baseline. Bariatric procedures included sleeve gastrectomy (N = 9), gastric bypass (N = 7), gastric banding (N = 3), and one conversion of band to gastric bypass. There were no intraoperative complications, but two conversions to laparotomy due to adhesions. Mean BMI change and excess weight loss at 1 year was 14.3 ± 5.7 kg/m(2) and 58.9 ± 21.1 %, respectively. Seven early postoperative complications occurred including dehydration (N = 5), pulmonary embolism (N = 1), and wound infection (N = 1). During a mean follow-up of 34.6 ± 21.7 months, five patients developed complications including pancreatitis (N = 2), ventral hernia (N = 2), and marginal ulcer (N = 1). Nine out of ten eligible patients experienced improvement in their IBD status.

CONCLUSIONS

Bariatric surgery is feasible and safe in morbidly obese patients suffering from IBD. In addition to being an effective weight loss procedure, bariatric surgery may help mitigate symptoms in this patient population.

The features of adipose-derived stem cells in patients with inflammatory bowel diseases

PURPOSE

The treatment outcomes for inflammatory bowel disease (IBD) have been improving, but the development of better therapies is needed. Stem cell therapy is promising, but little is known about the differences in adipose-derived stem cells (ADSCs) between IBD patients and healthy individuals.

METHODS

ADSCs were isolated from subcutaneous adipose tissue (SAT) in IBD (Crohn's disease, 3; ulcerative colitis, 2) and non-IBD (colorectal cancer, 5; breast cancer, 1) patients. We also analyzed the effects of tumor necrosis factor (TNF)-α on murine ADSCs.

RESULTS

The numbers of stromal vascular fraction (SVF) cells per gram of SAT were 7.72 ± 3.03 × 10⁵ in IBD and 8.51 ± 8.80 × 10⁵ in non-IBD patients (p > 0.05). The proportions of ADSCs in SVF cells were 4.98 ± 2.61% in IBD and 1.02 ± 0.67% in non-IBD patients. The numbers of ADSCs per gram of SAT were 4.16 ± 2.96 × 10⁴ in IBD and 0.88 ± 1.04 × 10⁴ in non-IBD patients. The proportions and numbers of ADSCs were significantly higher in IBD patients than in non-IBD patients. TNF-α significantly facilitated the proliferation and motility of murine ADSCs.

CONCLUSION

These results showed the potential advantage of freshly isolated autologous ADSCs in IBD patients.

Inflammatory Bowel Diseases: Review of Known Environmental Protective and Risk Factors Involved

Inflammatory bowel diseases consisting of Crohn's disease and ulcerative colitis are chronic inflammatory diseases of the gastrointestinal tract. In addition to genetic susceptibility and disturbances of the microbiome, environmental exposures forming the exposome play an important role. Starting at birth, the cumulative effect of different environmental exposures combined with a predetermined genetic susceptibility is thought to cause inflammatory bowel disease. All these environmental factors are part of a Western lifestyle, suiting the high incidence rates in Europe and the United States. Whereas receiving breastfeeding, evidence of a Helicobacter pylori infection and vitamin D are important protective factors in Crohn's disease as well as ulcerative colitis, increased hygiene, experiencing a bacterial gastroenteritis in the past, urban living surroundings, air pollution, the use of antibiotics, nonsteroidal anti-inflammatory drugs, and oral contraceptives are likely to be the most important risk factors for both diseases. Current cigarette smoking yields a divergent effect by protecting against ulcerative colitis but increasing risk of Crohn's disease, whereas former smoking increases chances of both diseases. This review gives a clear overview of the current state of knowledge concerning the exposome. Future studies should focus on measuring this exposome yielding the possibility of combining all involved factors to one exposome risk score and our knowledge on genetic susceptibility.

