Probiotics and prebiotics: effects on diarrhea.

Probiotics have preventive as well as curative effects on several types of diarrhea of different etiologies. Prevention and therapy (or alleviation) of diarrhea have been successfully investigated for numerous dietary probiotics to establish probiotic properties and to justify health claims (the medicinal use of probiotic food and the therapy of gastrointestinal diseases itself may not be advertised under current food laws). Other probiotic microorganisms (e.g., Lactobacillus rhamnosus GG, L. reuteri, certain strains of L. casei, L. acidophilus, Escherichia coli strain Nissle 1917, and certain bifidobacteria and enterococci (Enterococcus faecium SF68) as well as the probiotic yeast Saccharomyces boulardii have been investigated with regard to their medicinal use, either as single strains or in mixed-culture probiotics. However, the effects on humans have been assessed mainly in smaller (n<100) randomized, controlled clinical studies or in open label trials, but large intervention studies and epidemiological investigations of long-term probiotic effects are largely missing. Perhaps with the exception of nosocomial diarrhea or antibiotic-associated diarrhea, the results of these studies are not yet sufficient to give specific recommendations for the clinical use of probiotics in the treatment of diarrhea.