Role of diet in the development of inflammatory bowel disease.

The inflammatory bowel diseases (IBDs) are a group of heterogeneous disorders characterized by acute and chronic inflammatory changes in the small or large bowel, or in both. Increasing incidence and prevalence figures for IBD both in the developed and developing world indicate that environmental factors are at least as significant in IBD as genetic susceptibility. Of these, diet and the host microbiota are likely to play important but as yet poorly defined roles. The major constituents of a standard "Western" diet may contribute to, or protect against, intestinal inflammation via several mechanisms. These include the effects of insulin resistance and short-chain fatty acids such as butyrate, modification of intestinal permeability, the antiinflammatory role of polyunsaturated fatty acids, and the effect of sulfur compounds from protein on host microbiota. This detailed review critically assesses the evidence for the role of diet in the development of IBD and examines the evidence for obesity as a contributing factor to IBD pathogenesis. Particular attention is focused on methodological issues including suitability of cases and controls, confounders such as smoking, and total energy expenditure.

AuSPEN clinical practice guideline for home parenteral nutrition patients in Australia and New Zealand.

OBJECTIVE: Evidence based guidelines for home parenteral nutrition (HPN) were commissioned by the Australasian Society of Parenteral and Enteral Nutrition (AuSPEN) and developed by a multidisciplinary group. The guidelines make recommendations in four domains: patient selection, patient training, formulation and monitoring regimens, and preventing and managing complications. METHODS: The Appraisal of Guidelines Research and Evaluation guideline process was used to focus questions and identify evidence by systematic literature reviews of meta-analyses and randomized control trials in the Cochrane Library, Medline, Embase, and Cinahl to mid-2007. Where no randomized control trial evidence was found, the search was broadened to observational studies and expert opinion from related national and international guidelines as assessed by a validated appraisal process. RESULTS: Selection of patients must assess individual risk/benefit and medical ethics. Patient training should be undertaken within a structured framework. Access devices should be selected for lowest risk of complications, including occlusion, sepsis, and breakage and be managed by early diagnosis and treatment. HPN should be formulated according to individual patient requirements by professionals with relevant skills and training. Pumps and ancillary products should conform to quality standards. Other intravenous medications may be prescribed provided these are reviewed for compatibility and effects on metabolic status. CONCLUSION: Overall there is a lack of randomized control trials to provide high-quality evidence-based guidance but graded recommendations can be made. Multidisciplinary teams in centers with HPN management expertise are required for optimal care. This guideline should improve outcomes and quality of life for HPN patients in Australia and New Zealand.