Jianbo Yang

Prevalence of Sarcopenia and Its Impact on Postoperative Outcome in Patients With Crohn’s Disease Undergoing Bowel Resection

Background: Sarcopenia has been proposed to be a prognostic factor of outcomes for various diseases but has not been applied to Crohn’s disease (CD). We aimed to assess the impact of sarcopenia on postoperative outcomes after bowel resection in patients with CD. Materials and Methods: Abdominal computed tomography images within 30 days before bowel resection in 114 patients with CD between May 2011 and March 2014 were assessed for sarcopenia as well as visceral fat areas and subcutaneous fat areas. The impact of sarcopenia on postoperative outcomes was evaluated using univariate and multivariate analyses. Results: Of 114 patients, 70 (61.4%) had sarcopenia. Patients with sarcopenia had a lower body mass index, lower preoperative levels of serum albumin, and more major complications (15.7% vs 2.3%, P = .027) compared with patients without sarcopenia. Moreover, predictors of major postoperative complications were sarcopenia (odds ratio [OR], 9.24; P = .04) and a decreased skeletal muscle index (1.11; P = .023). Preoperative enteral nutrition (OR, 0.13; P = .004) and preoperative serum albumin level >35 g/L (0.19; P = .017) were protective factors in multivariate analyses. Conclusion: The prevalence of sarcopenia is high in patients with CD requiring bowel resection. It significantly increases the risk of major postoperative complications and has clinical implications with respect to nutrition management before surgery for CD.

Sodium Butyrate Reduces Colitogenic Immunoglobulin A-Coated Bacteria and Modifies the Composition of Microbiota in IL-10 Deficient Mice.

High levels of immunoglobulin A (IgA)-coated bacteria may have a role in driving inflammatory bowel disease (IBD). We therefore investigated the effect of sodium butyrate on microbiota in IBD prone interleukin (IL)-10−/− mice. At 8 weeks of age, mice were allocated into three groups (n = 4/group): normal (C57BL/6), IL-10−/−, and IL-10−/− treated with sodium butyrate (100 mM). Severity of colitis, inflammatory cytokine and short-chain fatty acid (SCFA) concentration in proximal colon contents, the percentage of IgA-coated bacteria and microbiota composition by 16S ribosomal RNA assessment of stool were measured after 4 weeks of treatment. Sodium butyrate ameliorated histological colitis and decreased levels of tumor necrosis factor (TNF)-α and IL-6 in IL-10−/− mice compared with those without treatment. At the phylum level, a reduction in Bacteroidetes and an increase in Firmicutes in IL-10−/− mice treated with sodium butyrate were observed. Additionally, Prevotellaceae species were reduced in IL-10−/− mice treated with sodium butyrate as compared with those without treatment. The level of biodiversity was slightly increased and the amount of IgA-coated bacteria decreased in IL-10−/− mice treated with sodium butyrate compared with those without treatment. Our results indicate that sodium butyrate protects against colitis, possibly through modifying the gut microbiota, enriching biodiversity and reducing the amount of colitogenic IgA-coated bacteria in IL-10−/− mice.

Soluble Dietary Fiber Ameliorates Radiation-Induced Intestinal Epithelial-to-Mesenchymal Transition and Fibrosis.

Background: Intestinal fibrosis is a late complication of pelvic radiotherapy. Epithelial-to-mesenchymal transition (EMT) plays an important role in tissue fibrosis. The aim of this study was to examine the effect of soluble dietary fiber on radiation-induced intestinal EMT and fibrosis in a mouse model. Materials and Methods: Apple pectin (4% wt/wt in drinking water) was administered to wild-type and pVillin-Cre-EGFP transgenic mice with intestinal fibrosis induced by a single dose of abdominal irradiation of 10 Gy. The effects of pectin on intestinal EMT and fibrosis, gut microbiota, and short-chain fatty acid (SCFA) concentration were evaluated. Results: Intestinal fibrosis in late radiation enteropathy showed increased submucosal thickness and subepithelial collagen deposition. Enhanced green fluorescent protein (EGFP)+/vimentin+ and EGFP+/&agr;–smooth muscle actin (SMA)+ coexpressing cells were most clearly observed at 2 weeks after irradiation and gradually decreased at 4 and 12 weeks. Pectin significantly attenuated the thickness of submucosa and collagen deposition at 12 weeks (24.3 vs 27.6 µm in the pectin + radiation-treated group compared with radiation-alone group, respectively, P < .05; 69.0% vs 57.1%, P < .001) and ameliorated EMT at 2 and 4 weeks. Pectin also modulated the intestinal microbiota composition and increased the luminal SCFA concentration. Conclusion: The soluble dietary fiber pectin protected the terminal ileum against radiation-induced fibrosis. This effect might be mediated by altered SCFA concentration in the intestinal lumen and reduced EMT in the ileal epithelium.