Reciprocal Inflammatory Signaling Between Intestinal Epithelial Cells and Adipocytes in the Absence of Immune Cells

Visceral fat accumulation as observed in Crohn's disease and obesity is linked to chronic gut inflammation, suggesting that accumulation of gut adipocytes can trigger local inflammatory signaling. However, direct interactions between intestinal epithelial cells (IECs) and adipocytes have not been investigated, in part because IEC physiology is difficult to replicate in culture. In this study, we originally prepared intact, polarized, and cytokine responsive IEC monolayers from primary or induced pluripotent stem cell-derived intestinal organoids by simple and repeatable methods. When these physiological IECs were co-cultured with differentiated adipocytes in Transwell, pro-inflammatory genes were induced in both cell types, suggesting reciprocal inflammatory activation in the absence of immunocompetent cells. These inflammatory responses were blocked by nuclear factor-κB or signal transducer and activator of transcription 3 inhibition and by anti-tumor necrosis factor- or anti-interleukin-6-neutralizing antibodies. Our results highlight the utility of these monolayers for investigating IEC biology. Furthermore, this system recapitulates the intestinal epithelium-mesenteric fat signals that potentially trigger or worsen inflammatory disorders such as Crohn's disease and obesity-related enterocolitis.

The Impact of Western Diet and Nutrients on the Microbiota and Immune Response at Mucosal Interfaces

Recent findings point toward diet having a major impact on human health. Diets can either affect the gut microbiota resulting in alterations in the host’s physiological responses or by directly targeting the host response. The microbial community in the mammalian gut is a complex and dynamic system crucial for the development and maturation of both systemic and mucosal immune responses. Therefore, the complex interaction between available nutrients, the microbiota, and the immune system are central regulators in maintaining homeostasis and fighting against invading pathogens at mucosal sites. Westernized diet, defined as high dietary intake of saturated fats and sucrose and low intake of fiber, represent a growing health risk contributing to the increased occurrence of metabolic diseases, e.g., diabetes and obesity in countries adapting a westernized lifestyle. Inflammatory bowel diseases (IBD) and asthma are chronic mucosal inflammatory conditions of unknown etiology with increasing prevalence worldwide. These conditions have a multifactorial etiology including genetic factors, environmental factors, and dysregulated immune responses. Their increased prevalence cannot solely be attributed to genetic considerations implying that other factors such as diet can be a major contributor. Recent reports indicate that the gut microbiota and modifications thereof, due to a consumption of a diet high in saturated fats and low in fibers, can trigger factors regulating the development and/or progression of both conditions. While asthma is a disease of the airways, increasing evidence indicates a link between the gut and airways in disease development. Herein, we provide a comprehensive review on the impact of westernized diet and associated nutrients on immune cell responses and the microbiota and how these can influence the pathology of IBD and asthma.

Visceral Adiposity, Genetic Susceptibility, and Risk of Complications Among Individuals with Crohn's Disease

INTRODUCTION

Adipose tissue in mesenteric fat plays a key role in systemic and luminal inflammation. However, little is known about the role of visceral adipose tissue (VAT) and its interaction with genetic predisposition in Crohn's disease (CD) progression.

METHODS

Our study population included patients with CD enrolled in Prospective Registry in Inflammatory Bowel Disease Study at Massachusetts General Hospital (PRISM). VAT volume was measured from computed tomography using Aquarius 3D. We used logistic regression models to estimate the multivariable-adjusted odds ratio and 95% CI. We tested for effect modification by genetic predisposition using the log likelihood ratio test.

RESULTS

Among 482 patients with CD with available data on VAT, 174 developed penetrating disease, 132 developed stricturing disease, 147 developed perianal disease, and 252 required surgery. Compared with individuals in the lowest quartile of VAT volume, the multivariable-adjusted odds ratio of surgery among individuals in the highest quartile was 2.02 (95% CI, 1.09-3.76; Ptrend = 0.006). Similarly, the risk of penetrating disease seemed to increase with greater VAT volume (Ptrend = 0.022) but not stricturing or perianal disease (all Ptrend > 0.23). The associations between VAT volume and CD complications were not modified by genetic predisposition (all Pinteraction > 0.12).

CONCLUSIONS

Visceral adiposity as measured by VAT volume may be associated with a significant increase in the risk of penetrating disease and surgery in CD. Our data suggest that visceral adiposity as measured by VAT may negatively impact long-term progression of CD regardless of genetic predisposition.

