title: Specific probiotics alleviate allergic rhinitis during the birch pollen season.
abstract: OBJECTIVE
  To investigate whether birch pollen allergy symptoms are linked with gut microbiota changes and whether probiotics have an effect on these.
  
  
  METHODS
  Forty seven children with confirmed birch pollen allergy were randomized to receive either a probiotic combination of Lactobacillus acidophilus (L. acidophilus) NCFM (ATCC 700396) and Bifidobacterium lactis (B. lactis) Bl-04 (ATCC SD5219) or placebo in a double-blind manner for 4 mo, starting prior to onset of the birch pollen season. Symptoms were recorded in a diary. Blood samples were taken for analysis of cytokines and eosinophils. Fecal samples were analysed for microbiota components, calprotectin and IgA. Nasal swabs were taken for analysis of eosinophils.
  
  
  RESULTS
  The pollen season induced a reduction in Bifidobacterium, Clostridium and Bacteroides which could not be prevented by the probiotic intervention. During the intervention, significantly higher numbers of B. lactis 11.2 x 10(7) +/- 4.2 x 10(7) vs 0.1 x 10(7) +/- 0.1 x 10(7) bacteria/g feces (P < 0.0001) and L. acidophilus NCFM 3.5 x 10(6) +/- 1.3 x 10(6) vs 0.2 x 10(6) +/- 0.1 x 10(6) bacteria/g feces (P < 0.0001) were observed in the probiotic group compared to the placebo group. During May, there was a tendency for fewer subjects, (76.2% vs 95.2%, P = 0.078) to report runny nose, while during June, fewer subjects, 11.1% vs 33.3%, reported nasal blocking in the probiotics group (P = 0.101). Concomitantly, fewer subjects in the probiotic group had infiltration of eosinophils in the nasal mucosa compared to the placebo group, 57.1% vs 95% (P = 0.013). Eye symptoms tended to be slightly more frequent in the probiotic group, 12.5 d [interquartile range (IQR) 6-18] vs 7.5 d (IQR 0-11.5) (P = 0.066) during May. Fecal IgA was increased in the placebo group during the pollen season; this increase was prevented by the probiotics (P = 0.028).
  
  
  CONCLUSIONS
  Birch pollen allergy was shown to be associated with changes in fecal microbiota composition. The specific combination of probiotics used was shown to prevent the pollen-induced infiltration of eosinophils into the nasal mucosa, and indicated a trend for reduced nasal symptoms.
authors: Health & Nutrition, Danisco Finland, 02460 Kantvik, Finland. arthur.ouwehand@danisco.com
authors: Arthur C
authors: AC
authors: Ouwehand
authors: Merja
authors: M
authors: Nermes
authors: Maria Carmen
authors: MC
authors: Collado
authors: Nina
authors: N
authors: Rautonen
authors: Seppo
authors: S
authors: Salminen
authors: Erika
authors: E
authors: Isolauri
mesh_terms: D000293:Adolescent; D000485:Allergens / Q000276:immunology; D029662:Betula / Q000276:immunology*; D001644:Bifidobacterium / Q000235:genetics / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000097:blood / Q000276:immunology; D004311:Double-Blind Method; D004804:Eosinophils / Q000276:immunology; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D007779:Lactobacillus acidophilus / Q000235:genetics / Q000276:immunology; D008297:Male; D010919:Placebos; D011058:Pollen / Q000276:immunology*; D019936:Probiotics / Q000627:therapeutic use*; D006255:Rhinitis, Allergic, Seasonal / Q000188:drug therapy* / Q000276:immunology / Q000382:microbiology; D012621:Seasons
chemical_list: D000485:Allergens; D016207:Cytokines; D010919:Placebos