Helicobacter pylori infects an estimated half of the world’s population and remains highly prevalent across the Eastern Mediterranean region. The bacterium colonizes the gastric mucosa, where it drives chronic inflammation and, in a subset of those infected, progresses to peptic ulcer disease, mucosa-associated lymphoid tissue lymphoma, or adenocarcinoma of the stomach. Eradicating the organism is therefore not merely a matter of relieving dyspepsia; it is a recognized cancer-prevention strategy. Yet the standard triple therapy that dominated H. pylori treatment for decades, a proton pump inhibitor combined with clarithromycin and amoxicillin, has been losing ground worldwide as clarithromycin resistance has climbed, and in Syria the decline has been compounded by antibiotic misuse, disrupted healthcare infrastructure, and limited access to diagnostic resources.

When clarithromycin-based regimens fail or cannot be relied upon, clinicians frequently turn to levofloxacin, a fluoroquinolone antibiotic, as the backbone of alternative combinations. Two such combinations were tested in this trial. The concomitant regimen delivers a proton pump inhibitor, levofloxacin, amoxicillin, and a fourth agent simultaneously for the full 14 days, so the patient takes all drugs at once throughout the treatment period. The sequential regimen splits the therapy into phases: one antibiotic pairing is given first, followed by a second pairing, with the theoretical rationale that an initial phase of amoxicillin reduces bacterial load and damages cell walls in a way that may improve the effectiveness of the subsequent phase while limiting the window in which resistance can emerge.

Sequential therapy has been promoted in some settings as a way to sidestep clarithromycin resistance, and it has been studied extensively in Europe and Asia, but it had never been formally evaluated in Syrian patients. The researchers, led by Marouf Alhalabi of Damascus Hospital together with colleagues at Ibn Al-Nafees Hospital and the Syrian Board in Gastroenterology, designed a single-center, prospective, open-label, randomized superiority trial to answer the question directly under local conditions. The trial was prospectively registered on ClinicalTrials.gov as NCT06065267 on October 3, 2023, and received ethics approval from the Damascus Hospital and Ibn Al-Nafees Ethics Committee under approval number 41/23.

The study enrolled 150 adults with histologically confirmed H. pylori infection, all of whom had never previously received eradication therapy. Participants were assigned equally, 75 to each arm, to either the concomitant or the sequential levofloxacin-based regimen, each lasting 14 days. The primary outcome was eradication success, confirmed by a negative stool antigen test performed six weeks after the completion of therapy, a timing chosen to allow residual bacterial antigen to clear and to avoid false-positive results. The analysis followed the intention-to-treat principle, meaning every randomized patient was counted in the group to which they were assigned regardless of whether they completed the full course, an approach that preserves the real-world validity of the comparison by accounting for dropouts and imperfect adherence.

The numbers told a story of near-equal performance. Concomitant therapy eradicated the infection in 63 of 75 patients, an intention-to-treat rate of 84 percent, while sequential therapy succeeded in 61 of 75, or 81.3 percent. The absolute risk difference was 2.7 percentage points, with a 95 percent confidence interval spanning from minus 9.4 to 14.8, and the comparison yielded a p value of 0.83 with an odds ratio of 1.20, corresponding to a confidence interval of 0.516 to 2.81. In plain terms, the data provide no evidence that one regimen outperforms the other, and the confidence interval is wide enough that a modest advantage in either direction cannot be excluded. The authors were careful to state that the absence of a statistically significant difference does not establish equivalence or non-inferiority, a distinction that matters in clinical trial interpretation: proving two treatments equal requires a trial designed and powered for that purpose, which this superiority trial was not.

Both regimens were generally well tolerated, an important consideration given that eradication therapy requires patients to take multiple medications daily for two weeks. Nausea was the most frequently reported adverse event in both groups, followed by anorexia, headache, a persistent bitter taste, and skin rash. There was no significant difference in the frequency of adverse events between the two arms, suggesting that the added complexity of the sequential schedule does not buy any tolerability advantage. Baseline characteristics of the two groups were comparable, reducing the likelihood that imbalances in age, sex, or disease profile skewed the outcome.

The findings arrive against a backdrop of genuine clinical constraint. In settings where culture and susceptibility testing are unavailable, clinicians must prescribe empirically, choosing regimens based on regional resistance data and local experience rather than on the resistance profile of an individual patient’s infection. Syria’s healthcare system has been strained by years of conflict and economic crisis, and the authors note that susceptibility-guided therapy and many of the internationally recommended first-line regimens may simply be unavailable. In that context, levofloxacin-based empirical therapy remains in use, and the question of which levofloxacin-based strategy to choose is not academic. The trial suggests that when such therapy is required, the simpler concomitant regimen may offer practical advantages: a single, uniform dosing schedule for 14 days is easier to explain, easier to follow, and less prone to the confusion that phased regimens can introduce, with no measurable cost in effectiveness.

