I was recently involved with a study that examined labels of probiotic dietary supplement products sold in retail outlets. In short, the label of every probiotic supplement in four retail stores in the Washington DC area was scrutinized. The perspective taken was two-pronged. First, evaluate the label from a consumer’s perspective. What can a consumer glean from the label? No effort was made to source the company website for further information, as we felt a consumer at point-of-sale was unlikely to do this. Second, two probiotic experts – Daniel Merenstein MD and I – took the information that we could glean from the label and determined if it was sufficient to link the product to any human efficacy study showing benefit. The paper is published here.
A total of 93 products were reviewed; 42 of those did not indicate strain designations on the label. If strain designations were not present, we assumed each product was different. Further, we could not determine if any evidence existed for any product without strain designations.
Fifty-one of 93 products indicated a total count (CFU) through the end of shelf life; others were labeled with count at time of manufacture. This isn’t very useful information for the consumer who isn’t taking the product at time of manufacture.
Based on strains indicated on the label, but without considering dose, we judged that 67 were unique formulations.
We found we could link 33 of the 93 products to at least one study in humans that showed efficacy.
Products with a greater number of strains, higher dose, or greater cost/dose were not more likely to be linked to evidence of efficacy. Consumers may believe that a product with more strains or a higher dose is a better product, but our survey does not support this assumption.
This survey was not designed to be a statistically valid assessment of probiotic products. Rather it was intended to give a snapshot of what a consumer might encounter when going to the store to buy a probiotic. Our results suggest that too often probiotic product labels do not provide essential information on contents. At a minimum, probiotic product labels should disclose traceable strain designations for all strains used in a product and provide the viable count of the product through the end of shelf life. Further, for products that are designed around one or a few ‘anchor’ strains (i.e., strains with strong substantiation data), viable count of those anchor strains through the end of shelf life should be provided.
No products displayed quality seals issued by a legitimate third-party certification authority (e.g., USP) that assures consumers that the product label is accurate. See here for an open-access paper describing the value and process of third party verification of probiotic products.
Georgetown University press release on this topic