The probiotics industry has seen a boom in the past decade – without much research to validate
their efficacy. We have all been told that we should take probiotics, especially after we are
prescribed antibiotics… But is this really helpful to our delicate microbiome? Could it be hurtful?
Over the years, there have been several studies that cast a doubt on the benefits of these highly
What Are Probiotics?
Probiotics are living microorganisims often sold in foods such as yogurt, supplements, and
drinks. The ultimate goal of these microorganisms is to take up a home in our digestive tract,
help fight infections, and help facilitate the breakdown and digestion of foods. Essentially, they
help rebalance the ecosystem of the gut if it has been altered through stress, sickness, or poor
Probiotics have never been approved by the FDA because they are not approved to treat or
prevent disease. Instead, they are considered a dietary supplement. Yet, in 2012, more than 4
million Americans were taking probiotics.
Do They Work?
Eran Elinav is a senior author and immunologist at the Weizmann Institute of Science in Israel, and has
been studying the effects of probiotics on the microbiome. While the vast majority of prior studies on probiotics have relied on analyzing stool to get an idea of the person’s gut microbiome, Elinav’s research team actually looked, with an endoscope, at bacteria present in the colon
itself – both in mice and in humans.
We all our unique individuals with unique microbiomes – it is essentially a fingerprint for your gut
After 25 healthy volunteers ate a generic probiotic with 11 strains of “good” bacteria, they all had probiotic
bacteria in their stool, which the research team expected. However, when doctors did the endoscopy to evaluate their intestines, they found that probiotics had only actually “stuck” and grown in a few people. Although all of our probiotic-consuming volunteers showed probiotics in their stool, only some of them showed them in their gut, which is where they need to be,” stated Eran Segal, also a biologist at the Weizmann Institute. (ABC NEWS)
If the probiotics are not ending up in the colon (as the advertisers and proponents claim) then they are, in essence, serving you no purpose.
These same researchers tested the common guidance from doctors to take probiotics after taking antibiotics. Antibiotics tend to remove much of the bad bacteria we want to get rid of, but at the cost of damaging our good bacteria. This can cause diarrhea and malabsorption of key nutrients, leading to nutrient deficiencies.
The researchers had volunteers take broad spectrum antibiotics, then looked at the gut bacteria of the
volunteers after taking probiotics. The key finding was that the probiotics actually colonized, but at the
expense of the normal gut microbiome. This delayed the return of the normal microbiome for several months.
We all our unique individuals with unique microbiomes – it is essentially a fingerprint for your gut – and so,
supplements aimed at the mass market may not be effective for every individual. Each person will have a
different result taking a broad spectrum probiotic.
Maybe as medicine becomes more and more personalized, we will be able to design a probiotic specifically
for each person – but for now, broadly aimed probiotics are less effective than many claim them to be.
This is an emerging science that keeps shifting – and the research is very new. Until we know more, maybe
you will rethink buying that 60$ probiotic!
Chris Kresser: What The Latest Research Says About Probiotics
Sending love and light!