scholarly journals Comparison of the human gastric microbiota in hypochlorhydric states arising as a result of Helicobacter pylori-induced atrophic gastritis, autoimmune atrophic gastritis and proton pump inhibitor use

2017 ◽  
Vol 13 (11) ◽  
pp. e1006653 ◽  
Author(s):  
Bryony N. Parsons ◽  
Umer Z. Ijaz ◽  
Rosalinda D’Amore ◽  
Michael D. Burkitt ◽  
Richard Eccles ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Proton Pump Inhibitor ◽  
Atrophic Gastritis ◽  
Proton Pump ◽  
Autoimmune Atrophic Gastritis ◽  
Gastric Microbiota

scholarly journals Comparison of the human gastric microbiota in hypochlorhydric states arising as a result of Helicobacter pylori-induced atrophic gastritis, autoimmune atrophic gastritis and proton pump inhibitor use

2017 ◽  
Author(s):  
Bryony N. Parsons ◽  
Umer Zeeshan Ijaz ◽  
Rosalinda D’Amore ◽  
Michael D. Burkitt ◽  
Richard Eccles ◽  
...  
Keyword(s):  
Proton Pump Inhibitor ◽  
Microbial Diversity ◽  
Atrophic Gastritis ◽  
Proton Pump ◽  
List Type ◽  
Gastric Corpus ◽  
H Pylori ◽  
Autoimmune Atrophic Gastritis ◽  
Gastric Malignancy ◽  
Gastric Microbiota

ABSTRACTObjectiveSeveral conditions associated with reduced gastric acid secretion confer an altered risk of developing a gastric malignancy. Helicobacter pylori-induced atrophic gastritis predisposes to gastric adenocarcinoma, autoimmune atrophic gastritis is a precursor of type I gastric neuroendocrine tumours, whereas proton pump inhibitor (PPI) use does not affect stomach cancer risk. We hypothesised that each of these conditions was associated with specific alterations in the gastric microbiota and that this influenced subsequent tumour risk.Design95 patients (in groups representing normal stomach, PPI treated, H. pylori gastritis, H. pylori-induced atrophic gastritis and autoimmune atrophic gastritis) were selected from a cohort of 1400. RNA extracted from gastric corpus biopsies was analysed using 16S rRNA sequencing (MiSeq).ResultsSamples from normal stomachs and patients treated with PPIs demonstrated similarly high microbial diversity. Patients with autoimmune atrophic gastritis also exhibited relatively high microbial diversity, but with samples dominated by Streptococcus. H. pylori colonisation was associated with decreased microbial diversity and reduced complexity of co-occurrence networks. H. pylori-induced atrophic gastritis resulted in lower bacterial abundances and diversity, whereas autoimmune atrophic gastritis resulted in greater bacterial abundance and equally high diversity compared to normal stomachs. Pathway analysis suggested that glucose-6-phospahte1-dehydrogenase and D-lactate dehydrogenase were over represented in H. pylori-induced atrophic gastritis versus autoimmune atrophic gastritis, and that both these groups showed increases in fumarate reductase.ConclusionAutoimmune and H. pylori-induced atrophic gastritis were associated with different gastric microbial profiles. PPI treated patients showed relatively few alterations in the gastric microbiota compared to healthy subjects.SIGNIFICANCE OF THIS STUDY1.What is already known about this subject?Some conditions which result in reduced gastric acid secretion and hypochlorhydria are associated with an increased risk of gastric tumourigenesis.This risk is different in patients with H. pylori-induced atrophic gastritis, autoimmune atrophic gastritis and chronic proton pump inhibitor use.Hypochlorhydria and H. pylori infection cause alterations in the composition of the gastric microbiota.2.What are the new findings?We used 16S rRNA sequencing to characterise the microbiota in gastric corpus biopsies from a well characterised cohort of patients.The gastric microbiota was different in patients who were hypochlorhydric as a result of H. pylori-induced atrophic gastritis, autoimmune atrophic gastritis and proton pump inhibitor use.Biochemical pathways associated with gastric carcinogenesis such as the fumarate reductase pathway were predicted to be altered in patients with atrophic gastritis.3.How might it impact on clinical practice in the foreseeable future?Understanding how the microbiota that colonise the hypochlorhydric stomach influence gastric carcinogenesis may ultimately permit stratification of patients’ subsequent tumour risk.Interventions that alter the composition of the gastric microbiome in hypochlorhydric patients with atrophic gastritis should be tested to investigate whether they alter the subsequent risk of developing gastric malignancy.