Response of gut microbiota and inflammatory status to bitter melon (Momordica charantia L.) in high fat diet induced obese rats

ETHNOPHARMACOLOGICAL RELEVANCE

Bitter melon (Momordica charantia L.) is rich in a variety of biologically active ingredients, and has been widely used in traditional Chinese medicine (TCM) to treat various diseases, including type 2 diabetes and obesity.

AIM OF THE STUDY

We aimed to investigate how bitter melon powder (BMP) could affect obesity-associated inflammatory responses to ameliorate high-fat diet (HFD)-induced insulin resistance, and investigated whether its anti-inflammatory properties were effected by modulating the gut microbiota.

MATERIALS AND METHODS

Obese SD rats (Sprague-Dawley rats, rattus norregicus) were randomly divided into four groups: (a) normal control diet (NCD) and distilled water, (b) HFD and distilled water, (c) HFD and 300mg BMP/kg body weight (bw), (d) HFD and 10mg pioglitazone (PGT)/kg bw.

RESULTS

We observed remarkable decreases in the fasting glucose, fasting insulin, HOMA-IR index, serum lipid levels, and cell sizes of epididymal adipose tissues in the BMP and PGT groups after 8 weeks. BMP could significantly improve the proinflammatory cytokine tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), anti-inflammatory cytokine interleukin-10 (IL-10), and local endotoxin levels compared to the HFD group (p<0.05). BMP suppressed the activation of nuclear factor-κB (NF-κB) by inhibiting inhibitor of NF-κB alpha (IκBα) degradation and phosphorylation of c-Jun N-terminal kinase/ p38 mitogen-activated protein kinases (JNK/p38 MAPKs) in adipose tissue. Sequencing results illustrated that BMP treatment markedly decreased the proportion of the endotoxin-producing opportunistic pathogens and increased butyrate producers.

CONCLUSIONS

These results demonstrate that BMP ameliorates insulin sensitivity partly via relieving the inflammatory status in the system and in white adipose tissues of obese rats, and is associated with a proportional regulation of specific gut microbiota.

Functional Analyses of the Crohn's Disease Risk Gene LACC1

BACKGROUND

Genetic variation in the Laccase (multicopper oxidoreductase) domain-containing 1 (LACC1) gene has been shown to affect the risk of Crohn's disease, leprosy and, more recently, ulcerative colitis and juvenile idiopathic arthritis. LACC1 function appears to promote fatty-acid oxidation, with concomitant inflammasome activation, reactive oxygen species production, and anti-bacterial responses in macrophages. We sought to contribute to elucidating LACC1 biological function by extensive characterization of its expression in human tissues and cells, and through preliminary analyses of the regulatory mechanisms driving such expression.

METHODS

We implemented Western blot, quantitative real-time PCR, immunofluorescence microscopy, and flow cytometry analyses to investigate fatty acid metabolism-immune nexus (FAMIN; the LACC1 encoded protein) expression in subcellular compartments, cell lines and relevant human tissues. Gene-set enrichment analyses were performed to initially investigate modulatory mechanisms of LACC1 expression. A small-interference RNA knockdown in vitro model system was used to study the effect of FAMIN depletion on peroxisome function.

RESULTS

FAMIN expression was detected in macrophage-differentiated THP-1 cells and several human tissues, being highest in neutrophils, monocytes/macrophages, myeloid and plasmacytoid dendritic cells among peripheral blood cells. Subcellular co-localization was exclusively confined to peroxisomes, with some additional positivity for organelle endomembrane structures. LACC1 co-expression signatures were enriched for genes involved in peroxisome proliferator-activated receptors (PPAR) signaling pathways, and PPAR ligands downregulated FAMIN expression in in vitro model systems.

CONCLUSION

FAMIN is a peroxisome-associated protein with primary role(s) in macrophages and other immune cells, where its metabolic functions may be modulated by PPAR signaling events. However, the precise molecular mechanisms through which FAMIN exerts its biological effects in immune cells remain to be elucidated.

