Yes, those helpful little guys have been put to a new task, and although they did not manage it completely, they did make a difference.
This is the story that 60 people with hayfever were given a probiotic yogurt containing Lactobacillus casei Shirota everyday for 16 weeks and then their hayfever response was measured by “nasal allergen challenge”.
The ingestion of the probiotic did not have a significant effect on the the incidence of hayfever (or induced hayfever in this case). But interesting what it did do, was modify “some parameters of allergic inflammation at the nasal mucosa”. In other words, the interaction of probiotics on the intestinal mucosa had an effect on the nasal mucosa, or drinking the yogurt has a knock on (apparently) beneficial effect on stuff going on in your nose.
The paper is avilable for all to read from the PLOS website.