In this Article

• Introduction to probiotics
• What is important to know about probiotics?
• What are probiotics, and which foods contain probiotics?
• What are the health benefits of probiotics?
• Do probiotics actually work?
• What are the side effects and risks of probiotics?
• Is there anything to take into consideration when taking probiotics?
• What research is being done on probiotics?
• Where can a person get more information about probiotics?
• Probiotics Index

What the science says

Scientific understanding of probiotics and their potential for preventing and treating health conditions is at an early stage, but moving ahead. In November 2005, a conference that was cofunded by the National Center for Complementary and Alternative Medicine (NCCAM) and convened by the American Society for Microbiology explored this topic.

According to the conference report, some uses of probiotics for which there is some encouraging evidence from the study of specific probiotic formulations are as follows:

• To treat diarrhea (this is the strongest area of evidence, especially for diarrhea from rotavirus)



• To prevent and treat infections of the urinary tract or female genital tract



• To treat irritable bowel syndrome



• To reduce recurrence of bladder cancer



• To shorten how long an intestinal infection lasts that is caused by a bacterium called Clostridium difficile



• To prevent and treat pouchitis (a condition that can follow surgery to remove the colon)



• To prevent and manage atopic dermatitis (eczema) in children

The conference panel also noted that in studies of probiotics as cures, any beneficial effect was usually low; a strong placebo effect often occurs; and more research (especially in the form of large, carefully designed clinical trials) is needed in order to draw firmer conclusions.

Some other areas of interest to researchers on probiotics are

• What is going on at the molecular level with the bacteria themselves and how they may interact with the body (such as the gut and its bacteria) to prevent and treat diseases. Advances in technology and medicine are making it possible to study these areas much better than in the past.



• Issues of quality. For example, what happens when probiotic bacteria are treated or are added to foods—is their ability to survive, grow, and have a therapeutic effect altered?



• The best ways to administer probiotics for therapeutic purposes, as well as the best doses and schedules.



• Probiotics' potential to help with the problem of antibiotic-resistant bacteria in the gut.



• Whether they can prevent unfriendly bacteria from getting through the skin or mucous membranes and traveling through the body (e.g., which can happen with burns, shock, trauma, or suppressed immunity).