Scientists are struggling to prove that the consumption of probiotic foods can help protect people against hayfever.
Research has shown that probiotics in the gut can induce changes in nasal mucus where pollen meets the immune system. But there is no conclusive evidence to suggest they can limit the impact of pollen on hayfever sufferers.
“Many randomised controlled trials have been performed to test the effectiveness of probiotics as a form of treatment in allergic rhinitis (inflammation inside the nose),” said Dr Kamal Ivory, a research scientist at the Institute of Food Research (IFR) working in this field.
Can improve quality of life
“Some have shown that probiotic intake can improve quality of life and decrease the number of episodes of rhinitis per-year in affected patients.”
She added that the changes noted by researchers in a recent study published in the journal Plos One, indicated the potential to alter the course of allergic reactions in the nose.
However, when scientists introduced pollen to the participants’ mucus samples, which was done in an “out of pollen season”, they did not measure a significant change in reaction. “It is not clear if this was because a single challenge failed to replicate occurrence during natural seasonal exposure to pollen in terms of dosage and timing,” said Ivory.
Cocktail of organisms
She suggested it might take a “cocktail” of different probiotic organisms for a positive reaction to take place, which would need to be carried out during the pollen season.
Ivory said more scientific research was needed generally to “secure the future of probiotics as functional food ingredients”.
Meanwhile, the Biotechnology and Biological Sciences Research Council (BBSRC) said hayfever was a complicated condition to assess and mimic in a clinical setting. The BBSRC added that the conditions in a laboratory did not reproduce what happens in nature.