New findings raise questions about the role of microbes living in the lungs.
More than 35 trillion bacteria live throughout the human body, forming microbiomes in the gut, mouth, lungs, skin, and urogenital tract.
Researchers increasingly recognize that these microbial communities are connected to both health and disease, but much about what individual microbes do and how they survive remains unknown.
A University of Michigan study now challenges a 100-year-old assumption about Prevotella melaninogenica, a common bacterial resident of the lungs.
Ariangela Kozik, Ph.D., Assistant Professor of Internal Medicine at U-M Medical School and Assistant Professor of Molecular, Cellular, and Developmental Biology at U-M, leads a laboratory that studies Prevotella. The bacteria are commonly found in the respiratory tract and have been associated with numerous chronic conditions, yet they also live in healthy people. Scientists have long classified P. melaninogenica as an obligate anaerobe, meaning it cannot survive in the presence of oxygen.
That raised a fundamental mystery about how it persists in the lungs.
Kozik, an asthma researcher, notes that Prevotella occurs at different levels in the respiratory tracts of both healthy people and people with asthma and COPD. They make up roughly 10% of microbial populations in healthy lungs and as much as 13% on average in people with respiratory disease.
Prevotella survives far more oxygen than expected
To investigate the contradiction, Kozik’s team exposed cultures of P. melaninogenica to progressively higher concentrations of oxygen and measured their growth and survival.
The bacteria were able to grow at oxygen concentrations between 5 and 8% and briefly survived exposure to levels as high as 21%.
Using a new real-time sensor platform and RNA sequencing, the researchers also found evidence that Prevotella may consume oxygen and respond to oxidative stress and DNA damage differently from other aerobic bacteria.
“Prevotella has all of these mechanisms to allow it to survive in oxygenated environments that previously were not appreciated for this organism at all, changing what we thought we knew,” said Kozik.
Oxygen tolerance may be more flexible
Kozik notes that a bacterium’s ability to tolerate oxygen may fall along a spectrum rather than fitting neatly into the traditional categories scientists have used.
Her laboratory next plans to investigate how the immune system responds to Prevotella and examine lung bacteria more closely to determine how these microbes interact with the body.
“We need to work to look at the bacterial community and ask, how does this community function currently? What metabolites are they making, what signals are they sending to the immune system? How’s the immune system responding to it? How does this activity differ in health versus in the context of chronic lung diseases?” said Kozik.
A clearer picture of how the body’s microbiomes function could eventually contribute to more targeted therapies, Kozik added.
“Those kinds of questions about the relationships between bacteria and the body are what is a big black box right now.”
Reference: “Aerotolerant capacity of the lung symbiont Prevotella melaninogenica” by Claire Albright, Gouri Anil, Jacob Evans, Souzane Ntamubano and Ariangela Kozik, 14 July 2026, Journal of Bacteriology.
DOI: 10.1128/jb.00142-26
News – Curated by Amanda Scott, Alias Group Creative
Follow her on Bluesky
Researcher at Russian plague laboratory dies of ‘unknown’ infection
Russian authorities have imposed "anti-epidemic measures" after a laboratory worker at an institute in Siberia dedicated to studying the plague and other infectious diseases died of a mysterious illness. The researcher, a 28-year-old female [...]
GHCE Concept
From the preface of the book Global Health Care Equivalency in the Age of Nanotechnology, Nanomedicine and Artificial Intelligence, Edited by Frank Boehm: Since the publication of my first book (Nanomedical Device and Systems [...]
A Surprising Brain Signal Could Explain Why Eating Less Protein Extends Lifespan
A new paper suggests that limiting protein intake triggers a coordinated response throughout the body that may help explain how protein restriction affects healthy aging. Animals respond to protein restriction, or reduced protein in [...]
Back and shoulder surgery is often worse than useless
Millions of operations should be scrapped SIX IN TEN Britons have surgery at some point. So do lots of Americans, at a cost of perhaps $500bn a year, a third of all spending on [...]
Cocaine plays with mind, hijacks brain circuit, drives increasingly rigid and repetitive behavior
Researchers have found that cocaine hijacks brain circuit, which to drive increasingly rigid and repetitive behavior. The brain circuit that normally participates in selecting natural mouth and face movements, but which becomes disproportionately engaged [...]
Injectable nanodevices could provide effective treatment for drug-resistant glioblastoma
The brain cancer glioblastoma is one of the most aggressive and treatment-resistant cancers known to medicine, carrying a median survival of just 12-15 months, even with the best available care. Now, researchers at the [...]
New Treatment Cuts “Bad” Cholesterol in Half for a Full Year
A single infusion of an experimental CRISPR-Cas9 therapy was reported to safely lower LDL cholesterol by 52.5% and triglycerides by 47.8%, as measured 12 months after treatment. What if one infusion could keep cholesterol [...]
Too Much RNA Can Drain a Cell’s Energy, Scientists Discover
A virus may cripple a cell’s power supply simply by producing too much of a molecule the cell needs to survive. New research from the Texas A&M College of Veterinary Medicine and Biomedical Sciences [...]
West African scientists warn of weakening health systems and urge stronger outbreak detection
LOME, Togo (AP) — West African laboratory scientists called on governments Friday to strengthen capacity to detect disease outbreaks to avoid another major outbreak, saying health systems across the region are becoming weaker. Participants [...]
A Little-Known Protein Could Point to a New Way To Treat Alzheimer’s
A study suggests that increasing SORLA protein levels could help treat Alzheimer’s disease and other disorders involving tau protein. Increasing SORLA, a protein with a protective role in the brain, helped mice withstand damage [...]
Cancer’s Hidden Antioxidant Shield Helps It Escape the Immune System
Blocking an antioxidant protein that tumors use to suppress immune attacks improved cancer immunotherapy responses in mice. Cancer cells can release antioxidants that interfere with the immune cells trying to kill them. Researchers have [...]
Scientists Find a Berry Compound That Helps Muscle Cells Burn Fat
Pterostilbene, a compound found naturally in some foods, affects how skeletal muscles process fats by stabilizing a protein called PPARδ and increasing its signaling activity. Pterostilbene, a natural compound found in blueberries, grapes, and [...]
Two Hidden Forces Help Build the Human Brain Before Birth
Scientists have uncovered two surprising forces that help guide how the human brain forms before birth. Before birth, the human brain is shaped in large part by an unusual class of stem cells known [...]
Researchers Uncover a Hidden Trigger Behind Chronic Inflammation
The findings offer new insights that could help guide the development of future therapies. A protein called human resistin may help flip on one of the immune system’s most powerful inflammatory switches. Researchers at [...]
Scientists Have Uncovered Previously Hidden Microbial Activity on Human Skin
The most abundant microbes on your skin may not be the ones doing most of the work. Human skin supports vast communities of bacteria, fungi, and viruses that can influence its protective barrier, immune [...]
Brazilian Tree Compounds Fight COVID-19 on Multiple Fronts
Scientists found compounds in a Brazilian tree that hit SARS-CoV-2 on multiple fronts, revealing a promising new lead in the search for COVID-19 treatments. Researchers have found that galloylquinic acids extracted from the leaves [...]
