Colonoscopy is central to colorectal cancer (CRC) screening. Success of CRC screening is dependent on colonoscopy quality. The NHS Bowel Cancer Screening Programme (BCSP) offers biennial faecal occult blood (FOB) testing to 60–74 year olds and colonoscopy to those with positive FOB tests. All colonoscopists in the screening programme are required to meet predetermined standards before starting screening and are subject to ongoing quality assurance. In this study, the authors examine the quality of colonoscopy in the NHS BCSP and describe new and established measures to assess and maintain quality.

The NHS BCSP database collects detailed data on all screening colonoscopies. Prospectively collected data from the first 3 years of the programme (August 2006 to August 2009) were analysed. Colonoscopy quality indicators (adenoma detection rate (ADR), polyp detection rate, colonoscopy withdrawal time, caecal intubation rate, rectal retroversion rate, polyp retrieval rate, mean sedation doses, patient comfort scores, bowel preparation quality and adverse event incidence) were calculated along with measures of total adenoma detection.

2 269 983 individuals returned FOB tests leading to 36 460 colonoscopies. Mean unadjusted caecal intubation rate was 95.2%, and mean withdrawal time for normal procedures was 9.2 min. The mean ADR per colonoscopist was 46.5%. The mean number of adenomas per procedure (MAP) was 0.91; the mean number of adenomas per positive procedure (MAP+) was 1.94. Perforation occurred after 0.09% of procedures. There were no procedure-related deaths.

The NHS BCSP provides high-quality colonoscopy, as demonstrated by high caecal intubation rate, ADR and comfort scores, and low adverse event rates. Quality is achieved by ensuring BCSP colonoscopists meet a high standard before starting screening and through ongoing quality assurance. Measuring total adenoma detection (MAP and MAP+) as adjuncts to ADR may further enhance quality assurance.

It is difficult to predict the outcome in patients with acute liver failure (ALF) using existing prognostic models. This study investigated whether early changes in the levels of dynamic variables can predict outcome better than models based on static baseline variables.

380 patients with ALF (derivation cohort n=244, validation cohort n=136) participated in a prospective observational study. The derivation cohort was used to identify predictors of mortality. The ALF early dynamic (ALFED) model was constructed based on whether the levels of predictive variables remained persistently high or increased over 3 days above the discriminatory cut-off values identified in this study. The model had four variables: arterial ammonia, serum bilirubin, international normalised ratio and hepatic encephalopathy >grade II. The model was validated in a cohort of 136 patients with ALF.

The ALFED model demonstrated excellent discrimination with an area under the receiver operator characteristic curve of 0.91 in the derivation cohort and of 0.92 in the validation cohort. The model was well calibrated in both cohorts and showed a similar increase in mortality with increasing risk scores from 0 to 6. The performance of the ALFED model was superior to the King's College Hospital criteria and the Model for End stage Liver Disease score, even when their 3-day serial values were taken into consideration. An ALFED score of ≥4 had a high positive predictive value (85%) and negative predictive value (87%) in the validation cohort.

The ALFED model accurately predicted outcome in patients with ALF, which may be useful in clinical decision-making.

Cirrhosis is one of the most frequent and severe chronic diseases worldwide. In the initial stages it has few or no symptoms, but advanced stages of cirrhosis are characterised by reduced liver function, complications due to portal hypertension and neuroendocrine abnormalities with increased activity of the sympathetic nervous system (SNS) and renin-aldosterone axis. The prognosis is severe, with an increasing frequency of complications including variceal bleeding, ascites and spontaneous infections with subsequent development of hepatic encephalopathy and hepatorenal syndrome. More than one-third of patients diagnosed with cirrhosis develop oesophageal varices within 3 years after the diagnosis is made. Varices develop and later bleed when the portal pressure is increased and the hepatic vein pressure gradient (HVPG) is more than 10–12 mm Hg. Life-threatening spontaneous bacterial infections are another common complication of advanced cirrhosis. The infections are mainly triggered by gut bacterial translocation, which is the migration of microorganisms from the intestinal...

The risk of oesophageal adenocarcinoma (OAC) in non-dysplastic Barrett's oesophagus (BO) may have been overestimated. The objective was to estimate the incidence of OAC in patients with BO without dysplasia.

