The eradication of Helicobacter pylori restores rather than disturbs the gastrointestinal microbiota in asymptomatic young adults

Abstract

Background The eradication of Helicobacter pylori (H pylori) has been suggested to reduce the risk of gastric cancer, but its impact on the gut microbiota has attracted public attention. This study aimed to investigate the short‐term and long‐term effects of bismuth quadruple therapy on both gastric and fecal microbiota. Methods Ten asymptomatic young adults with H pylori‐related gastritis were treated with bismuth quadruple therapy for 14 days, and 7 age‐matched adults without H pylori infection were enrolled as healthy controls. Both fecal and gastric mucosa samples were collected from H pylori‐positive patients at weeks 0, 6, and 26, while fecal samples were collected from healthy controls. The gastric and gut microbiota were analyzed by 16S rRNA gene sequencing. Results The structure of the gastric microbiota was significantly changed after the eradication of H pylori with increased alpha diversity over time. The relative abundance of H pylori sharply decreased from more than 70% to nearly 0% after treatment, while some beneficial bacteria, such as Lactobacillus and Bifidobacterium, were increased. The microbial diversity of gut microbiota was higher in H pylori‐infected patients than in healthy controls, which tended to decrease after eradication. The potentially beneficial gut bacteria Blautia and Lachnoclostridium were enriched at week 26 compared to week 0, while the pathogenic Alistipes were depleted to a level close to that of the healthy controls. Conclusions Bismuth quadruple therapy for H pylori eradication can restore the diversity of gastric microbiota with enrichment of beneficial bacteria. The composition of gut microbiota after H pylori eradication trends toward healthy status instead of becoming dysbiotic.

Lack of significant differences between gastrointestinal tract microbial population structure of Helicobacter pylori‐infected subjects before and 2 years after a single eradication event

“…23,47 Interestingly, recent report on the use of bismuth quadruple therapy indicates contradictory results, suggesting that H pylori eradication restores rather than disturbs the GIT microbiota by restoring the diversity of gastric microbiota with enrichment of beneficial bacteria, while other studies have shown alpha and beta diversity alterations. 45,48 As it is nowadays widely accepted that the gut microbiome is affected by a wide variety of factors, which includes physiological peculiarities of individual, BMI, gut-related and unrelated diseases, age, diet, and many other. Number of studies suggest that all these factors together mediate the unique composition of individual gut microbiome and our findings strongly support this by identifying "Individual" as major gut microbiome structure affecting factor in both main study groups.…”

Hellenic consensus on Helicobacter pylori infection

“…Probiotic supplementation slightly counteracts the pervasive effects of antibiotics on the intestinal microbiota (defined by fluorescence in situ hybridization and culture) [108]. Long-lasting perturbations of specific taxa (often beneficial) were also reported in recent studies using meta-genomic and genomic analyses [111][112][113]. The potential for inducing persistent macrolide resistance in the nostrils, throat and fecal microbiota following eradication therapy has been also reported [109].…”

Helicobacter pylori infection and eradication: Exploring their impacts on the gastrointestinal microbiota

“…Significant differences in microbial community structures were found between the H pylori ‐infected and negative control groups 33‐36 . The compositional analysis at the phylum level discovered that the abundance of Proteobacteria significantly increased in infected individuals, which could be due to the transfer of Helicobacter from the stomach to the intestinal lumen 6,34 . Of note, the Bacteroidetes:Firmicutes (B:F) ratio tended to be higher in the H pylori ‐positive group 6,31,37 .…”

“… 31,32 Strikingly, most studies investigating the relationship between H pylori infection and gut microbial diversity provided a positive correlation (Figure 2; Table 2). 31,33‐36 As higher microbial diversity is usually associated with an overall better health state, it will be interesting to explore whether the increased intestinal microbial diversity upon H pylori infection provides some beneficial effects to the host. Significant differences in microbial community structures were found between the H pylori ‐infected and negative control groups 33‐36 .…”

“… 31,33‐36 As higher microbial diversity is usually associated with an overall better health state, it will be interesting to explore whether the increased intestinal microbial diversity upon H pylori infection provides some beneficial effects to the host. Significant differences in microbial community structures were found between the H pylori ‐infected and negative control groups 33‐36 . The compositional analysis at the phylum level discovered that the abundance of Proteobacteria significantly increased in infected individuals, which could be due to the transfer of Helicobacter from the stomach to the intestinal lumen 6,34 .…”