A link between chronic inflammation and carcinogenesis has been depicted in many organ systems. Helicobacter pylori is the most prevalent bacterial pathogen, induces chronic gastritis and is associated with more than 90% of cases of gastric cancer (GC). However, the introduction of nucleotide sequencing techniques and the development of biocomputional tools have surpassed traditional culturing techniques and opened a wide field for studying the mucosal and luminal composition of the bacterial gastric microbiota beyond H. pylori. In studies applying animal models, a potential role in gastric carcinogenesis for additional bacteria besides H. pylori has been demonstrated. At different steps of gastric carcinogenesis, changes in bacterial communities occur. Whether these microbial changes are a driver of malignant disease or a consequence of the histologic progression along the precancerous cascade, is not clear at present. It is hypothesized that atrophy, as a consequence of chronic gastric inflammation, alters the gastric niche for commensals that might further urge the development of H. pylori-induced GC. Here, we review the current state of knowledge on gastric bacteria other than H. pylori and on their synergism with H. pylori in gastric carcinogenesis.
Keywords: H. pylori; carcinogenesis; gastric bacterial microbiome; gastric cancer; microbiota.
© The Author(s), 2019.
Conflict of interest statement
Conflict of interest statement: The authors declare that there is no conflict of interest.
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Differences in Gastric Mucosal Microbiota Profiling in Patients With Chronic Gastritis, Intestinal Metaplasia, and Gastric Cancer Using Pyrosequencing MethodsCS Eun et al. Helicobacter 19 (6), 407-16. PMID 25052961.In Helicobacter predominant patients, the microbial compositions of gastric mucosa from gastric cancer patients are significantly different to chronic gastritis and intes …
In Vivo Analysis of the Viable Microbiota and Helicobacter Pylori Transcriptome in Gastric Infection and Early Stages of CarcinogenesisK Thorell et al. Infect Immun 85 (10). PMID 28694295.Emerging evidence shows that the human microbiota plays a larger role in disease progression and health than previously anticipated. Helicobacter pylori, the causa …
Suicide Journey of H. Pylori Through Gastric Carcinogenesis: The Role of non-H. Pylori Microbiome and Potential Consequences for Clinical PracticePP de Assumpção et al. Eur J Clin Microbiol Infect Dis 38 (9), 1591-1597. PMID 31114971. - ReviewDespite being one of the most studied cancer-related infections, the relationship between Helicobacter pylori infection and gastric adenocarcinoma (GC) remains, in some p …
Imbalance of Gastrointestinal Microbiota in the Pathogenesis of Helicobacter pylori-Associated DiseasesC He et al. Helicobacter 21 (5), 337-48. PMID 26876927. - ReviewThe development of new nucleotide sequencing techniques and advanced bioinformatics tools has opened the field for studying the diversity and complexity of the gastrointe …
- Correa P. A human model of gastric carcinogenesis. Cancer Res 1988; 48: 3554–3560. - PubMed
- Schulz C, Schutte K, Malfertheiner P. Helicobacter pylori and other gastric microbiota in gastroduodenal pathologies. Dig Dis 2016; 34: 210–216. - PubMed
- Ekstrom AM, Held M, Hansson LE, et al. Helicobacter pylori in gastric cancer established by CagA immunoblot as a marker of past infection. Gastroenterology 2001; 121: 784–791. - PubMed
- Malfertheiner P, Link A, Selgrad M. Helicobacter pylori: perspectives and time trends. Nat Rev Gastroenterol Hepatol 2014; 11: 628–638. - PubMed