Do Probiotic Supplements Actually Work?

drugs - cropThe probiotic supplement business is a large and growing industry but, like its vitamin-pushing brethren, it may be pushing useless placebo pills. Sales of probiotic “products” are predicted to exceed $52 billion by 2020.   Since 2008, sales for this particular type of supplement has boomed. But are they any better than harmless sugar pills ?   The answer is probably not.    The bottom line is that the science simply doesn’t support the slogans pushed by this booming supplement industry.  Is it a scam?  Possibly!

There are some situations in which probiotics may be useful.   We’ll explore those exceptions below.  But for most healthy people, the money you are spending on probiotic supplements may be literally flushed down your toilet.

What’s the Scoop Behind Intestinal Bacteria

Here’s the scoop: your “gut health” or microbiome is real.  Scientists pretty much agree that the thousands upon thousands of different strains of bacteria in your intestines are essential to your well-being.  Gut bacteria are connected to cancer, autoimmune problems, intestinal bowel disorders, and more. The development of the gut bacteria community in children has been connected to childhood allergies, asthma, and maybe even autism. The human microbiota is an integral part of our bodies, especially our immune systems.

And it is not just gut bacteria, there are bacteria on our skin and in our respiratory tract that are also important for our health. In addition to suspected disease related events, theories are being floated that gut microbiomes can influence behavior, mood, fitness and a variety of other functionalities.   So bacteria in your gut are hugely important.   However,  the problem is that everyone’s gut is different — they are as unique as a fingerprint.  Moreover, science doesn’t know enough to identify, measure or supplement each individual’s internal probiotic map.

Why Probiotics Probably Don’t Actually Work

In all likelihood, you could be taking pills that don’t contain any of the bacteria you need to improve your own personal microbiome.   If you don’t believe us, just ask Consumers Union, the publisher of Consumer Reports.  In a 2015 article, they only recommend probiotics if you have taken antibiotics and are trying get some short-term relief from the damage that antibiotics do to your gut.   Similarly, the Berkeley Wellness newsletter only recommends oral probiotics for two purposes.

U.S. National Center for Complementary and Integrative Health (NCCIH) is also not sold on probiotics. They have been studied in a variety of conditions, including antibiotic-related diarrhea, digestive disorders, tooth decay, allergies, eczema, liver disease and even the common cold. But it could find no definitive evidence that probiotics work for any of these conditions.

But its even worse than that — the bacteria in that supplement may not even make it to your intestines.  In most people, once the gut microbiome is established in childhood, it stays fairly consistent through their life, with some possible changes due to diet and other factors. The new bacteria introduced in probiotics can be beneficial while they are in the gut, but usually the new bacteria are not able to colonize the gut, and therefore will get expelled, and not have a lasting effect.   Studies are not supporting industry claims that ingested (oral) probiotics have any long-term benefit.  In fact, most reputable studies show very limited effectiveness — if any at all.

A new study by scientists at the University of California has found that contents of many bifidobacterial probiotic products differ from the ingredients listed.  Unfortunately, it can be difficult for the consumer to know which products have strong scientific evidence behind them and which do not. And, since the majority of specific probiotic strains are patented, the fact that clinical trials have shown the effectiveness of one strain in treating infectious diarrhea, IBS, or IBD does not automatically mean that any probiotic will do.  Here’s what a review paper titled “Probiotics: determinants of survival and growth in the gut” had to say about the matter:

Although it is believed that the maximum probiotic effect can be achieved if the organisms adhere to intestinal mucosal cells, there is no evidence that exogenously administered probiotics do adhere to the mucosal cells. Instead, they seem to pass into the feces without having adhered or multiplied. Thus, to obtain a continuous exogenous probiotic effect, the probiotic culture must be ingested continually.

In 2018, Israeli scientists found probiotics were not only not helpful, but in some cases may be harmful.   Ultimately, because everyone’s gut flora is different, what works for some won’t work for others.

