Use of a fermented dairy probiotic drink containing Lactobacillus casei (DN-114 001) to decrease the rate of illness in kids: the DRINK study A patient-oriented, double-blind, cluster-randomized, placebo-controlled, clinical trial

Background: To evaluate whether a fermented dairy drink containing the probiotic strain Lactobacillus casei DN-114 001 could reduce the incidence of common infectious diseases (CIDs) and the change of behavior because of illness in children. Subjects/Methods: We conducted a double-blinded, randomized, placebo-controlled allocation concealment clinical trial in the Washington, DC metropolitan area. Participants were 638 children 3-6 years old in daycare/schools. The intervention was a fermented dairy drink containing a specific probiotic strain or matching placebo with no live cultures for 90 consecutive days. Two primary outcomes were assessed: incidence of CIDs and change of behavior because of illness (both assessed by parental report). Results: The rate of change of behavior because of illness was similar among active and control groups. However, the incidence rate for CIDs in the active group (0.0782) is 19% lower than that of the control group (0.0986) (incidence rate ratio = 0.81, 95% CI: 0.65, 099) P=0.046. Conclusions: Daily intake of a fermented dairy drink containing the probiotic strain L. casei DN-114 001 showed some promise in reducing overall incidence of illness, but was primarily driven by gastrointestinal infections and there were no differences in change of behavior. European Journal of Clinical Nutrition (2010) 64, 669-677; doi:10.1038/ejcn.2010.65; published online 19 May 2010