Duodenal Microbiota in Functional Dyspepsia

Overview

The goal of this observational study is to assess the type of duodenal microbiota and duodenal microbiome in in FD patients compared to control group. The main questions it aims to answer are: * What are the differences in the type of duodenal microbiota and is there a difference in duodenal microbiome diversity between patients diagnosed with functional dyspepsia (FD) and the control group? * Are there any significant variations in the composition and diversity of gut microbiota between patients with FD and the control group, considering the method of sample collection (duodenal brushing vs. duodenal biopsy)?

Dyspepsia, a common GI disorder, affects a significant portion of the global population, with a prevalence as high as 66% in Thailand. Functional dyspepsia (FD) is characterized by no detectable structural abnormalities during endoscopic examinations and significantly impacts health-related quality of life. Dysregulation of the gut-brain axis is hypothesized to contribute to motility disorders, visceral hypersensitivity, and mucosal/immune function changes in FD. Recent studies have characterized the microbiota of the duodenal mucosal-associated microbiome (MAM) in patients with functional dyspepsia (FD). However, duodenal microbiota in FD patients compared to healthy control remains unclear with conflicting results. The number of studies evaluating this is limited, and a well-designed study comparing the duodenal microbiota of patients with functional dyspepsia to control group will advance our understanding of the potential role of the microbiome in FD. Therefore, the aim of this study is to compare the duodenal microbiota of patients with FD and those without upper GI symptoms. This study is pilot phase, cross-sectional and case-control study that aims to evaluate microbiota profile in patients with functional dyspepsia, compared to those without functional dyspepsia by using mucosal brush sampling and mucosal biopsy sampling. Study protocol include Age, gender, BMI, smoking history, history of PPI use within 2 weeks, history of antibiotic use within 4 weeks, history of probiotic use within 4 weeks will be recorded in case record form. After consent, standard EGD will be performed. The duodenal mucosa using mucosal brushing with sterile sheathed brush, duodenal mucosal biopsy by standard forceps biopsy will be done respectively. ㆍ The duodenal mucosal specimen will be keep in sterile tube and immediate keep in freezing at -80C (allow room temperature \<2 hr) for 16sRNA sequencing analysis.