The authors searched MEDLINE and EMBASE from 1966 to 2011 and performed a bibliographic review of previous publications, excluding abstracts, non-peer-reviewed publications and those not published in English, for prospective or retrospective studies of the incidence of OAC in patients with BO. They excluded patients with any degree of dysplasia at baseline and those without documented intestinal metaplasia. Studies were independently reviewed by two individuals. 57 of 3450 studies were included. The authors extracted information on number of patients with BO, length of follow-up, incident cases of OAC, mean age of patients, country of origin, whether prospective or retrospective, mean length of BO segments and mortality from causes other than OAC. Study quality was assessed by the Ottawa Newcastle criteria.

The 57 included studies comprised 11 434 patients and 58 547 patient-years of follow-up. The pooled annual incidence of OAC was 0.33% (95% CI 0.28% to 0.38%). Among 16 studies that provided appropriate information on mortality, there were 56 incident cases of OAC but 684 deaths from apparently unrelated causes. Among 16 studies that provided information on patients with short-segment BO, the annual incidence of OAC was only 0.19%.

The incidence of OAC in non-dysplastic BO is around 1 per 300 patients per year. The incidence of OAC in short-segment BO is under 1 per 500 patients per year.

We read with interest the commentary by Bercik1 emphasising the influence that gut intestinal microflora may have on cognitive function—a model with clear therapeutic implications. We would like to propose, however, that a third party—the presence of autonomic nervous system dysfunction—complicates the relationship between cognitive impairment and gut microflora.

In a number of diseases, autonomic dysfunction has been associated with cognitive impairment,2 3 and its presence is associated with impaired gastrointestinal motility, a risk factor for changes in bacterial colonisation. Autonomic dysfunction is a common problem in patients with chronic liver disease (CLD)4—the group of patients highlighted in the commentary as having obvious cognitive problems, as benefiting from treatment aimed at modifying the gut flora and where abnormal gut permeability has been recognised.5 Cognitive problems are increasingly being recognised in patients with non-cirrhotic CLD, where hepatic encephalopathy...

Using genome-wide promoter methylation assay, B cell CLL/lymphoma 6 member B (BCL6B) was found to be preferentially methylated in cancer. A study was undertaken to examine the epigenetic regulation, biological function and clinical significance of BCL6B in gastric cancer (GC).

BCL6B promoter methylation was evaluated by combined bisulfite restriction analysis and sequencing. The biological functions of BCL6B were determined by cell viability, colony formation, flow cytometry and in vivo tumorigenicity assays. The molecular targets of BCL6B were identified by cDNA expression array.

BCL6B was silenced or downregulated in all nine GC cell lines and readily expressed in normal gastric tissues. Loss of BCL6B expression was regulated by promoter hypermethylation. Re-expression of BCL6B in GC cell lines inhibited colony formation, suppressed cell viability, induced apoptosis and restrained the tumorigenecity in nude mice. These effects were associated with upregulation of the pro-apoptosis genes tumour necrosis factor receptor superfamily member 1A, caspase-8, caspase-9, caspase-3 and caspase-7 and nuclear enzyme poly (ADP-ribose) polymerase, downregulation of the pro-proliferation genes S100 calcium binding protein A4 and vascular endothelial growth factor A, and induction of the tumour suppressor genes ataxia telangiectasia mutated homologue and p53. BCL6B hypermethylation was detected in 49.0% (102/208) and 66.3% (67/101) of two independent cohorts of patients with GC, respectively. BCL6B methylation was an independent factor for the survival of patients with GC (p=0.001 for cohort I, p=0.02 for cohort II).

BCL6B plays a pivotal role as a potential tumour suppressor in GC. Detection of methylated BCL6B may serve as an independent biomarker for the prognosis of GC.

Colon cancer is a leading cause of cancer deaths in Western countries and is associated with diets high in red meat. Haem, the iron-porphyrin pigment of red meat, induces cytotoxicity of gut contents and damages the colon surface epithelium. Compensatory hyperproliferation leads to epithelial hyperplasia which increases the risk of colon cancer. The aim of this study was to identify molecules signalling from the surface epithelium to the crypt to initiate hyperproliferation upon stress induced by haem.

C57Bl6/J mice (n=9/group) received a ‘westernised’ control diet (40 en% fat) with or without 0.5 μmol/g haem for 14 days. Colon mucosa was used to quantify cell proliferation and for microarray transcriptome analysis. Gene expression profiles of surface and crypt cells were compared using laser capture microdissection. Protein levels of potential signalling molecules were quantified.

