Helicobacter pylori Positivity and Quantitative Breath-Test Values in Relation to Lipid and Inflammatory Phenotypes Across Multiple Observational Datasets

Quantitative urea breath-test (UBT) values are routinely reported, but their systemic significance beyond Helicobacter pylori positivity remains uncertain. We analyzed 21,195 adults from two health-check cohorts, distinguishing test positivity from delta-over-baseline (DOB) variation among positive participants. We used adjusted models, cohort comparisons and false discovery rate (FDR) correction, with public serological and gastric expression datasets providing exploratory comparisons. Overall, 5484 participants tested positive. In pooled analyses, positivity was associated with higher white blood cell counts (adjusted difference, 0.302 × 109/L; 95% confidence interval, 0.249–0.355). Neutrophil counts were also higher (0.199 × 109/L; 0.164–0.234), whereas high-density lipoprotein (HDL) cholesterol was lower (−0.029 mmol/L; −0.038 to −0.019). The HDL association was not clearly replicated in Cohort 2. Associations within the positive range varied with model specification and were not consistently replicated. Additional adjustment for smoking and socioeconomic factors attenuated the leukocyte association in the serological data. Among 3670 positive adults with clinical records, ordinal associations with coded fatty liver, diabetes or hypertension were not FDR significant, and estimates remained imprecise. Gastric expression data supported local inflammation but did not establish a mechanism linking infection to circulating HDL. DOB within the positive range showed no consistent systemic gradient. Residual confounding and imprecise clinical estimates limit interpretation; nonsignificant results do not establish equivalence. These findings neither validate DOB as a measure of bacterial burden nor establish its incremental predictive value. They provide insufficient evidence to use DOB magnitude for metabolic risk assessment or treatment prioritization.