What Matters

What Matters: Probiotics for colds


 

References

In the midst of the cold and flu season, we should reflect on the fact that our patients are laying down billions of dollars annually on preventions and cures for respiratory tract infections.

An aside: I am frequently turned down on my offer of the influenza vaccine, for which we probably have the best evidence. But $60 per month for a completely unproven preventive/curative agent made in some random factory in some random foreign land with no guarantee of good manufacturing practices (never mind the lack of active ingredients)? Stores can’t keep it in stock.

But I digress.

Our patients may lack the awareness of where to access evidence-based information when seeking answers about efficacy for cold remedies. So, it’s up to us to have at least some sense of where to get reliable information.

Truth be told, I am an enormous fan of safe and effective nonmedication therapies for the treatment and prevention of disease. So, when time permits, I will do a quick PubMed.gov search limiting my articles to randomized trials or systematic reviews on the latest and greatest home remedy.

Probiotics have been around for a while, and I think of them as a cure in search of a disease. The Cochrane Collaboration conducted a systematic review evaluating probiotics for the prevention of upper respiratory tract infection. In this review, 13 randomized, controlled trials were included (Explore [NY]. 2015 Sep-Oct;11[5]:418-20).

Probiotics were observed to be significantly better than placebo for reducing episodes of upper respiratory tract infection, the mean duration of episodes, antibiotic prescription rates, and cold-related absences. The evidence was of moderate to low quality.

Some may wonder how an ingested probiotic helps the respiratory tract stave off or fight infection. The prevailing theory appears to be that probiotics may function by mobilizing cells from the intestine to immunomodulate respiratory mucosa.

As for what probiotic/organism to prescribe? On this issue, there is a lot of smoke and not a lot of heat.

In general, the product should be encapsulated, and the label should include the genus and species of the strains (e.g., Lactobacillus acidophilus), the number of organisms (e.g., 5 billion), storage conditions (e.g., refrigerated or room temperature), and the shelf life. Pharmacy chain house brands may be cheaper. Gummy and chewable products tend to have 92% fewer beneficial bacteria than standard formulations.

How can we ensure purity?

That is tough, because supplements like probiotics are not regulated by the Food and Drug Administration above and beyond the agency’s trying to ensure good manufacturing practices. However, companies such as LabDoor (which generates revenue through affiliate links) test and grade supplements for label accuracy and purity. Websites like this might be the best place to start.

Dr. Ebbert is professor of medicine, a general internist at the Mayo Clinic in Rochester, Minn., and a diplomate of the American Board of Addiction Medicine. The opinions expressed are those of the author and do not necessarily represent the views and opinions of the Mayo Clinic. The opinions expressed in this article should not be used to diagnose or treat any medical condition nor should they be used as a substitute for medical advice from a qualified, board-certified practicing clinician. Dr. Ebbert has no financial disclosures relevant to this article.

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