Probiotics and Prebiotics in Dietetics Practice

Journal of the American Dietetic Association
Volume 108, Issue 3, March 2008, Pages 510-521 Copyright © 2008 American Dietetic Association Published by Elsevier Inc.
Linda C. Douglas PhD, RD and Mary E. Sanders PhD

Probiotics and prebiotics share a unique role in human nutrition, largely centering on manipulation of populations or activities of the bacteria that colonize our bodies. Benefits of regular consumption of probiotics or prebiotics include enhanced immune function, improved colonic integrity, decreased incidence and duration of intestinal infections, down-regulated allergic response, and improved digestion and elimination. Research has shown that probiotics and prebiotics may be useful in achieving these and other positive effects, provided that proper strain, product selection, and dosing guidelines of commercial products are followed.

There is a need to consolidate the basic and applied research on probiotics and prebiotics into useful tools for food and nutrition professionals. Information on probiotic species, applications for specific strains, dosages and forms, safety, and shelf life is not sufficiently summarized to allow practical and consistent recommendations to be made by most food and nutrition professionals. In addition, prebiotic fibers—although providing nutraceutical and nutritional value—are a group of diverse carbohydrate ingredients that are poorly understood in regard to their origin, fermentation profiles, and dosages required for health effects. The science and practice-based guidelines presented here will enhance clinician and client understanding of probiotics and prebiotics, with the aim of improving appropriate recommendation and informed use of these emerging dietary ingredients and the products containing them.

Probiotics: sorting the evidence from the myths

Mimi Pham, Daniel A Lemberg and Andrew S Day
MJA 2008; 188: 304–308


  • Probiotics consist of yeast or bacteria, especially lactic acid bacteria. They are available as capsules, powder, fermented milks or yoghurts.
  • Probiotics exhibit strain-specific differences in their resistance to acid and bile, ability to colonise the gastrointestinal tract, clinical efficacy, and benefits to the health of the host.
  • There is level I evidence for the use of probiotics in treating acute infectious diarrhoea and preventing antibiotic associated diarrhoea, with Lactobacillus rhamnosus GG and accharomyces boulardii having the most evidence to support their use for these conditions.
  • There is level II evidence that S. boulardii combined with high-dose vancomycin is more effective than the antibiotic alone in preventing recurrent Clostridium difficile diarrhoea.
  • There is level I evidence that probiotics prevent traveller’s diarrhoea.
  • There is level I evidence for use of the high-potency probiotic SL#3 in preventing pouchitis, and level II evidence for this agent in preventing relapse in patients with ulcerative colitis.
  • Probiotics are generally regarded as safe and well tolerated. Some probiotics may be contraindicated in patients who are immuno compromised or have severe underlying illness, as they have been reported to cause fungaemia and bacteraemia.