Do Aged Cheeses Contain Probiotics?

Probiotics. The new darling of health and advertising. Do cheeses really contain any of these amazing, essential microbes?

Aged wheels of raw milk cheese - Elk Mtn by Pholia Farm

Aged wheels of raw milk cheese – Elk Mtn by Pholia Farm

While I have no letters after my name (unless I capriciously add them), it doesn’t require a university degree to understand that bacteria, both beneficial and hurtful, can only live under certain contidions. I am a cheesemaker and I study science as it relates to dairy. I know what cultures I add to milk to make cheese. Very few of these are currently considered probiotic. And even if they were, when cheese is aged, the bacteria gradually die off as they run out of food to metabolize. So even when probiotic cultures are used, they do not survive longterm aging*. In fact, I was at a conference in England this last summer where research into genetically modifying probiotic bacteria to survive cheesemaking and aging was discussed. (Without much enthusiasm on the part of the artisan cheesemakers present, I might add!)

* I did find that some aged cheeses are commercially being designed to include probiotic bacteria that survive long term aging. These cheeses are labeled as containing probiotics and are not available widely as of yet. I think you can expect to see more products such as this in the future- if nothing else, they will be introduced for the market value they will bring.

I was doing some research today for my latest book (on raw milk production and consumption). I was reading a on probiotics that I chose for it’s high ranking and great reviews on Amazon.  After perusing the front chapters, I skipped to the section containing information about cheese and dairy products – and immediately had to begin putting yellow highlighter frowny faces in the margins (my system for reviewing books). At first I wondered if perhaps my information was wrong, but then found another contradiction that basically confirmed that the author was not really aware of at least this portion of his subject. (I sure hate it when what you think is going to be a reputable source, turns out to be suspect.)

So lets go over a few basic things that you can always apply to probiotics -to help determine for yourself if a food is a good source of these helpful bacteria.

  1. In order to be probiotic, the bacteria must survive the harsh environment of our stomach and travel on to the next portions of our digestive system. Not very many bacteria have this capability – the stomach is one of the first defenses against bacterial contamination of food!
  2. Probiotic bacteria  in food must have a source of nourishment – or they will die (unless, of course, they are held in stasis through something such as freezing). This is true of all bacteria. Once a food is fully fermented, the bacteria begin to perish unless fermentation is suspended – through refrigeration or some other means. Even then, their life span is limited.
  3. High heat, such as scalding or boiling, kills all but bacteria that are capable of forming spores that protect them from the heat.  So even if milk or cheese or whey contains probiotic bacteria if it is cooked they will die.

The bacteria currently considered probiotic include only a couple of strains regularly used in making cheese. A fresh cheese that uses these bacteria as a part of its fermentation process will likely have some of these helpful microbes still living, but the longer a cheese is aged, the fewer bacteria remain alive. Aged hard cheeses are not sterile, but the life forms found on and around them are typically environmental, not those that were added during the cheesemaking process. In cheeses made using high heat and added acid, such as whey and milk ricotta, any probiotic bacteria in the whey will be killed during the high heat treatment (along with enzymes and milk’s natural defensive systems).

Bottom line, don’t look to aged cheeses as a probiotic source, yogurt is a no-brainer if probiotics are your goal! Instead, enjoy aged, natural cheeses for what they are meant to be – deliciously preserved (usually through fermentation) milk.

P.S.: So where can you find information on probiotics that you can trust? Hard to say! Popular topics are a magnet for publishers and writers. The best advice is to consult more than one source, preferably those that list scientific studies as their sources – but of course all the studies that will be helpful have not been done, nor is science a static subject.

Oh, here are a couple of sources I used to write this post:

Vet. Med. – Czech, 47, 2002 (6): 169–180 Review Article 169 – Lactic Acid Bacteria, Probiotics and the Immune System
R. HERICH, M. LEVKUT
Department of Pathology, University of Veterinary Medicine, Košice, Slovak Republic

J Dairy Sci. 1987 Jan;70(1):1-12.
Survival of lactic acid bacteria in the human stomach and adhesion to intestinal cells.
Conway PL, Gorbach SL, Goldin BR.

http://www.dairycouncilofca.org/pdfs/probiotics.pdf, “Friendly Bacteria with a Host of Benefits”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC106298/  Probiotic Cheese

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18 thoughts on “Do Aged Cheeses Contain Probiotics?

  1. Thanks for all the great information! How do you know which probiotic to choose if you have digestive issues? Any way to know which one could help the most?

