Changes in the taxonomic composition of the intestinal microbiota under the influence of Helicobacter pylori eradication therapy

The aim of the study: to evaluate the composition of gut microbiota in H. pylori-negative and H. pylori-positive patients, as well as to assess the influence of H. pylori eradication therapy on the gut microbiota composition immediately after and one month after completion of therapy. Materials and methods: stool samples from 93 H. pylori-positive and 42 H. pylori-negative (control group) patients were used for analysis. Stool samples immediately after and one month after completion of therapy were collected from 93 and 14 patients, respectively. Gut microbiota composition assessment including the evaluation of alpha diversity (Shannon index) was performed by shotgun sequencing. Results: Firmicutes (56,73±21,81)%, Bacteroidetes (35,97±23,65)%, Actinobacteria (2,42±4,24)%, Proteobacteria (2,37±7,00)%, Verrucomicrobia (0,94±2,54)% were the most represented bacterial phyla in the gut microbiota of H. pylori-positive patients before the eradication therapy. Immediately after eradication therapy the number of Verrucomicrobia and Actinobacteria bacterial phyla decreased, and, conversely, the representation of Proteobacteria phylum increased. In 4 weeks the representation of these phyla did not differ from the initial level. Representation of Firmicutes phylum had a tendency to decrease immediately after the completion of eradication therapy; there was a further decrease in their representation in a month. Bacterial genera: Bacteroides (15,1±17,32)%, Prevotella (14,07±21,60)%, Eubacterium (13,79±10,49)%, Faecalibacterium (6,26±5,85)%, Ruminococcus (5,61±6,00)%, Subdoligranulum (5,34±5,77)%, Butyrivibrio (4,57±13,26)% were predominat in the gut microbiota in H. pylori-positive patients before the treatment. Immediately after therapy the representation of almost all these genera decreased, except Bacteroides which representation increased. The abundance of Escherichia and Klebsiella bacterial genera also increased. One month after the therapy a tendency to return to initial composition was observed for most of bacterial genera. Conclusion: thus, H. pylori eradication therapy affects the gut microbiota composition. Some changes persist for one month after completion of therapy.

микробиота кишечника, H. pylori, метагеном, эрадикационная терапия, шотган-секвенирование, gut microbiota, H. pylori, metagenome, eradication therapy, shotgun sequencing