Effect of Helicobacter pylori on gastrointestinal microbiota: a population-based study in Linqu, a high-risk area of gastric cancer

Abstract

ObjectiveGastrointestinal microbiota may be involved in Helicobacter pylori-associated gastric cancer development. The aim of this study was to explore the possible microbial mechanisms in gastric carcinogenesis and potential dysbiosis arising from H. pylori infection.DesignDeep sequencing of the microbial 16S ribosomal RNA gene was used to investigate alterations in paired gastric biopsies and stool samples in 58 subjects with successful and 57 subjects with failed anti-H. pylori treatment, relative to 49 H.pylori negative subjects.ResultsIn H. pylori positive subjects, richness and Shannon indexes increased significantly (both p<0.001) after successful eradication and showed no difference to those of negative subjects (p=0.493 for richness and p=0.420 for Shannon index). Differential taxa analysis identified 18 significantly altered gastric genera after eradication. The combination of these genera into a Microbial Dysbiosis Index revealed that the dysbiotic microbiota in H. pylori positive mucosa was associated with advanced gastric lesions (chronic atrophic gastritis and intestinal metaplasia/dysplasia) and could be reversed by eradication. Strong coexcluding interactions between Helicobacter and Fusobacterium, Neisseria, Prevotella, Veillonella, Rothia were found only in advanced gastric lesion patients, and were absent in normal/superficial gastritis group. Changes in faecal microbiota included increased Bifidobacterium after successful H. pylori eradication and more upregulated drug-resistant functional orthologs after failed treatment.ConclusionH. pylori infection contributes significantly to gastric microbial dysbiosis that may be involved in carcinogenesis. Successful H. pylori eradication potentially restores gastric microbiota to a similar status as found in uninfected individuals, and shows beneficial effects on gut microbiota.

Long‐term changes in the gut microbiota after 14‐day bismuth quadruple therapy in penicillin‐allergic children

“…We searched PubMed using the terms “Helicobacter”, “eradication” and “microbiota” for papers published from January 1, 2000, to March 12, 2020, in English. Sixteen studies using high‐throughput sequencing to assess alterations in the gut microbiota before and after H pylori eradication are summarized in Table 17‐32 . 10 publications focus on the impact of standard triple therapy and 5 studies address the long‐term (at least one year) effect after treatment.…”

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

“…Sufficient evidence indicated that gastric microbial diversity increased significantly after successful clearance of H pylori but showed no improvement after failed treatment (Figure 2; Table 3). 9,19,21,23,34,46 Researchers suggested the recovery might take certain time as they presented that diversity increased gradually from week 0 to week 6 and week 26 34 . Additionally, studies unveiled that alpha diversity could be fully restored to the level of noninfected controls after successful eradication 9 .…”

“… 9,19,21,23,34,46 Researchers suggested the recovery might take certain time as they presented that diversity increased gradually from week 0 to week 6 and week 26 34 . Additionally, studies unveiled that alpha diversity could be fully restored to the level of noninfected controls after successful eradication 9 . In contrast, although community structure could also be partially restored after clearance of H pylori, controversy existed regarding whether significant differences remained between the post‐eradication group and negative controls.…”

“…In contrast, although community structure could also be partially restored after clearance of H pylori, controversy existed regarding whether significant differences remained between the post‐eradication group and negative controls. Some researchers detected that the composition of the gastric microbial community was restored in patients receiving anti‐ H pylori regimens to that of noninfected children 2 months after treatment, whereas other studies determined that samples from adults 6 months after successful treatment still showed different community structures with negative controls 9,21 . Different age‐groups included in the analysis might account for the opposite conclusions as another study recruiting children also found the community structure in the eradication group became close to that of the H pylori ‐negative group at 4 weeks after therapy 23 .…”

“…For example, researchers showed that the interactions among gastric microbes were greatly compromised in the presence of H pylori 8 . In the clinical scenario, H pylori‐ related dysbiosis has been linked to many digestive diseases 9‐11 . Thus, a better understanding of the dialogues between H pylori and other gastrointestinal microbial members might offer novel targets for prevention or treatment.…”