Breath Analysis Approach Offers Rapid Detection of Bacterial Infection

Infectious diseases are a major cause of mortality worldwide, and rising antibiotic resistance increases the need for fast, specific diagnostics. Existing methods such as cultures, imaging, and molecular assays can be slow, costly, or nonspecific. To address this need, researchers have introduced a breath-based approach that detects bacterial metabolism within minutes.

A study led by St. Jude Children's Research Hospital (Memphis, TN, USA) and the University of California, San Francisco (UCSF), reports a metabolism-targeted breath test designed to rapidly distinguish bacterial infection from other causes of inflammation. The approach leverages molecules selectively metabolized by infecting bacteria—rather than gut microbes—to generate a detectable breath signal.

The method centers on a version of mannitol enriched with carbon‑13, a naturally occurring isotope. After intravenous administration, only infecting bacteria catabolize the substrate for nutrients, releasing carbon‑13–labeled carbon dioxide (CO₂) that is exhaled. Exhaled CO₂ is then quantified using an inexpensive nondispersive infrared (NDIR) spectroscopy tabletop instrument.

In proof‑of‑concept testing, the breath readout detected signs of myositis, bacteremia, pneumonia, and osteomyelitis. The researchers focused on clinically common pathogens, including Staphylococcus aureus, Streptococcus pneumoniae, and Escherichia coli (E. coli), and also examined Salmonella enterica. The work was motivated by observations from a positron emission tomography (PET) study in which a radiolabeled form of mannitol was not absorbed by normal gut microbes.

The findings were published in ACS Central Science on March 18, 2026. Collaborating institutions included St. Jude Children’s Research Hospital; the University of California, San Francisco; Ghent University; Sable Systems International; and Zuckerberg San Francisco General Hospital. According to the authors, this study represents an initial step toward a safe, straightforward, and easily obtainable test and sets the stage for future clinical studies to evaluate feasibility in settings such as urgent care and emergency departments.

“When a patient presents with certain symptoms, doctors already have an idea of the likely pathogens,” said Kiel Neumann, PhD, St. Jude Department of Radiology. “We hope that this test could be a quick screening tool to know whether it's a bacterial infection or not.”

“We want to explore how we can use this technology to have an impact at ground level — patients checking into urgent care or an emergency room, for example,” added Dr. Neumann. “There's a lot of work to do in humans to establish a true protocol, but we are very enthusiastic about its potential.”

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St. Jude Children’s Research Hospital
University of California, San Francisco