Research update · 5 October 2026

Research gaps and timeline

Eradication trials strongly support a causal contribution to infected peptic-ulcer disease. NSAID-associated, idiopathic and time-dependent bleeding outcomes define remaining questions rather than overturning the established infected-disease result.

This dated addendum adds selected evidence and tests that could resolve the remaining questions. It does not regrade the archived review.

Questions the next study should resolve

Each question identifies a limit in the checked evidence. A missing search result alone does not establish a gap in the entire field.

Why does bleeding-prevention benefit vary with time?

Competing explanation: Reinfection, competing disease, medication changes or time-dependent susceptibility may contribute.

Discriminating test: Extended randomized-trial follow-up with repeat infection testing, medication ascertainment and prespecified time-varying/competing-risk analyses.

Evidence: PMID 36335970 · PMID 8419816 · PMID 1558340

Which patients need both eradication and protection against another cause?

Competing explanation: NSAIDs or aspirin can damage mucosa independently of infection.

Discriminating test: Factorial or comparative randomized prevention designs stratified by drug exposure and ulcer history; monitor eradication and bleeding rather than symptoms alone.

Evidence: PMID 9329511 · PMID 11274623 · PMID 36335970

What explains verified infection-negative ulcers?

Competing explanation: False-negative testing, occult drug exposure or distinct idiopathic biology may explain residual cases.

Discriminating test: Prospective repeat-test classification after appropriate washout, verified drug exposure and longitudinal endoscopic/bleeding outcomes.

Evidence: PMID 19445937 · PMID 11274623

How much benefit is mediated by altered acid physiology?

Competing explanation: Inflammatory or mucosal effects may operate alongside gastrin/acid changes.

Discriminating test: Time-ordered physiological measurements within eradication studies and complementary mediator perturbation; distinguish statistical mediation from necessity.

Evidence: PMID 8174954 · PMID 8419816

Selected research timeline · 8 reports

Electronic publication dates are used where recorded, with issue years shown separately. This is a selected chronology, not a claim of scientific priority or independent replication for every entry.

1985
Attempt to fulfil Koch's postulates for pyloric Campylobacter.
Single-volunteer oral challenge · Issue 1985 · PMID 3982345
Bacterial ingestion produced histologically documented gastritis.
What it cannot establish: Gastritis in one volunteer is not a controlled demonstration of chronic ulcer sufficiency.
1992
Effect of treatment of Helicobacter pylori infection on the long-term recurrence of gastric or duodenal ulcer. A randomized, controlled study.
Randomized eradication/ulcer recurrence study · Issue 1992 · PMID 1558340
Eradication markedly reduced long-term gastric and duodenal ulcer recurrence.
What it cannot establish: Failure to eradicate and NSAID exposure remained relevant.
1993
Eradicating Helicobacter pylori infection lowers gastrin mediated acid secretion by two thirds in patients with duodenal ulcer.
Paired physiological eradication study · Issue 1993 · PMID 8174954
Gastrin-mediated acid secretion decreased after eradication in duodenal-ulcer patients.
What it cannot establish: Paired mediator change does not isolate acid secretion as the only causal route.
1993
Effect of ranitidine and amoxicillin plus metronidazole on the eradication of Helicobacter pylori and the recurrence of duodenal ulcer.
Antibiotic plus ranitidine randomized trial · Issue 1993 · PMID 8419816
Eradication reduced recurrent duodenal ulcer compared with placebo antibiotics.
What it cannot establish: Applies to infected recurrent-ulcer patients, not every ulcer etiology.
1997
Randomised trial of eradication of Helicobacter pylori before non-steroidal anti-inflammatory drug therapy to prevent peptic ulcers.
Randomized eradication before NSAID treatment · Issue 1997 · PMID 9329511
Eradication reduced ulcer occurrence during subsequent naproxen use.
What it cannot establish: Prevention at NSAID initiation differs from established chronic NSAID use.
2001
Preventing recurrent upper gastrointestinal bleeding in patients with Helicobacter pylori infection who are taking low-dose aspirin or naproxen.
Recurrent-bleeding prevention randomized trial · Issue 2001 · PMID 11274623
Eradication and acid suppression differed by aspirin versus other NSAID use.
What it cannot establish: Drug-specific co-causation limits a universal eradication-only strategy.
2009
High incidence of mortality and recurrent bleeding in patients with Helicobacter pylori-negative idiopathic bleeding ulcers.
Idiopathic bleeding-ulcer cohort · Online 2009-05-13; issue 2009 · PMID 19445937
H. pylori-negative, non-NSAID ulcers had substantial recurrent-bleeding risk.
What it cannot establish: Negative tests and etiological classification require careful validation.
2022
Helicobacter pylori eradication for primary prevention of peptic ulcer bleeding in older patients prescribed aspirin in primary care (HEAT): a randomised, double-blind, placebo-controlled trial.
HEAT aspirin-user randomized trial · Issue 2022 · PMID 36335970
Early bleeding prevention benefit was not sustained with longer follow-up.
What it cannot establish: Time-varying effects and low event incidence matter; later HTA reporting is the same trial.

