Monday, September 10, 2018

Do Probiotics Deliver on their Promise?

We’ve all seen the commercials and some of us may have even jumped on the probiotic bandwagon, but new research suggests those pricy yogurts may not deliver on their promises. This may come as a heavy blow to the many people who put their faith in the many probiotic supplements available to build microbiota for treating digestive issues, counteracting the negative effects of antibiotics, of just feeling good in general.  

One study, from Weizmann Institute of Science, investigated the effects of supplements containing 11 bacterial strains on wild mice, special germ-free mice which had their normal microbes removed, and on healthy humans. The microbial populations already present in the wild mice resisted colonization by the new microbes, though these did take in the germ-free mice. In heathy humans, the new microbes were present in everyone’s stool, but only in the intestines of some of the participants. In other words, some people were able to colonize their guts with the new bacteria, but others just passed them from their systems.

A following study by the same team involved both mice and humans whose intestinal microbes were thinned out using antibiotics. Each species was divided into three groups; one received probiotics, one received fecal transplants, the last was observed without treatment. It was found in both mice and humans that not only did probiotic treatment not help, it delayed the populations of microbes in returning to normal.

Of course, this don’t necessarily mean there is no place for probiotics. Some of the humans in the first experiment did manage to add diversity to their gut microbiota. However more either passed the supplements with no effect or, in the second study, had a negative effect.  Perhaps more research paired with more precise use would be beneficial. For example, if doctors evaluated patients and paired them with supplements containing specific strains, rather than the relaxed attitude of people shopping for trendy supplements at health food stores after reading up on naturopathy. 


  1. With all the hype about probiotics, especially in the recent years, I find it interesting that the two conducted researches demonstrated that the effects of probiotics were either ineffective or harmful. The fact that it can possibly "delay the populations of microbes in returning to normal" seems a bit concerning. However, I do agree with you when you say that maybe better research should be conducted on particular patients that might actually need these supplements.

  2. With the fear of being obese on the rise, I think the supplement market is having a blast. What better way to complete one's overall nutrition than adding a scoop of green powder or taking a pill filled with probiotics that drastically increases your health. Unfortunately, the use of words such as "super greens", "organic", "raw whole food extractions" and "Alkalizing green blends" adds to the appeal of being natural/organic which is apparently enough to start a trend of supplementation, though not based on research. I wish more research like this can become more mainstream and that people could figure out that its hard to be healthy when your not eating healthy. However, if it turns out that probiotics, perhaps with a new formula, can be healthy and effective then I would not mind consuming it. Until that day comes, I think the use of probiotics will be a sense of relief when complementary to a poor diet and overall be a placebo.

  3. This is very interesting, we are constantly hearing about the benefits of probiotics, and making sure we incorporate them into our diets. I am somewhat surprised to learn that in this study, a lot of the time these probiotics simply passed through the human digestive system without making much impact. I would be curious to learn why the probiotics stay in the system of some individuals, and if there is a scientific explanation for that. I'm very curious for future research that confirms these findings, because if they do get similar results, that could lead to a few substantial changes in the way we view health and diet.