What is a probiotic?
Probiotics are commonly defined as live microorganisms which when administered in adequate amounts confer a health benefit on the host. The second part is important, they must confer a health benefit.
Researchers have studied probiotics for digestive disorders such as diarrhea caused by infections, antibiotic-associated diarrhea, irritable bowel syndrome, and inflammatory bowel disease and other conditions. However, in the United States probiotics are legally ‘dietary supplements’, this means that unlike “drug products that must be proven safe and effective for their intended use before marketing, there are no provisions in the law for FDA to ‘approve’ dietary supplements for safety or effectiveness before they reach the consumer” (1). In short, they may have no benefits. What we hear about probiotics is mostly through second-hand news reports of clinical studies. These studies are of varying size and often insufficient quality but are often believed to be established fact. Since the manufacturers don’t put the claims made by these studies on the label, no law has been broken.
If the government is not here to help – how do I evaluate probiotics?
You should always consult a physician if you have an active health condition that requires treatment. Probiotics may or may not have a role in the condition you are suffering from. You should discuss your own research with your doctor. Here is a good resource, the US Probiotics Guide. The tables are organized by condition (indication), age/gender, and brand name. Apps for iPhone and Android are available. What this site does is match probiotics with the evidence, however incomplete. This is the best we have right now.
What are some quality issues probiotics may have?
One concern is that the probiotics you take may contain mostly nonviable bacteria, ‘nonviable’ being a euphemism for dead. Indeed, a recent analysis revealed that about half of the products (16 of 37) recorded total viable bacteria amounts that were more than 50% off their label claims. Two of those products deviated from their total viable bacteria claims by more than 100%.
Health Canada leading the way
Health Canada has established a category of “Natural Health Products”. Unlike US FDA’s “Dietary Supplements”, probiotics licensed under the Canadian “Natural Health Products” category must submit evidence supporting the product’s efficacy, safety and quality. Specific claims that go beyond the ones listed in the Probiotics Monograph, such as for the relief of Irritable Bowel Syndrome (IBS) symptoms, must be specifically supported by clinical studies. You can search for licensed natural health products using Health Canada’s Licensed Natural Health Products Database.
Note: The FDA has a category called “Medical Foods” which is not comparable to the Canadian “Natural Health Products”.
See the slides for the talk “Women’s Health and Probiotics – What You Need To Know” at the Women’s Network of SLO on 10/18/2017: Probiotics Talk – Slides