Researchers at the Institute of Food Research in Norwich, have just published a study(1) indicating that probiotics (‘good’ bacteria) may help to keep hay fever symptoms at bay.

The researchers of this small study wanted to investigate whether the ‘good bacteria’ Lactobacillus casei Shirota (found in many probiotic supplements, yoghurts and drinks) played a role in modulating the symptoms of hay fever (seasonal allergic rhinitis).  Hay fever sufferers were given a milky drink, with or without the good bacteria, each day for five months.  The scientists kept track of, and compared the changes in, the immune system of the participants by collecting blood samples before, during and after grass pollen season.  

It was found that the probiotic being tested changed the way the body's immune cells responded to grass pollen.  The hay fever sufferers that had been drinking the probiotic containing drink had lower levels of the chemicals (interleukin 5 and 6 and interferon-gamma) partly responsible for the production of hay fever symptoms in the body.  They also had higher levels of specific antibodies (immunoglobulin G and E) which are associated with playing a protective role in allergy reactions.

The authors of the study conclude that “These data show that probiotic supplementation modulates immune responses in allergic rhinitis and may have the potential to alleviate the severity of symptoms.”

This was only a small study and the authors plan to do further work to further elucidate the role that probiotic ‘good’ bacteria may play in changing the immune status of hay fever sufferers.  As I mentioned in my post dated 19th May the good/friendly bacteria in our digestive system have been linked to positively enhancing the action of our immune system through their production of a variety of substances.  This study adds to the growing body of evidence which suggests that the bacteria in our digestive systems may be very important in affecting our overall health.

(1) Ivory K et al.  2008.  Oral delivery of Lactobacillus casei Shirota modifies allergen-induced immune responses in allergic rhinitis. Clin Exp Allergy. 2008 May 28. [Epub ahead of print]

Written by Ani Kowal