The moderate eradication rates observed in both arms, in the low-to-mid 80 percent range, also serve as a reminder that levofloxacin resistance itself is a growing problem in many regions, and that no empirical regimen can be assumed to work indefinitely. The authors emphasize that these findings should be interpreted in light of local resistance patterns and healthcare limitations, and they call for further multi-center studies that incorporate antimicrobial susceptibility testing. Such studies would allow clinicians to match therapy to the actual resistance profile of circulating H. pylori strains, an approach that international guidelines increasingly favor but that remains aspirational in much of the Eastern Mediterranean.

For the broader field, the trial adds a data point from a population that is rarely represented in H. pylori treatment literature. Most eradication trials are conducted in East Asia, Europe, or North America, where resistance patterns, drug availability, and patient populations differ substantially from those in conflict-affected or resource-limited settings. Demonstrating that a straightforward four-drug concomitant regimen achieves roughly 84 percent eradication in treatment-naïve Syrian patients, and that a more complex sequential schedule offers nothing extra, gives local clinicians an evidence-based reason to favor simplicity. As antibiotic resistance continues to erode the effectiveness of legacy regimens worldwide, trials like this one, grounded in the realities of a specific healthcare environment rather than in idealized conditions, are becoming an essential complement to guideline committees’ recommendations.

Subject of Research: A randomized trial comparing levofloxacin-based concomitant and sequential therapies for Helicobacter pylori eradication in treatment-naïve Syrian patients.

Article Title: Levofloxacin-based concomitant versus sequential therapy for Helicobacter pylori eradication in treatment-naïve Syrian patients: a randomized trial showing no superiority of sequential therapy

Article References: Alhalabi, M., Alshiekh, H. A., Sheikh Alhara, A. A., Ismail, A. A., Shehab, W., & Osamah, W. (2026). Levofloxacin-based concomitant versus sequential therapy for Helicobacter pylori eradication in treatment-naïve Syrian patients: a randomized trial showing no superiority of sequential therapy. Gut Pathogens. https://doi.org/10.1186/s13099-026-00881-x

Image Credits: AI Generated

DOI: 10.1186/s13099-026-00881-x

Keywords: Helicobacter pylori, levofloxacin, concomitant therapy, sequential therapy, eradication therapy, antibiotic resistance, randomized clinical trial, Syria, gastroenterology, stool antigen test, fluoroquinolone, clinical trial

The research team, led by Hisen Sulaiman of Al-Furat University and the Soil Science Society of Syria, together with colleagues at Damascus University and the Universidade de Vigo in Spain, examined three representative soil profiles at Al-Hasakah, Al-Qamishli, and Al-Malikiyah. These sites span an elevation range from roughly 300 to 598 meters above sea level and a precipitation gradient from about 280 to 650 millimeters per year, capturing the transition from hot semi-arid conditions at the lowest, driest site to the wetter, higher terrain near the Turkish border. Fieldwork was conducted in 2017, before the full weight of the Syrian conflict curtailed scientific access to the region, and the profiles were excavated to bedrock and described according to Food and Agriculture Organization guidelines.

The analytical program was comprehensive. The researchers measured particle-size distribution by the hydrometer method, bulk density with core samplers, and moisture content by oven-drying, alongside a chemical suite that included pH in a 1:2.5 soil-water suspension, electrical conductivity in a 1:5 extract, cation exchange capacity by the sodium acetate method, calcium carbonate by volumetric titration, organic carbon by the Walkley-Black procedure, and available phosphorus by Olsen extraction. Micronutrients, namely iron, manganese, zinc, and copper, were assessed using DTPA extraction, the standard diagnostic tool for neutral and calcareous alkaline soils, with all extractant concentrations quantified by atomic absorption spectrophotometry.

The physical results reveal a striking textural divide across the gradient. At Al-Hasakah, the driest and lowest site, the soil profile showed a clay loam texture with the lowest clay content recorded in the study, just 30.4 percent in the surface horizon, accompanied by relatively higher sand and silt fractions. By contrast, the profiles at Al-Qamishli and Al-Malikiyah were dominated by clay throughout most depths, with clay contents climbing to 57 and 59 percent respectively in deeper layers, a signature of the clay-rich calcareous vertisols typical of the region’s higher ground. The authors attribute the relative depletion of fine particles in the topsoil of the lowest site to aeolian erosion, which preferentially strips silt and clay from exposed surfaces and redistributes them downwind, while the increase of clay with depth points to eluviation, the downward migration of clay particles carried by percolating water.

Bulk density values ranged from 1.20 to 1.35 grams per cubic centimeter and increased with depth, consistent with silt-enriched subsurface horizons, diminishing organic matter, and limited structural development below the surface. Soil moisture in the topsoil remained below 6 percent at all sites, a stark indicator of the water-limited conditions that constrain rain-fed agriculture across the governorate, although moisture rose both with depth and along the elevation and precipitation gradient, suggesting that the wetter upper landscape retains measurably more plant-available water.

