March Health Genie: The Story of Probiotics


Note: These articles are not meant as a substitute for proper medical advice. Please consult with your medical practitioner before using any type of remedy, herbal or otherwise.

Whether it’s after a regimen of antibiotics, for digestive support, or aiding in immunity, many people seek a quality probiotic.  A common question that arises during the process of one’s decision to buy a probiotic is why are some products refrigerated and others not?  We covered this topic briefly a few years ago, but here is some additional information.

First, a little bit of background: Probiotics are cultures of beneficial bacteria (and can also include cultures of fungi or yeast) that match or are similar to the cultures that are normally found in the human intestines.  These microorganisms are naturally occurring in many food items such as unpasteurized milk products, cultured yogurts, kefir, kombucha, sauerkraut, kimchi, and many other fermented products.  Since the modern diet doesn’t include enough naturally occurring probiotics and the average person is exposed to many antibiotics and chemicals (like chlorine) that kill these beneficial organisms, many healthcare practitioners and consumers are turning toward probiotic supplementation. 

Most probiotic products are measured in CFU (colony forming units) (usually measured in the millions or billions) and will include a variety of different probiotic strains- such as Lactobacillus acidophilus or Saccharomyces boulardii.   Most quality probiotic companies will guarantee their advertised CFU count at the date of expiration (assuming you keep the probiotic away from heat and light).  Even at ideal storage conditions, CFU will naturally decline over time.  In order for probiotic companies to make a CFU claim at expiration, they will add in extra CFU’s and so the product will actually have a higher CFU count than the label states when the bottle is first opened.

Probiotic supplementation is usually aimed at a specific target: the lower gastrointestinal (GI) tract.  When taking a probiotic, you want to make sure that the probiotic you are taking is going to first make it through your digestive process unharmed and then be able to reproduce and live in your GI tract.  The success of these two things is what is going to help give you the results you are looking for.  So a good probiotic company will try and present a probiotic that is able to do those two things: survive & reproduce. 

The two main hindrances to the survival of probiotics are heat and moisture.  Although the bacteria are alive in the capsule, they are “dormant” meaning they are not feeding and reproducing.  Heat will kill the bacteria while moisture “activates” them.  Once activated, they will quickly die if they do not receive any nourishment (aka food that would be found in your intestines).  The whole idea behind probiotics is that they are alive and dormant in the capsule and then once they reach the GI tract, the capsule is opened and the bacteria activates. The GI tract provides the ideal temperature, moisture, and nutrition for these bacteria to live and thrive- if they can make it there alive.   

So, moisture in the GI tract= good, moisture before the GI tract= bad.   Since colder refrigerated air holds less moisture, and therefore keeps the bacteria dormant, it is the easiest way to ensure the survival of the bacterial strains.  However, there are ways to keep these bacteria alive at room temperature.   First, many probiotic companies freeze dry their shelf stable probiotics.  This sucks out all the moisture and stabilizes the strains in their inactive state (but allows for activation in the GI tract).  Some companies will put their shelf stable probiotics in blister packs (the individual “push outs”) which seals out moisture for each individual capsule.  Other companies that decide to opt out of the blister packs will instead put in a freshness packet or cotton ball to absorb excess moisture. 

So, in summary, the stability of a probiotic formula will depend on temperature, humidity, and packaging.  Heat and moisture will decrease the efficacy of probiotic supplement.   Since shelf stable probiotics are exposed to more heat and moisture than the refrigerated varieties, most companies take extra steps, like freeze drying the bacteria, packaging in blister packs, and adding moisture absorbers to ensure the active CFU count.  Following the instructions on the bottle will help ensure the survival and viability of the probiotic.  If you are going to take the time and make the investment in a probiotic, it’s worth knowing the difference between the products and how to get the most out of each capsule.

The Health Genie

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