The effect of probiotics on shortening episodes of acute infectious diarrhea has been well-documented. Enterococcus faecium , Streptococcus faecium SF68 and certain lactobacillus strains have proven efficacy. A metaanalysis of previously published randomized, controlled studies of lactobacillus therapy reveals that the duration of diarrhea in hospitalized children is shortened by an average of 0.7 days. Similarly a randomized, placebo-controlled trial in a cohort of nonhospitalized children attending day-care centers also reduced the mean duration of diarrhea. The underlying mechanism by which probiotics produce their clinical effect is likely multifactorial and has led to much speculation. Some theorize that lactobacilli enhance the expression and elaboration of intestinal mucins. These glycoproteins appear to be protective during intestinal infections. However, protective qualities may be overcome by mucinase-producing bacteria. Others hypothesize that rotavirus causes biphasic diarrhea, the first osmotic and the second due to overgrowth of urease-producing bacteria; probiotics prevent bacterial overgrowth.
In studies of the immunomodulating effects of probiotics, 49 children with acute rotavirus diarrhea were randomized to receive Lactobacillus GG (LGG), Lactobacillus casei subsp. rhamnosus ( Lactophilus ) or a combination of Streptococcus thermophilus and Lactobacillus delbruckii (Yalacta). Mean duration of diarrhea was 1.8 days for children in the LGG group, 2.8 in the Lactophilus group and 2.6 in the Yalacta group. Only LGG significantly increased the number of rotavirus-specific IgA-secreting cells and serum IgA level in the convalescent stage. This and similar studies suggest that the humoral immune system is significant in the effect of probiotics. However, enhanced humoral response does not fully explain the clinical effect of probiotics as evidenced by a study comparing the efficacy of heat-inactivated LGG against viable bacteria in the treatment of rotaviral diarrhea. Reduction in the duration of diarrhea was the same for both groups, but significantly fewer infants receiving the heat-inactivated strains had detectable IgA responses.
Pediatr Infect Dis J. 2005;24(3):267-268. © 2005 Lippincott Williams & Wilkins
Cite this: Probiotics and the Treatment of Infectious Diarrhea - Medscape - Mar 01, 2005.