Sources, reading depth and Methods

Case-specific Consensus records assisted gap discovery, chronology and targeted paper questions. Shared template wording about an amyloid-specific Deep follow-up is not evidence of a Deep run for this topic; the dated source records establish the actual use and access limits. Primary identifiers, selected abstract passages, correction notices and available primary-body passages were cross-checked. Generated absence cells, duplicate milestones and unsupported access claims were rejected.

Primary abstract/metadata checked. Additional Consensus full-text details remain provider-reported because a separately readable body was unavailable in this update.

This focused addendum does not establish 50–70 complete primary Methods/Results examinations per review. Baseline reading receipts and scores retain their original scope.

Selected full-text checks: 0; abstract checks: 8; metadata-only anchors: 0. Complete-paper examinations credited in this update: 0.

New enrichment: HSEF v5.3 causal distinctions. Archived scorecard schema: 5.4; retained as recorded.

Attempt to fulfil Koch's postulates for pyloric Campylobacter.
PMID 3982345 · DOI 10.5694/j.1326-5377.1985.tb113443.x
Selected abstract passages checked. Primary record and selected abstract passages checked; no complete-paper appraisal credited.
No independence claim made; cohort identity beyond the cited report was not exhaustively audited.
Effect of treatment of Helicobacter pylori infection on the long-term recurrence of gastric or duodenal ulcer. A randomized, controlled study.
PMID 1558340 · DOI 10.7326/0003-4819-116-9-705
Selected abstract passages checked. Primary record and selected abstract passages checked; no complete-paper appraisal credited.
No independence claim made; cohort identity beyond the cited report was not exhaustively audited.
Effect of ranitidine and amoxicillin plus metronidazole on the eradication of Helicobacter pylori and the recurrence of duodenal ulcer.
PMID 8419816 · DOI 10.1056/NEJM199302043280503
Selected abstract passages checked. Primary record and selected abstract passages checked; no complete-paper appraisal credited.
No independence claim made; cohort identity beyond the cited report was not exhaustively audited.
Eradicating Helicobacter pylori infection lowers gastrin mediated acid secretion by two thirds in patients with duodenal ulcer.
PMID 8174954 · DOI 10.1136/gut.34.8.1060
Selected abstract passages checked. Primary record and selected abstract passages checked; no complete-paper appraisal credited.
No independence claim made; cohort identity beyond the cited report was not exhaustively audited.
Randomised trial of eradication of Helicobacter pylori before non-steroidal anti-inflammatory drug therapy to prevent peptic ulcers.
PMID 9329511 · DOI 10.1016/s0140-6736(97)04523-6
Selected abstract passages checked. Primary record and selected abstract passages checked; no complete-paper appraisal credited.
No independence claim made; cohort identity beyond the cited report was not exhaustively audited.
Preventing recurrent upper gastrointestinal bleeding in patients with Helicobacter pylori infection who are taking low-dose aspirin or naproxen.
PMID 11274623 · DOI 10.1056/NEJM200103293441304
Selected abstract passages checked. Primary record and selected abstract passages checked; no complete-paper appraisal credited.
No independence claim made; cohort identity beyond the cited report was not exhaustively audited.
High incidence of mortality and recurrent bleeding in patients with Helicobacter pylori-negative idiopathic bleeding ulcers.
PMID 19445937 · DOI 10.1053/j.gastro.2009.05.006
Selected abstract passages checked. Primary record and selected abstract passages checked; no complete-paper appraisal credited.
No independence claim made; cohort identity beyond the cited report was not exhaustively audited.
Helicobacter pylori eradication for primary prevention of peptic ulcer bleeding in older patients prescribed aspirin in primary care (HEAT): a randomised, double-blind, placebo-controlled trial.
PMID 36335970 · DOI 10.1016/S0140-6736(22)01843-8
Selected abstract passages checked. Primary record and selected abstract passages checked; no complete-paper appraisal credited.
HEAT; the 2025 HTA report is expanded reporting of this trial.

Read the dated addendum · Video script and storyboard insert · References (RIS) · References (BibTeX)

Research gaps and timeline

Questions the next study should resolve

Attempt to fulfil Koch's postulates for pyloric Campylobacter.

Effect of treatment of Helicobacter pylori infection on the long-term recurrence of gastric or duodenal ulcer. A randomized, controlled study.

Eradicating Helicobacter pylori infection lowers gastrin mediated acid secretion by two thirds in patients with duodenal ulcer.

Effect of ranitidine and amoxicillin plus metronidazole on the eradication of Helicobacter pylori and the recurrence of duodenal ulcer.

Randomised trial of eradication of Helicobacter pylori before non-steroidal anti-inflammatory drug therapy to prevent peptic ulcers.

Preventing recurrent upper gastrointestinal bleeding in patients with Helicobacter pylori infection who are taking low-dose aspirin or naproxen.

High incidence of mortality and recurrent bleeding in patients with Helicobacter pylori-negative idiopathic bleeding ulcers.

Helicobacter pylori eradication for primary prevention of peptic ulcer bleeding in older patients prescribed aspirin in primary care (HEAT): a randomised, double-blind, placebo-controlled trial.