Time filter

Source Type

Harrell L.,University of Chicago | Wang Y.,University of Chicago | Antonopoulos D.,University of Chicago | Young V.,University of Michigan | And 4 more authors.
PLoS ONE | Year: 2012

Background & Aims: Past studies of the human intestinal microbiota are potentially confounded by the common practice of using bowel-cleansing preparations. We examined if colonic lavage changes the natural state of enteric mucosal-adherent microbes in healthy human subjects. Methods: Twelve healthy individuals were divided into three groups; experimental group, control group one, and control group two. Subjects in the experimental group underwent an un-prepped flexible sigmoidoscopy with biopsies. Within two weeks, subjects were given a standard polyethylene glycol-based bowel cleansing preparation followed by a second flexible sigmoidoscopy. Subjects in control group one underwent two un-prepped flexible sigmoidoscopies within one week. Subjects in the second control group underwent an un-prepped flexible sigmoidoscopy followed by a second flexible sigmoidoscopy after a 24-hour clear liquid diet within one week. The mucosa-associated microbial communities from the two procedures in each subject were compared using 16S rRNA gene based terminal restriction fragment length polymorphism (T-RFLP), and library cloning and sequencing. Results: Clone library sequencing analysis showed that there were changes in the composition of the mucosa-associated microbiota in subjects after colonic lavage. These changes were not observed in our control groups. Standard bowel preparation altered the diversity of mucosa-associated microbiota. Taxonomic classification did not reveal significant changes at the phylum level, but there were differences observed at the genus level. Conclusion: Standard bowel cleansing preparation altered the mucosal-adherent microbiota in all of our subjects, although the degree of change was variable. These findings underscore the importance of considering the confounding effects of bowel preparation when designing experiments exploring the gut microbiota. © 2012 Harrell et al. Source

Gitlin L.,Gastroenterology Institute | Borody T.J.,Center for Digestive Diseases | Chamberlin W.,Texas Tech University | Campbell J.,Center for Digestive Diseases
Journal of Clinical Gastroenterology | Year: 2012

The relation of Mycobacterium avium ss paratuberculosis (MAP) to Crohn's Disease (CD) and other MAP-associated conditions remains controversial. New data, coupled with the analogous Helicobacter pylori (H. pylori) story, has permitted us to piece together the MAP puzzle and move forward with a more scientific way of treating inflammatory bowel disease, particularly CD. As infection moves centre stage in inflammatory bowel disease, the dated "aberrant reaction" etiology has lost scientific credibility. Now, our growing understanding of MAP-associated diseases demands review and articulation. We focus here on (1) the concept of MAP-associated diseases; (2) causality, Johne Disease, the "aberrant reaction" hypothesis; and (3) responses to published misconceptions questioning MAP as a pathogen in CD. Copyright © 2012 by Lippincott Williams & Wilkins. Source

Rex D.K.,Indiana University | Adler S.N.,Digestive Diseases Institute | Aisenberg J.,Mount Sinai School of Medicine | Burch W.C.,Franklin Gastroenterology PLLC | And 18 more authors.
Gastroenterology | Year: 2015

Background & Aims Capsule colonoscopy is a minimally invasive imaging method. We measured the accuracy of this technology in detecting polyps 6 mm or larger in an average-risk screening population. Methods In a prospective study, asymptomatic subjects (n = 884) underwent capsule colonoscopy followed by conventional colonoscopy (the reference) several weeks later, with an endoscopist blinded to capsule results, at 10 centers in the United States and 6 centers in Israel from June 2011 through April 2012. An unblinded colonoscopy was performed on subjects found to have lesions 6 mm or larger by capsule but not conventional colonoscopy. Results Among the 884 subjects enrolled, 695 (79%) were included in the analysis of capsule performance for all polyps. There were 77 exclusions (9%) for inadequate cleansing and whole-colon capsule transit time fewer than 40 minutes, 45 exclusions (5%) before capsule ingestion, 15 exclusions (2%) after ingestion and before colonoscopy, and 15 exclusions (2%) for site termination. Capsule colonoscopy identified subjects with 1 or more polyps 6 mm or larger with 81% sensitivity (95% confidence interval [CI], 77%-84%) and 93% specificity (95% CI, 91%-95%), and polyps 10 mm or larger with 80% sensitivity (95% CI, 74%-86%) and 97% specificity (95% CI, 96%-98%). Capsule colonoscopy identified subjects with 1 or more conventional adenomas 6 mm or larger with 88% sensitivity (95% CI, 82%-93) and 82% specificity (95% CI, 80%-83%), and 10 mm or larger with 92% sensitivity (95% CI, 82%-97%) and 95% specificity (95% CI, 94%-95%). Sessile serrated polyps and hyperplastic polyps accounted for 26% and 37%, respectively, of false-negative findings from capsule analyses. Conclusions In an average-risk screening population, technically adequate capsule colonoscopy identified individuals with 1 or more conventional adenomas 6 mm or larger with 88% sensitivity and 82% specificity. Capsule performance seems adequate for patients who cannot undergo colonoscopy or who had incomplete colonoscopies. Additional studies are needed to improve capsule detection of serrated lesions. Clinicaltrials.gov number: NCT01372878. © 2015 AGA Institute. Source

