Helicobacter pylori and gastric disease: what current evidence is really telling clinicians

Helicobacter pylori and gastric disease: what current evidence is really telling clinicians

Recent literature (January 2026) no longer supports a narrow, infection-centric view of Helicobacter pylori. Instead, it consistently describes a disease continuum in which H. pylori eradication efficacy, host response, microbial ecology, and long-term mucosal remodeling interact in ways that directly influence outcomes. What emerges is not a collection of disconnected discoveries, but a clearer map of why H. pylori eradication succeeds in some patients, fails in others, and why cancer risk persists despite H. pylori eradication.

Helicobacter pylori eradication therapy: why simplification works, and when it does not

Several clinical studies converge on a practical truth: Helicobacter pylori eradication failure is more often a systems problem than a drug problem. Trials of vonoprazan-based dual therapies demonstrate that when intragastric pH is consistently maintained at bactericidal levels, fewer antibiotics can achieve H. pylori eradication rates comparable to traditional quadruple regimens, with substantially fewer adverse effects and higher completion rates. This effect is most evident in rescue settings, where intolerance and prior failure undermine adherence.

However, molecular studies explain why simplification alone is insufficient. Ultra-deep sequencing of H. pylori isolates reveals intra-host heterogeneity of resistance mutations, meaning that minor resistant subclones may survive otherwise effective regimens and later dominate. This finding aligns with real-world cohorts showing unpredictable failure even in adherent patients treated according to guidelines. Together, these data argue against repeating empiric therapy after failure without new biological information.

Emerging diagnostic platforms reinforce this shift. Rapid biopsy-based profiling of H. pylori virulence factors and resistance determinants demonstrates that resistance assessment is moving from centralized laboratories toward near-patient diagnostics, shortening decision cycles and reducing empiricism. This is not theoretical innovation; it directly addresses the mismatch between guideline recommendations and local resistance realities documented in multicenter and regional studies.

Acid suppression is not background therapy, it is a determinant of success

The body of work examining CYP2C19 genotype-guided dosing reframes acid suppression as a modifiable biological variable rather than a fixed background condition. Poor metabolizers and ultra-rapid metabolizers exhibit markedly different intragastric pH profiles under standard dosing, with downstream effects on eradication success, symptom control, and mucosal healing.

This mechanistic variability explains why vonoprazan-based regimens show more consistent outcomes across populations: not because they are “stronger,” but because they are less vulnerable to host pharmacogenetic variability. In this context, pharmacogenomics emerges not as routine screening, but as a targeted tool in refractory disease and unexplained treatment failure.

Re-examining long-term PPI exposure through robust population data

One of the most consequential findings comes from large Nordic registry-based analyses examining long-term proton pump inhibitor use and gastric cancer risk. After accounting for confounding by indication and reverse causality, these studies fail to demonstrate a clear independent association between chronic PPI exposure and gastric adenocarcinoma.

This finding matters clinically because it disentangles acid suppression from carcinogenesis, redirecting attention toward the true drivers of risk: chronic mucosal inflammation, atrophy, metaplasia, and immune-metabolic remodeling. It supports continued use of PPIs when indicated, while maintaining vigilance for mucosal disease rather than medication avoidance.

The post-H. pylori eradication stomach: where risk actually resides

Multiple studies converge on a critical conclusion: H. pylori eradication reduces risk, but does not normalize it. Long-term follow-up data demonstrate that gastric cancer occurring more than a decade after H. pylori eradication is strongly associated with pre-existing extensive atrophy and intestinal metaplasia. Infection status becomes secondary once the mucosal field has been irreversibly altered.

This concept is reinforced by work highlighting discrepancies between pre-endoscopic assessment and final pathology, subepithelial-appearing gastric cancers, and non-curative resections after ESD. These are not technical failures; they reflect biological heterogeneity within a remodeled gastric mucosa. The implication is clear: surveillance must be phenotype-driven, not bacterium-driven.

The growing recognition of H. pylori–naïve gastric neoplasms further supports this shift. As infection prevalence declines, cancers arising outside the classic inflammation–atrophy–metaplasia cascade become more visible, challenging long-standing diagnostic assumptions and reinforcing the need for careful histologic and molecular correlation.

