What your breath says about the bacteria in your gut Metabolites in mouse and human breath correlate to gut-microbe populations and might be helpful in diagnosing disease. By Edward Chen

https://www.nature.com/articles/d41586-026-00219-2?utm_source=Live+Audience&utm_campaign=f4f2b22b7f-nature-briefing-daily-20260123&utm_medium=email&utm_term=0_-33f35e09ea-50432164 The chemicals found in a person’s breath might reveal the identity of the microbes in their gut. Researchers measured the levels of bacterial metabolites in the exhaled breath of mice and children and showed that they could be used to partially predict the identity and abundance of certain gut bacteria, including one species that is associated with asthma. The findings could lead to devices that help to guide treatment of conditions influenced by gut bacteria more quickly than existing methods that test stool samples.