Haem-fed mice showed epithelial hyperproliferation and decreased apoptosis, resulting in hyperplasia. Microarray analysis of the colon mucosa showed 3710 differentially expressed genes (false discovery rate (q) <0.01), with many involved in the cell cycle. Expression levels of haem- and stress-related genes showed that haem affected surface cells but did not directly affect crypt cells. Injured surface cells should therefore signal to crypt cells to induce compensatory hyperproliferation. Haem downregulated the inhibitors of proliferation, Wnt inhibitory factor 1, Indian Hedgehog and bone morphogenetic protein 2. Interleukin-15 was also downregulated. Haem upregulated amphiregulin, epiregulin and cyclo-oxygenase-2 mRNA in surface cells. Their protein/metabolite levels were, however, not increased as haem induced surface-specific inhibition of translation by increasing 4E-BP1.

Haem induces colonic hyperproliferation and hyperplasia by inhibiting the surface to crypt signalling of feedback inhibitors of proliferation.

One of the most important hormones in the human stomach is the peptide gastrin. It is mainly required for the regulation of gastric pH but is also involved in growth and differentiation of gastric epithelial cells. In Helicobacter pylori infected patients, gastrin secretion can be upregulated by the pathogen, resulting in hypergastrinaemia. H pylori induced hypergastrinaemia is described as being a major risk factor for the development of gastric adenocarcinoma.

In this study, the upstream receptor complex and bacterial factors involved in H pylori induced gastrin gene expression were investigated, utilising gastric epithelial cells which were stably transfected with a human gastrin promoter luciferase reporter construct.

Integrin linked kinase (ILK) and integrin β5, but not integrin β1, played an important role in gastrin promoter activation. Interestingly, a novel CagL/integrin β5/ILK signalling complex was characterised as being important for H pylori induced gastrin expression. On interaction of H pylori with αvβ₅-integrin and ILK, the epidermal growth factor receptor (EGFR) ->Raf->mitogen activated protein kinase kinase (MEK)->extracellular signal regulated kinase (Erk) downstream signalling cascade was identified which plays a central role in H pylori gastrin induction.

The newly discovered recognition receptor complex could be a useful target in treating precancerous conditions triggered by H pylori induced hypergastrinaemia.

Non-alcoholic fatty liver disease is an obesity-related chronic liver disorder ranging from simple steatosis to non-alcoholic steatohepatitis (NASH), which may progress to liver fibrosis and cirrhosis.

Tto investigate the role of Toll-like receptor (TLR) 4 in mediating the transition from steatosis to inflammation.

ApoE^–/–/TLR4^mut mice and ApoE^–/–/TLR4 wild-type mice (ApoE^–/–/TLR4-WT) were generated by cross-breeding an ApoE-deficient (ApoE^–/–) strain with TLR4-mutant (TLR4^mut) mice, which were fed with high-fat, high-cholesterol (HFHC) diet to induce obesity.

ApoE^–/–/TLR4-WT mice fed with an HFHC diet for 12 weeks developed typical pathological features of NASH, which is associated with obesity and the metabolic syndrome. By contrast, ApoE^–/–/TLR4^mut mice lacking functional TLR4 were resistant to HFHC diet-induced liver inflammation and injury and were less susceptible to the diet-induced production of reactive oxygen species (ROS) and proinflammatory cytokines. In ApoE^–/–/TLR4-WT mice, X-box binding protein-1 (XBP-1), a transcription factor involved in the unfolded protein responses, was activated in the liver by an HFHC diet, whereas XBP-1 activation was abrogated in ApoE^–/–/TLR4^mut mice. In primary rat Kupffer cells, endotoxin induced XBP-1 activation through ROS production, whereas siRNA-mediated knockdown of XBP-1 expression resulted in a marked attenuation in endotoxin-evoked NF-B activation and cytokine production. Furthermore, adenovirus-mediated expression of dominant negative XBP-1 led to a significant attenuation in HFHC diet-induced liver inflammation and injury in mice.

These findings support the key role of TLR4 in Kupffer cells in mediating the progression of simple steatosis to NASH, by inducing ROS-dependent activation of XBP-1.

