Su1902 Molecular Analysis of Human Gastric Microbiota by Pyrosequencing for 16s rRNA Gene in Patients With Gastric Cancer Depending on H. pylori Positivity

Su1902 Molecular Analysis of Human Gastric Microbiota by Pyrosequencing for 16s rRNA Gene in Patients With Gastric Cancer Depending on H. pylori Positivity

(454 Life Sciences/Roche) and analyzed by metagenomic bioinformatics. In case of HPpositive biopsy were taken after HP eradication every one year. Res...

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(454 Life Sciences/Roche) and analyzed by metagenomic bioinformatics. In case of HPpositive biopsy were taken after HP eradication every one year. Results: The mean pH of gastric cancer and control was different as 4.56 and 2.00, respectively (p ,0.05). Microbiota from the initial biopsy specimen showed 11 phyla and 411 genera in which Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes occupied majority. In case of HP- control group (n=10) Proteobacteria, Firmicutes, and Actinobacteria were 60.6%, 18.9%, and 14.0%, respectively, which is similar to those of the HP+ control group (n=10), 77.0%, 17.5%, and 2.7%, respectively. In case of HP- cancer group (n=10) Proteobacteria, Firmicutes, and Actinobacteria were 31.1%, 44.5%, and 16.6%, respectively, which was different from those of the HP+ cancer group (n=10), 85.9%, 8.4%, and 3.6%, respectively. Average number of operational taxonomic units (OUT) were 270.5 (HP- control), 210.2 (HP+ control), 306.7 (HP- cancer) and 122.4 (HP+ cancer). The proportion of nitrosation bacteria was found to be 2.4% in case of HP- control, 77% in HP+ control, 9.7% in HP- cancer and 81% in HP+ cancer, in which HP looked like to determine the proportion. Conclusion: The pH of gastric cancer group was higher than the control group. The presence of HP affected the composition of the gastric community, especially in the gastric cancer group. These results suggest that microbiota could affect the expression of gastric cancer. The analysis of long-term followup change of microbiota is undergoing.

*Cochran-Armitage Trend Test, adjusted for 3 comparisons ,s.†.Adjusted for 3 comparisons PPI=proton pump inhibitor Su1901 The Additive Value of High Resolution Impedance to Esophageal Pressure Topography Erick R. Singh, Sankara N. Sethuraman, Dharma S. Thiruvaiyaru, Arie Mack, Satish S. Rao BACKGROUND - Esophageal multichannel intraluminal impedance along with manometry is regarded as gold standard for evaluation bolus transit physiologically. Whether high resolution (HR) impedance provides additional pathophysiological information compared to high resolution esophageal pressure topography (HREPT) analysis alone is not known. We investigated inter-test agreement of (1) HR impedance - manometry (HRIM) & HREPT to waveform impedance studies for analysis of complete bolus transit & (2) inter-test agreement of HRIM to HREPT for HREPT contraction patterns & swallows integrity. METHODS - 145 random swallows from 10 subjects (M:F = 4:6; median age = 60) with reflux or dysphagia, without achalasia, hiatal hernia or post-surgery patients were analyzed. Subjects underwent esophageal HRIM (Given Imaging, Yoqneam, Israel - 36 pressure & 18 impedance channel catheter). Swallows were analyzed in 3 separate settings (solo-HREPT, waveform impedance, & combined HRIM). Impedance was analyzed as complete or incomplete. HR of each swallow was analyzed for distal contractile integrals (DCI), contractile frontal velocity (CFV), integral residual pressure (IRP), intrabolus pressure (IBP). Swallow integrity and contraction pattern were assessed (Chicago Classification). Manometric variables were compared using two-tailed t-test. The inter-test agreement (Kappa) for HREPT, waveform impedance, & HRIM bolus clearance & swallows were assessed. Cochran-Mantel-Haenszel (CMH) test was performed to test association between complete bolus transit, swallow integrity, & contraction patterns. RESULTS - Bolus clearance identified by HRIM agreed with waveform impedance (% agreement = 96.6%, k=0.65) more strongly than solo-HREPT identification (% agreement = 94.5%, k=0.40). Contraction pattern & swallow integrity identification between HREPT & HRIM revealed good inter-test correlation (k =0.82 & 0.77). Differences in HR manometric properties were not different (Table 1). No significant association was found between waveform impedance, HREPT, and HRIM for complete bolus transit (p= 0.32) or for swallow integrity or contraction patterns (p=0.54 & p=0.80). CONCLUSIONSThe addition of HR impedance to HREPT improved identification of complete bolus transit compared to solo-HREPT. However, HRIM does not seem to influence manometric data analysis. HR contraction pattern & swallow integrity interpretation correlates well with both HREPT and HRIM. The true utility of HRIM may be in the evaluation of post-surgical or dysmotility-related dysphagia while HREPT is adequate for routine manometry. HR manometric measures assessed via HREPT and HRIM

