Pathogen-Specific Effects of Probiotics in Children with Acute Gastroenteritis Seeking Emergency Care: A Randomized Trial.

BACKGROUND It is unknown if probiotics exert pathogen-specific effects in children with diarrhea secondary to acute gastroenteritis. METHODS Analysis of patient-level data from two multi-center randomized, placebo controlled, trials conducted in pediatric emergency departments in Canada and the U.S.. Participants were 3-48 months with >3 diarrheal episodes in the preceding 24 hours, and were symptomatic for <72 hours and <7 days in the Canadian and U.S. studies, respectively. Participants received either placebo or probiotic preparation (Canada-Lactobacillus rhamnosus R0011/L. helveticus R0052; U.S.-L. rhamnosus GG). The primary outcome was post-intervention moderate-to-severe disease [i.e. ≥9 on the Modified Vesikari Scale (MVS)]. RESULTS Pathogens were identified in specimens from 59.3% (928/1565) children. No pathogen groups were less likely to experience an MVS ≥9 based on treatment allocation (test for interaction=0.35). No differences between groups were identified for adenovirus (aRR: 1.42; 95%CI: 0.62, 3.23), norovirus (aRR: 0.98; 95%CI: 0.56, 1.74), rotavirus (aRR: 0.86; 95%CI: 0.43, 1.71) or bacteria (aRR: 1.19; 95%CI: 0.41, 3.43). At pathogen-group and among individual pathogens there were no differences in diarrhea duration or the total number of diarrheal stools between treatment groups, regardless of intervention allocation or among probiotic sub-groups. Among adenovirus-infected children, those administered the Lactobacillus rhamnosus R0011/L. helveticus R0052 product experienced fewer diarrheal episodes (aRR: 0.65; 95%CI: 0.47 to 0.90). CONCLUSIONS Neither probiotic product resulted in less severe disease compared to placebo across a range of the most common etiologic pathogens. Clarifying the etiology of diarrhea among those without pathogens identified is warranted.