Objective Non-erosive reflux disease (NERD) is a prevalent gastrointestinal disorder with complex pathophysiology. Recent evidence suggests a potential role of gut microbiota in its development. This study aimed to characterize the gut microbiota in patients with NERD, and to explore microbial biomarkers for disease differentiation. Methods We enrolled 40 patients with NERD, along with 18 healthy controls (HCs). Fecal samples were collected and analyzed using 16S ribosomal RNA (rRNA) gene sequencing. Gut microbial diversity and composition, linear discriminant analysis effect size (LEfSe), and receiver operating characteristic (ROC) curves were evaluated. Results The microbial structure and composition of NERD patients were distinct from those of HCs. Alpha diversity was significantly lower in NERD patients than in controls ( p 0.01). At the phylum level, Actinobacteriota was increased, while Bacteroidota and Proteobacteria were decreased in NERD patients. At the genus level, Faecalibacterium and Bacteroides were decreased, whereas Streptococcus , Blautia , Bifidobacterium , and Enterococcus were enriched in NERD patients. Additionally, LEfSe was developed to identify several bacterial genera that can differentiate patients with NERD from those HCs. Furthermore, the area under the curve (AUC) value of Streptococcus for distinguishing NERD from HCs was 0.9333, indicating exceptionally high diagnostic power. Conclusion This study identified microbiota dysbiosis of gut microbiota in NERD patients. Streptococcus showed extremely high diagnostic efficacy, which can be used as a microbial biomarker, and may serve as potential therapeutic target for NERD.
Wei et al. (2026) studied this question.