The National Institutes of Health defines probiotics as live microorganisms that, when taken in adequate amounts, can bring about health benefits. These bacteria and yeasts naturally occur in fermented foods, although they can be found in supplements and skincare as well.
With all the processing done to create probiotic-rich foods, supplements, and cosmetics, one question is often asked: “Are most of the microbes in probiotics dead?” To answer that, you need to read on to find out more about this controversial issue.
The Probiotic Paradox
The answer to the above-stated question is answered by researcher Clifford Adams in his study, “The probiotic paradox: live and dead cells are biological response modifiers”. According to the Belgian scientist, not all microbes in probiotic products are 'live'. Some are ‘inactivated’, either by heat, chemicals, UV ray exposure, or sonication (the application of sound to extract substances from microbes).
When microorganisms are inactivated, cell structure and size are changed. In some cases, the cell walls are ruptured, leading to the release of bacterial lysates. These are substances and components that comprise the ‘dead parts’ of a probiotic food source, supplement, or skincare product.
With that being said, the answer is YES, some of the microbes in probiotics are dead.
Although that is the case, dead probiotics may still bring about health benefits to the body. They may be just as beneficial as its live counterparts – and this is what Adams defines in his study as the "Probiotic Paradox”. The researcher goes on to explain that the helpful effects of the live microorganisms are mostly due to the byproducts of the lifeless cells.
To wit, dead probiotics help the live probiotics do their work. As is the case of the gut, some live organisms cannot completely penetrate some layers in the stomach. Dead probiotics, however, can penetrate these layers – preparing the surface for the live bacteria so they can exert their benefits to the maximum effect.
The mutual relationship of the live and dead bacteria can be seen in its effects on the gut’s immune system. The dead ones exert an anti-inflammatory effect on the digestive tract, enabling the live probiotics to help improve the gut's immune response.
It’s Kind of Hard to Count
With regards to determining the number of live probiotics from the dead, Adams says that this is a problematic thing to undertake. Live bacteria may increase or decrease in quantity according to certain conditions, as such it is difficult to know the count or ratio between the live and dead microbes. This uncertainty in numbers may be one of the reasons why people have different kinds of responses to probiotic foods or supplements.
Although it is hard to determine the bacterial ratio, the Food and Drug Administration has introduced a useful test. This aims to manage probiotic growth and curb the contamination of harmful germs.
Dead Microbes? They Should be Called Paraprobiotics Instead
With many studies showing the benefits of inactivated probiotics, it comes as no surprise that more and more researchers are working hard to unlock their mysteries. And with this newfound popularity, some scientists have argued that they should be given a new name. Since they are not alive – the word 'live' is a vital keyword in the definition of probiotics – they should be called paraprobiotics instead.
Experts also add that paraprobiotics should be regulated by the FDA as they would do drugs – simply because dead microbes act like such.
Dead Probiotics May Help Boost Immunity
Despite the naming controversy, more and more scientists are exploring the health benefits of dead probiotics.
According to the study printed in the Journal of Microbial Ecology in Health and Disease, dead bifidobacteria may help stimulate the production of TNF-alpha, a substance that increases one’s resistance to infection and certain cancers.
Dead probiotics stimulate the release of other immunity-enhancing substances as well. Heat-killed Enterococcus faecalis bacteria may help improve gut immunity. The same dead strain may help increase the number of phagocytes, immune cells that eliminate bacteria and other harmful germs from the system.
How Dead Probiotics May Help Enhance Your Immune System:
Dead Probiotics May Help Improve Your Skin Too
Apart from improving immune response, inactivated probiotics may help alleviate the symptoms of some skin disorders. Research shows that it works the same way as live bacteria, although it has the advantage of lasting longer in the system.
Such a feat was seen in a study published in the Journal of Microbiology and Immunology. Results show that tyndallized (heat-inactivated) Lactobacillus rhamnosus may help reduce itchiness and other symptoms associated with atopic dermatitis.
Dead probiotics may also help provide some protection from harmful bacteria. A study conducted by researchers from the University of Manchester has shown that lysates (the byproducts of dead cells) may help defend the skin from infections that result from the disruption of the skin microbiome. The use of antibiotics or the lack of probiotics in the system may result in the overgrowth of Staphylococcus aureus, a naturally-occurring bacteria on the skin. When this happens, unsightly boils and furuncles may occur.
Apart from being a natural alternative for skin disorders, the application of dead probiotics may help beautify the skin as well. A study of heat-killed Lactococcus has shown that it may help improve the skin as well as live cells.
Because of the dermatologic promise of dead probiotics, researchers have recommended the inclusion of bacterial lysates in creams and soaps. With the aforementioned benefits, dead probiotics are slowly gaining footing in the world of supplements and cosmetics.
Not only are they safe, dead probiotics have long shelf-lives as well. Inactivated cells may also help prevent infection and bacterial translocation, which may occur with live probiotic use.
Probiotic-rich food, supplements, and skincare products do not only contain live bacteria, they may contain inactivated bacteria as well. Although some of the microbes are dead, they bring about some health benefits too.
Dead probiotics may help improve the performance of live cultures. With their ability to penetrate layers that live bacteria can't burrow themselves into, they can help enhance the action of live probiotics. So the next time you see lysates or inactivated bacteria on your supplement label, you need panic. Remember, they may help improve your immunity – as well as your skin status!