Allergy season is upon us again, sending many of us rushing to the drugstore for anti-histamines to deal with the symptoms. But researchers believe that there may be another way to relieve the symptoms of seasonal allergies: probiotics.
Probably most commonly known for being present in yogurt and other fermented foods, probiotics are living microorganisms that are generally believed to have gastrointestinal benefits(1). But research on the benefits of probiotics is thin due to their status as a supplement, rather than as a drug. With this in mind, several researchers conducted a systematic review – published in the journal International Forum of Allergy and Rhinology – of existing medical literature and studies on the subject of probiotics and allergies.
Reviewing The Evidence
The topic of probiotics as a potential treatment for allergies is ripe for future research, according to lead study author Justin Turner, an assistant professor of Otolaryngology. Of the 23 studies that were reviewed, 17 showed that probiotics were linked to improvement in at least one facet of a patient’s health.
“When you look at all the studies combined, there was a statistically significant improvement in both the rhinitis-specific quality of life of those patients and in their nasal specific quality of life,” he said(2).
However, not all the studies they reviewed came to consistent conclusions.
“Six studies did not show any benefit at all, so it’s hard to make any firm conclusions about that,” said Turner. “We also found that the studies were very variable so they used a lot of different bacterial strains and treatment durations.”
In other words, while the results are promising, the jury’s still out.
“Probiotics may be beneficial in improving symptoms and quality of life in patients with allergic rhinitis; however, current evidence remains limited due to study heterogeneity and variable outcome measures. Additional high-quality studies are needed to establish appropriate recommendations,” the study concludes(3).
A Widespread Problem
Many people – especially those who don’t experience the symptoms – dismiss seasonal allergies as a harmless condition, since they tend to not be life-threatening. But seasonal allergies affect enough people that doctors, researchers and pharmaceutical companies all have a vested interest in figuring out how best to address these conditions.
While there are many possible treatments for seasonal allergies, not all are created equal. According to a 2008 review of treatments:
“Placebo-controlled trials show that sodium cromoglicate relieves symptoms, especially if it is used before symptoms appear. Adverse effects are rare with sodium cromoglicate nasal solutions and eye drops. Nasal steroids have well-documented efficacy… adverse effects include epistaxis, nasal irritation, and occasionally, systemic disorders. Oral antihistamines are less effective than nasal steroids. They also provoke adverse effects, especially drowsiness.”(4)
In other words, side-effect-free treatments for seasonal allergies are rare, and the most effective treatments for seasonal allergies to date can carry significant adverse effects.
Probiotics offer the potential for a therapeutic approach that doesn’t have the drawbacks of steroids or over the counter anti-histamine medication. But the science has a ways to go yet before researchers can be sure of their efficacy.
Nonetheless, scientists are excited about the possibilities presented by this new research.