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How to Test Your Probiotic Supplement: An Easy At-Home Experiment

Robyn Openshaw - Updated: April 5, 2024 - - This Post May Contain Affiliate Links

Want to know if that probiotic supplement on your shelf and in your fridge is still working to give you a healthy gut?

As living organisms, probiotics have a short lifespan, and many factors can influence how long they last: the origin of the materials, the length of the supply chain, the types of processing used, storage conditions on store shelves or at home, and more.

Because these living "cultures" are fragile, I hate to tell you that most probiotics on the market are garbage. And I've proven it.

In this post:

Frankly, it's not EASY to bring a good probiotic to market.

Manufacturers want you to think that how many billions of probiotic organisms, and how many varieties, are the "proof in the pudding" of whether the product is good, better, or best. That's only part of the story though, and not necessarily the best, or only, yardstick.

There is a simple at-home test you can do to check if your probiotics are still alive and able to colonize your gut, giving you all those incredible digestive, immunity, and mental health benefits you buy them for.

Graphic of the benefits of probiotics from "How to Test Your Probiotic Supplement: An Easy At-Home Experiment" at Green Smoothie Girl.

Probiotics have a multitude of benefits, but they won't work if they're too old!

We did this test with different brands sent to us by our readers, and the results were surprising. Most of the probiotics didn’t work! In fact, only TWO brands still had living organisms in them, and all the rest were dead!

You can do this experiment on any probiotic that contains the lactobacillus acidophilus strain (check the label), and you’ll know within a day or so if it's still viable.

How To Test Your Probiotic At Home

Step 1

Put half a cup (4 oz) of milk into a small bowl, jar, or cup, and let it come to room temperature for 1-2 hours.

Step 2

Open up your probiotic capsule and sprinkle the contents into the milk

Step 3

Let the milk sit for up to 24 hours.

Step 4

Check to see if the milk has cultured -- either formed some lumps or created a thickened, yogurt-like consistency. If so, your probiotics supplement is still viable.

The Best Probiotics Supplement

Once you know if your probiotics supplement is still viable and working, that’s only part of the story. Besides fresh ingredients, a good-quality probiotic supplement will have these qualities to give you the best results for a healthy microbiome:

1. At least 10-15 strains of probiotics (the more, the better).

Since different bacteria do different jobs, you need a broad diversity of types to strengthen and colonize your gut. Check the label and make sure you’ve got strains from these groups:

  • Bifidobacteria, like B. bifidum, B. breve, B. infantis, B. lactis, and B. Longum. These versatile bacteria compete with harmful bacteria, digest a variety of molecules, break down waste, and stimulate the immune system. They tend to be susceptible to antibiotics, so they are very important to take if you’ve ever had even one course of antibiotics in your life, even if it was a long time ago. Many people do not recover immune function after antibiotic use and suffer for years afterward.
  • Lactobacillus, like L. acidophilus, L. brevis, L. bulgaricus, L. casei, L. lactis, L. plantarum, L. rhamnosus, and L. salvarius. These fairly hardy bacteria help increase nutrient absorption, stimulate antibody production, break down food into energy, produce amino acids, act as anti-inflammatories, and more.

2. At least 5 billion CFU (“colony forming units”) per capsule.

3. An added prebiotic.

Prebiotics feed probiotics, increasing their number and optimizing their ability to do their work in the gut. Unlike probiotics, prebiotics aren’t alive. They are a very specific fuel (fermentable dietary fiber, preferably from a food like yacon, chicory, or artichoke), and without them, you’ll have less productive bacteria that’s slow to multiply, sluggish, and may even die.

When I couldn’t find an ideal probiotics supplement that had everything I wanted, I created one. This undertaking gave me the opportunity to add more ingredients to help digestion, including:

  1. Digestive Enzymes: Digestive enzymes take the food you eat and break it down into useable molecules for energy production and cell function. These enzymes also play an important role in metabolic processes. We added lipase, protease, and amylase to help you digest fats, proteins, and carbohydrates easily.
  1. Organic Trace Minerals: Minerals are enzyme cofactors, the triggers that enable digestive enzymes to work. Since most Americans are mineral deficient, including these cofactors is important so the enzymes can function properly.
  2. Chlorophyllin: Derived from chlorophyll, chlorophyllin is what gives PreZymePro capsules their distinctive green color. Chlorophyllin helps relieve constipation, reduce flatulence, and even control body odors.