Bariatric surgery in morbidly obese patients with inflammatory bowel disease: A systematic review

BACKGROUNDS

With increased prevalence of obesity, the number of inflammatory bowel disease (IBD) patients suffering from morbid obesity has raised. It is not clear yet if bariatric surgery is a safe and effective option in this population.

OBJECTIVES

Our systematic review aims to summarize the available literature on the safety and efficacy of bariatric surgery in morbidly obese patients with IBD.

SETTING

University hospital, Iran.

METHODS

A PubMed/MEDLINE search was performed to identify studies reporting the outcome of morbidly obese IBD patients. Postoperative outcome of IBD patients after bariatric surgery were pooled for early and late complications, change of IBD status, and medication alteration.

RESULTS

A total of 7 studies reported post-bariatric surgery outcomes of 43 morbidly obese IBD patients (31 females, 11 males) with an age ranging from 30 to 64 years and a body mass index from 35.7 to 71 kg/m². Of these, 25 suffered Crohn's disease (CD) (58.2%) and 18 were ulcerative colitis (UC) patients (41.8%). The small bowel was the most common involved gastrointestinal segment in 27.3% of patients. CD patients more commonly underwent sleeve gastrectomy (72%), while UC patients similarly underwent sleeve gastrectomy and Roux-en-Y gastric bypass (44.4%). After a follow-up of 8 to 77 months, IBD patients lost up to 71.4%±5.9% of excess weight and 14.3 kg/m²±5.7 kg/m² of body mass index. There were 9 early (21.4%) and 10 late (23.8%) postoperative complications related to the bariatric procedure. IBD remitted in 20 patients (47.6%), improved in 2 patients (4.8%), but exacerbated in 7 patients (16.7%).

CONCLUSIONS

Although available data on morbidly obese patients with IBD is scarce, bariatric surgery seems to be a safe and effective option for these patients with no added morbidity or mortality. Further studies are necessary to confirm this data.

Adipokines and the role of visceral adipose tissue in inflammatory bowel disease

Recently, adipocytes have been recognized as actively participating in local and systemic immune responses via the secretion of peptides detectable in relevant levels in the systemic circulation, the so-called "adipo(cyto)kines". Multiple studies appearing within the last 10-15 years have focused on the possible impact of adipose tissue depots on inflammatory bowel disease (IBD). Consequently, various hypotheses regarding the role of different adipokines in inflammatory diseases in general and in intestinal inflammatory processes in particular have been developed and have been further refined in recent years. After a focused summary of the data reported concerning the impact of visceral adipose tissue on IBD, such as Crohn's disease and ulcerative colitis, our review focuses on recent developments indicating that adipocytes as part of the innate immune system actively participate in antimicrobial host defenses in the context of intestinal bacterial translocation, which are of utmost importance for the homeostasis of the whole organism. Modulators of adipose tissue function and regulators of adipokine secretion, as well as modifiers of adipocytic pattern recognition molecules, might represent future potential drug targets in IBD.

Psoriasis and inflammatory bowel disease: links and risks

Psoriasis and the spectrum of inflammatory bowel diseases (IBD) are chronic, inflammatory, organotropic conditions. The epidemiologic coexistence of these diseases is corroborated by findings at the level of disease, biogeography, and intrafamilial and intrapatient coincidence. The identification of shared susceptibility loci and DNA polymorphisms has confirmed this correlation at a genetic level. The pathogenesis of both diseases implicates the innate and adaptive segments of the immune system. Increased permeability of the epidermal barrier in skin and intestine underlies the augmented interaction of allergens and pathogens with inflammatory receptors of immune cells. The immune response between psoriasis and IBD is similar and comprises phagocytic, dendritic, and natural killer cell, along with a milieu of cytokines and antimicrobial peptides that stimulate T-cells. The interplay between dendritic cells and Th17 cells appears to be the core dysregulated immune pathway in all these conditions. The distinct similarities in the pathogenesis are also reflected in the wide overlapping of their therapeutic approaches. Small-molecule pharmacologic immunomodulators have been applied, and more recently, biologic treatments that target proinflammatory interleukins have been introduced or are currently being evaluated. However, the fact that some treatments are quite selective for either skin or gut conditions also highlights their crucial pathophysiologic differences. In the present review, a comprehensive comparison of risk factors, pathogenesis links, and therapeutic strategies for psoriasis and IBD is presented. Specific emphasis is placed on the role of the immune cell species and inflammatory mediators participating in the pathogenesis of these diseases.

