Probiotics are absolutely trending right now both in the slimier supplement sales corners of the internet and also in legitimate clinical research. I wrote about the new frontier of gut health and bacteria research last week. A probiotic is live microorganism that, when given in adequate doses, provides some benefit to the host (i.e. person). They come in all sorts of formulations. Across the internet, they are sold as magical gut cures for any GI ailment. I wanted to answer a few questions with this post:
Do probiotics work? Are they worth the money?
The answer to both questions is 'maybe, for some people'. They are unlikely to hurt you and may help in the long run.
I approached this research in two ways:
- What does the every day consumer see when they search Google for "Should I take a probiotic?"
- What new evidence came up in 2014 and 2015 around consuming probiotics?
First up, the every day consumer.
My initial approach is to ignore the advertisements for probiotics. There is no way I am going to get effective information that way. Then I look for reputable sources in the first few results. Most consumers don't make it past the first search page so neither will I.
This set of results brought up pages from Harvard Medical School, Dr. David Williams and Dr. Andrew Weil. I knew of Harvard and Dr. Weil, but Dr. Williams was unfamiliar.
Dr. David Williams calls himself a researcher, biochemist and chiropractor. This is a man who likely has some critical thinking skills and I was interested in what he had to say. I quickly found that his blog is essentially a marketing effort for his vast supplement empire, which included a number of probiotic lines. The blog entries themselves are low on evidence and high on pseudo-science, despite his credentials. So I closed that window.
The Harvard publication looked really promising and they appeared to endorse probiotics but the information is behind a $4.99-per-month-paywall. So, the average consumer can't really see the logic behind probiotics. At least they're not asking me to purchase Harvard ProbioticsTM on their site. Browser window closed.
Dr. Weil is an integrative physician who really emphasizes prevention and mindfulness in his work. I own one of his mindfulness CDs from 2008 and I've used his breathing exercises. So I am positively inclined towards Dr. Weil. However, his blog is also a marketing article farm for his supplement products. He sells a GI health vitamin pack for $50 USD per month. That's exorbitant and it's quite difficult for me to take his recommendation seriously.
The results of this search are typical of any supplement. The internet itself is a giant marketplace filled with inappropriate information about what to buy and what will make you healthier. Some sites claim that probiotics will cure mental illness, inflammatory bowel disease and all sorts of other chronic diseases. I wish this were true. If this were true, it would change lives and we would all be better off. Unfortunately, the evidence shows a possible small benefit but definitely not a cure.
Next up, the research from 2014 and 2015.
I did a broad search for probiotics in recent literature and narrowed down to individual studies, review articles, systematic reviews and meta-analyses. The most important point to take away is that the research on probiotics is relatively new but very exciting. If you decide to take probiotic as part of your regular health regime, there isn't any definitive guidance on whether to take a capsule, a liquid a yogurt, etc. Do what fits your budget and make sure you tell your doctor that you've started because they may see something about your individual circumstances that makes probiotics a bad idea.
The key take homes from the research on probiotics are here:
- The research is new and definitive answers don't exist.
- There could be benefit to taking probiotics and little risk of harm for most people.
- Altered gut flora likely has a role in a number of inflammatory conditions, including eczema, asthma, allergic rhinitis, obesity and auto-immune diseases. There may be benefits to adding probiotics to change the gut flora.
- Most of the research looks at all strains of probiotics but the benefits are probably different with each strain. The two most commonly studied strains are Lactobacilllus and Bifidobacterium.
- The quality of evidence for probiotic treatment of irritable bowel syndrome is pretty low, even though it is one of the most common marketing targets.
- There is mixed evidence for probiotics and reduction of diarrhea associated with antibiotics, including C. difficile. The evidence is likely favoured towards probiotics as making a difference. The pharma funded systematic reviews are high quality but found a difference. The non-pharma funded systematic review from 2013 found a significant difference. The non-pharma funded single trial showed no difference and was also of high quality.
- Probiotics probably won't prevent acute sickness, in the cases of common infectious illnesses, but they may reduce duration of symptoms which could have a large overall effect on the health system and the economy.
- Cases of sepsis and severe infection from taking probiotics have been documented in very ill or immunocompromised people. Other side effects can be bloat, hiccups and gas. Otherwise, probiotics are usually very well tolerated.
- New directions include probiotics and mental health as well as diabetes and metabolic syndrome. A few small studies in these areas have established more interesting questions. Again, nothing concrete but certainly interesting.
Here is the mind map (References below):