We make this product in small batches, so you’re always getting fresh ingredients for the best benefits.

Now you know how to test any probiotic product for yourself, for its efficacy. Even if you test your own probiotic product and find that it contains living cultures, I still recommend you vary your brands, using a few different ones, if the brand you use has fewer than about 10 different probiotic strains. This will give you the best chance at a thriving gut and healthy life.

Read next: 7 Natural Immune Boosters

Photograph of Robyn Openshaw, founder of Green Smoothie GirlRobyn Openshaw, MSW, is the bestselling author of The Green Smoothies Diet, 12 Steps to Whole Foods, and 2017’s #1 Amazon Bestseller and USA Today Bestseller, Vibe. Learn more about how to make the journey painless, from the nutrient-scarce Standard American Diet, to a whole-foods diet, in her free video masterclass 12 Steps to Whole Foods.

Disclosure: This post may contain affiliate links that help support the GSG mission without costing you extra. I recommend only companies and products that I use myself.

How to test your probiotics

Posted in: Supplements, Videos, Whole Food

23 thoughts on “How to Test Your Probiotic Supplement: An Easy At-Home Experiment”

Leave a Comment
  1. Lisa says:

    Will this test work with raw milk?

  2. Mary Calaway says:

    Will this test work with Almond Milk?

    1. Jessica says:

      I can’t say for almond, but I made yogurt with this method using coconut milk. I think almond should work too.

    2. Gail says:

      Does it work with almond milk

      1. Julieta says:

        I’m following a recipe to make almond milk yogurt, si if the probióticos are good then yes it will work

    3. Crystal says:

      No. needs the lactose from milk.

  3. Frances says:

    What about expiry dates? Some say its guaranteed until expiry date.

    1. Rose Butler GSG says:

      Frances, you can test your product the way Robyn shows us to in this post. If it does not culture, it does not have live cultures in there in the first place (whether it is in date or not). You can take that information to the manufacturer if you wish, and get your money back.

  4. Marthalyn Hendrich says:

    What about making my own kefir, water kefir, kombucha and fermented vegetables. Is that enough probiotics?

    1. Julieta says:

      Depends how much you need and i don’t know how or if it’s possible to measure the quantity of probiótics, but yes they can be very effective for gut batería

  5. Before I do this test, please let us know what if this will work with any kind of milk, or just cow’s milk? Also, what was the other probiotic besides yours that worked in your testing?

    1. Julieta says:

      In the test described you’re basically making yogurt, and yes it works with natural plant milks, eg coconut milk, soy milk, almond milk.. I’ve used flavoured soy milks too but probably natural is best

  6. Pam says:

    Before I waste one of my existing probiotics (just in case they pass the test), I, too, would like to know if this method will work with a plant-based (almond, coconut, etc) milk as well. Thanks!

    1. Julieta says:

      I think it’s the protein that coagulates, so soy, coconut, almond all work if your probióticos are good. I imagine other nut milks would too

  7. Lupe Candiliere. says:

    How about Yogurt Products? are They a good way to get Probiotics.? That is what I take instead of capsules Suplements.

    1. Carol says:

      I also use yogurt for probiotics. Wonder if I could grow a tsp of yogurt in milk?

    2. Crystal says:

      Yogurt is only 1-2 CFU if that. Basically yogurt is chump change compared to probiotic capsules that are alive which should be 5-10 CFU

  8. Deb says:

    I was just wondering how to tell if my probiotics were still active and opened my email to find your post. Thank You Robin for the information!

  9. Janet Henderson says:

    I don’t think this test works on ultra pasteurized milk. UP milk is dead and even yogurt makers don’t use this milk. They use low pasteurized milk or raw milk. In order to have a successful culture, I think it depends not only on the bacterial culture but the level of pasteurization the milk has gone through as well.

    1. Jan H says:

      I make Instant Pot yogurt from Fairlife milk all the time, and it is ultra-pasturized. It works fine.

  10. Jon says:

    Robyn did not say if after adding the probiotics, does the milk need to stay at room temperature for the 24 hours ?

    1. Sarah Greg says:

      You can leave milk out at room temp for 24 hours. And then discard after test. Thanks!

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