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder that may be triggered by enteric pathogens and has also been linked to alterations in the microbiota and the host immune response. The authors performed a detailed analysis of the faecal microbiota in IBS and control subjects and correlated the findings with key clinical and physiological parameters.

The authors used pyrosequencing to determine faecal microbiota composition in 37 IBS patients (mean age 37 years; 26 female subjects; 15 diarrhoea-predominant IBS, 10 constipation-predominant IBS and 12 alternating-type IBS) and 20 age- and gender-matched controls. Gastrointestinal and psychological symptom severity and quality of life were evaluated with validated questionnaires and colonic transit time and rectal sensitivity were measured.

Associations detected between microbiota composition and clinical or physiological phenotypes included microbial signatures associated with colonic transit and levels of clinically significant depression in the disease. Clustering by microbiota composition revealed subgroups of IBS patients, one of which (n=15) showed normal-like microbiota composition compared with healthy controls. The other IBS samples (n=22) were defined by large microbiota-wide changes characterised by an increase of Firmicutes-associated taxa and a depletion of Bacteroidetes-related taxa.

Detailed microbiota analysis of a well-characterised cohort of IBS patients identified several clear associations with clinical data and a distinct subset of IBS patients with alterations in their microbiota that did not correspond to IBS subtypes, as defined by the Rome II criteria.

Hepatitis C virus (HCV) persistence is associated with impaired CD8 functions. Whether functional restoration of CD8 T cells chronically exposed to antigen can be obtained once the antigen is removed remains to be clarified.

To determine whether clearance of HCV by antiviral treatment can fully restore the antiviral function of HCV-specific CD8 cells.

Peripheral blood HCV-, Flu- and cytomegalovirus (CMV)-specific CD8 cells were quantified by tetramer staining in 28 patients whose HCV infection resolved after peginterferon or peginterferon/ribavirin treatment for either acute or chronic hepatitis and in eight subjects with acute HCV infection which resolved spontaneously for comparison. HCV-specific CD8 cells were evaluated for their phenotypic and functional characteristics by comparing different patient groups and CD8 cells with different viral specificities in the same patients.

Sustained viral response (SVR) did not lead to full maturation of a functional memory CD8 cell response. In particular, SVR in chronic infection was associated with a greater level of T cell dysfunction than responders after acute infection, who showed HCV-specific CD8 responses comparable to those of spontaneous resolvers but weaker than those of Flu-specific CD8 cells. Higher programmed death (PD)-1 expression was detected on HCV than on Flu- and CMV-specific CD8 cells and the effect of PD-1/PD-L1 blockade was better in SVRs after chronic than after acute HCV infection.

A better restoration of HCV-specific CD8 function was detectable after SVR in patients with acute hepatitis than in those with chronic disease. Thus, the difficulty in achieving a complete restoration of the antiviral T cell function should be considered in the design of immunomodulatory therapies.

Probiotics and their metabolic products, here called postbiotics, have been proposed as food supplements for a healthier intestinal homeostasis, but also as therapeutic aids in inflammatory bowel disease (IBD) with, however, very little clinical benefit. This may be due to the lack of reliable preclinical models for testing the efficacy of different strains.

The activity of three probiotic strains of Lactobacillus (or a postbiotic) was analysed and compared with a pathogenic strain of Salmonella on a novel organ culture system of human healthy and IBD intestinal mucosa developed in our laboratory. The system maintains an apical to basolateral polarity during stimulation due to the presence of a glued cave cylinder. The cylinder is detached at the end of the experiment and the tissue is processed for histology and immunohistochemistry. Cytokines released from the basolateral side are analysed.

The model system provides several physiological characteristics typical of a mucosal microenvironment including the presence of an organised mucus layer and an apical to basolateral polarity. Polarised administration of bacteria is critical to control the ensuing immune response as it mimics the physiological entrance of bacteria. The authors show that probiotics are not always beneficial for the healthy host and can also be detrimental in inflamed IBD. This study shows that a potent postbiotic can protect against the inflammatory properties of invasive Salmonella on healthy tissue and also downregulate ongoing inflammatory processes in IBD tissue.

Probiotics can have inflammatory activities in both healthy and IBD tissue. Valid preclinical data on proper model systems should therefore be obtained before specific probiotic strains enter the clinics, especially if administered during acute inflammatory responses. Postbiotics may be a safe alternative for the treatment of patients with IBD in the acute inflammatory phase.