High Visceral to Subcutaneous Fat Ratio Is Associated with Increased Postoperative Inflammatory Response after Colorectal Resection in Inflammatory Bowel Disease

Aim Excessive postoperative inflammatory response, which is characterized by overproduction of cytokines, often leads to complications after colorectal surgery. However, the impact of body composition on postoperative inflammatory response is largely unknown. The aim of this study is to elucidate whether body fat amount and its distribution affects postoperative inflammation after colorectal surgery in IBD patients. Methods Eighty-six patients undergoing colorectal resection for IBD from June 2014 to Jan 2017 were enrolled. Abdominal CT images within one week prior to surgery were assessed for visceral fat, subcutaneous fat, and muscle mass. Postoperative inflammatory response was evaluated using serum CRP, PCT, and IL-6 levels on postoperative days 1, 3, and 5. Univariate analysis was conducted to identify risk factors for infectious complications. The correlation between body composition and postoperative plasma concentration of inflammatory markers was analyzed using a linear regression model. ROC curve was applied to analyze the effect of different body composition parameters on postoperative infectious complications and to determine the relationship between inflammatory markers and infectious complications. Results Neither volume of fat or muscle was related to postoperative plasma concentrations of CRP, IL-6, and PCT. However, visceral to subcutaneous fat ratio was associated with PCT levels on postoperative days (POD) 1, 3, and 5, with the highest regression coefficient on POD1 (β = 0.360; 95% CI, 0.089–0.631; P = 0.010). Body composition did not predict postoperative infectious complications, while CRP on POD 3 was predictive of infectious complications. Conclusion Increased visceral to subcutaneous fat ratio was associated with postoperative inflammatory response in IBD patients undergoing colorectal resection. This may partly explain the increased incidence of postoperative complications in patients with visceral obesity.

N-3 polyunsaturated fatty acids ameliorate hepatic steatosis via the PPAR-α/CPT-1α pathway in a mouse model of parenteral nutrition

Parenteral nutrition (PN) is one of the basic therapies for patients with intestinal failure; however, hepatic steatosis associated with PN limits the long-term use of PN. N-3 polyunsaturated fatty acids (PUFAs) have been used to improve clinical outcomes of patients receiving PN; however, the mechanisms by which n-3 PUFAs ameliorate hepatic steatosis remain unclear. In the present study, C57BL/6J mice were randomly assigned to three treatment groups, namely, enteral nutrition (EN), n-3 PUFAs, and n-6 PUFAs. Additionally, MK 886 was used to inhibit PPAR-α. After 7 days of intervention, mice were sacrificed, and liver tissue and serum samples were collected. Results from liver weight and liver triglyceride measurements and Oil Red O staining showed that n-3 PUFAs significantly reduced the liver triglyceride levels. In addition, treatment with n-3 PUFAs resulted in a greater decrease in serum triglyceride and low-density lipoprotein cholesterol levels compared to n-6 PUFAs. The key enzymes involved in FA oxidation, namely, PPAR-α and CPT-1α, were significantly restored at both the mRNA and protein levels in the n-3 PUFAs group. However, the benefits of n-3 PUFAs in improving serum and liver TG levels were abolished when the PPAR-α/CPT-1α pathway was blocked by MK 886. The results of this study indicated that n-3 PUFAs ameliorated the PN-associated hepatic steatosis by activating the PPAR-α/CPT-1α pathway. The present study provided a reliable scientific basis supporting the potential beneficial effects of n-3 PUFAs for improving hepatic steatosis in patients receiving long-term parenteral nutrition.

Preoperative Intra-abdominal Sepsis, Not Penetrating Behavior Itself, Is Associated With Worse Postoperative Outcome After Bowel Resection for Crohn Disease: A Retrospective Cohort Study.

AbstractIt is generally believed that penetrating behavior is associated with worse surgical outcomes in Crohn disease (CD). We hypothesized that intra-abdominal sepsis (IAS), but not penetrating behavior itself, contributes to postoperative morbidity in patients undergoing bowel resection for CD.Patients who underwent surgery from April 2010 to April 2014 were retrospectively identified from a prospectively maintained database. Demographic information and preoperative and operative data were collected. The outcomes following surgery in patients who had penetrating disease with or without IAS versus nonpenetrating CD were compared.Of 288 patients, 180 had penetrating CD, including 54 who had IAS. Preoperative characteristics were similar between the groups, except for serum albumin, abdominal drainage, and prior bowel resection. Patients with penetrating CD with IAS were more likely to have a stoma, surgical site complications, postoperative IAS complications, and major complications than patients with penetrating CD without IAS or nonpenetrating CD. There were no significant differences between patients with penetrating CD without IAS and nonpenetrating CD. The postoperative outcome was strengthened after propensity-score matching analysis. Moreover, penetrating CD with IAS (odds ratio [OR], 13.034; P = 0.004) is a risk predictor for major postoperative complications, and preoperative serum albumin (OR, 0.095; P = 0.002) and preoperative enteral nutrition (OR, 0.203, P = 0.049) are protective.Penetrating CD without IAS did not adversely affect postoperative outcome after bowel resection compared with penetrating CD with IAS. These results may revise the notion that all patients with penetrating CD have worse postoperative complications.