Conclusion : Based on the available data and taking into account the safety profile of RCTs , probiotic consumption appears to be a feasible way to decrease the incidence of RTIs in children
Background : Respiratory tract infections ( RTIs ) represent one of the main health problems in children .
Probiotics are viable bacteria that colonize the intestine and affect the host intestinal microbial balance .
Accumulating evidence suggests that probiotic consumption may decrease the incidence of or modify RTIs .
The authors systematic ally review ed data from r and omized controlled trials ( RCTs ) to investigate the effect of probiotic consumption on  RTIs in children .
Effects of Consumption of a Fermented Dairy Product Containing the Probiotic Lactobacillus casei DN-114 001 on Common Respiratory and Gastrointestinal Infections in Shift Workers in a Randomized Controlled Trial
Objective : The risk of infection may be increased in people under stress such as shift workers . This study examined the effect of a fermented dairy product containing the probiotic Lactobacillus casei DN-114 001 ( verum ) on the incidence of respiratory and gastrointestinal common infectious diseases ( CIDs ) and on immune functions in healthy shift workers . Methods : The study was single-center , r and omized , double-blind , and controlled . Volunteers  received 200 g/day of verum ( n = 500 ) or control product ( n = 500 ) for 3 months ; 1-month follow-up was carried out . Results : The cumulated number of CIDs ( primary outcome ) was not significantly different between groups . Because the Poisson distribution of the primary parameter did not fully fit the observed data , a post hoc categorical analysis was applied and showed a significantly lower cumulated number of CIDs in the verum group during the product consumption phase ( odds ratio [ OR ] = 0.75 , 95 % confidence interval [ CI ] 0.59–0.95 , p = 0.017 ) . Verum also reduced the proportion of volunteers experiencing at least 1 CID ( 43 % vs. 51 % , p = 0.005 ) , increased the time to the first occurrence of CID ( p = 0.017 ) in the whole population , and reduced the cumulated number of CIDs in the subgroup of smokers ( p = 0.033 ) . In the course of CID , cumulated duration of fever was lower in the verum group ( in the whole study phase ) ( p = 0.022 ) , and an increase in leukocyte , neutrophil , and natural killer ( NK ) cell counts and activity ( p = 0.047 to p < 0.001 ) was observed compared with control group . Verum was safe and well tolerated . Conclusion : The results indicate that daily consumption of a fermented dairy product containing Lactobacillus casei DN-114 001 could reduce the risk of common infections in stressed individuals such as shift workers
Conclusion : Based on the available data and taking into account the safety profile of RCTs , probiotic consumption appears to be a feasible way to decrease the incidence of RTIs in children
Background : Respiratory tract infections ( RTIs ) represent one of the main health problems in children .
Probiotics are viable bacteria that colonize the intestine and affect the host intestinal microbial balance .
Accumulating evidence suggests that probiotic consumption may decrease the incidence of or modify RTIs .
The authors systematic ally review ed data from r and omized controlled trials ( RCTs ) to investigate the effect of probiotic consumption on  RTIs in children .