There’s a lot more of the bacterial species Streptococcus salivarius (shown) in the noses of people with hay fever than the noses of those without, researchers have found. The overabundance may be exacerbating allergy symptoms.
DR KARI LOUNATMAA/Science Source
A type of bacteria that’s overabundant in the nasal passages of people with hay fever may worsen symptoms. Targeting that bacteria may provide a way to rein in ever-running noses.
Hay fever occurs when allergens, such as pollen or mold, trigger an inflammatory reaction in the nasal passages, leading to itchiness, sneezing and overflowing mucus. Researchers analyzed the composition of the microbial population in the noses of 55 people who have hay fever and those of 105 people who don’t. There was less diversity in the nasal microbiome of people who have hay fever and a whole lot more of a bacterial species called Streptococcus salivarius , the team reports online January 12 in Nature Microbiology .
Headlines and summaries of the latest Science News articles, delivered to your email inbox every Thursday.
Thank you for signing up!
There was a problem signing you up.
S. salivarius was 17 times more abundant in the noses of allergy sufferers than the noses of those without allergies, says Michael Otto, a molecular microbiologist at the National Institute of Allergy and Infectious Diseases in Bethesda, Md. That imbalance appears to play a part in further provoking allergy symptoms. In laboratory experiments with allergen-exposed cells that line the airways, S. salivarius boosted the cells’ production of proteins that promote inflammation.
And it turns out that S. salivarius really likes runny noses. One prominent, unpleasant symptom of hay fever is the overproduction of nasal discharge. The researchers found that S. salivarius binds very well to airway-lining cells exposed to an allergen and slathered in mucus — better than a comparison bacteria that also resides in the nose.
The close contact appears to be what makes the difference. It means that substances on S. salivarius’ surface that can drive inflammation — common among many bacteria — are close enough to exert their effect on cells, Otto says.
Hay fever, which disrupts daily activities and disturbs sleep , is estimated to affect as many as 30 percent of adults in the United States. The new research opens the door “to future studies targeting this bacteria” as a potential treatment for hay fever, says Mahboobeh Mahdavinia, a physician scientist who studies immunology and allergies at Rush University Medical Center in Chicago.
But any treatment would need to avoid harming the “good” bacteria that live in the nose, says Mahdavinia, who was not involved in the research.
The proteins on S. salivarius’ surface that are important to its ability to attach to mucus-covered cells might provide a target, says Otto. The bacteria bind to proteins called mucins found in the slimy, runny mucus. By learning more about S. salivarius’ surface proteins, Otto says, it may be possible to come up with “specific methods to block that adhesion.”
P. Miao et al . Exacerbation of allergic rhinitis by the commensal bacterium Streptococcus salivarius . Nature Microbiology . Published online January 12, 2023. doi: 10.1038/s41564-022-01301-x
Aimee Cunningham is the biomedical writer. She has a master’s degree in science journalism from New York University.
Our mission is to provide accurate, engaging news of science to the public. That mission has never been more important than it is today.
As a nonprofit news organization, we cannot do it without you.
Your support enables us to keep our content free and accessible to the next generation of scientists and engineers. Invest in quality science journalism by donating today.
Science News was founded in 1921 as an independent, nonprofit source of accurate information on the latest news of science, medicine and technology. Today, our mission remains the same: to empower people to evaluate the news and the world around them. It is published by the Society for Science, a nonprofit 501(c)(3) membership organization dedicated to public engagement in scientific research and education (EIN 53-0196483).
Subscribers, enter your e-mail address for full access to the Science News archives and digital editions.
Not a subscriber?
Become one now .
