June 4, 2008 -- If springtime's splendor leaves you sniffling,
"good" bacteria may one day provide relief. New research suggests probiotics
can alter the body's immune response to grass pollen -- a common cause of
rhinitis, or hay fever.
The landmark study published in Clinical and Experimental Allergy
suggests that in the future, "good" bacteria, or probiotics, may
potentially offer a treatment option to the estimated 35.9 million people in
the U.S. who have seasonal hay fever.
Probiotics are beneficial bacteria similar to those that naturally occur in
the human gut and help promote a healthy digestive system. Changes in the delicate balance of
intestinal bacteria have been linked to certain allergic disorders, leading
scientists to theorize that probiotics may affect the body's immune system.
For the current study, researchers with the Institute of Food Researchers
randomly assigned 10 volunteers to drink a daily glass of regular milk or milk
containing the probiotic Lactobacillus casei Shirota. Lactobacillus
casei has been widely studied for its health benefits. The volunteers drank
the milk each day and were followed for five months.
The research team took blood samples from each volunteer before, during, and
after grass pollen season, checking for antibody levels of immunoglobulin E
(IgE). If you have hay fever or other allergies, your immune system produces IgE in response to
exposure to pollen. IgE is a key player in allergic reactions.
The blood tests revealed similar levels of IgE between both groups of
volunteers at the start of the study. However, those who drank the probiotic
drink had significantly lower levels of IgE specific for grass pollens and
other allergy-related immune substances at peak season and afterward.
"The probiotic strain we tested changed the way the body's immune cells
respond to grass pollen, restoring a more balanced immune response," Kamal
Ivory of the division of Gastrointestinal Biology and Health at the Institute
of Food Research says in a news release.
"This was a pilot study based on small numbers of patients, but we were
fascinated to discover a response," research leader Claudio Nicoletti says.
"The probiotic significantly reduced the production of molecules associated
However, the researchers admit further studies are needed to determine if
probiotic supplementation results in fewer hay fever symptoms. Phase II of the
study will address that question.