Overturning 100-Year-Old Belief About Lung Bacteria

Recent research from the University of Michigan, published in the Journal of Bacteriology on July 14, 2026, has overturned a century-old belief regarding the lung bacterium Prevotella melaninogenica by demonstrating that it can tolerate significantly higher oxygen concentrations than previously assumed. Traditionally classified as an obligate anaerobe that cannot survive in oxygen, laboratory tests revealed this common respiratory microbe can grow at oxygen concentrations between 5 and 8 percent and briefly survive exposure levels up to 21 percent. Lead researcher Ariangela Kozik and her team aim to challenge rigid microbial categorizations, suggesting that a bacterium's ability to tolerate oxygen falls along a flexible spectrum rather than binary classifications. This discovery resolves a fundamental mystery regarding how Prevotella persists in the lungs, where it comprises roughly 10 percent of microbial populations in healthy individuals and up to 13 percent in those with chronic respiratory diseases such as asthma and COPD. The study utilized a novel real-time sensor platform and RNA sequencing to uncover mechanisms allowing Prevotella to consume oxygen and manage oxidative stress and DNA damage. These insights radically alter the scientific understanding of microbial survival strategies within the human respiratory tract and provide a foundational shift for studying lung microbiome dynamics. These findings pave the way for future investigations into how lung bacteria interact with the host immune system and produce metabolites in health versus disease states. Gaining a clearer picture of these microbial communities could eventually contribute to more targeted therapies for chronic lung conditions and decode complex host-pathogen interactions currently viewed as a major scientific black box.