口服干酪乳杆菌——代田株对军训士兵上呼吸道感染及免疫功能的影响

Effects of oral probiotics supplementation on respiratory infection and body immune function of soldiers in military training

目的观察口服补充干酪乳杆菌-代田株(Lactobacillus caseistrain Shirota,Lc S)对军事训练条件下士兵的炎症水平、上呼吸道感染率及免疫功能的影响。方法于2017年1月招募接受一定强度军事训练的男性士兵志愿者100名,随机分为实验组(n=50)和对照组(n=50),分别口服补充含Lc S的发酵乳饮料和普通牛奶100 ml,每天2次,分别于干预0、2、4个月时调查膳食摄入、上呼吸道感染和胃肠道疾病情况,测定血常规、NK细胞活性、血清炎性因子、免疫指标及唾液Ig A水平。结果共87名受试者完成研究(实验组45人,对照组42人),失访率为13%。干预2个月时,实验组血清lg G(1 268.24±290.81)mg/dl、CD3(0.72±0.07)及CD4(0.38±0.07)水平较对照组[(1 124.53±272.79)mg/dl、(0.66±0.05)、(0.35±0.05)]显著升高(P均<0.05);4个月时,实验组血清lg E(231.14±177.71)mg/dl、lg G(1 243.22±290.58)mg/dl、CD3(0.70±0.05)、CD4(0.41±0.06)、CD4/CD8比值(1.68±0.43)、唾液lg A水平(181.67±39.12)μg/ml、中性粒细胞计数(0.57±0.06)和淋巴细胞计数(0.53±0.08)较对照组[(142.74±112.08)mg/dl、(1 036.23±228.71)mg/dl、(0.65±0.04)、(0.34±0.04)、(1.31±0.32)、(147.38±33.53)μg/ml、(0.53±0.08)、(0.33±0.06)]均显著增高,而血清C反应蛋白(0.31±0.02 vs 0.51±0.25)mg/dl、IL-1水平(9.96±4.44 vs 14.51±6.67)pg/ml以及白细胞计数(5.10±0.35 vs 7.12±0.93)109/L显著降低(P均<0.05);实验组胃肠道疾病发生次数明显低于对照组(2个月时4.45%vs 23.80%,4个月时4.45%vs 21.43%)(P均<0.05),上呼吸道感染发生率有下降趋势,两组无统计学差异(2个月时8.89%vs 11.90%,4个月时8.89%vs 11.90%)(P均>0.05)。结论军事训练条件下士兵长期口服补充干酪乳杆菌-代田株能够降低机体炎症反应,改善免疫功能,对预防上呼吸道感染发生可能有益。

Objective To observe the effects of oral probiotics supplementation （Lactobacilluscasei strain Shirota, LcS） on inflammatory response, upper respiratory-tract infection, and immune function of soldiers in military training. Methods This was a randomized controlled trial. We recruited 100 male volunteers from soldiers in Chinese PLA General Hospital. The volunteers were randomly divided into experimental group （n=50, received 100 ml of fermented milk beverage containing LcS twice a day） and control group （n=50, received 100 ml of ordinary milk twice a day）. The dietary intake, upper respiratory tract infection and gastrointestinal reaction were investigated and the NK cell activity, serum inflammatory factors, and immune indicators and saliva IgA levels were measured at 0, 2 and 4 months, respectively. Results A total of 87 subjects completed the intervention （45 in experimental group and 42 in control group）, with the lost to follow-up rate of 13%. At 2 months, the levels of serum lgG, CD3 and CD4 were significantly higher in the experimental group than those of control group [IgG, （1 268.24 ± 290.81） mg/dl vs （1 124.53 ± 272.79） mg/dl; CD3, （0.72 ±0.07） vs （0.66 ±0.05）; CD4, （0.38 ±0.07） vs （0.35 ± 0.05）; all P 〈 0.05]; At 4 months, the levels of serum lgE, lgG, CD3, CD4, CD4/CD8, saliva lgA, neutrophils and lymphocytes were significantly higher in experimental group than control group [IgE, （231.14 ±177.71）mg/dl vs （142.74 ± 112.08） mg/dl; IgG, （1 243.22 ± 290.58） mg/dl vs （1 036.23± 228.71） mg/dl; CD3, （0.70±0.05） vs （0.65 ± 0.04）; CD4, （0.41 ± 0.06） vs （0.34 ±0.04）; CD4/CD8, （1.68 ± 0.43） vs （1.31 ± 0.32）; saliva lgA, （181.67 ± 39.12） μ g/ml vs （147.38 ± 33.53） μ g/ml; neutrophils, （0.57 ± 0.06） vs （0.53 ± 0.08）; lymphocytes, （0.53 ±0.08） vs （0.33 ± 0.06）; all P 〈 0.05], while serum C-reactive protein, IL-1 level and white blood cell count were significantly lower in experimental group than control group [serum C-reactive protein, （0.31 ± 0.02） mg/dl vs （0.51 ±0.25） mg/dl; IL-1,（9.96 ± 4.44） pg/ml vs （14151 ± 6.67） pg/ml; white blood cell, （5.10 ±0.35）109/L vs （7.12 ± 0.93）109/L; all P 〈 0.05]; The incidence of gastrointestinal disease in experimental group was significantly lower than that of control group （2 months, 4.45% vs 23.80%; 4 months, 4.45% vs21.43%; P 〈 0.05, respectively）; The incidence of upper respiratory tract infection in the two groups showed no significant difference （2 months, 8.89% vs 11.90%; 4 months, 8.89% vs 11.90%; P 〉 0.05, respectively）, but it showed a downward trend. Conclusion Long-term oral LcS supplementation can reduce the inflammatory response and improve the immune function, which may be beneficial to preventing upper respiratory tract infection.