Dawn W. Adams

Alterations in lipid, amino acid, and energy metabolism distinguish Crohn’s disease from ulcerative colitis and control subjects by serum metabolomic profiling

IntroductionBiomarkers are needed in inflammatory bowel disease (IBD) to help define disease activity and identify underlying pathogenic mechanisms. We hypothesized that serum metabolomics, which produces unique metabolite profiles, can aid in this search.ObjectivesThe aim of this study was to characterize serum metabolomic profiles in patients with IBD, and to assess for differences between patients with ulcerative colitis (UC), Crohn’s disease (CD), and non-IBD subjects.MethodsSerum samples from 20 UC, 20 CD, and 20 non-IBD control subjects were obtained along with patient characteristics, including medication use and clinical disease activity. Non-targeted metabolomic profiling was performed using ultra-high performance liquid chromatography/mass spectrometry (UPLC-MS/MS) optimized for basic or acidic species and hydrophilic interaction liquid chromatography (HILIC/UPLC-MS/MS).ResultsIn total, 671 metabolites were identified. Comparing IBD and control subjects revealed 173 significantly altered metabolites (27 increased and 146 decreased). The majority of the alterations occurred in lipid-, amino acid-, and energy-related metabolites. Comparing only CD and control subjects revealed 286 significantly altered metabolites (54 increased and 232 decreased), whereas comparing UC and control subjects revealed only five significantly altered metabolites (all decreased). Hierarchal clustering using significant metabolites separated CD from UC and control subjects.ConclusionsWe demonstrate that a number of lipid-, amino acid-, and tricarboxylic acid cycle-related metabolites were significantly altered in IBD patients, more specifically in CD. Therefore, alterations in lipid and amino acid metabolism and energy homeostasis may play a key role in the pathogenesis of CD.

Parenteral Nutrition: Indications, Access, and Complications

Parenteral nutrition (PN) is a life-sustaining therapy in patients with intestinal failure who are unable to tolerate enteral feedings. Patient selection should be based on a thorough assessment to identify those at high nutrition risk based on both disease severity and nutritional status. This article reviews both the acute and chronic indications for PN as well as special formulation consideration in specific disease states, vascular access, and complications of both short-term and long-term PN.

Nutritional Consideration in Celiac Disease and Nonceliac Gluten Sensitivity

Celiac disease is an autoimmune disorder due to the inflammatory response to gluten in genetically predisposed individuals. It causes an enteropathy associated with several nutritional complications. Strict compliance to a gluten-free diet (GFD) is the current primary therapy. Nonceliac gluten sensitivity (NCGS) is a condition in which gluten ingestion leads to systemic symptoms but is not associated with small bowel atrophy or abnormal celiac serologies. A GFD heals celiac disease enteropathy and improves symptoms in NCGS. However, a long-term GFD can be associated with nutritional deficiencies and requires monitoring and guidance.