The changing epidemiology of inflammatory bowel disease (IBD) across time and geography suggests that environmental factors play a major role in modifying disease expression. Disease emergence in developing nations suggests that epidemiological evolution is related to westernisation of lifestyle and industrialisation. The strongest environmental associations identified are cigarette smoking and appendectomy, although neither alone explains the variation in incidence of IBD worldwide. Urbanisation of societies, associated with changes in diet, antibiotic use, hygiene status, microbial exposures and pollution have been implicated as potential environmental risk factors for IBD. Changes in socioeconomic status might occur differently in different geographical areas and populations and, consequently, it is important to consider the heterogeneity of risk factors applicable to the individual patient. Environmental risk factors of individual, familial, community-based, country-based and regionally based origin may all contribute to the pathogenesis of IBD. The geographical variation of IBD provides clues for researchers to investigate possible environmental aetiological factors. The present review aims to provide an update of the literature exploring geographical variability in IBD and to explore the environmental risk factors that may account for this variability.

Many studies have reported on the use of narrow band imaging (NBI) colonoscopy to differentiate neoplastic from non-neoplastic colorectal polyps. It has potential to replace pathological diagnosis of diminutive polyps. We aimed to perform a systematic review and meta-analysis on the real-time diagnostic operating characteristics of NBI colonoscopy.

Screening individuals at increased risk for pancreatic cancer (PC) detects early, potentially curable, pancreatic neoplasia.

Pancreatic cancer remains one of the most aggressive tumours with a 5-year survival rate of less than 5%. The dismal prognosis of this tumour entity that is associated with a high degree of drug resistance has not changed over the past decades. Since 1997, gemcitabine-based regimens have been the therapy of choice for advanced pancreatic cancer. Recently, however, new combination chemotherapy regimens achieved a significant survival benefit compared to gemcitabine-based therapies. In addition, novel approaches to improve drug delivery are currently being developed, and new drugs targeting signalling pathways both within the tumour cells and the tumour microenvironment are undergoing preclinical and clinical validation. Furthermore, efforts are being made to identify predictive markers for individualised treatment approaches based on molecular tumour characteristics. This review provides an overview on current and emerging concepts as well as novel targets for systemic treatment of advanced pancreatic cancer. Combination therapies incorporating drugs directed against these new targets may open new avenues for improving the efficacy of current treatment approaches and overcoming the devastating prognosis of pancreatic cancer patients.

The Atlanta classification of acute pancreatitis enabled standardised reporting of research and aided communication between clinicians. Deficiencies identified and improved understanding of the disease make a revision necessary.

The central nervous system interacts dynamically with the immune system to modulate inflammation through humoral and neural pathways. Recently, in animal models of sepsis, the vagus nerve (VN) has been proposed to play a crucial role in the regulation of the immune response, also referred to as the cholinergic anti-inflammatory pathway. The VN, through release of acetylcholine, dampens immune cell activation by interacting with α-7 nicotinic acetylcholine receptors. Recent evidence suggests that the vagal innervation of the gastrointestinal tract also plays a major role controlling intestinal immune activation. Indeed, VN electrical stimulation potently reduces intestinal inflammation restoring intestinal homeostasis, whereas vagotomy has the reverse effect. In this review, we will discuss the current understanding concerning the mechanisms and effects involved in the cholinergic anti-inflammatory pathway in the gastrointestinal tract. Deeper investigation on this counter-regulatory neuroimmune mechanism will provide new insights in the cross-talk between the nervous and immune system leading to the identification of new therapeutic targets to treat intestinal immune disease.

Interleukin 13 (IL-13) is a cytokine of increasing interest to gastroenterologists because of its developing role in ulcerative colitis, eosinophilic oesophagitis (EO) and fibrosis. Recent data show that IL-13 may play an important role in a novel innate immune response since it can be released by signals from an injured or inflamed epithelium, of particular relevance to the gut. Animal models of IL-13-driven inflammation (from asthma to colitis and EO) are being translated to human disease and providing insight into potential strategies for new therapies. In fact, multiple clinical trials using anti-IL-13 drugs are underway in asthma and are being extended to gastrointestinal diseases. This review presents the current knowledge on IL-13 production and function in the gut, including the cells and receptor signalling pathways involved in mediating IL-13 effects, the proposed mechanisms of IL-13 induced gut disease and the many drugs currently being tested that target IL-13 related pathways.

