This work contributes to the development of robust and interpretable diagnostic models, and supports the future integration of real-time, low-cost breath analysis into clinical workflows. Helicobacter pylori is a spiral-shaped bacterium that colonizes the human stomach and causes chronic inflammation of the gastric mucosa. Its urease activity leads to ulcer formation, which is a known risk factor for gastric cancer. The ¹³C-Urea Breath Test (UBT) detects this infection by measuring ¹³CO₂ in exhaled breath after ingestion of labeled urea. The diagnostic decision traditionally relies on the Delta Over Baseline (DOB) metric, defined as the difference in ¹³C values before and after the ingestion.