Probiotics have long been proposed as a way to soften these side effects, potentially by attenuating antibiotic-induced disruption of the gut microbiota, reinforcing colonization resistance, and modulating mucosal immune responses. Previous meta-analyses, however, pooled trials that mixed proton pump inhibitors, vonoprazan, and other acid suppressants with different antibiotic backbones, probiotic strains, doses, and durations. That heterogeneity, the review authors argued, obscured what probiotics actually add when the underlying regimen is otherwise fixed.

To answer that narrower question, the team searched eight bibliographic databases and three trial registries from inception through mid-July 2026, with no language restrictions. Eligible studies were randomized controlled trials in adults with confirmed H. pylori infection comparing a vonoprazan-based regimen plus a probiotic against the identical regimen without one, with probiotic administration overlapping the eradication course. The searches identified 506 database records and 19 registry records; after screening, sixteen reports corresponding to nine independent randomized studies met the criteria, encompassing 1,270 participants.

All nine trials were conducted in China, one multicenter and eight single-center, published or completed between 2023 and 2026. Six evaluated vonoprazan-amoxicillin dual therapy, one vonoprazan-based triple therapy, and two bismuth-containing quadruple therapy, with treatment durations of 10 days, 14 days, or, in one atypical case, four weeks. The probiotic interventions were biologically diverse, ranging from Bacillus subtilis plus Enterococcus faecium and Saccharomyces boulardii to compound lactic acid bacteria, Bifidobacterium capsules, Bacillus licheniformis, and a Bifidobacterium tetravaccine.

Eradication was generally confirmed by urea breath testing at least four weeks after treatment. Statistically, the team pooled risk ratios using restricted maximum-likelihood random-effects models with Hartung-Knapp confidence intervals, and reported 95 percent prediction intervals to estimate what a future comparable trial might show. The primary outcome was the proportion of participants experiencing at least one adverse event, treated as a participant-level binary measure rather than a count of episodes.

The reviewers used the Cochrane Risk of Bias 2 tool for outcome-specific bias assessments and GRADE to rate certainty, and excluded studies with ambiguous adverse-event totals or serious allocation concerns from the primary analyses. The tolerability signal was striking. Across five studies involving 611 participants, adjunctive probiotics reduced the risk of experiencing at least one adverse event by roughly 70 percent (risk ratio 0.30, 95 percent confidence interval 0.17 to 0.53; P = 0.004), with zero statistical heterogeneity.

The prediction interval, 0.12 to 0.79, remained entirely below the null, suggesting benefit would be expected in a future similar trial. Translated into absolute terms, the risk fell from 261 to about 79 per 1,000 treated, meaning roughly one additional patient avoids an adverse event for every six given probiotics. Sensitivity analyses kept the estimate between 0.31 and 0.38, and GRADE certainty was rated moderate.

The efficacy picture was far less convincing. Intention-to-treat eradication across seven studies and 910 participants showed a small apparent benefit (risk ratio 1.09, 95 percent confidence interval 1.00 to 1.19), but the prediction interval of 0.92 to 1.30 crossed no effect, and statistical significance vanished in sensitivity analyses that excluded dissertation-based or methodologically atypical studies. Per-protocol eradication showed little or no difference (risk ratio 1.03), and adherence, already high at about 95 percent in control groups, was not clearly improved.

Individual symptoms such as constipation, bloating, and nausea trended in probiotics' favor, but these analyses rested on few events and were graded very-low-certainty. Discontinuation and serious adverse events were too rare to yield interpretable estimates. The authors caution that all included trials were conducted in China, and that regional differences in antimicrobial resistance, prior antibiotic exposure, diet, baseline microbiota, probiotic product quality, and symptom-reporting behavior may limit generalizability to other populations.

Most trials were also open-label, a concern for subjectively reported adverse events, and the data cannot identify an optimal probiotic strain, dose, or timing. The reviewers conclude that probiotics are best framed as supportive care to improve tolerability during vonoprazan-based therapy, not as a means of raising cure rates, and they call for adequately powered, placebo-controlled, multicenter trials with standardized outcome definitions and strain-level reporting to confirm the findings in diverse settings.