Lipopolysaccharide induces catecholamine production in mesenteric adipose tissue of rats previously exposed to immobilization stress

Catecholamines (CAs) are mainly produced by sympathoadrenal system but their de novo production has been also observed in adipose tissue cells. The aim of this work was to investigate whether immune challenge induced by lipopolysaccharide (LPS) modulates biosynthesis of CAs in mesenteric adipose tissue (MWAT), as well as whether previous exposure to immobilization (IMO) stress could modulate this process. Sprague-Dawley rats were exposed to single (2 h) or repeated (2 h/7 days) IMO and afterwards injected with LPS (i.p., 100 μg/kg body weight) and sacrificed 3 h later. LPS did not alter CA biosynthesis in MWAT in control rats. Single and repeated IMO elevated CAs and expression of CA biosynthetic enzymes in MWAT, including adipocyte and stromal/vascular fractions (SVF). Repeated IMO followed by LPS treatment led to the up-regulation of CA-biosynthetic enzymes expression, elevation of CAs in SVF but depletion of norepinephrine and epinephrine in adipocyte fraction. Prior IMO caused a marked LPS-induced macrophage infiltration in MWAT as evaluated by F4/80 expression. A positive correlation between expression of tyrosine hydroxylase and F4/80 suggests macrophages as the main source of LPS-induced CA production in MWAT. Furthermore, prior exposure to the single or repeated IMO differently affected immune responses following LPS treatment by modulation of inflammatory cytokine expression. These data suggest that stress might be a significant modulator of immune response in MWAT via stimulation of the macrophage infiltration associated with cytokine response and de novo production of CAs.

The Role of the Mesentery in Crohn's Disease: The Contributions of Nerves, Vessels, Lymphatics, and Fat to the Pathogenesis and Disease Course

Crohn's disease (CD) is a complex gastrointestinal disorder involving multiple levels of cross talk between the immunological, neural, vascular, and endocrine systems. The current dominant theory in CD is based on the unidirectional axis of dysbiosis-innate immunity-adaptive immunity-mesentery-body system. Emerging clinical evidence strongly suggests that the axis be bidirectional. The morphologic and/or functional abnormalities in the mesenteric structures likely contribute to the disease progression of CD, to a less extent the disease initiation. In addition to adipocytes, mesentery contains nerves, blood vessels, lymphatics, stromal cells, and fibroblasts. By the secretion of adipokines that have endocrine functions, the mesenteric fat tissue exerts its activity in immunomodulation mainly through response to afferent signals, neuropeptides, and functional cytokines. Mesenteric nerves are involved in the pathogenesis and prognosis of CD mainly through neuropeptides. In addition to angiogenesis observed in CD, lymphatic obstruction, remodeling, and impaired contraction maybe a cause and consequence of CD. Lymphangiogenesis and angiogenesis play a concomitant role in the progress of chronic intestinal inflammation. Finally, the interaction between neuropeptides, adipokines, and vascular and lymphatic endothelia leads to adipose tissue remodeling, which makes the mesentery an active participator, not a bystander, in the disease initiation and precipitation CD. The identification of the role of mesentery, including the structure and function of mesenteric nerves, vessels, lymphatics, and fat, in the intestinal inflammation in CD has important implications in understanding its pathogenesis and clinical management.