The British Society of Gastroenterology guidelines on the management of cholangiocarcinoma were originally published in 2002. This is the first update since then and is based on a comprehensive review of the recent literature, including data from randomised controlled trials, systematic reviews, meta-analyses, cohort, prospective and retrospective studies.

Recent studies have identified mucosal healing on endoscopy as a key prognostic parameter in the management of inflammatory bowel diseases (IBD), thus highlighting the role of endoscopy for monitoring of disease activity in IBD. In fact, mucosal healing has emerged as a key treatment goal in IBD that predicts sustained clinical remission and resection-free survival of patients. The structural basis of mucosal healing is an intact barrier function of the gut epithelium that prevents translocation of commensal bacteria into the mucosa and submucosa with subsequent immune cell activation. Thus, mucosal healing should be considered as an initial event in the suppression of inflammation of deeper layers of the bowel wall, rather than as a sign of complete healing of gut inflammation. In this systematic review, the clinical studies on mucosal healing are summarised and the effects of anti-inflammatory or immunosuppressive drugs such as 5-aminosalicylates, corticosteroids, azathioprine, ciclosporin and anti-TNF antibodies (adalimumab, certolizumab pegol, infliximab) on mucosal healing are discussed. Finally, the implications of mucosal healing for subsequent clinical management in patients with IBD are highlighted.

Gastric adenocarcinoma (gastric cancer, GC) is a major cause of global cancer mortality. Identifying molecular programmes contributing to GC patient survival may improve our understanding of GC pathogenesis, highlight new prognostic factors and reveal novel therapeutic targets. The authors aimed to produce a comprehensive inventory of gene expression programmes expressed in primary GCs, and to identify those expression programmes significantly associated with patient survival.

It is increasingly perceived that gut host-microbial interactions are important elements in the pathogenesis of functional gastrointestinal disorders (FGID). The most convincing evidence to date is the finding that functional dyspepsia and irritable bowel syndrome (IBS) may develop in predisposed individuals following a bout of infectious gastroenteritis. There has been a great deal of interest in the potential clinical and therapeutic implications of small intestinal bacterial overgrowth in IBS. However, this theory has generated much debate because the evidence is largely based on breath tests which have not been validated. The introduction of culture-independent molecular techniques provides a major advancement in our understanding of the microbial community in FGID. Results from 16S rRNA-based microbiota profiling approaches demonstrate both quantitative and qualitative changes of mucosal and faecal gut microbiota, particularly in IBS. Investigators are also starting to measure host-microbial interactions in IBS. The current working hypothesis is that abnormal microbiota activate mucosal innate immune responses which increase epithelial permeability, activate nociceptive sensory pathways and dysregulate the enteric nervous system. While we await important insights in this field, the microbiota is already a therapeutic target. Existing controlled trials of dietary manipulation, prebiotics, probiotics, synbiotics and non-absorbable antibiotics are promising, although most are limited by suboptimal design and small sample size. In this article, the authors provide a critical review of current hypotheses regarding the pathogenetic involvement of microbiota in FGID and evaluate the results of microbiota-directed interventions. The authors also provide clinical guidance on modulation of gut microbiota in IBS.

Intestinal epithelial cells (IEC) are organised as a single cell layer which covers the intestine. Their primary task is to absorb nutrients present in the intestinal lumen. However, IEC also play an important role in the immune defence of our body by building a barrier that separates the bowel wall from potentially hazardous bacteria present in the gut lumen. The life cycle of IEC is determined by the time span in which cells migrate from their place of origin at the crypt base to the villus tip, from where they are shed into the lumen. Cell death in the intestinal epithelium has to be tightly regulated and irregularities might cause pathologies. Excessive cell death has been associated with chronic inflammation as seen in patients with Crohn's disease and ulcerative colitis. While until recently apoptosis was discussed as being essential for epithelial turnover and tissue homeostasis in the intestinal epithelium, recent data using gene deficient mice have challenged this concept. Moreover, an apoptosis-independent mode of programmed cell death, termed necroptosis, has been identified and described in the intestinal epithelium. The following article reviews previous studies on cell death regulation in IEC and a potential role of necroptosis for gut homeostasis.

