Breath Test Detects Bacterial Infections

New study shows simple, affordable test can identify bacterial infections faster than traditional methods.

Mar. 19, 2026 at 2:02am by Ben Kaplan

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Researchers have developed a breath test that can quickly and affordably detect bacterial infections. The test works by identifying molecules that are only broken down by infecting bacteria, not gut bacteria. By enriching these molecules with a carbon-13 isotope, the researchers found that the resulting carbon dioxide can be easily detected in a person's breath using inexpensive infrared scanners. This proof-of-concept study could lead to a rapid screening tool to determine if a patient has a bacterial infection, reducing unnecessary antibiotic prescriptions.

Why it matters

Traditionally, bacterial infections are diagnosed through lab cultures, which can take days. This new breath test approach offers a much faster and more accessible way to identify bacterial infections, which is crucial for providing appropriate treatment and curbing the overuse of antibiotics.

The details

The study, led by researchers from St. Jude Children's Research Hospital and the University of California, San Francisco, focused on common pathogens like Staphylococcus aureus, Streptococcus pneumoniae, and Escherichia coli, as well as Salmonella enterica. They found that the carbon-13 enriched molecules are only broken down by infecting bacteria, producing a labeled carbon dioxide byproduct that can be detected in a person's breath using inexpensive infrared scanners.

  • The study was published on March 18, 2026.

The players

Kiel Neumann

Co-corresponding author of the study and researcher in the Department of Radiology at St. Jude Children's Research Hospital.

David Wilson

Co-corresponding author of the study and researcher at the University of California, San Francisco.

Marina López-Álvarez

First author of the study and researcher at the University of California, San Francisco.

St. Jude Children's Research Hospital

The institution where part of the research was conducted.

University of California, San Francisco

The institution where part of the research was conducted.

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What they’re saying

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

— Kiel Neumann, Researcher, Department of Radiology, St. Jude Children's Research Hospital

“A patient might complain of nonspecific symptoms, like pain and swelling, but it is likely a vaso‑occlusive crisis — purely inflammatory. It could be an infection, however, and because the risk of missing an infection is high, they get antibiotics anyway, even if unnecessary.”

— Kiel Neumann, Researcher, Department of Radiology, St. Jude Children's Research Hospital

What’s next

The researchers plan to conduct further clinical studies to establish a protocol for using the breath test to detect bacterial infections in a wide range of clinical settings, such as urgent care and emergency rooms.

The takeaway

This new breath test technology has the potential to revolutionize the way bacterial infections are diagnosed, offering a fast, affordable, and accessible alternative to traditional lab-based methods. If proven effective in clinical trials, it could help reduce unnecessary antibiotic prescriptions and improve patient outcomes.