Li H.,University of Texas Southwestern Medical Center | Chan L.,University of Texas Southwestern Medical Center | Bartuzi P.,University of Groningen | Melton S.D.,Dallas Medical Center | And 25 more authors.
Gastroenterology | Year: 2014

Background & Aims Activation of the transcription factor nuclear factor-κB (NF-κB) has been associated with the development of inflammatory bowel disease (IBD). Copper metabolism MURR1 domain containing 1 (COMMD1), a regulator of various transport pathways, has been shown to limit NF-κB activation. We investigated the roles of COMMD1 in the pathogenesis of colitis in mice and IBD in human beings. Methods We created mice with a specific disruption of Commd1 in myeloid cells (Mye-knockout [K/O] mice); we analyzed immune cell populations and functions and expression of genes regulated by NF-κB. Sepsis was induced in Mye-K/O and wild-type mice by cecal ligation and puncture or intraperitoneal injection of lipopolysaccharide (LPS), colitis was induced by administration of dextran sodium sulfate, and colitis-associated cancer was induced by administration of dextran sodium sulfate and azoxymethane. We measured levels of COMMD1 messenger RNA in colon biopsy specimens from 29 patients with IBD and 16 patients without (controls), and validated findings in an independent cohort (17 patients with IBD and 22 controls). We searched for polymorphisms in or near COMMD1 that were associated with IBD using data from the International IBD Genetics Consortium and performed quantitative trait locus analysis. Results In comparing gene expression patterns between myeloid cells from Mye-K/O and wild-type mice, we found that COMMD1 represses expression of genes induced by LPS. Mye-K/O mice had more intense inflammatory responses to LPS and developed more severe sepsis and colitis, with greater mortality. More Mye-K/O mice with colitis developed colon dysplasia and tumors than wild-type mice. We observed a reduced expression of COMMD1 in colon biopsy specimens and circulating leukocytes from patients with IBD. We associated single-nucleotide variants near COMMD1 with reduced expression of the gene and linked them with increased risk for ulcerative colitis. Conclusions Expression of COMMD1 by myeloid cells has anti-inflammatory effects. Reduced expression or function of COMMD1 could be involved in the pathogenesis of IBD. © 2014 by the AGA Institute. Source

Malnick S.D.H.,Kaplan Medical Center | Melzer E.,Gastroenterology Institute | Attali M.,Kaplan Medical Center | Duek G.,Gastroenterology Institute | Yahav J.,Hebrew University of Jerusalem
World Journal of Gastroenterology | Year: 2014

Helicobacter pylori (H. pylori) is a Gram-negative spiral bacterium that is present in nearly half the world's population. It is the major cause of peptic ulcer disease and a recognized cause of gastric carcinoma. In addition, it is linked to non-ulcer dyspepsia, vitamin B12 deficiency, iron-deficient anemia and immune thrombocytopenic purpura. These conditions are indications for testing and treatment according to current guidelines. An additional indication according to the guidelines is "anyone with a fear of gastric cancer" which results in nearly every infected person being eligible for eradication treatment. There may be beneficial effects of H. pylori in humans, including protection from gastroesophageal reflux disease and esophageal adenocarcinoma. In addition, universal treatment will be extremely expensive (more than $32 billion in the United States), may expose the patients to adverse effects such as anaphylaxis and Clostridium difficile infection, as well as contributing to antibiotic resistance. There may also be an as yet uncertain effect on the fecal microbiome. There is a need for robust clinical data to assist in decision-making regarding treatment of H. pylori infection. © 2014 Baishideng Publishing Group Inc. All rights reserved. Source

Discover hidden collaborations