Chemically, the soils told a story of aridity written in carbonates and salts. All profiles exhibited neutral to slightly alkaline pH, beginning at 7.66 in the surface of the Al-Hasakah profile and exceeding 8.0 at depth, a pattern the researchers link to leaching and salt accumulation in the subsoil combined with low organic matter. Electrical conductivity in the topsoil indicated moderate salinity for clay soils, above 0.51 decisiemens per meter, but its vertical distribution differed sharply among sites. The lowest-elevation profile showed evidence of upward salt movement driven by capillary rise from deeper horizons, the mid-elevation profile at Al-Qamishli displayed the highest surface salinity with a downward leaching trend, and the highest site showed no significant change with depth, likely because its dense clay matrix slows water movement and diffuses salt concentrations. Calcium carbonate contents ranged from 22.81 to 40.23 percent, classifying the soils as extremely calcareous under FAO guidelines, with carbonate increasing with depth, particularly at the driest site where limited precipitation suppresses leaching.

Perhaps the most consequential findings concern fertility. Organic matter was uniformly low, at or below 1 percent, and soil organic carbon did not exceed 0.56 percent, declining with depth, values consistent with sparse vegetation cover, absent organic fertilization, and the hot, dry climate in which biomass production is minimal while mineralization rates remain high. Available phosphorus was critically deficient, staying below 3.62 milligrams per kilogram and concentrated in surface horizons, a limitation the authors attribute to the absence of mineral fertilization and to phosphorus fixation under alkaline conditions. Cation exchange capacity, by contrast, was a relative strength, rated medium at Al-Hasakah and high to very high at the two higher sites, dominated by exchangeable calcium and magnesium supplied by the carbonate-rich parent materials and minerals such as palygorskite, with localized basaltic intrusions near Al-Malikiyah contributing additional base cations.

The micronutrient picture was nuanced and carries direct implications for crop management. Measured against conventional critical levels developed for temperate agricultural soils, the profiles would register moderate to severe deficiencies, echoing global findings that aridity suppresses micronutrient availability in drylands. Yet when evaluated against thresholds developed specifically for arid and semi-arid regions, most soils showed adequate copper, iron, and manganese, while zinc concentrations of 0.6 to 1 milligram per kilogram fell in the low to moderate range. The researchers argue this discrepancy demonstrates the need for agroecological, climate-based thresholds for micronutrient availability rather than blanket application of standards derived from favorable environments, a point with practical weight for the region’s wheat and barley farmers.

Statistical analysis reinforced the climatic signal. Clay content correlated strongly and positively with both precipitation and elevation, each at a coefficient of 0.79, while sand content was strongly and negatively correlated with elevation at minus 0.88. Cation exchange capacity and exchangeable calcium and magnesium rose significantly with elevation and precipitation, whereas exchangeable potassium declined, and calcium carbonate showed an inverse relationship with the gradient. Soil pH and electrical conductivity, however, showed no significant variation along the gradient, which the authors suggest reflects the relatively narrow environmental range sampled, roughly 350 meters of elevation and 400 millimeters of precipitation, combined with high evaporation rates that attenuate the leaching influence of rainfall. The region’s flat relief also limits lateral water redistribution, distinguishing these patterns from the steep-topography gradients documented in mountain studies elsewhere.

The authors are candid about the limitations of a three-profile design with restricted spatial coverage, and they note that temporal soil dynamics, total nitrogen, available sulfur, and fertility management practices were not assessed. Even so, the study delivers novel baseline data for a region where published soil characterization is scarce and where the stakes are high. The Al-Hasakah Governorate remains Syria’s largest wheat-producing province, and the agricultural sector once employed nearly 22 percent of Syrians before the conflict that ran from 2011 to 2024. The researchers conclude that sustainable production in these soils will require organic amendments to rebuild carbon, phosphatic fertilization to overcome severe phosphorus deficiency, zinc supplementation, and improved drainage at the lower-elevation sites where salinity risk is greatest. As droughts intensify and temperatures rise across the eastern Mediterranean, the findings offer farmers, land managers, and researchers a technical foundation for protecting one of the Middle East’s most strategically important agricultural landscapes, and a template for soil assessment in arid regions where the ground itself may hold the keys to food security.

Subject of Research: Physicochemical soil properties along elevation and precipitation gradients in arid northeastern Syria

Article Title: Changes in soil physico-chemical properties along elevation and precipitation gradients in Northeastern Syria

Article References: Sulaiman, H., Jaafar, A. A. K., Salim, S., & Rodríguez-Seijo, A. (2026). Changes in soil physico-chemical properties along elevation and precipitation gradients in Northeastern Syria. Environmental Earth Sciences, 85(15), Article 397. https://doi.org/10.1007/s12665-026-13122-w

Image Credits: AI Generated

DOI: 10.1007/s12665-026-13122-w

Keywords: soil science, Syria, Al-Hasakah, elevation gradient, precipitation gradient, soil fertility, micronutrients, vertisols, calcareous soils, arid soils, cation exchange capacity, soil organic carbon