How to evaluate a probiotic's potency

The gastrointestinal tract is host to countless bacteria, some estimate as many as 100 trillion microbes alone. These have a powerful impact on our health. As the benefits of probiotics are becoming more and more understood, the number of available products has also escalated.

I still always start with the basic principle that diet is critical to promoting overall health and reducing the risk for most chronic diseases. This same diet also promotes a healthy gut microbial community.

Eating with the notion in mind that I am also feeding my gut bacteria is important. Supplementing healthy eating habits with a probiotic has certainly become more common. The challenge is how to sort through the numerous choices available.

The first thing I do when making a selection is to look at the number of colony forming units. This gives me an idea of just how many probiotics are in each capsule. This can range from 100 million to 900 billion.

The problem with this number alone is that it does not determine potency. For this we need to know how many strains there are, which species were selected, how the product was handled before purchase, and whether the ex- pressed count was determined at time of manufacturer or is guaranteed at expiration.

The timing of potency is critical. One product may indicate 80 billion and another, 20 billion. At first, it seems the higher number is stronger. But probiotics will deteriorate over time and are affected by temperature, so the lower number could be a more potent option if measured at expiration.

The next thing we’ll need to know is the genus and species included, and how much of each. You can have anywhere from 1 to 30, or more, species. This will be in the supplement facts box, such as Lactobacillus acidophilus.

Higher, again, is not always better, as a larger number of strains will diminish the potency of each individual strain. Overcrowding can also create chaos and competition since bacteria are antagonistic.

Carefully look for the amount for each species. I like to see this measured in CFUs and not just milligrams. If this is listed as a blend, you won’t really know how much you are actually getting.

It is important to consider the viability and efficacy of the individual probiotic strains. This is the most significant factor in terms of potency. Even single strain probiotics can be very effective. Each strain survives differently, and some need to be refrigerated. Others don’t, especially ones that are microencapsulated or spore based.

Strains are identified by their brand name, like CL1285 or NCFM. Too often these are not disclosed, yet tied to important clinical tests and studies.

It’s also a good thing to know if these are normally occurring in your gut or are soil based organisms. Knowing why you are taking a probiotic helps with selecting the most effective strains.

Strains must be live, or in spore form, at the time of consumption, and must survive the stomach acidity and biliary salts in order to reach the intestines. Some are pretty hearty and can do this on their own, others need a bit more protection. Look for the type of capsule used to see if it dissolves slower.

The specific strains also have different properties of adhering to the gut wall lining, though some strains are more transient and still work well. Knowing the strains is helpful.

Once you have a good idea of the potency, you’ll then be able to compare products based on price. I’ve seen some products have four times the potency for half the price of another brand. So once more, higher, is not necessarily better.

Look at the list of other ingredients. Sometimes I’ll find things like yogurt concentrates, magnesium stearate, and titanium dioxide. And don’t forget to look at the serving size. Come on down and I’ll help you understand how to evaluate probiotics.

Scott Porter is a functional medicine pharmacist at Sandpoint Super Drug. He is a member of the Sandpoint Wellness Council.