Intestinal inflammation requires FOXO3 and prostaglandin E2-dependent lipogenesis and elevated lipid droplets

Intestinal inflammation has been recently characterized by the dysregulation of lipids as metabolic and energy sources, revealing a novel feature of its pathophysiology. Because intracellular lipids, stored in dynamic lipid droplets (LDs), provide energy for cellular needs, we investigated whether they play a role in intestinal inflammation. In the inflamed intestine of mice, elevated LDs were found in colonic and infiltrating immune cells as shown by staining for the LD coat protein PLIN2 and for lipids with BODIPY. In colonic cells, TNF stimulated LD increases by receptor signaling rely on phosphatidylinositol 3-kinase activation. Downstream, TNF triggered a negative regulatory loop between LDs and the transcription factor FOXO3. This was shown in the colon of Foxo3-deficient mice, where elevation in PLIN2 and lipids were further facilitated by inflammation and were more prominent relative to wild-type, whereas, in colonic cells, inhibition of lipogenesis blocked the TNF-mediated loss of FOXO3. Furthermore, blockade of PGE2 synthesis abrogated TNF-stimulated increases in LDs and FOXO3 inactivation. We found in colonic tissue of Foxo3-deficient mice higher levels of cyclooxygenase-2, a mediator of prostaglandin E2 (PGE2) synthesis, supporting involvement of PGE2 in the LD-FOXO3 regulatory loop. Ultimately, TNF-stimulated lipogenesis leading to elevated LDs facilitated NF-κB-mediated increases in IL-8 protein, which is associated with the surface of LDs found in the lumina of the endoplasmic reticulum and Golgi apparatus. This novel immunometabolic mechanism of colonic inflammation involving elevated LDs could provide opportunities for new treatment options.

The Prevalence of Incidentally Detected Idiopathic Misty Mesentery on Multidetector Computed Tomography: Can Obesity Be the Triggering Cause?

PURPOSE

Misty mesentery appearance is commonly reported in daily practice, usually as a secondary finding of various pathological entities, but sometimes it is encountered as an isolated finding that cannot be attributed to any other disease entity. We aimed to assess the prevalence of cases with incidentally detected idiopathic misty mesentery on computed tomography (CT) and to summarize the pathologies leading to this appearance.

METHODS

Medical records and initial and follow-up CT features of patients with misty mesentery appearance between January 2011 and January 2013 were analysed. The study included cases with no known cause of misty mesentery according to associated CT findings, clinical history, or biochemical manifestations, and excluded patients with diseases known to cause misty mesentery, lymph nodes greater than a short-axis diameter of 5 mm, discrete mesenteric masses, or bowel wall thickening.

RESULTS

There were a total of 561 patients in whom misty mesentery appearance was depicted on abdominopelvic CT scans. A total of 80 cases were found to have isolated incidental idiopathic misty mesentery, giving a prevalence of 7%. The common indication for CT examination was abdominal pain. There was a slight female predominance (51.3%). 67.5% of all patients were classified as obese and 17.5% as overweight.

CONCLUSIONS

The results of the present study show that idiopathic incidental misty mesentery appearance has a significant prevalence. Also, the high body mass index of these patients and the growing evidence of obesity-induced inflammatory changes in adipose tissue are suggestive of an association between obesity and misty mesentery appearance on CT.

Association between high visceral fat area and postoperative complications in patients with Crohn's disease following primary surgery

AIM

The aim of this study was to determine the association between visceral fat area (VFA) on CT and postoperative complications after primary surgery in patients with Crohn's disease (CD).

METHOD

Inclusion criteria were patients with a confirmed diagnosis of CD who had preoperative abdominal CT scan. The areas of total fat, subcutaneous fat and visceral fat were measured using an established image-analysis method at the lumbar 3 (L3) level on CT cross-sectional images. Visceral obesity was defined as a visceral fat area (VFA) of ≥ 130 cm(2) . Clinical variables, intra-operative outcomes and postoperative courses within 30 days were analysed.

RESULTS

A total of 164 patients met the inclusion criteria. Sixty-three (38.4%) patients had postoperative complications. The mean age of the patients with complications (the study group) was 40.4 ± 15.4 years and of those without complications (the control group) was 35.8 ± 12.9 years (P = 0.049). There were no differences in disease location and behaviour between patients with or without complications (P > 0.05). In multivariable analysis, VFA [odds ratio (OR) = 2.69; 95% confidence interval (CI): 1.09-6.62; P = 0.032] and corticosteroid use (OR = 2.86; 95% CI: 1.32-6.21; P = 0.008) were found to be associated with postoperative complications. Patients with visceral obesity had a significantly longer operative time (P = 0.012), more blood loss (P = 0.019), longer bowel resection length (P = 0.003), postoperative ileus (P = 0.039) and a greater number of complications overall (P < 0.001).

