Duodenal microbiomes differ between lumen, mucosa in functional dyspepsia
Between people with and without functional dyspepsia, the duodenal luminal microbiome was different and the mucosal microbiome was similar, according to a presenter at UEG Week Virtual.
“Recently, we showed that dyspeptic symptoms correlated with increased duodenal mucosal eosinophils in functional dyspepsia patients off protein pump inhibitors,” Lucas Wauters, MD of UZ Leuven’s department of gastroenterology and hepatology, KU Leuven’s TARGID and Rega Institute and VIB Center for Microbiology in Belgium, said during a presentation.
“Moreover, protein pump inhibitors not only decreased duodenal eosinophils levels but clinical efficacy was also associated with changes in eosinophils, pointing to new causal anti-inflammatory effects, similar to in the esophagus of eosinophilic esophagitis patients. ... We also observed luminal protein pump inhibitor effects, which increased eosinophils being linked with changes in duodenal bile salts in controls, suggesting the role of the microbiome.”
Aimed to investigate the variation in duodenal luminal and mucosal microbiome in patients with functional dyspepsia during PPI therapy, Wauters and colleagues examined 28 patients with functional dyspepsia (24 women; mean age, 31.7 years) and 30 controls (21 women; mean age, 32.3 years) through aseptic duodenal biopsies and brushes before and after 4 weeks of daily 40 mg pantoprazole. They found sampling in the lumen vs. mucosa and subject were significantly associated with duodenal community variation, whereas having or not having functional dyspepsia, PPI and demographics were not.
According to study results, both groups had 45 differentially abundant genera in the lumen and mucosa with Streptococcus being the most common. Luminal genera differed between functional dyspepsia and healthy patients, as “Porphyromonas, Neisseria, Haemophilus, Fusobacterium and Selenomonas were lower in functional dyspepsia patients vs. controls and Prevotella decreased after PPI,” Wauters and colleagues wrote. There were no differences in mucosal genera.
In the lumen at baseline, Porphyromonas was inversely associated with symptoms and eosinophils, though its change was not associated with reduction of symptoms and eosinophils. In the control group, luminal Streptococcus correlated with eosinophils, and increases in eosinophils associated with Streptococcus changes, according to the abstract.
“Despite a potential role for Porphyromonas in functional dyspepsia pathophysiology, changes were unrelated to clinical and mucosal PPI effects in functional dyspepsia patients,” Wauters said. “In contrast, increased eosinophils and bile salts were associated with changes Streptococcus, which suggests a role for these luminal microbiome changes that may also counteract eosinophil reducing effects after long-term PPI therapy in functional dyspepsia patients.”