Subject of Research: Adjunctive probiotics during vonoprazan-based Helicobacter pylori eradication therapy

Article Title: Adjunctive probiotics may reduce adverse events during vonoprazan-based Helicobacter pylori eradication: a systematic review and meta-analysis

Article References: Lin, C.-J., Ren, P.-Y., Chen, H.-Y., Zheng, M.-Q., Jiang, Y.-X., Li, G., Fu, M., & Guo, Y.-H. (2026). Adjunctive probiotics may reduce adverse events during vonoprazan-based Helicobacter pylori eradication: a systematic review and meta-analysis. Frontiers in Pharmacology, 17, Article 1946885. https://doi.org/10.3389/fphar.2026.1946885

Image Credits: AI Generated

DOI: 10.3389/fphar.2026.1946885

Keywords: Helicobacter pylori, vonoprazan, probiotics, meta-analysis, adverse events, eradication therapy, gut microbiota, potassium-competitive acid blocker, tolerability, randomized controlled trials, GRADE certainty, gastroenterology

Helicobacter pylori remains one of the most consequential human pathogens on the planet, colonizing the gastric mucosa of roughly half the world’s population and serving as the dominant risk factor for peptic ulcer disease, chronic gastritis, and gastric adenocarcinoma. Eradicating the bacterium has become progressively harder over the past two decades as clarithromycin and levofloxacin resistance has spread, pushing clinicians toward bismuth quadruple therapy and, more recently, toward dual therapies that pair a potent acid suppressant with high-dose amoxicillin. The logic of these dual regimens is elegant: by driving intragastric pH sharply upward, the acid blocker undermines H. pylori’s ecological niche and enhances amoxicillin’s stability and activity against actively dividing bacteria, while restricting the antibiotic arsenal to a single agent helps preserve susceptibility of other organisms. The arrival of vonoprazan, which binds reversibly to the gastric H+/K+-ATPase at a potassium-binding site and achieves faster, stronger, and more sustained acid inhibition than classical proton pump inhibitors, has energized this strategy, but direct comparisons with optimized proton pump inhibitor dual regimens have remained limited, particularly regarding collateral effects on the gut microbiome.

To address that gap, the research team enrolled a total of 110 H. pylori-positive patients and non-randomly assigned them to one of two fourteen-day-style dual regimens. Fifty patients received the P-CAB regimen, consisting of vonoprazan 20 milligrams twice daily combined with amoxicillin 750 milligrams four times daily, while sixty patients received the PPI regimen, comprising esomeprazole 20 milligrams four times daily with the same amoxicillin dosing. Twenty-two H. pylori-negative individuals served as healthy controls for microbiota benchmarking. Eradication success was determined four weeks after completion of therapy using the 13C-urea breath test, a noninvasive assay that exploits the bacterium’s urease enzyme to detect active infection. The investigators also gathered fecal samples at three time points, baseline before treatment, roughly two weeks into the post-therapy window, and at week six, to characterize shifts in microbial diversity, community composition, and predicted functional pathways through 16S rRNA gene sequencing.

On the pharmacological front, the two acid suppressants differ in ways that matter clinically. Proton pump inhibitors such as esomeprazole are acid-activated prodrugs that require an acidic environment to engage the pump irreversibly, meaning their effect accumulates over several doses and is blunted in the very hypersecretory or proton-pump-dense patients who most need acid control. Vonoprazan, by contrast, is active at neutral pH, accumulates in parietal cells, and exerts dose-dependent, reversible inhibition that reaches near-anacidic gastric conditions within hours and persists through once- or twice-daily dosing. That kinetic advantage is thought to explain why vonoprazan-based dual therapy performs well even in regions with high amoxicillin resistance, since sustained acid suppression amplifies amoxicillin’s bactericidal window. The esomeprazole arm in this study used a four-times-daily schedule specifically to maximize acid suppression and keep the comparison fair against the twice-daily vonoprazan regimen.

The headline efficacy finding favored vonoprazan across every analysis population. The P-CAB group achieved an eradication rate of 97.73 percent in the per-protocol analysis, compared with 84.20 percent in the esomeprazole group, a difference that reached statistical significance at P equals 0.04. Although the intention-to-treat and modified intention-to-treat analyses showed the same directional advantage for the vonoprazan regimen, those comparisons did not cross the threshold of statistical significance, a nuance the authors attribute in part to the non-randomized design and the modest sample size. Still, a cure rate approaching 98 percent in patients who completed the prescribed course places the vonoprazan dual approach among the most effective antibiotic-sparing strategies reported, comfortably exceeding the 90 percent benchmark that international consensus guidelines set for first-line eradication therapy.

