Objectives: To evaluate whether daily administration of Lactobacillus reuteri DSM 17938 reduces the frequency and duration of diarrheal episodes and other health outcomes in day school children in Mexico.

Methods: Healthy children (born at term, aged 6-36 months) attending day care centers were enrolled in this randomized, double-blind, placebo-controlled trial. They received L. reuteri DSM 17938 10⁸ CFUs (n = 168) or identical placebo (n = 168) by mouth, daily for 3 months, after which they were followed-up after a further 3 months without supplementation.

Results: Data from all children were included in the final analysis. L. reuteri DSM 17938 significantly reduced the frequency and duration of episodes of diarrhea and respiratory tract infection at both 3 and 6 months (P < .05). Additionally, the number of doctor visits, antibiotic use, absenteeism from day school and parental absenteeism from work were significantly reduced in the L. reuteri group (P < .05). A cost-benefit analysis revealed significant reductions in costs in the L. reuteri-treated children. No adverse events related to the study product were reported.

Conclusions: In healthy children attending day care centers, daily administration of L. reuteri DSM 17938 had a significant effect in reducing episodes and duration of diarrhea and respiratory tract infection, with consequent cost savings for the community.