Gastric Microbiota Restoration Related to Eradication of Helicobacter pylori

Helicobacter pylori bacteria. Computer illustration of Helicobacter pylori bacteria in a human stomach. Formerly known as Campylobacter pyloridis, these are spiral-shaped Gram-negative bacteria. The terminal flagella (hair-like structures) are used for locomotion. Colonies of H. pylori are found in the mucus lining of the stomach. They cause gastritis, and are also the most common cause of stomach ulcers. H. pylori may also be a cause or co-factor for gastric cancer, as its presence increases the risk of developing stomach tumours.
The impact of eradicated Helicobacter pylori on the pediatric gastric microbial community structure shows restoration of bacterial diversity consistent with noninfected children in the same endemic region.

Helicobacter pylori (H pylori) changes the gastric microbial composition and leads to reduced gastric inflammatory disease in children.

The impact of eradicated H pylori on the pediatric gastric microbial community structure shows restoration of bacterial diversity consistent with noninfected children in the same endemic region, according to a review published in Gastroenterology.

The investigators of this study sought to determine the impact of H pylori eradication on the bacterial community structure in Venezuelan children.

The study included 16 children aged 13 years or younger who presented with nausea and abdominal discomfort without receiving antibiotic or antacid therapy within the previous month. Participants underwent endoscopic antral biopsy for H pylori testing and histology and microbiota analysis; children who were found positive for infection (n=11) were treated with amoxicillin, clarithromycin, and omeprazole for 14 days. After 2 months, the participants underwent a second biopsy for H pylori testing and microbiota analysis. To identify microbial communities, DNA from the biopsy was isolated, and the V4 region of the 16S rRNA bacterial gene was amplified via polymerase chain reaction; 250 base single-end reads were then sequenced and analyzed.

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The investigators found that the overall gastric bacterial community structure in children with H pylori infection differed from that of noninfected children according to unweighted UniFrac analysis (P =.002), weighted UniFrac analysis (=.005), and Bray-Curtis analysis (P =.006). Children with H pylori infection were found to have significantly less diverse gastric bacterial communities vs noninfected children, demonstrated in both Shannon (P =.008) and Simpson (P =.02) indices. A secondary analysis of the gastric microbial composition in children whose H pylori infection was successfully eradicated through antibiotics (n=7) showed that their bacterial community structure was similar to that of noninfected children in unweighted UniFrac (P =.107), weighted UniFrac (P =.439), and Bray-Curtis (P =.260) analyses. Additionally, children who received H pylori clearance demonstrated significantly increased gastric bacterial diversity based on comparisons of Shannon and Simpson indices (P =.04).

A limitation to the study was the small study population and the need for future studies adding to the characterization of gastric microbiota in pediatric _H pylori_infection affecting different endemic regions of the world.

The investigators suggest these findings demonstrate the impact of H pylori on the gastric microbial community structure of Venezuelan children, in which the eradication of H pylori in infected children was associated with the restoration of gastric microbiota similar to the noninfected children.


Serrano CA, Pierre R, Van Der Pol WJ, Morrow CD, Smith PD, Harris PR. Eradication of Helicobacter pylori in children restores the structure of the gastric bacterial community to that of non-infected children [published online August 20, 2019]. Gastroenterology. doi: 10.1053/j.gastro.2019.08.017