Gastric carcinogenesis: immune suppression and metabolic rewiring as central mechanisms

Mechanistic studies provide coherence to these clinical observations. Research identifying CD38-positive mast cells as suppressors of CD8-mediated cytotoxicity through adenosine metabolism offers a direct explanation for immune escape in gastric cancer. This finding integrates well with proteogenomic analyses mapping immune-cold tumor subtypes and identifying therapeutic vulnerabilities linked to immune metabolism.

In parallel, metabolic studies show that H. pylori can redirect epithelial energy utilization through pathways such as uridine salvage, bypassing glycolysis. These changes persist beyond active infection and help explain why carcinogenic momentum can continue after eradication. Epigenetic studies further support this model, demonstrating that transient inflammatory exposure can imprint long-lasting transcriptional repression in gastric epithelial cells.

Taken together, these data argue that gastric cancer is not simply infection-driven, but infection-programmed.

The microbiome beyond H. pylori: amplifying or sustaining disease

Several studies broaden the lens to include non-H. pylori microbial influences. Alterations in oral–gastric microbial axes, bacterial extracellular vesicles inducing barrier disruption, and shifts in bile and gastric microbiota associated with malignancy suggest that once acid secretion and epithelial integrity are compromised, other organisms can perpetuate inflammation and dysplasia.

This helps reconcile why H. pylori eradication alone does not always reverse disease trajectories and why adjunctive strategies targeting microbiome balance or barrier protection may have value—not as primary therapy, but as disease-modifying interventions.

Prevention at scale: evidence supports organized intervention

Population-level studies and national experiences demonstrate that H. pylori eradication can function as cancer prevention when implemented systematically. Modeling of future gastric cancer burden shows that a substantial proportion of cases remain attributable to H. pylori infection, validating screen-and-treat strategies when paired with risk-based endoscopic surveillance.

Importantly, analyses of social determinants show that infection prevalence and eradication failure cluster along socioeconomic gradients. This finding reinforces that prevention is inseparable from access, adherence, and health-system design.

Adjuncts and innovation: where evidence is supportive and where it remains exploratory (Table 1)

The “adjuncts” literature falls into two very different worlds. One world is clinically oriented and already useful at the bedside (supporting completion of antibiotic therapy, improving mucosal healing, reducing adverse effects, and—sometimes—modestly improving eradication). The other world is largely mechanistic or preclinical (nanocarriers, plant extracts, enzyme inhibitors, microbiome-modulating polysaccharides, signaling-pathway modifiers). The second world is scientifically exciting, but it should not be allowed to blur into patient-facing claims of eradication.

Probiotics: supportive as an add-on, weak as a stand-alone

Probiotics look most credible when used as a supportive tool alongside standard H. pylori eradication regimens—especially bismuth quadruple therapy—rather than as a replacement for antibiotics.

A systematic review and meta-analysis specifically evaluating probiotics combined with bismuth-containing quadruple therapy found a measurable benefit in both efficacy and tolerability. The signal clinicians care about is twofold: a modest improvement in H. pylori eradication outcomes and a consistent reduction in gastrointestinal adverse effects that otherwise drive poor adherence (diarrhea, abdominal discomfort, dyspeptic symptoms). This is the type of adjunct that matters because eradication therapy fails in real life far more often due to incomplete courses than due to theoretical pharmacology.

In contrast, probiotic monotherapy is a different category. A meta-analysis focusing on probiotic monotherapy examined probiotics as a non-antibiotic intervention capable of reducing colonization or test “signals,” but the clinical implication remains limited: probiotics alone may reduce H. pylori bacterial load or breath-test delta values in some settings, yet they should not be framed as reliably eradicating H. pylori. In practical terms, probiotic monotherapy can be discussed as symptom- or microbiome-supportive, not as a definitive cure.

This distinction—adjunct versus replacement—is one of the clearest “translation rules” emerging from the recent literature.