Su1903 A Novel Method of Quantifying Small Intestinal Bacterial Overgrowth (SIBO) Using Duodenal Brushing Chirajyoti Deb, Devendra I. Mehta, Janet M. Conrad, Patrick Pignon, Jeffrey A. Bornstein, Karoly Horvath Background: Small intestinal bacterial overgrowth (SIBO) is commonly diagnosed by hydrogen/methane breath test, though is often inaccurate. The current gold standard method of SIBO diagnosis is the quantitative culture of duodenal aspirate that is normally collected during esophagogastroduodenoscopy (EGD). Unfortunately, duodenal fluid is not always found in the lumen for sampling. In addition, the duodenal aspirates typically get contaminated with the oral and upper airway flora and gastric fluid or the fluid may have been recently secreted from pancreatobiliary system as a result of the EGD. We hypothesized that duodenal brushing specimens will contain the more appropriate microbial population, with less contamination from the upper airway flora for accurate detection of overgrowth. Methodology: Small intestinal aspirate and brushing samples were collected from the pediatric patients (age 1.5-17 years) undergoing medically indicated EGD. The small intestine was brushed using a cytology brush (Kimberly-Clark #60314). The brush tip was placed in a sterile tube and the fluid was collected aseptically. Calibrated loops (1 μl) were used to streak media plates. The colony-forming units (cfu) were counted and averaged from a set of plates grown under aerobic and anaerobic conditions, respectively. Results: A total of 27 of 32 pediatric patients enrolled in this prospective pilot study had both duodenal fluid and brushing samples collected. Eight/27 had .104 cfu using aspirates compared with 10/ 27 using Brushing sample (P,0.001 Fishers). Using log10 transformation, the two methods were strongly correlated at 0.73 R2 (P,0.001 Pearson's). The duodenal aspirates (mean 3x105) tended to have more cfu than corresponding brushing (mean 3X104). Receiver operating characteristic (ROC) curve showed at a cut off of cfu log10 4.4, equivalent to 2.5 x 104, sensitivity was 87.5% and specificity 95% for brushing. Under the aerobic and anaerobic growth conditions 56% and 59% of the brushing and 37% and 44% of the aspirate samples developed colonies on media plates. Duodenal aspirates had more oral flora than brushings. In contrast, brushing samples produced more microbial growth in tubed liquid media corresponding to cultivable fastidious and facultatively anaerobic and microaerophilic organisms. Conclusion: Duodenal brushing correlated well with duodenal aspirate for small bowel bacterial cfu. The findings suggest brushings may be better than aspirates based on both higher levels of oral flora in aspirates, which may be contaminants and a better yield of fastidious and facultatively anaerobic as well as microaerophilic organisms with brushings. Further characterization of the microbiome using molecular methods is warranted.

Identification of Complete Bolus Transit

Su1902 Su1904 Molecular Analysis of Human Gastric Microbiota by Pyrosequencing for 16s rRNA Gene in Patients With Gastric Cancer Depending on H. pylori Positivity Nayoung Kim, Yoon Jin Choi, Ji Yeon Kim, Ryoung Hee Nam, Mi Ji Choi, Jiwoo Kang, Hyun Jin Jo, Dong Ho Lee, Hyun Chae Jung

A Prospective Multi-Center Study of the AIMS65 Score Compared to the Glasgow-Blatchford Risk Score in Predicting Outcomes in Patients With Upper Gastrointestinal Hemorrhage Marwan Abougergi, Joseph Charpentier, Abbas H. Rupawala, Joan Kheder, Dominic J. Nompleggi, John R. Saltzman

Background and Aims: The prevalence of HP negative gastric cancer has been found to be 5.3% in Korea, in which case the microbiota of human stomach such as nitrate reducing bacteria might play a role in the gastric carcinogenesis. The aim of this study was to determine the microbial composition in patients with gastric cancer and healthy controls depending on HP positivity in Korea and its change along the long-term follow-up. Methods: Antral gastric mucosa were obtained from controls (n=20) and patients with gastric cancer (n=20), who were followed-up at least for 5 years. Before getting biopsy the pH of gastric juice was measured. Pyrosequencing for 16S rRNA gene was performed by genome sequencer FLX

Introduction: The AIMS65 and the Glasgow-Blatchford risk scores are validated prognostic scores for patients with upper gastrointestinal hemorrhage (UGIH). We prospectively compared the ability of the AIMS65 score to the Glasgow-Blatchford risk score (GBRS) to predict clinically important outcomes. Methods: This is a prospective study of patients with UGIH identified in two academic medical centers. Inclusion criteria were history of coffee-ground emesis, hematemesis or melena. Exclusion criteria were age less than 18 years or a final diagnosis other than UGIH. The AIMS65 and GBRS scores were calculated for each patient.

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AGA Abstracts

AGA Abstracts

groups (25-40, 41-65, .65), the univariate association of survey period with dysphagia was significant in the oldest age group (9.4% in Phase I vs. 5.2% in Phase II, p ,0.05, adjusted for three comparisons). Conclusions: In this population-based study, dysphagia symptoms were significantly decreased over time, especially in older age groups. PPI use may explain changes in the prevalence of dysphagia over time in a US population. Proportion of dysphagia or PPI use according to the age groups