CONCLUSION

High VFA was found to be associated with an increased risk for 30-day postoperative complications in patients with CD undergoing primary surgery.

Mesenteric Adipocyte Dysfunction in Crohn's Disease is Associated with Hypoxia

BACKGROUND

Abnormalities in mesenteric adipose tissue (MAT) have long been recognized; however, the functional changes in the mesenteric adipocytes as well as the underlying mechanisms are not entirely clear. The aim of this study was to analyze the function and morphology of the MAT in patients with Crohn's disease (CD) and the underlying mechanism.

METHODS

The MAT specimens were obtained from areas adjacent to the intestinal wall in patients with CD (n = 33) and without CD (control, n = 23) who underwent intestinal resection. For patients with CD, paired samples were obtained from the macroscopically hypertrophic mesenteric adipose tissue (htMAT), adjacent to the involved ileum, and the macroscopically normal mesenteric adipose tissue (nMAT), contiguous with the healthy segment of the ileum. Morphological and molecular techniques were used to detect the characteristics of the MAT of CD and compare them with the characteristics of the control tissues. Hypoxia was confirmed by a high expression of hypoxia-inducible factor 1α.

RESULTS

The function and morphology of the nMAT in patients with CD were similar to those of the control tissues. htMAT of CD was dysfunctional based on the evidence that htMAT exhibited decreased lipid store, fatty acid synthase, and adipose triglyceride lipase, but increased levels of glucose transporter 1, aldolase C, and lactate when compared with those from nMAT and control tissues (P < 0.01). In addition, the structure of htMAT was found to be disorganized and characterized by higher levels of collagen content, interleukin 1β, interleukin 6, tumor necrosis factor α, and MCP-1 when compared with nMAT and control tissues (P < 0.01). htMAT was in a hypoxic condition, based on the findings that htMAT had a higher level of hypoxia-inducible factor 1α and a decreased number of vessels per adipocyte compared with those of nMAT and the control tissues (P < 0.01). The transforming growth factor β/Smad and nuclear factor-kappa B signaling pathways were found to be activated in htMAT, which may be associated with hypoxia.

CONCLUSIONS

The disorganized structure and dysfunction of mesenteric adipocyte tissue in CD was confirmed, and these alterations may be associated with hypoxia. It is possible that amelioration of mesenteric adipocyte hypoxia may help attenuate CD with underlying MAT inflammation.

Impact of metabolic syndrome on the hospitalization rate of Crohn's disease patients seen at a tertiary care center: a retrospective cohort study

BACKGROUND/AIMS

Recent studies suggest that markers of mesenteric inflammation, such as increased adipose tissue, may be associated with poor outcomes in Crohn's disease (CD). This study's hypothesis is that CD patients with metabolic syndrome (MetS) have more CD-related hospitalizations than CD patients without MetS.

METHODS

We conducted a retrospective cohort study of CD patients seen from 2000 to 2012 at our tertiary care center. We analyzed crude and age-, sex- and duration of CD-adjusted incidence rate ratio (IRR) of CD-related hospitalization of those with MetS versus those without MetS. We also investigated possible associations between individual component conditions of MetS and rate of CD-related hospitalization.

RESULTS

A total of 868 CD patients were included. There were 37 (4%) patients with MetS at initial observation. After multi-variable adjustment, patients with MetS had a CD-related hospitalization rate twice that of those who did not have MetS. High triglycerides (TG), low high density lipoprotein (HDL) cholesterol and diabetes mellitus (DM) were associated with increased risk of CD-related hospitalization.

CONCLUSIONS

CD patients with MetS have a higher rate of CD-related hospitalization compared to those without MetS. Hypertriglyceridemia, low HDL cholesterol and DM may be good markers of local and systemic inflammation as seen in CD.