The trial, published in Frontiers in Cellular and Infection Microbiology, compared bismuth-containing quadruple therapy built around the new proton pump inhibitor anaprazole against the classical second-generation PPI rabeprazole. Both regimens paired their respective PPI with amoxicillin, furazolidone, and colloidal bismuth pectin, given twice daily for 14 days. A total of 320 treatment-naive patients with confirmed H. pylori infection were enrolled between August 2025 and February 2026 and randomly assigned in a 1:1 ratio. Eradication was assessed by the 13C-urea breath test four weeks after therapy completion, an objective endpoint that is unlikely to be swayed by the open-label design.

The choice of antibiotics was deliberate and rooted in regional resistance data. A 2024 meta-analysis in China reported resistance rates of 70.14 percent for metronidazole, 30.72 percent for clarithromycin, and 32.98 percent for levofloxacin, while resistance to amoxicillin, tetracycline, and furazolidone remained strikingly low at 2.41, 2.53, and 1.54 percent respectively. Surveillance from Nanjing confirmed even more extreme figures, with clarithromycin resistance at 50.01 percent and metronidazole resistance at 84.45 percent, while furazolidone and amoxicillin resistance measured just 0.19 and 0.51 percent. The 2022 Chinese national clinical practice guideline explicitly endorses a bismuth quadruple regimen containing amoxicillin and furazolidone in high-resistance regions such as Jiangsu, making this combination the logical backbone for the trial.

But antibiotics alone do not clear the infection. The degree of acid suppression delivered by the PPI is a critical determinant of success, because raising intragastric pH shifts H. pylori from a dormant state into active replication, rendering it vulnerable to bactericidal agents. Amoxicillin is particularly pH-dependent: when intragastric pH rises from 5.5 to 7.5, its minimum inhibitory concentration against the bacterium drops from 0.5 to 0.06 micrograms per milliliter, dramatically amplifying its killing power. Previous work established that successful eradication with bismuth quadruple therapy requires a median 24-hour intragastric pH of 5.7 or higher. The problem is that conventional PPIs are heavily influenced by CYP2C19 genetic polymorphisms, and rapid metabolizers frequently experience treatment failure due to inadequate acid suppression.

This is where anaprazole’s pharmacology becomes compelling. The novel benzimidazole-class PPI, developed domestically in China and approved by the National Medical Products Administration for duodenal ulcers, features a dihydrofuran ring and a modified pyridine core that reshape its metabolic fate. Clearance is split between non-enzymatic pathways, accounting for 49 percent, and the cytochrome P450 system, accounting for 51 percent. Crucially, CYP3A4 is the dominant enzyme at 48.3 percent of metabolism, while CYP2C19 contributes only 3.5 percent. This profile minimizes the impact of CYP2C19 polymorphisms on acid suppression, promises more consistent interindividual efficacy, and lowers the risk of drug-drug interactions. Radiolabel studies showed total cumulative excretion of 93.20 percent, split between urinary and fecal routes, indicating high absorption and extensive metabolism that may reduce renal burden.

The trial’s non-inferiority design set a prespecified margin of minus 10 percent, a threshold the investigators justified on the grounds that both arms received identical antibiotics and bismuth, leaving the PPI as the only variable. A loss exceeding 10 percent would signal clinically inferior acid suppression, while anything within that margin would preserve the regimen’s utility. Sample size calculations assumed a 90 percent eradication rate for both groups, requiring 142 participants per arm for 80 percent power, with 160 per group enrolled to account for attrition. Randomization used block sizes of four generated by a biostatistician with SAS software, and all centers followed standardized operating procedures with the same medication batches and electronic questionnaires to ensure data consistency.

The results were remarkably tight. In the intention-to-treat analysis, eradication rates were 81.9 percent for anaprazole and 80.0 percent for rabeprazole, a difference of 1.9 percent with a confidence interval spanning minus 6.7 to 10.5 percent. Modified intention-to-treat analysis yielded 89.1 versus 88.9 percent, and per-protocol analysis showed 90.9 versus 90.0 percent. In every analysis set, the lower limit of the 95 percent confidence interval sat comfortably above the minus 10 percent non-inferiority margin, with non-inferiority P values below 0.001. The findings align with earlier phase II and III trials demonstrating anaprazole’s non-inferiority to rabeprazole in duodenal ulcer healing, suggesting its acid-suppressive potency is sufficient to support the intragastric pH target required for eradication, though the study did not directly measure gastric pH.

Safety and adherence data reinforced the picture of equivalence. Adverse events occurred in 22.50 percent of the anaprazole group versus 15.00 percent of the rabeprazole group, a numerical difference that did not reach statistical significance. Specific events including nausea and vomiting, diarrhea, abdominal bloating, rash, constipation, abdominal pain, allergic reactions, and drug fever all showed no significant between-group differences, and no serious adverse events were reported. Medication adherence exceeded 87 percent in both arms, attributed to the simple twice-daily 14-day schedule and stringent guidance. Univariate logistic regression found no significant associations between eradication outcome and sex, age, body mass index, comorbidities, smoking, alcohol use, dining habits, or family history of infection, though a history of other or unknown antibiotic use emerged as a significant risk factor for failure with an odds ratio of 3.874.

