Summary
What are probiotics? Probiotics are viable (living or hibernating) bacteria and/or yeasts that confer a health benefit. Probiotics are sold as cultured foods and beverages, such as yogurts and kefirs, as well as in capsules, tablets, and powders.
What are the health benefits of probiotics? Certain probiotic strains may be helpful for constipation, bloating, diarrhea and irritable bowel syndrome, while others may be helpful for throat and respiratory infections, and other uses.
What are the best probiotic supplements? We suggest that you check our Results table to find identify products "Approved" for quality in our testing. Then consider the following:
- Choose a product that contains the type(s) and amounts of probiotic organism(s) shown to work for your condition. See the "What They Do" section and then check the Results table for products that contain that/those organism(s).
- See our Top Picks for some of the most common uses of probiotics.
- Be aware that there can be huge variation in the number of viable cells (CFUs) from product to product. Among products tested, this ranged from just 100 million to hundreds of billion! Typically, an adult probiotic should provide at least 1 billion cells daily — although, as discussed in the "What They Do" section, some probiotics have been shown to work at a lower dose.
- Caution: If you have a milk allergy, be aware that trace amounts of milk proteins may occur in some probiotics (see Concerns and Cautions).
What are prebiotics and postbiotics? Prebiotics promote the growth of probiotic bacteria and may be beneficial for irritable bowel syndrome, constipation, blood sugar control, lowering cholesterol, and other conditions, although in some cases, results are mixed (see All About Prebiotics). Postbiotics include heat-killed probiotics as well as the byproducts of fermentation carried out by probiotic organisms. These may be beneficial for diarrhea, Crohn's disease, irritable bowel syndrome, weight loss, and preventing common colds (see All About Postbiotics).
