Eating bacteria may be the key to overcoming a potentially life-threatening food allergy, according to new research from Australia.
A team of researchers helped more than 20 children with peanut allergies overcome their condition after eating a daily dose of a strain of Lactobacillus—a beneficial bacteria found in some fermented food products, and which is thought to be valuable in maintaining digestive health.
More than 3 million Americans have some kind of reaction to peanuts. Like many other food allergies, it is on the rise in most industrialized countries, according to the National Institutes of Health. But researchers so far have not been able to determine the reason for the increase.
The reaction, though still relatively rare, can be life-threatening. Patients can go into anaphylaxis, a condition where muscles in the body tighten rapidly, restricting movement, limiting breathing and sometimes leading to death.
Researchers have had some luck treating peanut allergies by introducing very small amounts of peanut into a diet under clinical supervision over a long period of time—this is commonly referred to as oral immunization therapy (OIT).
In some cases, patients have been able to build a resistance to the allergen, but success has been limited. The therapy seems to desensitize people to the effects of the allergic reaction, but it does not actually switch off the underlying allergy. And once patients stop their daily OIT dose, they tend to revert back to having reactions.
Professor Mimi Tang and her colleagues at the Murdoch Childrens Research Institute in Australia wondered if they could achieve a more permanent result if they tried oral immunization therapy, but introduced a strain of bacteria called Lactobacillus rhamnosus, which had previously shown promise in helping with food allergies.
"So I had an idea to combine a probiotic together with the OIT—I believed that giving the probiotic together with the food allergen would drive the immune response towards tolerance and switch off the allergy," Tang told CNBC.
The team fed a group of 28 children a daily dose of the probiotic bacteria mixed with peanut flour for 18 months. They gave a fixed dose of the probiotic, but began with a tiny amount of peanut flour, and gradually increased the dose over time—the common OIT approach.
A separate control group of kids received the same peanut flour doses without the probiotic. Then the team stopped the treatment and administered a "peanut eating challenge"—they gave the kids a single large dose of peanuts, to see if they would have any negative reactions.
The results astounded the researchers. More than 80 percent of children who received the bacteria treatment were able to tolerate peanuts well at the end of the trial, compared with less than 4 percent of the control group. The team published its findings in The Journal of Allergy and Clinical Immunology.
Not to be tried at home
There were some other notable important results. Tang told CNBC that she was surprised to see that children in both groups reported asthma and eczema during the trial—this suggested that children who suffer from food allergies also have other allergy problems.
And about 10 percent of the kids taking the bacteria still had episodes of anaphylaxis—about the same percentage as would be seen under normal circumstances, Tang said. That suggests the therapy may not work in every case.
Though pleased with the findings, Tang said she and her team need to answer big questions. First, are the kids who took the bacteria truly tolerant to peanuts—have they switched off the allergy completely? In future studies, Tang plans to wait longer after stopping treatment to test the subjects.
Second, how long will the effects last? The team plans to test the same children again in a future study, to see if they have retained their tolerance over a period of years.
Researchers also strongly advised against trying this at home, since people can develop fatal reactions.
For now, it is probably a good idea to hold on to the epinephrine injector. But in the future, it may be the sort of treatment people could get from their local doctor.