In the first human study of its kind, scientists at the Institute of Food Research found that probiotics can modify the immune system’s response to grass pollen, a common cause of seasonal hay fever.
Taking a daily probiotic "changed the way" the body responded to pollen.
"This was a pilot study based on small numbers of patients, but we were fascinated to discover a response," says research leader Professor Claudio Nicoletti. "The probiotic significantly reduced the production of molecules associated with allergy."
Hay fever is an allergic reaction to pollen or fungal spores, most commonly grass pollen. The immune system mistakes the spores for harmful invaders and produces excessive amounts of the antibody IgE to bind to them and fight them off. IgE stimulates the release of histamine, which produces the symptoms of hay fever.
In this study, volunteers with a history of seasonal hay fever drank a daily milk drink with or without live bacteria (Lactobacillus casei) over 5 months.
Blood samples were taken before the grass pollen season, then again when it was at its peak, and 4 weeks after the end of season. There were no significant differences in levels of IgE between the two groups at the start of the study, but IgE levels were lower in the probiotic group both at the peak season and afterwards. At the same times, levels of an antibody thought to play a protective role against allergic reactions were higher.
"The probiotic strain we tested changed the way the body’s immune cells respond to grass pollen, restoring a more balanced immune response," says Dr Kamal Ivory, a senior member of the research group.
Source: Institute of Food Research, June 3, 2008