Safety work on probiotic strains: helpful, but not equivalent to therapeutic proof

One reason probiotics are increasingly discussed in clinical conversations is that safety datasets are becoming more rigorous. The in vivo and in vitro toxicity assessment of Lactobacillus salivarius AP-32 reported a broad safety profile across standard toxicology and genotoxicity testing, with additional functional characteristics relevant to gastrointestinal survival (acid and bile tolerance, adhesion, antimicrobial activity signals). This kind of work supports the plausibility of prescribing specific strains with more confidence, but it still does not establish H. pylori eradication efficacy in humans. It strengthens the “can this be used safely?” side of the equation more than the “will this eradicate H. pylori?” side.

Mucosal protectants and “barrier therapy”: rebamipide as the most clinically mature example

Among non-antibiotic supportive therapies, rebamipide sits closest to routine gastroenterology practice. A recent umbrella review (Maev IV, et al. Pharmaceuticals (Basel) 2026;19:144.) synthesizing meta-analyses across gastrointestinal disorders is important because it evaluates rebamipide not as a fashionable add-on, but as a repeatedly studied mucosal-protective agent with a long publication trail. The weight of such an umbrella review is not that it creates a new indication overnight, but that it places mucosal protection on firmer evidence footing—particularly for symptom improvement and mucosal healing endpoints in selected settings.

Clinically, this is relevant because a growing proportion of patients presenting after H. pylori eradication (or during attempts at eradication) remain symptomatic due to mucosal inflammation, dyspepsia mechanisms, or ulcer vulnerability. In those contexts, barrier-focused adjuncts can improve patient tolerance and reduce discontinuation—even if they do not directly kill H. pylori.

Herbal and “traditional medicine” adjuncts: intriguing signals, but heavily dependent on study design

A real-world retrospective study examining adjunctive Chinese herbal decoction in H. pylori–positive chronic atrophic gastritis showed that it is not purely theoretical: it explores clinical outcomes and safety in routine practice conditions. Still, the interpretation must stay disciplined. Retrospective designs are prone to confounding (selection bias, differences in baseline severity, co-interventions), so these signals should be treated as hypothesis-strengthening rather than practice-changing on their own. In a cautious clinical synthesis, this category is best presented as “adjuncts under evaluation”, not as standardized eradication solutions.

A similar caution applies to individual-case or integrative medicine reports (e.g., single case reports in reflux care). Such publications can be useful for generating questions and refining symptom frameworks, but they do not provide stable effect estimates for guidelines.

“Natural supplements” in ulcer models: mechanistic plausibility, not clinical equivalence

One of the most common sources of patient confusion is the leap from animal models to clinical H. pylori eradication claims. The rat indomethacin-ulcer model study evaluating three natural supplements against H. pylori colonization combined antibacterial/antibiofilm assessments with oxidative stress and inflammatory markers, including signaling-relevant targets like HIF-1α and TGF-β. This is valuable for mechanistic mapping showing that certain compounds may influence bacterial burden and mucosal injury pathways in a controlled model. It does not mean that these supplements can replace H. pylori eradication therapy in humans, nor does it solve questions of dosing, bioavailability, and resistance selection. The correct clinical framing is “supportive mechanistic evidence that may inform future adjunct trials”.

The same category includes fucoidan work derived from sea cucumber cooking liquid, where protective effects were linked to gut microbiota modulation and downstream inflammatory signaling in an H. pylori gastritis model. Again, the strength is biological plausibility: microbiota-driven effects and inflammatory pathway modulation are consistent with current understanding of mucosal disease. The weakness is translation: preclinical benefit does not guarantee clinically meaningful H. pylori eradication or prevention effects in humans.

Enzyme inhibitors and docking studies: early-stage discovery, not H. pylori treatment

Several papers explore urease inhibition or docking-based targeting of H. pylori enzymes. This line of research addresses a real need—new antibacterial targets that bypass existing resistance pathways—but docking results and in vitro enzyme inhibition are at the beginning of the translational pipeline. They identify candidates, not therapies.

The mistletoe (Viscum album) study is a good example: it combines computational binding predictions with an in vitro anti-urease assay, but the assay is not even performed on H. pylori urease directly (it uses Proteus mirabilis urease as a model). This is scientifically legitimate as a screening approach, but it should be presented as “target discovery and proof-of-concept,” not as clinical anti-H. pylori therapy.

