Nancy Toedter Williams


Am J Health Syst Pharm. 2010;67(6):449-458. 

In This Article

Dosages and Product Selection

Probiotics are available as supplements (i.e., tablets, capsules, or powders) and as fermented dairy products (i.e., yogurt and milk). Their efficacy relies on their ability to survive passage through the gastrointestinal tract and colonize a tissue section. To prevent destruction by gastric acid and intestinal bile salts, some probiotic preparations may be enteric coated or microencapsulated. For colonization to occur, probiotics must contain living, viable organisms and must be ingested on a regular basis in order to maintain effective concentrations.[57–60] Unfortunately, the manufacturing process may cause living organisms to become nonviable, thus reducing probiotic effectiveness.[32] The quantity, quality, and purity of the bacteria or yeast in probiotics can vary among products due to the complexity of quality control with live microorganisms and the lack of universal quality-assurance programs.[13,38,57] One study analyzed 18 commercially available probiotic products available in the United States and found that 7 (39%) had differences between the stated and actual concentrations of bacteria.[61]

Probiotic dosing varies depending on the product and specific indication. No consensus exists about the minimum number of microorganisms that must be ingested to obtain a beneficial effect.[16] Typically, a probiotic should contain several billion microorganisms to increase the likelihood of adequate gut colonization.[28] For lactobacilli, typical doses used in studies ranged from 1–20 billion colony-forming units per day. For S. boulardii, most studies examined daily doses ranging from 250 to 500 mg.[57] Table 2 summarizes dosing for various probiotic strains based on doses found to be efficacious in human studies. Products should be stored according to the manufacturer's recommendations, since some may require refrigeration. In addition, preparations may have a limited shelf life, and many preparations contain several different species, so dosing may vary depending on the product.

Various probiotics are available in the United States; however, only those products that have been evaluated in controlled human studies should be recommended. Some examples of these commercially available preparations include LGG (Culturelle, Amerifit Brands, Fairfield, NJ), S. boulardii (Florastor, Biocodex, Inc., Beauvais, France), B. infantis 35624 (Align, JB Laboratories, Holland, MI), and VSL#3.[62] Yogurt products fermented with probiotics should be labeled with a "Live and Active Cultures" seal, specifying that the preparation contains a minimum of 100 million viable bacteria per gram at the time of manufacture. An example is Activia yogurt (Dannon/Danone, Paris, France), which contains B. animalis DN-173 010, marketed by Dannon/Danone as "Bifidus regularis."[57,62,63]


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.