Reviews & Analysis

As pregnancies frequently occur in patients with IBD, and given that TNF inhibitors are increasingly being used for treatment of this chronic intestinal disease, the discontinuation of biologic agents during the third trimester in patients with quiescent disease has been advocated owing to safety concerns.

Ciclosporin and infliximab are used as rescue therapies for the treatment of severe steroid-refractory ulcerative colitis. Now, an open-label, head-to-head randomized controlled trial has demonstrated that these drugs are well-tolerated and have equivalent efficacy in inducing short-term clinical response, mucosal healing and decreasing colectomy rates at 3 months.

Richard Guerrant and colleagues discuss the growing evidence that vicious cycles of early childhood enteric infections and malnutrition are associated with obesity and its comorbidities in later life, forming a triple burden of poverty. The potential mechanisms and interventions that must be understood and applied to prevent this loss of human potential are also presented.

The enteric nervous system (ENS) arises from neural crest-derived cells. Here, Heather Young and colleagues provide an overview of the progress made in the past five years in our understanding of ENS development and the potential involvement of defects in ENS development in paediatric motility disorders.

Ischaemia–reperfusion injury (IRI) in the liver is a major complication of transplantation. This Review outlines our current understanding of the cellular and molecular mechanisms that underlie liver IRI and summarizes the latest progress in large animal models and clinical trials of liver IRI.

Treatment of recurrent Clostridium difficile infection is challenging. New research now replicates human disease in a mouse model, shedding light on why antibiotics often fail to prevent further recurrences and demonstrating that targeted manipulation of the gut microbiota could be a feasible treatment option.

The risk of venous thromboembolism (VTE) is known to be increased in patients with IBD. However, no specific consensus statements exist regarding the prevention of postoperative VTE in patients with this disease. The results of a large retrospective cohort study quantifying the risk of postoperative VTE in patients with IBD are discussed.

Treatment success for Helicobacter pylori, a major human pathogen, with popular drug regimens has generally declined to unacceptably low levels. As part of the worldwide effort to identify novel drug regimens that will reliably achieve high levels of success, Tay, Marshall and colleagues report their results with novel multidrug-tailored therapies.

Novel findings draw attention to the adverse effect that neoplastic transformation of epithelial cells has on intestinal barrier function and cancer progression. An impaired intestinal barrier facilitated the translocation of microbial products, which promoted cytokine production and subsequent tumour progression in mice. The findings could open new therapeutic avenues for patients with early stage colorectal cancer.

The advent of CT colonography (CTC) for colorectal cancer screen-ing has generated the need for conservative policies for post-test colonoscopy referral. This Perspectives summarizes the evidence on the natural history and management of subcentimetric colorectal polyps, and suggests a patient-tailored approach when these lesions are detected by CTC in a screening setting.

Upper gastrointestinal tract cancers (UGICs) pose a major health risk around the world, and therapeutic improvements have been very slow and small. Increased understanding of the role of microRNAs in UGICs could lead to novel prevention strategies, early detection and improved therapeutics for these cancers.

The permeability of the intestinal epithelial barrier has a central role in the regulation of fluid and nutrient intake as well as in the control of the passage of pathogens. In this Review, Michel Neunlist and colleagues summarize current studies characterizing neuronal and glial effects on the intestinal epithelial barrier and outline the novel concept of a digestive neuronal–glial–epithelial unit.

Hepatocellular carcinoma (HCC) is a heterogeneous cancer with variable outcomes after treatment. Prognosis of HCC cannot be accurately predicted by current clinical staging systems. Development of prognostic biomarkers is critical to improve treatment outcome. Recent studies indicate that inflammatory and immunological markers might provide reliable prognostic classification in HCC.

As the burden of hepatocellular carcinoma (HCC) continues to increase, attention turns to the appropriate management of the disease. In this Review, the authors discuss and critique the currently available medical interventions for the treatment and management of HCC, as well as introduce future developments in the field.

IBS is a common disorder that can have an enormous negative effect on patients and society as a whole; however, many patients do not achieve adequate symptom relief with the currently available therapies. In this Review, Magnus Halland and Nicholas Talley discuss the latest treatments for IBS, including novel nonpharmacological and pharmacological approaches.

Targets for the medical management of NAFLD remain elusive and no medications have been approved by the FDA to date. Instead, lifestyle modification via diet and exercise is most commonly recommended. The optimal physical activity regimen in terms of both effectiveness and compliance remains to be determined and is the focus of this Review.

In an attempt to better characterize mucosal healing in ulcerative colitis, various endoscopic scoring systems have been introduced. However, most have limited interobserver agreement. A recent study has validated the ulcerative colitis colonoscopic index of severity and found that this new scoring system provides reproducible results among gastroenterologists.

Colorectal cancer (CRC) largely affects patients >75 years old, yet no evidence-based guidelines are available for this age group. In this article, Riccardo Audisio and Demetris Papamichael discuss the various treatment options available for older patients with CRC and suggest that treatment should be tailored to the individual patient.

Elastography has been shown to increase the accuracy of endoscopic ultrasonography for the differential diagnosis of pancreatic masses. Recent data have led to questions about the validity of its use in a routine clinical setting, outside controlled studies. Further improvements of the technique are needed to increase the reproducibility of its results and make it a useful clinical tool.

This Review focuses on several of the hormones released by the gastrointestinal tract prior to or during nutrient ingestion that have key roles in maintaining energy balance. These hormones include the gastric orexigenic hormone, ghrelin, and the distal L cell anorex-igenic and metabolic hormones, glucagon-like peptide (GLP) 1, GLP 2, oxyntomodulin and peptide YY. Their biological actions are outlined, as well as potential or actual uses as treatments for obesity and type 2 diabetes mellitus.