Probiotics and the Treatment of Infectious Diarrhea

Jonathan E. Teitelbaum, MD


Pediatr Infect Dis J. 2005;24(3):267-268. 

In This Article


Research efforts have focused on the various mechanisms by which pathogenic bacteria achieve their detrimental effects. Recently attention has turned to the indigenous nonpathogenic microorganisms and ways in which they benefit the host. This is particularly relevant as microorganisms have developed resistance to antibiotics, thus prompting the need for alternative treatments for gastrointestinal diseases. Probiotics, an emerging alternative therapy popularized in 1908 by Metchnikoff as a link between fermented foods and longevity, are intestinal bacteria that promote health by stimulating optimal mucosal immune responses and by preventing gastrointestinal infections.

Although probiotics are considered benign and without pathologic potential, there are case reports of bacteremia or fungemia, most often in immunocompromised hosts. The Food and Drug Administration has no authority to establish a formal regulatory category for functional foods, including probiotics. There is great variability among products; in some studies, preparations contained no viable bacteria.[1] There is a common, but largely untrue, belief that American yogurts provide probiotic effects; low colony counts of bacteria survive the pasteurization process, and the specific strains of bacteria used in the culturing process have not been shown to be therapeutic.

Some of the best evidence of probiotics efficacy has been in the treatment of diarrheal illnesses. The mechanisms by which probiotics prevent or ameliorate diarrhea are stimulation of the immune system, competition for binding sites on intestinal epithelial cells and elaboration of bacteriocins. Efficacy depends on the type of diarrhea and differs in viral, antibiotic-associated and traveler's diarrhea.