Probiotics are one of the therapies I frequently discuss here that I suspect may actually have some benefit(1, 2), though the evidence does not currently support routine clinical use. However, as with most herbal remedies, supplements, and nutraceuticals, a lack of meaningful government regulation (3, 4) allows these products to be marketed with no reasonable supporting clinical evidence and despite potential risks and significant problems with quality control (5, 6).
A new study illustrates why even a potentially promising therapy like probiotics is likely to end up as no more than a collection of dubious commercial products without a strong commitment to evidence-based research and development enforced by adequate regulatory oversight.
Weese, JS. Martin H. Assessment of commercial probiotic bacterial contents and label accuracy. Canadian Veterinary Journal 2011;52:43–46.
The authors purchased and evaluated 25 commercial veterinary probiotic products and evaluated both the labels and the contents. A medicine should have a clear label that indicates what the active ingredient is, how much of it is present, when it expires, and other such information that the consumer needs to evaluate the product and use it safely and effectively. Even though there is not yet much clinical research to support the benefits of probiotic therapy, the marketers of such remedies could at least ensure accurate labeling of their products. But that appears to be the exception, not the rule.
Of the 25 products tested, only two had accurate labels that identified the organism (and spelled it correctly) and actually had in the preparation what the labeled claimed was in it. (Interestingly, one of these was Prostora, from the IAMS company, which is also the only veterinary probiotic product for which there is a reasonably good quality clinical trial looking at efficacy. And no, I don’t get any money from them.)
Only 60% of the products indicated on the label how many bacteria they contained in a way that made any sense. Three products used a used names for an organism that doesn’t exist as well as a real name to describe their active ingredient. 32% of the labels spelled the name of the bacteria incorrectly. This may seem like a minor error, but the level of attention to detail required in the manufacture of medicine should be higher than is expected in ordinary activities. How much confidence would you have in an antibiotic, heart medication, or other drug if the manufacturer couldn’t even spell the name of it correctly?
Only 27% of the products had as much or more of the bacteria in them as was claimed on the label. And while there is no established “dose” for probiotic bacteria, since there hasn’t been enough research to determine what this would be, the studies that have been done to test if probiotic bacteria can colonize the intestines after being taken orally have used doses which could not possibly be achieved by most of the products tested in this study.
This study does not directly address the question of whether or not probiotics in general are actually safe and beneficial for clinical use in dogs or cats. But it does highlight that even if they are, most of the veterinary probiotics currently available are inadequately or improperly labeled and do not have meaningful numbers of active bacteria in them anyway. A lack of research evidence combined with a lack of effective regulation, due primarily to the lobbying efforts of the supplement industry, undermine the potential value of these therapies and make confident routine use of the products now on the market nearly impossible.
If the industries that produce and sell these products wish to continue to discourage government interference with their activities, then they should bear the burden of ensuring accuracy in labeling and quality control for their products. And if they truly care about the welfare of our animal companions, rather than only about profit, then they ought to fund the kind of objective, high-quality research that would tell us if these products are of any real value. Some of these companies are doing this, but clearly most are not.