    • Hi Hannah,
      I am not a probiotic expert by any means, but I believe it is best if you try to get a dose of as many different probiotic strains as possible – every day. Good quality, fresh yogurt, fermented foods such as kraut and kombucha are also great sources. Of course you can buy some great probiotic supplements too. The more I read about these bacteria the more I am convinced that hardly any of us are getting the amount we need. Also, many of the foods we eat do not provide “prebiotics” – substances that assist and augment probiotic bacteria. I hope you give them a try and find better health!
      g

    • It is hard to say, Deborah. Some of the lactic acid bacteria in milk could be probiotic, depending upon how they got into the milk. The adventitious bacteria (those that are desirable that enter the milk during collection) in raw milk are being studied, but in general I believe that at this time they are for the most part not believed to be probiotic. BUT the enzymes and vitamins in the raw milk could be prebiotic and help health. So much is still unknown.
      Fermented foods are are known to have probiotic bacteria, but remember that with vegetables those bacteria are already on them, for the most part, or enter through the environment. When you make kraut, for example, you don’t add any bacteria. So raw foods could also be a source of probiotic bacteria, I believe. So much to learn!

  2. “In order to be probiotic, the bacteria must survive the harsh environment of our stomach and travel on to the next portions of our digestive system. Not very many bacteria have this capability [...]”

    Lactobacilli and bifidobacteria have roughly a 90% survival rate in the presence of buffered hydrochloric acid (in the stomach) after a one hour exposure. (Milk provides additional protection, since it curdles in the stomach.) They have an additional 60% survival rate in the presence of bile salts in the small intestine. Regardless, it’s not the sheer number of ingested live probiotics that counts; it’s a matter of adhesion to the epithelium (intestinal lining), reproduction, and colonization.

    “Probiotic bacteria in food must have a source of nourishment – or they will die.”

    Not entirely true for freeze-dried probiotics. This is how manufactures are able to keep them alive on the shelf for months (or years!) at a time; including shelf-stable and room temperature stable forms. Bacteria surrounded in micro-crystalline cellulose and starch provides an additional extension to their life.

    @Deborah
    “I have seen a few people claim that raw milk contains probiotics, which I doubted.”

    The source from which the bacteria is found is irrelevant to whether or not something is considered a probiotic. What matter is the (beneficial) effects it has on the host organism. I’ve only heard of one recent study to test the potential of live bacteria in raw milk, but such research will be limited because raw milk versus commercial milk is a political and financial matter, not a health or safety matter.

    • Great points, I added a phrase regarding holding bacteria in stasis for long term survival, which of course every cheesemaker that uses freeze dried cultures counts on. Also, I am hope I came across as fully in support and belief of the absolutely amazing ability of probiotic bacteria (and other essential microbes) to survive and thrive within us. My post was in regard to the ability of bacteria currently known to be probiotic surviving in aged cheeses. Again, who knows which of the many bacteria that grow on and in aged cheeses might one day be recognized for their benefit to our health, but for now, it is not really accurate to say that all aged cheeses contain probiotics. Thanks, T. Nate, for your great input. I think the nascent field of appreciating the microbiome within is quite exciting

      • “My post was in regard to the ability of bacteria currently known to be probiotic surviving in aged cheeses.”

        I found your post very helpful. I had entertained the thought of probiotics in aged cheeses (i.e, “Surely there’s still some live bacteria in there?”). After reading your article, however, it appears that such is unlikely the case due to the die-off and neutral (non-beneficial) strains of bacteria used.

        What SHOULD be stressed about cheese (especially hard and aged varieties) is their vitamin K2 (menaquinone) content! (Not to be confused with vitamin K1, phylloquinone.) You know the French and Greek paradox, right? “How could such people eat all of that saturated fat and have superior cardiovascular health to other populations?” We’ve tried to pin it on wine and olive oil. That’s really pushing it. The real answer is in plain sight: It’s the vitamin K2 found in the cheese they consume. Vitamin K2 removes calcium from soft tissues, blood vessels, organs, and intracellular space; it excretes excess calcium through the urine; and it deposits calcium into the bone matrix. It possibly plays a role in DNA, in which the research is only hypothetical at this point.

        Yes, there is some naturally occurring K2 in the milk used to make cheese, but this depends on the region, climate, season, and the diet and health of the dairy cows. However, most of the K2 in cheese is synthesized by the bacteria.

  3. “[...] many of the foods we eat do not provide ‘prebiotics’ – substances that assist and augment probiotic bacteria.”

    Most species of probiotics can live off of the mucins secreted by the epithelial cells along the intestinal wall. They are able to use the carbohydrate portions of these glycosylated proteins.

    Additional prebiotics from our diet is helpful, but not necessary for our guta flora’s growth and health.

    • Hi Tony, I don’t, but fermented veggies in general, do have probiotics from the lactobacillus that are doing the fermenting. As long as they are preserved properly after fermentation is completed. I recommend reading The Art of Fermentation by Sandor Katz.

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