I was quickly trying to get some transactions done at my bank, and a familiar cashier asked, “Did you see ABC segment on probiotics?”.  I said, “Yes, what do you think about it?” She said, “I don’t know, just bought my months supply and now I am confused”.

We had a bit more chitchat, but I want to emphasize how she applied the word “confused”. With a recent news item that caught on I received at least a twenty-five messages, and an equal number of emails about the topic from many who know I am working with a human microbiome-based products company.

Acknowledging two studies by Dr. Elinav, who has done some contributions to the human microbiome science, I must repudiate his far-reaching comments, including “results reveal a new potential adverse side effect of probiotic use with antibiotics that might even bring long-term consequences” and “In contrast, replenishing the gut with one’s own microbes is a personalized mother-nature-designed treatment that led to a full reversal of the antibiotics’ effects”. His comments are based on his study of only seven people! The media has unduly highlighted his comments as hundreds of shades of study results…This is not right!

I have four points to make and reflect on concerning this recent media blitz.

First, natural probiotics are traditionally used in different cuisines around the world. I remember thick, non-flavored yogurt my mom used to feed me as a kid. Around the world, people use probiotic and fermented foods in many different forms…kefir, sauerkraut, kombucha, kimchi and yogurts are examples. Traditional wisdom says fermented probiotics are really good for you, especially if you need to balance your stomach issues. The reason I point this out is because people connect the word ‘probiotics’ and any “bad press” relating to it with things that they are familiar with…items on their grocery lists.

When a researcher conducting a study on a group of seven people manages to gain the media’s attention and wire services pick up the story, and a “buzz” is created, people need to be so easily influenced to the point where they make unqualified decisions about their nutrition and uses for probiotics.

Second, look at the status of probiotics in the scientific literature. If you search the word ‘probiotics’ in PubMed, a popular search engine for peer-reviewed scientific articles, you will have a list of 19,000 articles (3). This includes published literature on benefits, mechanism of action, and stability of probiotics in both human and other animal-use over the span of 30-40 years. If probiotics were not efficient, you would not have a huge list of peer-reviewed articles! Science would not have “persisted” and interest in probiotics would have perished long ago. There are thousands of articles on the benefits of probiotics in very prestigious scientific journals. How can you justify the thought that all those articles and knowledge base is worthless with just two studies! As researchers, we build new evidences and discoveries into body of work that already exists, and suggest better explanations and future studies to follow up the observations. Because I do not think that a single research group can discover and validate all about a new discovery. Most importantly, it is those critical follow-up studies that make the original discovery more credible and meaningful.

Third, we know that, historically, the dietary supplement market has been under-regulated, until recently! Today, the FDA has taken serious measures for the regulation of the dietary supplement sector. Going forward, we will see improvements with serious compliance protocols by regulatory agencies.

Today you can find probiotic products almost everywhere, from the dollar store to reputable specialty nutrition stores to the internet, priced from $1 to $80 per bottle.  Why pay $20 or $80 when you can buy it for $5?  I conducted a personal study and grabbed 15-20 probiotic products from various stores to see what’s really in them. Results were…you get what you pay for.  As a dietary supplement customer, thestandard of purchase’ is that you do diligence on products you are considering, whether it is probiotics or omega-3 or Vitamin D3. You will find big differences in quality, effectiveness and user reviews. With probiotics, the specific strains supplements contain are very important.

Fourth, it is a fallacy if anyone dreaming that you are seeding 100billion CFU of your probiotics into your GI tract, and there comes all the great benefits! Think in a slightly different way. It is estimated that 100 trillion bacteria are there in your gut and most of them do not like oxygen (or anaerobic). So your 100 billion probiotic bugs will not make a huge impact on your core microbiota, however, it will deliver some incremental benefits especially if your diet is not diversified. Your gut microbiota is also a reflection of what you eat, if you have a diversified diet with vegetables and fruits, there is a good chance that you have diversified and stabilized flora. I personally suggest people to take probiotics, which also has a good mix of prebiotics because prebiotics is the type of food that your gut microbiota needs to grow and flourish. Further, all the benefits of probiotics are not coming from the live bacteria, there are benefits from dead probiotic cells that have non-specific signaling to immune system and to nurture a favorable gut milieu for flourishing good flora. There is, at least, one ingredient that I am familiar from Japanese probiotic market place, which is heat-killed probiotic and has published several human clinical studies on efficacy on immune enhancement and warding off upper respiratory infections (4-5). Whether the probiotic colonize to ‘persist’ in the gut or transiently pass through to ‘resist’ colonization in human, if it deliver some meaningful benefits on the gut environment, we all should take it, because, remember the fact that GI tract is also human body’s largest immune organ.

I thought of wrapping up by commenting on the good side of science. Dr. Elinav is a thought leader and published some seminal works on human gut microbiota. The experimentation and models he used to study the impact of probiotics in this model is pretty impressive from a very basic scientific standpoint but I do not know whether I agree with all the conclusions unless another lab takes up and follow up some of these studies. Also the conclusions that he suggested to generalize probiotics from an applied standpoint were not right, at least from my viewpoint. Does Dr. Elinav suggest having fecal transplant as an alternative to probiotics and probiotic-based foods after antibiotic regimen? I think it is pretty radical thinking.

Another critical thing is that how the media interpreted this; even the author has suggested the limitations of this study however; the major news media released only the highlight of this study overlooking the major limitations of the study.

We all look forward on the new discoveries on human microbiome and how it modulate human physiology in ways that we would never have imagined 10 years ago. According to me, microbiome as a sub-sector is a radical revolution in life science and medicine; something, which has, came out of nowhere and suddenly become mainstream. We, as a generation, is fortunate to witness how fast this sector is progressing to reveal groundbreaking studies which will have ramifications in cancer medicine to brain diseases to other inflammatory conditions.


1. Zmora et al. Personalized gut mucosal colonization resistance to empric probiotics is associated with unique host and microbiome features. Cell 174, 1388-1405.

2.  Suez et al. Post-antibiotic gut mucosal microbiome reconstitution is impaired is impaired by probiotics and improved by autologous 174, 1476-1423.

3. https://www.ncbi.nlm.nih.gov/pubmed/?term=probiotics

4. Arimori Y et al.Daily intake of heat-killed Lactobacillus plantarum L-137 enhances type I interferon production in healthy humans and pigs. 2012 Dec;34(6):937-943

5.  Hirose Y et al.Oral intake of heat-killed Lactobacillus plantarumL-137 decreases the incidence of upper respiratory tract infection in healthy subjects with high levels of psychological stress. J Nutr Sci. 2013 Dec 6;2:e39. doi: 10.1017/jns.2013.35. eCollection 2013.