The Research Team for Social Participation and Community Health, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan.
Br J Nutr. 2013 May 28;109(10):1856-65. doi: 10.1017/S0007114512003753. Epub 2012 Sep 5.
Oral intake of Lactobacillus pentosus strain b240 (b240) has been shown to enhance the secretion of salivary secretory IgA in elderly adults. However, its clinical benefits remain to be determined. We tested the hypothesis that b240 exerts a protective effect against the common cold in elderly adults. The design of the present study was a randomised, double-blind, placebo-controlled trial (RCT) with parallel three-group comparison. For this purpose, 300 eligible elderly adults were randomly allocated to one of three groups, namely a placebo, low-dose or high-dose b240 group. Participants in the low-dose and high-dose b240 groups were given tablets containing 2 × 10(9) or 2 × 10(10) cells, respectively, of heat-killed b240, while those in the placebo group were given tablets without b240. Each group consumed their respective tablets once daily for 20 weeks. The common cold was assessed on the basis of a diary. Change in quality of life was evaluated using the SF-36. Of the total participants, 280 completed the 20-week RCT. The accumulated incidence rate of the common cold was 47·3, 34·8 and 29·0 % for the placebo, low-dose b240 and high-dose b240 groups, respectively (P for trend = 0·012). Lower incidence rates were consistently observed throughout the experimental period in the b240 groups (log-rank test, P= 0·034). General health perception, as determined by the SF-36®, dose-dependently increased in the b240 groups ( P <0·025). In conclusion, oral intake of b240 significantly reduced the incidence rate of the common cold in elderly adults, indicating that b240 might be useful in improving resistance against infection through mucosal immunity.
口服植物乳杆菌 b240（b240）已被证明可增强老年人唾液分泌型免疫球蛋白 A 的分泌。然而，其临床获益仍有待确定。我们检验了以下假设，即 b240 可对老年人普通感冒产生保护作用。本研究设计为一项随机、双盲、安慰剂对照试验（RCT），采用平行三组比较。为此，300 名符合条件的老年人被随机分配至安慰剂组、低剂量 b240 组或高剂量 b240 组。低剂量和高剂量 b240 组分别服用含有 2×10(9)或 2×10(10)个已灭活 b240 细胞的片剂，而安慰剂组服用不含 b240 的片剂。每组每日服用各自的片剂一次，共 20 周。感冒通过日记评估。采用 SF-36 评估生活质量的变化。在总计的参与者中，280 人完成了 20 周的 RCT。安慰剂组、低剂量 b240 组和高剂量 b240 组普通感冒的累积发病率分别为 47.3%、34.8%和 29.0%（趋势 P=0.012）。b240 组在整个实验期间感冒发病率持续较低（对数秩检验，P=0.034）。b240 组的一般健康感知（通过 SF-36®评估）呈剂量依赖性增加（P<0.025）。总之，口服 b240 可显著降低老年人普通感冒的发病率，表明 b240 可能通过黏膜免疫提高抗感染能力。
