title: Clinical efficacy of probiotic Bifidobacterium longum for the treatment of symptoms of Japanese cedar pollen allergy in subjects evaluated in an environmental exposure unit.
abstract: BACKGROUND
  Japanese cedar pollinosis (JCPsis) affects nearly one in six Japanese. Oral administration of Bifidobacterium longum BB536 has been shown to be effective in relieving JCPsis symptoms during the pollen season.
  
  
  METHODS
  This double- two-way crossover study was designed to evaluate the efficacy of BB536 on reducing symptoms in JCPsis patients exposed to Japanese cedar pollen (JCP) in an environmental exposure unit (EEU) outside of the normal JCP season. After a 1-week run-in period, subjects (n=24) were randomly allocated to receive BB536 powder (approximately 5x1010) or placebo twice a day for 4 weeks. After a 2-week washout period, subjects were crossed over to another 4 weeks of intake. At the end of each intake period, subjects received controlled JCP exposure for 4 hours in the EEU. Symptoms were self-rated 30 minutes before and every 30 minutes during the exposures. From the first day of exposure through the next 5 successive days, participants self-rated their delayed symptoms and medication uses. Blood samples were taken before the exposures. The mean JCP levels for exposures were 6500 to 7000 grains/m3 air.
  
  
  RESULTS
  In comparison with placebo, BB536 intake significantly reduced the ocular symptom scores during JCP exposures. Evaluating delayed symptoms after exposures indicated that scores for disruption of normal activities were significantly lower in the BB536 group compared with the placebo group. Prevalence of medication use was markedly reduced by BB536 intake.
  
  
  CONCLUSIONS
  These results suggest the potential beneficial effect of BB536 in relieving symptoms of JCP allergy.
authors.affiliation: Food Research and Development Laboratory, Morinaga Milk Industry Co., Ltd., Kanagawa, Japan. j_xiao@morinagamilk.co.jp
authors.forename: Jin-zhong
authors.initials: JZ
authors.lastname: Xiao
authors.forename: Shizuki
authors.initials: S
authors.lastname: Kondo
authors.forename: Naotake
authors.initials: N
authors.lastname: Yanagisawa
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Miyaji
authors.forename: Keisuke
authors.initials: K
authors.lastname: Enomoto
authors.forename: Takema
authors.initials: T
authors.lastname: Sakoda
authors.forename: Keiji
authors.initials: K
authors.lastname: Iwatsuki
authors.forename: Tadao
authors.initials: T
authors.lastname: Enomoto
mesh_terms: D000328:Adult; D044466:Asian People; D001644:Bifidobacterium / Q000276:immunology*; D018592:Cross-Over Studies; D032485:Cryptomeria / Q000276:immunology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000517:prevention & control*; D008297:Male; D011058:Pollen / Q000276:immunology; D019936:Probiotics / Q000627:therapeutic use*