A host of tiny microbes common to both human mouth and gut microbiomes have been shown to capably diffuse several hazardous proteins known to trigger peanut allergies.
In other words, some of our very own saliva and stomach juices may already contain the microbes needed to break down some of the most dangerous allergens associated with peanuts. Among the microbes studied, a bacterium of the genus Rothia, named Rothia aeria ASV 14171, proved to be the most effective at reducing allergic responses and may lead to new medical treatments in the future.
“Peanut allergies can cause serious reactions like difficulty breathing, and in some cases, can even be life threatening,” according to Liam Rondeau, a postdoctoral fellow with McMaster University’s Farncombe Family Digestive Health Research Institute in Ontario, which led the multicenter study. “However, some people with peanut allergies can still eat small amounts without having a reaction,” Rondeau noted in a statement. “We were curious about why.”
A tough legume to crack
Peanut allergies are the most common form of food allergy, at least in Western nations, where they currently impact about 2% of the general population. The condition is also among the most likely food allergies to lead to unintended exposures and severe episodes—with somewhere between seven and 14% of all people who are allergic to peanuts experiencing a reaction annually.
Anywhere from one-third to one-half of those unwanted annual episodes include anaphylaxis: a potentially fatal immune system response marked by skin rashes, nausea, steep drops in blood pressure, and a suffocating narrowing of the breathing pathway.
Adding to these dangers, peanut allergies are much more likely than other food allergies to endure onward into adulthood, extending these risks for up to 80% of the children who share this diagnosis.
Two proteins present in peanuts, labelled Ara h 1 and 2, have long been determined to be the dominant allergenic compounds responsible for these overwrought and dangerous immune system freak-outs. And, to test which common digestive bacteria worked best to neutralize these proteins, the researchers turned to specialized lab mice with peanut allergies, as well as to carefully segregated petri dishes of individual bacteria from human mouths and small intestines.
Peanut busters
Given how quickly a peanut allergy can take hold, the team focused on the bacteria present in human saliva for their in vitro, or Petri dish, trials, examining bacterial samples from 13 hardy volunteers with no reported food allergies. (Bacteria more often found in the small intestine were tested as well, taken from the mouths of five similarly resilient human volunteers.)
While bacteria capable of degrading the Ara h 1 and 2 proteins were detected and isolated for a variety of genera, including Staphylococcus, Streptococcus, and Veillonella, bacteria from the genus Rothia proved to be the most consistent defender against these peanut allergen proteins.
Rothi