Effect of Lactobacillus paracasei ST11 on a nasal provocation test with grass pollen in allergic rhinitis

Cite this as: J. Wassenberg, S. Nutten, R. Audran, N. Barbier, V. Aubert, J. Moulin, A. Mercenier and F. Spertini, Clinical & Experimental Allergy, 2011 (41) 565–573. Summary Background Probiotics have been associated with prevention and improvement of symptoms in atopic diseases such as atopic dermatitis. However, few studies exist that document their efficacy for upper airways allergies such as allergic rhinitis. Objective To investigate the effect of short‐term oral administration of Lactobacillus paracasei ST11 on a nasal provocation test (NPT) with grass pollen. Methods Thirty‐one adult volunteers with allergic rhinitis were enrolled in a randomized, double‐blind, placebo‐controlled study, based on two 4‐week cross‐over periods of product consumption (ST11‐fermented milk vs. placebo), separated by a wash‐out period of 6–8 weeks. Objective and subjective clinical parameters of NPT as well as systemic and nasal immunological parameters were compared between the two treatment periods (registration number: NCT 011 50 253). Results Subjects that received ST11‐fermented milk had lower nasal congestion than subjects under placebo (visual analogical scale; P