Page 136 - Ebook-Book JCMS 2025

Comparative Study Using Mucosal Brushing and Mucosal
Biopsy for Detecting Duodenal Microbiome in Functional
Dyspepsia
Chatpol Samuthpongtorn1, Thanrada Vimonsuntirungsri2, Pisit Tangkijvanich3, Rapat Pittayanon2*
1 Department of Medicine, Faculty of Medicine, Chulalongkorn University and King
Chulalongkorn Memorial Hospital
2 Division of Gastroenterology, Department of Medicine, Faculty of Medicine, Chulalongkorn
University and King Chulalongkorn Memorial Hospital
3 Department of Biochemistry, Faculty of Medicine, Chulalongkorn University
*Corresponding Author E-mail: rapat125@gmail.com
Background: Methods: Results: Conclusion: Abstract
Functional dyspepsia (FD) is a common gastrointestinal disorder with emerging evidence
suggesting the involvement of the duodenal microbiota via the gut-brain axis. However, the
optimal sampling method and key microbial features associated with FD remain unclear.
This study aimed to compare mucosal brushing and biopsy methods and assess microbiota
differences between FD patients and controls.
Patients undergoing esophago-gastro-duodenoscopy (EGD) between February and
November 2024 were recruited. FD was diagnosed using ROME IV criteria, and sex-matched
controls were included. Duodenal samples were collected using both mucosal brushing and
biopsy, followed by 16S rRNA sequencing (V1–V2 region). Microbial α-diversity (richness
and Shannon index) and β-diversity (Bray-Curtis dissimilarity) were analyzed. Group
comparisons used the Mann-Whitney U test, and associations with FD were assessed using
generalized linear mixed models adjusting for age, smoking, and alcohol.
Seventy-six samples were analyzed (36 FD, 40 controls). Mucosal brushing yielded
significantly higher richness (Figure A) and Shannon diversity (Figure B) than biopsy
samples (both p < 0.0001). β-diversity analysis showed distinct microbial profiles
between sampling methods (PERMANOVA R² = 0.16, p = 0.001) (Figure C). Across groups,
Bacteroidota, Proteobacteria, and Firmicutes were the most abundant phyla (Figure D).
In mucosal brushing samples, 27 genera differed significantly between FD and controls
(Figure E); 11 genera differed in tissue samples. Streptococcus, a genus previously
implicated in FD, was significantly elevated in FD patients in both brushing (β= 0.086, p=
0.047) (Figure F) and tissue samples (β= 0.031, p = 0.001). Subgroup analysis revealed
stronger associations in the EPS subtype (brushing: β = 0.19, p = 0.022; tissue: β = 0.10,
p = 0.0006).
Mucosal brushing offers a less invasive and more comprehensive method for assessing
duodenal microbiota. FD patients exhibit distinct microbial signatures, particularly elevated
Streptococcus, with strongest associations in the EPS subtype.
134 Joint Conference in Medical Sciences 2025