The study’s limitations are worth noting. Antimicrobial susceptibility testing was not performed, so primary versus secondary resistance could not be disentangled. The sample size was powered for non-inferiority rather than risk factor analysis, and multivariable modeling was not conducted. All four centers were located in Jiangsu Province, which may limit generalizability across China’s vast and heterogeneous resistance landscape. The open-label design, chosen for operational feasibility, may have introduced information bias in self-reported adverse events, though the objective primary endpoint mitigates this concern. A visual-assisted recall method for antibiotic history, while reducing bias compared with unaided questioning, cannot fully eliminate recall error.

Nevertheless, the trial represents the first randomized clinical evaluation of anaprazole-based quadruple therapy for H. pylori eradication, and its conclusion is clear: the anaprazole-containing regimen is non-inferior to the rabeprazole-based standard across efficacy, safety, and adherence. As antimicrobial resistance continues to erode the effectiveness of first-line antibiotics worldwide, the availability of a PPI with more stable, genotype-independent acid suppression offers a meaningful tool for clinicians. Future studies with double-blind designs, broader geographic coverage, and integrated susceptibility testing will be needed to confirm these findings and refine individualized treatment strategies, but for now, anaprazole has earned a place in the conversation about optimizing H. pylori eradication in the resistance era.

Subject of Research: Anaprazole-based versus rabeprazole-based bismuth quadruple therapy for Helicobacter pylori eradication

Article Title: Anaprazole-based versus rabeprazole-based quadruple therapy for Helicobacter pylori eradication: a prospective, multicenter, randomized controlled trial

Article References: Wang, X., Wang, H., Wang, Y., Shen, L., Li, G., Zhu, J., Li, C., Gao, J., & Zhang, Z. (2026). Anaprazole-based versus rabeprazole-based quadruple therapy for Helicobacter pylori eradication: a prospective, multicenter, randomized controlled trial. Frontiers in Cellular and Infection Microbiology, 16, Article 1972507. https://doi.org/10.3389/fcimb.2026.1972507

Image Credits: AI Generated

DOI: 10.3389/fcimb.2026.1972507

Keywords: Helicobacter pylori, anaprazole, rabeprazole, proton pump inhibitor, bismuth quadruple therapy, antibiotic resistance, furazolidone, amoxicillin, eradication therapy, randomized controlled trial, CYP2C19 polymorphism, gastric cancer

Phantosmia, the perception of an odor when no external odorant is present, sits within a broader family of qualitative olfactory disorders that also includes parosmia, in which a real odor is perceived in a distorted form. Clinicians generally group smell disturbances into quantitative problems, such as reduced sensitivity or complete loss of smell, and qualitative problems, in which perception is altered or invented. Quantitative losses are far more commonly reported and studied, which is partly why a case of phantom cigarette smoke tied to digestive disease stands out. The olfactory system’s wiring also helps explain why smell symptoms can be so unsettling: olfactory signals travel to structures involved in memory and emotion, and irritation anywhere along the nasal mucosa, olfactory epithelium, or central olfactory pathways can potentially distort perception. Because phantom odors can occasionally signal serious underlying conditions, including tumors, epileptic foci, or neurodegenerative disease, the authors of the report were careful to weigh alternative explanations before suggesting a reflux connection.

The temporal pattern in this case is what gives the observation its interest. The patient’s heartburn and bloating worsened for a week before the smoke sensations began, the olfactory episodes fluctuated alongside her digestive symptoms, and both briefly returned together during a flare before subsiding for good. This kind of symptom concordance, in which two seemingly unrelated complaints rise and fall in parallel, is often more persuasive than simple improvement after treatment, because it reduces the chance that the association is coincidental. The authors noted that the patient herself perceived the connection and adjusted her diet accordingly, an observation that, while subjective, illustrates how patients sometimes detect symptom relationships before formal testing can confirm them.

Several mechanisms could plausibly link reflux to smell disturbances. Refluxate containing acid and bile can reach the pharynx and larynx, and experimental and clinical work has suggested that this material may inflame the nasal and upper airway mucosa. Chronic inflammation of the olfactory epithelium can damage olfactory receptor neurons or alter their signaling, potentially producing both quantitative losses and qualitative distortions. Microaspiration of refluxate into the airway during sleep is another proposed pathway, and it is notable that this patient’s episodes clustered around sleep and waking. Additionally, vagal reflexes connecting the esophagus and airway could theoretically modulate nasal sensation, although this remains speculative. The authors of the case report did not identify which mechanism applied to their patient, and no objective olfactory testing was performed, so the pathway remains an open question.

