Foregut Microbiome and Risk of Gastric Intestinal Metaplasia, and Gastric Cancer Risk

The study is composed of two sub-studies. The first study, conducted by NYU Grossman School of Medicine, is a case-control study of 89 cases with gastric intestinal metaplasia (IM) and 89 matched controls who underwent upper gastrointestinal endoscopy at three sites affiliated with NYU Langone Health. Shotgun metagenomic sequencing using oral wash samples from the 89 case-control pairs and antral mucosal brushing samples from 55 case-control pairs were conducted. The other study, conducted by Vanderbilt University Medical Center, is a prospective case-control study on the oral microbiome and gastric cancer risk, utilizing shotgun metagenomic sequencing data of pre-diagnostic buccal samples from 319 Asians, 118 African Americans and 51 European Americans. This study includes data from three population-based studies: the Southern Community Cohort Study (SCCS), the Shanghai Women's Health Study (SWHS), and the Shanghai Men's Health Study (SMHS). The SWHS and SMHS include 74,941 women aged 40-70 years and 61,480 men aged 40-74 years, respectively, who were permanent residents of Shanghai and recruited to the cohorts between 1997 and 2006. The SCCS is an ongoing prospective cohort study, including ~86,000 participants recruited during 2002 and 2009 from 12 Southeastern states. Nearly 67% of study participants are African Americans (AAs) and the remaining are European American (EA) subjects.]]>
The NYU Study:
Inclusion criteria: Cases with newly diagnosed intestinal metaplasia in the gastric antrum or body/fundus. Non-cases with normal gastric histology or superficial gastritis without any atrophy that provided saliva/oral wash samples.Exclusion criteria: 1) prior gastric surgery, 2) use of antimicrobial agents within the prior 2 months, 3) current use of anticoagulants, 4) active gastrointestinal bleeding, and 5) having had or suspected to have esophageal varices.
The Vanderbilt Study:
Inclusion criteria: Incident gastric cancer cases, according to the International Classification of Diseases (ICD-10) code C-16, who donated a buccal sample at study enrollment. Two controls were randomly selected and individually matched to each case on age at gastric cancer diagnosis (± two years), race (AA/EA/other; SCCS only), sex, smoking status (current/former/never), and buccal sample collection date (± 30 days) and time (morning/afternoon).
Exclusion criteria: Subjects who used antibiotics within a week before buccal sample collection.]]>