Impact of Colonoscopy Bowel Preparation on Intestinal Microbiota

The gut microbiota is important in maintaining human health, but numerous factors have the potential to alter its composition. Our aim was to examine the impact of a standard bowel preparation on the intestinal microbiota using two different techniques. Fifteen subjects undergoing colonoscopy consumed a bowel preparation comprised of 10 mg bisacodyl and 2 L polyethylene glycol. The microbiota of stool samples, collected one month before, one week before (pre-colonoscopy), and one week, one month, and three to six months after colonoscopy (post-colonoscopy) was evaluated. Two samples were taken three to six months apart from five healthy subjects who did not undergo colonoscopy. Universal primers targeting the V2-V3 region of the 16S rRNA gene were used to PCR amplify all samples for denaturing gradient gel electrophoresis (PCR-DGGE). Pre- and post-colonoscopy samples were compared using Dice's similarity coefficients. Three samples from ten subjects who underwent colonoscopy, and both samples from the five subjects who didn't, were used for high-throughput sequencing of the V1-V3 region of the 16S rRNA gene. Samples were curated and analysed in Mothur. Results of the DGGE analyses show that the fecal microbiota of a small number of subjects had short-term changes. High-throughput sequencing results indicated that the variation between the samples of subjects who underwent colonoscopy was no greater than the variation observed between samples from subjects who did not. We conclude that bowel preparation does not have a lasting effect on the composition of the intestinal microbiota for the majority of subjects.This work was funded by an Australian Post-Graduate Award scholarship. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript

Australian clinical practice guidelines for the diagnosis and management of Barrett's esophagus and early esophageal adenocarcinoma

Author version made available following 12 month embargo from date of publication according to publisher copyright policy.Barrett's esophagus (BE), a common condition, is the only known precursor to esophageal adenocarcinoma (EAC). There is uncertainty about the best way to manage BE as most people with BE never develop EAC and most patients diagnosed with EAC have no preceding diagnosis of BE. Moreover, there have been recent advances in knowledge and practice about the management of BE and early EAC. To aid clinical decision making in this rapidly moving field, Cancer Council Australia convened an expert working party to identify pertinent clinical questions. The questions covered a wide range of topics including endoscopic and histological definitions of BE and early EAC; prevalence, incidence, natural history, and risk factors for BE; and methods for managing BE and early EAC. The latter considered modification of lifestyle factors; screening and surveillance strategies; and medical, endoscopic, and surgical interventions. To answer each question, the working party systematically reviewed the literature and developed a set of recommendations through consensus. Evidence underpinning each recommendation was rated according to quality and applicability

Advances in the management of inflammatory bowel disease

Our understanding of inflammatory bowel diseases (IBD) is constantly evolving, and many new treatment options have emerged recently. This review critically examines the evidence for these new developments and aims to provide an overview for medical professionals involved in the care of patients with IBD. Proposed changes in the use of aminosalicylates, immunosuppressants and biological agents are described, and the evidence for several promising novel agents is reviewed

Impact of colonoscopy bowel preparation on intestinal microbiota.

The gut microbiota is important in maintaining human health, but numerous factors have the potential to alter its composition. Our aim was to examine the impact of a standard bowel preparation on the intestinal microbiota using two different techniques. Fifteen subjects undergoing colonoscopy consumed a bowel preparation comprised of 10 mg bisacodyl and 2 L polyethylene glycol. The microbiota of stool samples, collected one month before, one week before (pre-colonoscopy), and one week, one month, and three to six months after colonoscopy (post-colonoscopy) was evaluated. Two samples were taken three to six months apart from five healthy subjects who did not undergo colonoscopy. Universal primers targeting the V2-V3 region of the 16S rRNA gene were used to PCR amplify all samples for denaturing gradient gel electrophoresis (PCR-DGGE). Pre- and post-colonoscopy samples were compared using Dice's similarity coefficients. Three samples from ten subjects who underwent colonoscopy, and both samples from the five subjects who didn't, were used for high-throughput sequencing of the V1-V3 region of the 16S rRNA gene. Samples were curated and analysed in Mothur. Results of the DGGE analyses show that the fecal microbiota of a small number of subjects had short-term changes. High-throughput sequencing results indicated that the variation between the samples of subjects who underwent colonoscopy was no greater than the variation observed between samples from subjects who did not. We conclude that bowel preparation does not have a lasting effect on the composition of the intestinal microbiota for the majority of subjects

Haptic feedback tuning in colonoscopy simulation

International audience— According to medical experts, haptic realism is difficult to achieve, and even more difficult to have inter-expert agreement on the haptic feedback of one simulation. However haptic feedback is important in medical training, and allows educators to share the forces felt during a procedure if they know and trust what a particular virtual simulator will provide to the trainee. A new approach is proposed to refine bio-mechanical models with experts' input, to closely match the forces felt during a simulated procedure with an expert trainer's expectations. By allowing experts to tune a training scenario's haptic feedback as they trial a newly developed case, the experts can replicate their haptic perception and match their expectations with the simulation

Clinical utility of the Glasgow Blatchford Score in patients presenting to the emergency department with upper gastrointestinal bleeding: A retrospective cohort study