The prior literature on reflux and smell provides useful context. Studies have documented impaired odor threshold, discrimination, and identification in patients with GERD, and some work has correlated the severity of reflux with subjective taste and smell complaints. A scoping review concluded that while the evidence base is limited and heterogeneous, several studies support an association between laryngopharyngeal reflux and olfactory dysfunction. More persuasively, a prospective study found that measured olfactory function improved after twelve weeks of proton pump inhibitor therapy in patients with laryngopharyngeal reflux, suggesting that the relationship may be at least partly reversible with acid suppression. What none of these studies established was a link specifically to phantosmia, which is the gap this case report begins to fill. The distinction matters because quantitative and qualitative olfactory disorders may involve different mechanisms; a phantom odor suggests aberrant firing or disinhibition within the olfactory system rather than simple receptor damage.

The diagnostic workup in this case also illustrates the practical challenges of evaluating phantosmia. Formal olfactory testing, such as standardized smell identification batteries, was not performed, nor was ambulatory reflux monitoring, which would have objectively correlated reflux episodes with olfactory symptoms. The patient declined recommended upper endoscopy, leaving the hiatal hernia and reflux documented only on barium esophagram. After a fall, a head CT showed no acute intracranial abnormality, but that scan was obtained for trauma evaluation rather than as a targeted assessment of the olfactory complaints, and no EEG, dedicated brain MRI, or neurologic consultation was completed. These gaps mean that focal epilepsy, in particular, was considered but not definitively excluded. The déjà vu that accompanied the episodes is a feature that neurologists typically associate with temporal lobe seizures, and the authors acknowledged this possibility while noting that the episodes occurred during routine waking activities without loss of consciousness and that the tight coupling with heartburn argued against a purely epileptic process.

The alternative diagnoses considered reflect the standard differential for phantom odors. Migraine with aura can produce olfactory hallucinations, and this patient carried that diagnosis. Allergic rhinitis, which she also had, is a well-recognized cause of smell disturbance through mucosal inflammation. Psychiatric conditions, medications, and prior head trauma round out the usual considerations. The authors’ approach of treating the most likely contributor while keeping alternatives in view is consistent with general guidance that unexplained phantosmia warrants evaluation for neurologic, sinonasal, and psychiatric causes before attributing symptoms to a gastrointestinal source.

The treatment response adds another layer of interest. The patient took omeprazole each morning before breakfast, a timing chosen to maximize acid suppression when proton pumps are most active after eating. She also adopted lifestyle measures including trigger avoidance, earlier meals, head-of-bed elevation, and weight management. Because she was already using intranasal corticosteroids and an oral antihistamine for allergic rhinitis without a change in that regimen when the olfactory symptoms began, the authors argued that the improvement was more plausibly attributable to the reflux-directed therapy than to any new rhinitis treatment. Still, the outcomes were entirely patient-reported, and placebo effects or natural symptom fluctuation cannot be excluded in a single unblinded case.

The authors were appropriately measured in their conclusions, emphasizing that a single case cannot establish causation. Case reports serve primarily to generate hypotheses and alert clinicians to possibilities they might otherwise overlook. If the association between GERD and phantosmia is real, confirming it would require systematic studies with objective olfactory testing, validated reflux monitoring such as pH impedance, and comparison groups. Until such evidence exists, the practical takeaway for clinicians is less about treatment and more about attention: patients presenting with phantom odors may merit questions about digestive symptoms, and patients with reflux flares who report new smell disturbances may deserve a fuller evaluation rather than immediate reassurance. The case also underscores the value of careful timelines in clinical documentation, since the parallel course of heartburn and olfactory symptoms was only visible because both were tracked over months.

For patients, the report offers a reminder that symptoms in one organ system can sometimes manifest in another, and that describing symptom relationships to clinicians, as this patient did, can shape diagnosis. The complete resolution of her phantom smoke sensations by three months, alongside controlled reflux, provided reassurance during a stressful period of her life that included an international move. Whether future research will confirm reflux as a genuine cause of phantosmia, or reveal that this case reflected an unusual coincidence of two common conditions, the observation expands the recognized clinical footprint of gastroesophageal reflux disease and highlights how much remains to be learned about the interactions between the digestive tract and the senses.

Subject of Research: Phantosmia associated with gastroesophageal reflux disease in a single case report

Article Title: Case Report: When reflux smells like smoke: a case of phantosmia associated with gastroesophageal reflux

Article References: Visak, C., Ketteler, S., Husami, S., & Shafqat, I. (2026). Case Report: When reflux smells like smoke: a case of phantosmia associated with gastroesophageal reflux. Frontiers in Gastroenterology, 5, Article 1867837. https://doi.org/10.3389/fgstr.2026.1867837

Image Credits: AI Generated

DOI: 10.3389/fgstr.2026.1867837

Keywords: phantosmia, gastroesophageal reflux disease, olfactory dysfunction, proton pump inhibitor, case report, hiatal hernia, laryngopharyngeal reflux, omeprazole, olfactory hallucinations, migraine with aura, focal seizures, allergic rhinitis

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