scholarly journals Autoimmune Gastritis and Gastric Microbiota

2020 ◽  
Vol 8 (11) ◽  
pp. 1827
Author(s):  
Laura Conti ◽  
Bruno Annibale ◽  
Edith Lahner
Keyword(s):  
Helicobacter Pylori ◽  
Atrophic Gastritis ◽  
Autoimmune Gastritis ◽  
Gastric Disease ◽  
Rrna Gene ◽  
Microbiota Composition ◽  
Microbial Composition ◽  
Oxyntic Mucosa ◽  
Autoimmune Atrophic Gastritis ◽  
Gastric Microbiota

Autoimmune atrophic gastritis is an organ-specific immune-mediated condition characterized by atrophy of the oxyntic mucosa. Autoimmune atrophic gastritis (AIG) is characterized by a progressive loss of acid-secreting parietal cells leading to hypo-achlorhydria. Due to this peculiar intra-gastric environment, gastric microbiota composition in individuals with autoimmune atrophic gastritis was first supposed and then recently reported to be different from subjects with a normal acidic healthy stomach. Recent data confirm the prominent role of Helicobacter pylori as the main bacterium responsible for gastric disease and long-term complications. However, other bacteria than Helicobacter pylori, for example, Streptococci, were found in subjects who developed gastric cancer and in subjects at risk of this fearful complication, as well as those with autoimmune gastritis. Gastric microbiota composition is challenging to study due to the acidic gastric environment, the difficulty of obtaining representative samples of the entire gastric microbiota, and the possible contamination by oral or throat microorganisms, which can potentially lead to the distortion of the original gastric microbial composition, but innovative molecular approaches based on the analysis of the hyper-variable region of the 16S rRNA gene have been developed, permitting us to obtain an overall microbial composition view of the RNA gene that is present only in prokaryotic cells.

scholarly journals Canadian Helicobacter Study Group Consensus Conference: Update on the Approach to Helicobacter Pylori Infection in Children and Adolescents – an Evidence-Based Evaluation

2005 ◽  
Vol 19 (7) ◽  
pp. 399-408 ◽  
Author(s):  
Nicola L Jones ◽  
Philip Sherman ◽  
Carlo A Fallone ◽  
Nigel Flook ◽  
Fiona Smaill ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Proton Pump Inhibitor ◽  
Proton Pump ◽  
Consensus Conference ◽  
Helicobacter Pylori Infection ◽  
Diagnostic Tools ◽  
Study Group ◽  
Evidence Based ◽  
H Pylori

As an update to previously published recommendations for the management of Helicobacter pylori infection, an evidence-based appraisal of 14 topics was undertaken in a consensus conference sponsored by the Canadian Helicobacter Study Group. The goal was to update guidelines based on the best available evidence using an established and uniform methodology to address and formulate recommendations for each topic. The degree of consensus for each recommendation is also presented. The clinical issues addressed and recommendations made were: population-based screening for H pylori in asymptomatic children to prevent gastric cancer is not warranted; testing for H pylori in children should be considered if there is a family history of gastric cancer; the goal of diagnostic interventions should be to determine the cause of presenting gastrointestinal symptoms and not the presence of H pylori infection; recurrent abdominal pain of childhood is not an indication to test for H pylori infection; H pylori testing is not required in patients with newly diagnosed gastroesophageal reflux disease; H pylori testing may be considered before the use of long-term proton pump inhibitor therapy; testing for H pylori infection should be considered in children with refractory iron deficiency anemia when no other cause has been found; when investigation of pediatric patients with persistent or severe upper abdominal symptoms is indicated, upper endoscopy with biopsy is the investigation of choice; the 13C-urea breath test is currently the best noninvasive diagnostic test for H pylori infection in children; there is currently insufficient evidence to recommend stool antigen tests as acceptable diagnostic tools for H pylori infection; serological antibody tests are not recommended as diagnostic tools for H pylori infection in children; first-line therapy for H pylori infection in children is a twice-daily, triple-drug regimen comprised of a proton pump inhibitor plus two antibiotics (clarithromycin plus amoxicillin or metronidazole); the optimal treatment period for H pylori infection in children is 14 days; and H pylori culture and antibiotic sensitivity testing should be made available to monitor population antibiotic resistance and manage treatment failures.

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