Nanotechnology and mucus-layer delivery: the most genuinely “next-step” innovation

If one innovation category looks closest to future clinical translation, it is not herbs or docking—it is gastric mucus-layer drug delivery designed to increase local antibiotic exposure while reducing systemic disruption.

The silk-based biomimetic nanocomposite study is a standout because it tackles a concrete pharmacologic limitation: conventional antibiotics often fail to maintain adequate, sustained concentrations at the gastric mucus interface where H. pylori resides. The work reports conformal mucus coverage, sustained release, improved tissue retention, and superior in vivo eradication compared with conventional amoxicillin at equivalent doses, with the additional goal of preserving gut microbiome stability. This directly targets two modern priorities: higher eradication probability and less collateral microbiome damage.

A related direction is represented by the silk fibroin nanoparticle work using DL-3-n-butylphthalide (NBP) as the antibacterial payload. The study’s emphasis on nanoparticle stability, encapsulation efficiency, and mechanistic antibacterial potential reinforces that the field is not only searching for new molecules, but also for better delivery architectures that protect drugs from acid, localize exposure, and potentially address biofilm behavior. This remains preclinical/early translational, but the logic is clinically coherent.

This “delivery-first” innovation is also conceptually aligned with broader trends in H. pylori care: rapid resistance profiling (so the right antibiotic is chosen) and smarter local delivery (so the antibiotic reaches the target niche effectively).

Signaling-pathway modifiers: promising biology with a long road to clinical use

A mechanistic example in the recent literature on H. pylori is the hydrogen sulfide (H₂S) donor work showing inhibition of H. pylori–induced gastric fibroblast activation and pro-tumorigenic signaling, linked to suppression of the NF-κB/STAT3 axis. This is not an eradication adjunct; it is closer to a “cancer-preventive microenvironment modifier” concept. The attractiveness is obvious—interrupt stromal reprogramming that may support carcinogenesis. The limitation is equally obvious—dose, delivery, safety, and human outcome evidence are not established.

Where “adjunctive quadruple modifications” fit

Finally, a practical adjunct category is not biological but formulary-based: modified regimens that incorporate additional protective agents. The Chinese multicenter study evaluating magaldrate granules as part of a quadruple regimen (with rabeprazole, amoxicillin, clarithromycin) represents a pragmatic attempt to improve tolerability or mucosal protection within a standard antibiotic framework. Such work is clinically relevant because it speaks to regimen “survivability” in real patients, though external generalizability depends on resistance patterns—particularly clarithromycin resistance.

Table 1. Adjuncts and innovation

How this table should be read clinically

• Supportive adjuncts are those that increase the probability that standard eradication succeeds by improving tolerability, adherence, or mucosal recovery (probiotics, rebamipide).

• Exploratory adjuncts demonstrate biological plausibility but lack sufficient human evidence to justify routine clinical use.

• Nanotechnology-based delivery systems represent the most coherent future direction, as they directly address antibiotic exposure at the gastric mucus niche rather than attempting to replace antibiotics.

• None of the adjuncts listed replace evidence-based eradication regimens; their value lies in supporting or enhancing established therapy.

Take home messages

1. H. pylori eradication success depends on predictable acid suppression, resistance biology, and treatment completion—not on regimen complexity alone.
2. Antibiotic resistance of H. pylori is heterogeneous and dynamic, explaining unexpected failures and supporting the move toward rapid, biopsy-based diagnostics.
3. Long-term gastric cancer risk is determined by the residual mucosal field; H. pylori eradication lowers risk but does not erase it in advanced atrophy or intestinal metaplasia.
4. Immune suppression, metabolic rewiring, and epigenetic memory explain why carcinogenesis may continue after H. pylori clearance.
5. Proton pump inhibitors, when appropriately indicated, are not convincingly linked to gastric cancer in robust population studies.
6. Gastric cancer prevention is achievable at scale, but only when H. pylori eradication is paired with surveillance, risk stratification, and attention to social context.
7. The currrent 2026 integrated view replaces “treat the bacterium” with manage the gastric ecosystem over time.