The treatment of infectious diarrhea poses multiple challenges. The causes
of infectious diarrhea are diverse, ranging from bacterial to viral to fung
al, and the types of available treatments are equally diverse. Traditional
therapeutic approaches with antibiotics, changes in diet, and oral rehydrat
ion therapy have been useful, but the need for alternative treatments exist
s. The use of beneficial living organisms or biotherapeutic agents has been
investigated and found safe and effective for various types of infectious
diarrhea and the treatment of Clostridium difficile disease. Although there
are numerous types of microbial preparations available, only a few are bac
ked by large, placebo-controlled clinical trials. The microbial agents with
adequate scientific evidence include Saccharomyces boulardii, Lactobacillu
s rhamnosus GG, and several species of bifidobacteria and lactobacilli. The
scientific evidence for these agents is reviewed and analyzed in this arti
cle.