Equally important for practice, the safety and tolerability picture was essentially identical between arms. Adverse reactions, which in dual amoxicillin regimens typically include diarrhea, nausea, taste disturbances, rash, and abdominal discomfort, occurred at comparable frequencies in the two groups, and patient compliance did not differ significantly between the P-CAB and PPI regimens. Neither regimen caused treatment-related events severe enough to disrupt the comparison, suggesting that the pharmacological intensity of vonoprazan did not translate into a clinical tolerability penalty. For gastroenterologists weighing first-line options, this aligns the choice more squarely on efficacy grounds, since the operational burden of four-times-daily amoxicillin dosing applies to both regimens equally.

The microbiota component of the study adds a layer of ecological context that eradication trials rarely capture. Using 16S rRNA gene amplicon sequencing of the V3 and V4 hypervariable regions, the team quantified alpha diversity, assessed community structure with principal co-ordinates analysis, and predicted functional shifts against the Kyoto Encyclopedia of Genes and Genomes reference pathways. Both eradication regimens delivered a discernible shock to the gut ecosystem: microbial diversity declined after treatment, community composition shifted measurably away from baseline and from the healthy control profile, and predicted metabolic pathways were transiently perturbed. Importantly, these disturbances followed a recovery trajectory over the follow-up period, with communities migrating back toward their pretreatment configuration by week six.

The two regimens left subtly different ecological fingerprints. The early decline in microbial diversity was more pronounced in the vonoprazan group, an observation consistent with the deeper and more sustained acid suppression that P-CABs deliver, since gastric acid and its downstream influence on the entire intestinal milieu shape which microbes survive transit into the lower gut. Yet the vonoprazan group also showed a tendency toward faster restoration of functional pathway profiles, hinting that the compositional damage and the functional damage may recover on different clocks. Across both arms, the researchers documented an increase in potential pathogenic bacteria and a corresponding decrease in short-chain fatty acid-producing bacteria after treatment, a pattern that matters because short-chain fatty acids such as butyrate fuel colonocytes, maintain epithelial barrier integrity, and exert anti-inflammatory signaling throughout the body. The fact that these SCFA producers rebounded over the six-week window will reassure clinicians, though the study’s design cannot exclude longer-lasting effects in some individuals.

The authors caution, appropriately, that the study was non-randomized, single-center, and modest in size, so the eradication difference should be interpreted as hypothesis-confirming rather than definitive, and the microbiota findings describe short-term dynamics only. Even so, the report lands at a moment when clinicians worldwide are retooling first-line H. pylori strategies amid rising antibiotic resistance. Vonoprazan-based dual therapy is already endorsed by growing bodies of guideline literature as a first-line option, and this comparison provides practical reassurance on two fronts simultaneously: it beats an optimized esomeprazole dual regimen where it counts, achieving eradication close to the theoretical ceiling while matching that regimen on safety and adherence, and the collateral microbiota damage it inflicts appears to be transient and self-repairing. For a bacterium that infects billions and drives one of the world’s most common cancers, treatment strategies that maximize cure rates while minimizing ecological and resistance costs represent exactly the kind of progress the field has been seeking, and this study offers a candid, quantified look at both sides of that bargain.

Subject of Research: Comparative efficacy of vonoprazan-based versus esomeprazole-based dual therapy for Helicobacter pylori eradication and short-term gut microbiota changes

Article Title: Comparative effects of vonoprazan-based and esomeprazole-based dual therapy on Helicobacter pylori eradication and short-term gut microbiota changes

Article References: Liu, Y., Qian, X., Yao, J., Fei, C., Zhang, Z., & Jiang, Z. (2026). Comparative effects of vonoprazan-based and esomeprazole-based dual therapy on Helicobacter pylori eradication and short-term gut microbiota changes. Gut Pathogens. https://doi.org/10.1186/s13099-026-00867-9

Image Credits: AI Generated

DOI: 10.1186/s13099-026-00867-9

Keywords: Helicobacter pylori, vonoprazan, esomeprazole, dual therapy, eradication, gut microbiota, 16S rRNA sequencing, potassium-competitive acid blocker, proton pump inhibitor, short-chain fatty acids, amoxicillin, 13C-urea breath test