Gastric and Duodenal Microbiota in Dyspeptic Subjects

Overview

The composition of gastric microbiota is determined by the status of Helicobacter pylori infection. In subjects who have never been infected by H. pylori, gastric microbiota includes various bacteria, creating ideal microbial diversity. This ideal microbial diversity is destroyed by H. pylori infection at low intragastric pH. Since it is difficult for most bacteria to proliferate within an acidic stomach, relative H. pylori abundance gives rise to microbial dysbiosis. Conversely, unideal microbial diversity is often observed in infected individuals with impaired gastric secretory ability at hypochlorhydric condition. Bacteria producing carcinogenic N-nitrosamine compounds are often detected in individuals with past or chronic H. pylori infection at high intragastric pH. Nonetheless, microbial imbalance that occurs in the earlier phase before gastric carcinognenesis is uncertain.

Full Title of Study: “Composition of Gastric and Duodenal Microbiota in Dyspeptic Subjects”

Study Type

  • Study Type: Observational
  • Study Design
    • Time Perspective: Prospective
  • Study Primary Completion Date: March 2018

Detailed Description

Dominant colonization of a specific microbiota leading to dysbiosis may lead to inflammation of the mucosa. We hypothesized that the degree of inflammation depend on the composition of microbiota. This study was aimed to define gastric and duodenal microbiota leading to abnormal histopathology. We further tried to elucidate whether the composition of duodenal microbiota is altered by gastric microbiota. Among the dyspeptic subjects who visited for upper gastrointestinal (UGI) endoscopy, subjects with drug intake (antibiotics, PPIs, laxatives, antidepressants, statins, metformin) within 3 months will be excluded. Three biopsies will performed at the greater curvature side of the mid-antrum, greater curvature side of the mid-body, and at the duodenum, respectively. Next generation sequencing analysis will be performed for 16S rRNA variable regions using the biopsied samples. Primary study endpoint is 16S rRNA sequencing findings of gastric and duodenal microbiota. Secondary endpoints are microbiota linked with higher degrees of inflammation, activity, atrophy and intestinal metaplasia based on the updated Sydney classification. Furthermore, correlation between the microbiota and endoscopy finding will be analyzed.

Interventions

  • Genetic: 16S rRNA pyrosequencing analysis
    • Next generation sequencing analysis will be done for 16S rRNA V1,2 hypervariable regions at Biocore (Seoul, Korea).

Arms, Groups and Cohorts

  • Subjects for pyrosequencing analysis
    • Dyspeptic subjects who visited for evaluation and agreed on 16S rRNA pyrosequencing analysis

Clinical Trial Outcome Measures

Primary Measures

  • Next generation sequencing analysis for microbiota
    • Time Frame: up to 6 months
    • 16S rRNA pyrosequencing analysis findings of the gastric and duodenal biopsies

Secondary Measures

  • Updated Sydney classification
    • Time Frame: up to 6 months
    • 0=none, 1=mild, 2= moderate, 3=marked infiltration
  • Gastrointestinal endoscopy finding
    • Time Frame: up to 6 months
    • Upper gastrointestinal endoscopy findings
  • Gastrointestinal symptom and food intake score
    • Time Frame: up to 6 months
    • Scoring system published in Neurogastroenterol Motil 2016;28:1401-1408

Participating in This Clinical Trial

Inclusion Criteria

  • Dyspeptic subjects who visited for evaluation including upper gastrointestinal endoscopy and biopsies – Age >20 years old Exclusion Criteria:

  • Underlying disease(s) that requires managements – Recent intake of drug(s) – History of gastrectomy

Gender Eligibility: All

Minimum Age: 20 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Konkuk University Medical Center
  • Provider of Information About this Clinical Study
    • Principal Investigator: Sun-Young Lee, Professor – Konkuk University Medical Center
  • Overall Official(s)
    • Sun-Young Lee, M.D., Ph.D., Principal Investigator, Konkuk University

References

Lee SY, Moon HW, Hur M, Yun YM. Validation of western Helicobacter pylori IgG antibody assays in Korean adults. J Med Microbiol. 2015 May;64(Pt 5):513-518. doi: 10.1099/jmm.0.000050. Epub 2015 Mar 9.

Lee SP, Lee SY, Kim JH, Sung IK, Park HS, Shim CS, Moon HW. Correlation between Helicobacter pylori infection, IgE hypersensitivity, and allergic disease in Korean adults. Helicobacter. 2015 Feb;20(1):49-55. doi: 10.1111/hel.12173. Epub 2014 Sep 25.

Lee SY. Future candidates for indications of Helicobacter pylori eradication: do the indications need to be revised? J Gastroenterol Hepatol. 2012 Feb;27(2):200-11. doi: 10.1111/j.1440-1746.2011.06961.x.

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