A non-endoscopic device to sample the oesophageal microbiota: a case-control study.

Area of Science:

• Microbiology
• Gastroenterology
• Oncology

Background:

• Gastroesophageal reflux disease is a major risk factor for oesophageal adenocarcinoma.
• Rising oesophageal adenocarcinoma incidence correlates with Helicobacter pylori eradication.
• Both reflux and H. pylori eradication may impact oesophageal microbiota.

Purpose of the Study:

• To profile the oesophageal microbiota across Barrett's carcinogenesis stages.
• To evaluate the Cytosponge as a minimally invasive tool for oesophageal microbiota sampling.

Main Methods:

• Case-control study using 16S rRNA gene amplicon sequencing on 210 oesophageal samples from 86 patients.
• Samples included normal, non-dysplastic, dysplastic Barrett's oesophagus, and oesophageal adenocarcinoma.
• Comparison of Cytosponge, endoscopic brushings, and tissue for microbial DNA yield, diversity, and composition.

Main Results:

• Decreased microbial diversity in oesophageal adenocarcinoma vs. controls (OTU richness, Chao, Shannon indices).
• Enrichment of Lactobacillus fermentum and dominance of lactic acid bacteria in oesophageal adenocarcinoma.
• Cytosponge yielded 10x more microbial DNA than brushes/biopsies and detected diversity changes in high-grade dysplasia.

Conclusions:

• Microbial community alterations occur in the lower oesophagus during Barrett's carcinogenesis.
• These changes are detectable at the pre-invasive high-grade dysplasia stage using the Cytosponge.
• Findings support early disease detection and future longitudinal microbiota monitoring.