Why Probiotics Don't Always Work




In an online poll taken during a recent webinar on gut health, we asked our listeners to tell us about how they’re using probiotic supplements in their practices. Specifically, we asked about how frequently they are currently recommending probiotics to their patients.

The responses were surprising. Nearly one-third of the audience said they recommend probiotics to over 70% of their patients. An additional 26% are recommending them to at least half of all their patients.

There are a lot of people out there taking a lot of probiotics!

That’s why probiotics are now a $30 billion global industry, with over 180 products on the market.

In general, that’s a promising sign, indicating that doctors and patients really are thinking beyond the pharmaceutical options when it comes to managing digestive system problems and other chronic disorders.

But like so many things in life, it’s really easy to overdo it with probiotics.

The more we learn about the gut microbiome, the more I think we need to check our zeal for probiotics. To be sure, probiotics can be a valuable tool in the context of a comprehensive treatment approach, but as with any other tool, excessive or inappropriate use can be problematic.


It has been estimated the optimal healthy human gut should contain between 20,000 and 30,000 species of bacteria. Variety is key. The greater the diversity, the healthier the microbiome.

The issue I have with our current approach to probiotic use is that it is doing on a microscopic level what crop monoculture is doing in agriculture: favoring a relatively small number of species at the expense of ecosystem diversity.

A typical probiotic supplement delivers 35 billion to 50 billion CFUs of just a few species. While some products contain up to 24 species of bacteria, that’s still a far cry from the diversity that we know to be optimally healthy.

Giving 35 billion copies of the same bacteria over and over again in the gut is absolutely creating monoculture. You might call them “good bacteria,” but if you're using them chronically, you could create real problems.


In my early years as a physician, the only tools I had when I was thinking about gut health were basically acid-suppressing drugs, which are incredibly damaging, and then digestive enzymes and probiotics, which I didn't really reach for until I was out of the Western medicine mind and started to become more of an integrative practice.


As functional medicine doctors, a whole group of us jumped on, 10 or 15 years ago, and said gut health is important; we said probiotics are critical, and every patient needs to be on a probiotic regimen.

Many physicians and their patients became enamored of probiotics because they recall those first two weeks of first being on a probiotic. Most of these patients were recovering from gastroenteritis or from antibiotic exposure, chronic fatigue, whatever it was. Their physician finally recommended a probiotic, and they finally felt some improvement.

They were like, "Okay, that's a good edge off my pain or suffering" or whatever it is, my irritable bowel syndrome. They get stuck in the mentality of, "I remember I was worse, then I started this and I was better," so they assume that if they stop that they're going to get worse again.

Stop Micromanaging the Gut


Many of our patients really do feel better in the first couple of weeks on probiotics, even if they have gut overgrowth of invasive species like E. coli. When you take a probiotic and overwhelm that biome with seven species that are good, you're going to feel better, but then you will plateau.

In people with longstanding digestive system disorders, the benefit obtained from probiotics can only really occur for those first couple of weeks.

Thereafter, the chance of actually obtaining long-term symptomatic relief is almost zero.

I don't see probiotics being helpful at all in the long-term management of a patient. If I see a patient who's coming to the clinic and they've been on chronic probiotics, I generally stop them cold turkey.

It is important for you to start backing off, to let the carbon redox system – the communication system between the bacteria in the gut – reestablish a healthy balance in the gut.

What I’m saying is, we need to stop trying to micromanage the gut.

At our clinic, we always stop probiotics after one to two weeks. The only time we use them clinically now is if there's been exposure to antibiotics or to a chemotherapy agent, or occasionally if there's a severe gastroenteritis or viral infection.

We now understand the gut health is really a discussion, not just about the microbiome, but about the microbiome's relationship to tight junctions, and the gastrointestinal-associated lymphoid tissue, or GALT.

Toxic peptides enter the gut, producing Zonulin, which leads to tight junction breakdown and creates the leaky gut, leading to chronic inflammation, which is the root cause of disease.

Probiotics can do many things physiologically, but they cannot restore the tight junctions or re-establish normal gut barrier function.

In recognising the inherent limitations of probiotic-based treatment, I am not saying that I am against probiotics, or that they should not be used.  Quite the opposite: they have a place, especially when they are coming from food sources.

NOTE: This is not the full article, if you wish to know more, please go to his website.

Image by Heather Barnes
Image by Milada Vigerova