Clinical efficacy of probiotic Bifidobacterium longum for the treatment of symptoms of Japanese cedar pollen allergy in subjects evaluated in an environmental exposure unit.

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.

「環境曝露ユニットで評価された被験者におけるスギ花粉症症状の治療に対するプロバイオティクスBifidobacterium longumの臨床効果」

背景:スギ花粉症(JCPsis)は、ほぼ6人に1人の日本人に影響を与える。Bifidobacterium longum BB536の経口投与は、花粉の季節にJCPsis症状を緩和するのに有効であることが示されている。

方法:この二重双方向クロスオーバー試験は、通常のJCPの季節以外の時期に環境曝露ユニット(EEU)でスギ花粉(JCP)に曝露されたJCPsis患者の症状軽減に対するBB536の有効性を評価するために設計された。1週間のラン・イン期間の後、被験者(n=24)を、1日2回4週間のBB536粉末(約5×1010)またはプラセボ摂取に無作為に割り付けた。2週間のウォッシュアウト期間後、被験者は、内容をクロスオーバーしてさらに4週間の摂取を行った。各摂取期間の終了時、被験者はEEU内で管理されたJCP曝露を4時間受けた。症状は、曝露の30分前、および曝露中30分毎に自己評価した。暴露初日から連続5日間、参加者は遅延症状と薬物治療の利用を自己評価した。血液試料は曝露前に採取した。曝露に用いた平均JCPレベルは、6500~7000 粒/m3 空気であった。