Gut Bacteria May Hold Key To Preventing Severe Peanut Allergies

Key TakeawaysPeanut allergy is among the most common in the U.S. and CanadaResearchers have discovered why people who are sensitive to peanuts react so differently to themThey found that a type of gut bacteria called Rothia helps stop the process that triggers a reaction.MONDAY, July 20, 2026 (HealthDay News) — Why is a peanut allergy a life-and-death event for some folks but a minor inconvenience to others?Chalk it up to different populations of bacteria colonizing the mouth and gut, new research suggests."We found evidence that some of these microbes may help break down peanut components in ways that could influence allergic responses," said researcher Dr. Alberto Caminero Fernandez, an associate professor of medicine at McMaster University in Ontario, Canada. "These findings point to a newly identified pathway linking the oral and gut microbiome with food allergy."The study — recently published in Cell Host & Microbe — shows how gut bacteria break down parts of an allergenic food and influence a person’s reaction to peanuts in particular. Peanut allergies are among the most common allergies in both Canada and the U.S. In all, 2% to 3% of Americans have a peanut allergy."Peanut allergies can cause serious reactions like difficulty breathing, and in some cases, can even be life-threatening," study co-author Liam Rondeau, a postdoctoral fellow at McMaster’s Farncombe Family Digestive Health Research Institute, said in a news release. "However, some people with peanut allergies can still eat small amounts without having a reaction. We were curious about why this happens."For the study, he and his colleagues examined saliva and upper gut samples from healthy volunteers. While they identified several species of bacteria that were able to break down major peanut allergens, one stood out.Species of Rothia could limit the ability of peanut proteins to bind with antibodies — the process that triggers allergic reactions. Participants who had more of these allergen-degrading bacteria were able to tolerate more peanuts before having a reaction."These findings point to a newly identified pathway linking the oral and gut microbiome with food allergy, and they may help guide future work on prediction and treatment," Fernandez said.Researchers validated their findings in a group of 120 children. Those who had greater tolerance for peanuts had significantly more Rothia. They said these bacteria let fewer peanut allergens reach the bloodstream and reduced activation of immune cells that cause the life-threatening allergic reaction, anaphylaxis. The result: A much milder allergic reaction after exposure.In Canada, where peanut allergy is the most common affecting children, strict avoidance is the only way recommended to manage it. About 1 in 3 kids have an accidental exposure each year.Researchers said their findings pave the way for new approaches in prevention and treatment, such as microbial or probiotic therapies, as well as oral immunotherapies.The study also included researchers in the U.S. and Spain.More informationThe Mayo Clinic has more about peanut allergy.SOURCE: McMaster University, news release, March 3, 2026.What This Means For YouNew understanding of how gut bacteria affect a person's reaction to peanuts could lead to new treatments for peanut allergy..Sign up for our weekly HealthDay newsletter

Gut Bacteria May Hold Key To Preventing Severe Peanut Allergies

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