Objective: Upper gastrointestinal bleeding (UGIB) is a common presentation to EDs. Limited Australian data are available. Study aims were to assess mortality and re-bleeding rates in patients presenting with UGIB as risk-stratified by the Glasgow Blatchford Score (GBS). Methods: We conducted a retrospective medical chart review of all patients presenting with UGIB to a Brisbane tertiary hospital ED over a 12-month period. This descriptive study summarised the medical characteristics related to UGIB as risk-stratified by the GBS. Non-variceal bleeding was categorised as low-risk (GBS 0–2) or high-risk (GBS 3+). Variceal bleeding was not risk stratified. Results: A total of 211 patients presented with UGIB to the ED. The median age was 57 years, 67% were male. Mortality rates at 30 days were: 0% for GBS 0–2, 3% (95% confidence interval [CI] 0–6) for GBS 3+ and 10% (95% CI 0–21) for variceal groups. The overall 30-day re-bleeding rate was 4.3% (95% CI 2–7). High-risk patients accessed endoscopy according to international best practice of less than 24 h (GBS 3+, 23.7 h; variceal bleeding, 7.3 h). Conclusions: Mortality and re-bleeding outcomes are similar to other international UGIB cohorts. Patients with a low-risk bleed were appropriately identified and discharged home. Those at higher risk were correctly identified and accessed timely endoscopy. The GBS demonstrated clinical utility in an Australian ED cohort of UGIB bleeding patients.</p

Automated visibility map of the internal colon surface from colonoscopy video

International audiencePurposeOptical colonoscopy is a prominent procedure by which clinicians examine the surface of the colon for cancerous polyps using a flexible colonoscope. One of the main concerns regarding the quality of the colonoscopy is to ensure that the whole colonic surface has been inspected for abnormalities. In this paper, we aim at estimating areas that have not been covered thoroughly by providing a map from the internal colon surface.MethodsCamera parameters were estimated using optical flow between consecutive colonoscopy frames. A cylinder model was fitted to the colon structure using 3D pseudo stereo vision and projected into each frame. A circumferential band from the cylinder was extracted to unroll the internal colon surface (band image). By registering these band images, drift in estimating camera motion could be reduced, and a visibility map of the colon surface could be generated, revealing uncovered areas by the colonoscope. Hidden areas behind haustral folds were ignored in this study. The method was validated on simulated and actual colonoscopy videos. The realistic simulated videos were generated using a colonoscopy simulator with known ground truth, and the actual colonoscopy videos were manually assessed by a clinical expert.ResultsThe proposed method obtained a sensitivity and precision of 98 and 96 % for detecting the number of uncovered areas on simulated data, whereas validation on real videos showed a sensitivity and precision of 96 and 78 %, respectively. Error in camera motion drift could be reduced by almost 50 % using results from band image registration.ConclusionUsing a simple cylindrical model for the colon and reducing drift by registering band images allows for the generation of visibility maps. The current results also suggest that the provided feedback through the visibility map could enhance clinicians’ awareness of uncovered areas, which in return could reduce the probability of missing polyps

Summary of high-throughput sequencing parameters.

#<p>number of quality sequences obtained for a given sample.</p>*<p>number of observed operational taxonomic units.</p>**<p>Shannon diversity index.</p>$<p>Good’s coverage; C = 1 n₁/N, where n₁ is the number of OTUs that have been sampled once, and N is the total number of sequences.</p>†<p>Calculated with Mothur at the 3% distance level. Values in brackets are 95% confidence intervals as calculated by Mothur.</p>∧<p>For subjects who underwent colonoscopy: −1m, −1w, sample obtained one month, one week pre-colonoscopy, +1w, +1m, +3m, sample obtained 1 week, one month, or 3–6 months post-colonoscopy, respectively. For subjects who did not undergo colonoscopy: +3m, sample obtained 3–6 months after the first sample.</p

Dice similarity coefficients (%) of 16S rRNA amplicon DGGE profiles for fecal samples collected pre- and post-colonoscopy bowel preparation.

†<p>1 week post-colonoscopy sample not obtained.</p>*<p>LS, last sample, obtained 1 week post-colonoscopy.</p>**<p>LS, last sample, obtained 1 month or 3–6 months post-colonoscopy.</p>***<p>Samplesobtained 3–6 months apart, patient did not undergo colonoscopy.</p>∧<p>The post-colonoscopy comparisons are invalid for technical reasons.</p

Comparison of the composition of the fecal microbial communities of each sample using the Jaccard similarity coefficient.

<p>Distances between communities, based on the presence and absence of 16S rRNA sequences, were calculated with the Jaccard coefficient (jclass) within Mothur and clustered using the UPGMA algorithim. The first numeral/letter (subjects that underwent colonoscopy/subjects who did not) corresponds to the subject, the last numeral indicates when the sample was obtained. For subjects who underwent colonoscopy: −1m, −1w, sample obtained one month, one week pre-colonoscopy, +1w, +1m, +3m, sample obtained 1 week, one month, or 3–6 months post-colonoscopy, respectively. For subjects who did not undergo colonoscopy: +3m, sample obtained 3–6 months after the first sample.</p