Treatment modalities for gastro-oesophageal reflux disease (GORD) mirror the pathophysiology of the disease. Since acid plays a key role in GORD-associated mucosal lesions, proton pump inhibitors (PPIs) are the dominant GORD treatment, being the most potent inhibitors of acid secretion available. However, the clinical effectiveness of PPIs varies with the specific symptoms being treated; they are more effective for heartburn than for regurgitation than for extra-oesophageal symptoms. An alternative therapeutic approach to GORD is to prevent the most fundamental cause of reflux symptoms, reflux itself, which most commonly occurs by transient lower oesophageal sphincter relaxation (TLOSR). Among potential pharmaceutical agents developed to target TLOSRs, the most advanced are GABA(B) (γ-aminobutyric acid) agonists, which experimentally reduce the occurrence of TLOSRs by about 40% in both animal and human studies. However, the effectiveness of GABA(B) agonists in clinical trials of patients with GORD with an incomplete response to PPI treatment has been modest. In part, this is probably attributable to the difficult problem of patient selection in these trials. Identifying patients by partial response to PPI treatment results in a heterogeneous population, including those with persistent weakly acidic reflux, patients with visceral hypersensitivity and those with functional heartburn, dyspepsia, or chest pain. From the clinical data available, the best treatment results and, hence, the patients most likely to benefit from reflux inhibitors, are those with persistent reflux, most commonly manifest as persistent regurgitation despite PPI treatment.

Approximately a third of patients with suspected gastro-oesophageal reflux disease are resistant or partial responders to proton pump inhibitors (PPIs). Many of these patients do not have gastro-oesophageal reflux disease, but suffer from functional heartburn or dyspepsia. The potential mechanisms underlying failure of PPI treatment in patients with reflux-related symptoms include persistence of isolated or mixed acid, weakly acidic, bile or gas reflux, impaired oesophageal mucosal integrity, chemical or mechanical hypersensitivity to refluxates and psychological comorbidity. After thorough clinical evaluation and failure of empirical changes in PPI dose regime, diagnostic investigations include endoscopy and reflux monitoring with pH or pH-impedance monitoring. If symptoms are clearly related to persistent reflux, baclofen, antireflux surgery or pain modulators can be considered. If not, pain modulators are the only currently available therapy.

Advances in sequencing technology and the development of metagenomic and bioinformatics methods have opened up new ways to investigate the 10(14) microorganisms inhabiting the human gut. The gene composition of human gut microbiome in a large and deeply sequenced cohort highlighted an overall non-redundant genome size 150 times larger than the human genome. The in silico predictions based on metagenomic sequencing are now actively followed, compared and challenged using additional 'omics' technologies. Interactions between the microbiota and its host are of key interest in several pathologies and applying meta-omics to describe the human gut microbiome will give a better understanding of this crucial crosstalk at mucosal interfaces. Adding to the growing appreciation of the importance of the microbiome is the discovery that numerous phages, that is, viruses of prokaryotes infecting bacteria (bacteriophages) or archaea with a high host specificity, inhabit the human gut and impact microbial activity. In addition, gene exchanges within the gut microbiota have proved to be more frequent than anticipated. Taken together, these innovative exploratory technologies are expected to unravel new information networks critical for gut homeostasis and human health. Among the challenges faced, the in vivo validation of these networks, together with their integration into the prediction and prognosis of disease, may require further working hypothesis and collaborative efforts.

Chronic hepatitis B virus (HBV) infection remains a major health burden and the main risk factor for the development of hepatocellular carcinoma worldwide. However, HBV is not directly cytopathic and liver injury appears to be mostly caused by repeated attempts of the host's immune responses to control the infection. Recent studies have shown that the unique replication strategy adopted by HBV enables it to survive within the infected hepatocyte while complex virus-host interplays ensure the virus is able to fulfil its replication requirements yet is still able to evade important host antiviral innate immune responses. Clearer understanding of the host and viral mechanisms affecting HBV replication and persistence is necessary to design more effective therapeutic strategies aimed at improving the management of patients with chronic HBV infection to eventually achieve viral eradication. This article focuses on summarising the current knowledge of factors influencing the course of HBV infection, giving emphasis on the use of novel assays and quantitative serological and intrahepatic biomarkers as tools for predicting treatment response and disease progression.