(MEMPHIS, Tenn. – March 18, 2026) A groundbreaking study led by St. Jude Children’s Research Hospital and the University of California, San Francisco, suggests that a simple breath test could soon make it easier to distinguish bacterial infections from viral infections and noninfectious inflammation. This innovative approach could significantly reduce the time and cost involved in diagnosing bacterial infections, potentially transforming healthcare practices worldwide.
The study, published today in ACS Central Science, demonstrates how molecules broken down by infecting bacteria—but not by gut bacteria—can be detected using a breath test. By enriching these molecules with a naturally occurring carbon isotope, the researchers found that the resultant carbon dioxide is easily detectable using inexpensive infrared scanners. This proof-of-concept study paves the way for clinical testing and could lead to rapid, affordable identification of bacterial infections, thereby reducing unnecessary antibiotic prescriptions.
Infrared Detection for Bacterial Infection
Traditionally, diagnosing bacterial infections involves taking samples and growing them in laboratory cultures, a process that can take several days. The breath test, however, offers a rapid alternative. Kiel Neumann, PhD, co-corresponding author and a member of the St. Jude Department of Radiology, explains the potential impact: “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 determine whether it’s a bacterial infection or not.”
In recent trials using positron emission tomography (PET) scans, Neumann observed that a radiolabeled form of mannitol—a molecule metabolized exclusively by bacteria—was not absorbed by the body’s natural gut microbes. Building on this, the researchers developed a version of mannitol enriched with carbon-13, a naturally occurring isotope. When administered intravenously, this carbon-13 molecule is metabolized only by infecting bacteria, producing a labeled carbon dioxide byproduct that is exhaled and can be measured using a nondispersive infrared (NDIR) spectroscopy tabletop instrument.
Potential Impact on Clinical Settings
The researchers focused on pathogens commonly found in clinical settings, including Staphylococcus aureus, Streptococcus pneumoniae, and Escherichia coli, as well as Salmonella enterica. While the latter is not usually a concern for healthy immune systems, it poses significant risks for immunocompromised individuals, such as those with sickle cell disease, where infection and inflammation are often conflated.
“A patient might complain of nonspecific symptoms, like pain and swelling, but it is likely a vaso-occlusive crisis—purely inflammatory,” Neumann notes. “It could be an infection, however, and because the risk of missing an infection is high, they get antibiotics anyway, even if unnecessary.”
Implications for Future Research and Healthcare
The study represents a crucial first step toward developing a safe, straightforward, and easily obtainable test for bacterial infections. “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,” Neumann says. “There’s a lot of work to do in humans to establish a true protocol, but we are very enthusiastic about its potential.”
The announcement comes as healthcare systems worldwide grapple with the challenge of antibiotic resistance, which is exacerbated by the over-prescription of antibiotics. A rapid and reliable test for bacterial infections could help mitigate this issue by ensuring that antibiotics are prescribed only when necessary.
Authors and Funding
The study’s co-corresponding author is David Wilson from the University of California, San Francisco. The first author is Marina López-Álvarez, also from the University of California, San Francisco. Other contributors include Sang Hee Lee, Anju Wadhwa, Mohammad Yaqoob Bhat, Jung Min Kim, Anil Bidhar, Joseph Blecha, Robert Flavell, Renuka Sriram, and Joanne Engel from the University of California, San Francisco; Shari Dhaene and Tom Desmet from Ghent University; Marshall McCue from Sable Systems International; Michael Ohliger from the University of California, San Francisco and Zuckerberg San Francisco General Hospital; and Tyler Simmons, Spenser Simpson, Jeffrey Steinberg, Amanda Green, and Jason Rosch from St. Jude.
The research was supported by the National Institutes of Health (R01-EB030897, R01-AI181378, R01-AI161027, R21-AI164684, R01-EB028338, and R01-AI192221), the Cystic Fibrosis Foundation (20A0), and the American Lebanese Syrian Associated Charities (ALSAC), the fundraising and awareness organization of St. Jude.
As the study moves towards clinical trials, the potential for this breath test to revolutionize the diagnosis of bacterial infections remains significant. The healthcare community eagerly anticipates further developments, which could lead to more efficient and targeted treatment strategies, ultimately improving patient outcomes and reducing the burden on healthcare systems.