So Probiotic Bacteria Get To Where They Need to Go

Bacteria in probiotics probably follow the same fate as all other foreign bacteria we swallow everyday. They get disposed off by gastric acid and other substances with bactericidal properties present in saliva, gastric and enteric juices, extreme pHs and all the cellular elements present in the submucosa of the small bowel.   In other words, any live bacteria targeted for your intestines likely don’t get there because of the numerous defense mechanisms in your digestive system designed to protect you from harmful bacteria.   Your internal bacteria are “planted” from birth and may not be supplemented through ingestion at all.   Fecal transplants are one method by which gut bacteria are added to your intestines, but even that process is complicated and uncertain.

Soil-Based Bacteria Aren’t Any More Effective

The newest rage is soil-based probiotics that, in theory, last longer and are not as easily destroyed by stomach acids.  However, it turns out that these types of bacteria can also be harmful, because they are unnatural to the body. The uncertainty is so great that the European Union has banned the use of the word “probiotic” in marketing unless a product receives approval for a health claim. No such approvals have been granted.

The Bottom Line On Probiotics

In the U.S., probiotic supplements are not regulated and therefore not subject to FDA oversight unless they start making consumers sick. Even worse, research shows that many probiotic supplements don’t contain what’s on the label.  A 2015 analysis of 16 probiotic products, for example, found that only one of 16 exactly matched the bacterial species claims on the label in every sample tested.

So, we are left with the reality that eating Greek yoghurt for breakfast or popping probiotic pills that contain a couple of Lactobacillus strains is not going to get us very far in terms of building a healthy, flourishing community of hundreds of species of gut microbes. Some high-potency probiotic supplements and probiotic-enriched foods may even do us more harm than good, in the sense that they could stimulate the adult immune system in evolutionarily novel ways and/or block the development of a robust adult gut microbiota. The focus should be on developing a healthy, diverse gut microbiota, not on pouring huge numbers of “probiotics” into the system every day.

In short, there’s no scientific support for the use of probiotic supplementation as a long-term solution for achieving good gut health. Yet,many online retailers and marketers offer exceedingly expensive probiotics that claim to be “beneficial” to your digestive system, despite the fact that there’s little science to support that claim.  (Note: they usually avoid suggesting any medical benefits so that they can fly below the FDA’s radar).

Why Probiotics Are Horribly Overpriced

Aside from the absence of scientific support, probiotics are often horribly overpriced.  For example, Probiotic America sells 30 capsules of its “proprietary” formula of probiotics called ‘Perfect Probiotics‘ for $69.95.   Compare this to $16 for 60 capsules charged by online retailer Vitacost, who generally produces high-quality supplements.   Probiotic America is effectively charging 800% more for its special formula of what could be entirely useless pills, no better than placebos.   Why the price difference?   It may be attributable to the $44 upfront payment to affiliate marketers who push Probiotic America products on an unsuspecting public:


This advert is targeted to all of those useless, “infoscam” websites that hawk overpriced or useless products.  They do it because they get paid big bucks for any consumer who succumbs to their tangled web-pitches.

We strongly recommend that rather than going to the health food store to buy a probiotic supplement that contains a carefully selected mix of 5 or 10 microorganisms, you’re probably better of focusing on boosting your intake of fiber-rich foods, exchanging bacteria with healthy friends and family members, eating more raw, minimally cleaned fruits and vegetables, spending more time in natural environments, and reducing your use of cosmetic products, lotions, cleaning detergents, and other products that contain a wide range of potentially harmful substances.   Even more surprisingly, drinking wine, tea or coffee may be more beneficial to your intestines;  it turns out that consuming these beverages is associated with a healthier and more diverse community of microbes living in the gut.   Who woulda thought?

The Exceptions

As promised above, there may be some circumstances where probiotics can be helpful.  Probiotics can provide temporary immune support, help ward off infections, and shorten the recovery time from some acute illnesses (e.g., diarrhea). In other words, those with chronic, hard-to-treat gut disease, acute illness, and/or a severely compromised immune system may benefit from using probiotics.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.