The British Nutrition Foundation reviewed the effect of probiotics on health.

Good evidence

  • Probiotics prevent antibiotic-associated diarrhea.

Only few studies

  • Probiotics might prevent potentially fatal Clostridium difficile-associated diarrhea.

Limited number of studies

  • Probiotics show conflicting results in people with constipation, with promising results for certain strains.
  • Consuming probiotic strains reduces irritable bowel syndrome symptoms, although there is a  high placebo effect.

The bottom line?

It’s a relatively new field of research. Over time, many of the issues will be resolved.

5/22/10 12:31 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.