Probiotics and zinc in acute infectious gastroenteritis in children: are they effective?

OBJECTIVE: Several studies in recent decades have assessed the effects of different probiotics in acute gastroenteritis, showing that specific strains of Lactobacilli (mainly Lactobacillus casei GG) and Saccharomyces boulardii may exert some beneficial therapeutic actions, mainly when used in rotavirus gastroenteritis, at a high dose, and in the early phase. The mechanisms of action of probiotics are not completely elucidated but seem to involve a complex interaction among epithelial, molecular, metabolic, and immune responses. Data on the prevention of community-acquired, nosocomial, and travelers' diarrhea are currently conflicting. Because each micro-organism has different properties, an accurate selection of the strain, dose, and patient should be cautiously considered. METHODS AND RESULTS: Several reports from developing countries have demonstrated that supplements of zinc also provide significant reduction in stool output and duration, persistency, and severity of diarrhea. In view of the published data and of the different actions of zinc (such as improvement of the immune status, intestinal permeability, epithelial and enzymatic function, and electrolyte transport), the use of zinc as adjunctive therapy to oral rehydration solution has the potential to improve the management of diarrhea and decrease complications in children worldwide. In contrast to probiotics, which most trials in the developed world have used, there has been no trial with zinc performed in developed countries. CONCLUSION: Data on the effect of a combined administration of zinc and probiotics in acute gastroenteritis are urgently needed.