Patients infected with Helicobacter pylori develop chronic gastritis with a subgroup progressing to further complications.
The role of microbiota from the oral cavity swallowed with saliva and either transiting the stomach or persisting in the gastric mucosa is uncertain.
It is also not known whether the bacterial community differs in luminal and mucosal niches.
A key question raised by Professor Dietmar Pieper and colleagues from Germany is whether Helicobacter pylori influences the bacterial communities of gastroduodenal niches.
Saliva, gastric and duodenal aspirates as well as gastric and duodenal biopsies were collected during esophagogastroduodenoscopy from 24 patients.
The researchers extracted RNA and the V1–V2 region of the retrotranscribed bacterial 16S rRNA amplified and sequenced on the Illumina MiSeq platform.
|Helicobacter spp were shown to dominate the mucosa-associated community in the stomach|
Overall, 687 bacterial phylotypes that belonged to 95 genera and 11 phyla were observed.
Each individual comprised a unique microbiota composition that was consistent across the different niches.
However, the team observed that the stomach fluid enriched for specific microbiota components.
Helicobacter spp were shown to dominate the mucosa-associated community in the stomach, and to significantly influence duodenal and oral communities.
Professor Pieper and team comment, "The detailed analysis of the active global bacterial communities from the five distinct sites of the upper GI tract allowed for the first time the differentiation between host effects and the influence of sampling region on the bacterial community."
"The influence of Helicobacter spp on the global community structures is striking."