Eradication of Helicobacter pylori in Children Restores the Structure of the Gastric Bacterial Community to That of Noninfected Children

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

“…The phenomenon could be attributed to the harsh environment at the end stage since H pylori itself was sharply reduced through gastric carcinogenesis 26 . Most studies revealed that individuals infected with H pylori had distinct community structures compared with H pylori ‐negative counterparts 19‐23,25,27 . However, in two earlier studies, neither alpha diversity nor community structures were found to be different between H pylori ‐positive and H pylori‐ negative groups 4,28 .…”

“…Generally, researchers showed that colonization with H pylori was associated with significantly reduced alpha diversity (Figure 2; Table 1). 6,18‐25 Quantitatively, one study detected an inverse relationship between microbial diversity and Helicobacter abundance 18 . Some researchers explored this inverse association during the progression from gastritis to gastric neoplasms, reporting the correlation tended to be weak in cancer cases 19 .…”

“…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 .…”

“…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 .…”

Changes in Gastric Microbial Composition before and after Helicobacter pylori Eradication Therapy

“…8,9 특히, 헬리코박터 파일로리 제 균 치료 후 변화하는 위 내 미생물군집의 특성을 파악하려는 연구가 다수 진행되었다. 6,[10][11][12][13][14][15][16] 19 헬리코박터 파일로리에 감염되지 않은 건강인의 위 내 미생물군 집에는 Firmicutes, Proteobacteria, Cyanobacteria, Bacteroidetes, Actinobacteria, Acidobacteria 등 다양한 phylum이 관찰되 며, 다양성 역시 높은 수준이다. 11,13 반면, 헬리코박터 파일로리 에 감염된 환자의 경우 위 내 미생물군집 중 헬리코박터 파일 로리의 상대 풍부도(relative abundance)는 90% 이상이며, 13 헬리코박터 파일로리의 생태적 지위가 올라감에 따라 잠재적으 로 헬리코박터 파일로리와 경쟁할 수 있는 다른 미생물의 서식 가능성이 줄어들고, 결과적으로 위 내 미생물군집의 다양성은 매우 낮아진다.…”