Progress In Finding Targeted Bacteria to Potentially Treat a Variety of Issues

Again, trying to stay positive this month, for the sake of all our mental health:  the results of a recent large, international dietary study including Harvard physicians confirm yet again that a diet rich in plant-based foods is linked with a lower risk of developing obesity, type 2 diabetes and cardiovascular disease.[i]  The researchers looked at the composition of individuals’ microbiota as well as long-term dietary information and metabolic and cardiovascular blood markers.  They found “strong evidence” that the make-up of the microbiota is linked with these disorders and in fact, are much more important to the risk of their development than are genetics!

The study included 1098 participants from both the UK and the US who were a part of the PREDICT trial (Personalised Responses to Dietary composition Trial).  They found  “…many significant associations between microbes and specific nutrients, foods, food groups and general dietary indices, which were driven especially by the presence and diversity of healthy and plant-based foods.”  They also found microbiome-based biomarkers for obesity, cardiovascular disease and issues with glucose tolerance.  A microbiome rich in Prevotella copri and Blastocystis species was associated with keeping blood sugar low after eating.  (I have written about P. copri many times on this blog.  If you’re interested in learning more about it, look here first.  In general, it is a probiotic species but like so many other bacterial species, it has its bad side too.)

What’s particularly amazing is that their results were so consistent throughout this incredibly varied population that they believe that microbiome data can be used to determine the risk of cardiovascular disease in people, even before they have symptoms!  A personalized diet can then be created to reduce the risk of developing disease.  Says one of the senior researchers, from Harvard:  “”This study demonstrates a clear association between specific microbial species in the gut, certain foods, and risk of some common diseases…We hope to be able to use this information to help people avoid serious health problems by changing their diet to personalize their gut microbiome.”[ii]

And more good news:  other researchers, at MIT and Harvard, are working on isolating what gut bacteria influence cholesterol levels.[iii]  They found bacteria that produces a substance called ismA, which breaks cholesterol down and people with it have lower blood and fecal cholesterol levels:  “By introducing cholesterol-metabolizing gut bacteria into human gut microbiotas, or by increasing their abundance with prebiotics, it may be possible to achieve targeted effects on host serum cholesterol, a strategy that has already shown promise in influencing other areas of human metabolism.”  The bacteria involved were previously uncharacterized and have yet to actually be cultured in a lab, which is why it’s taken so long to find them and track down this particular pathway.  So, while it will be awhile before these bacteria hit the market in a probiotic product, at least we now know what bacteria are needed…which is a huge step forward.

So all in all, some good news on the “targeted” probiotic front!


[i] Microbiome connections with host metabolism and habitual diet from 1,098 deeply phenotyped individuals, Nature Medicine (2021). DOI: 10.1038/s41591-020-01183-8 ,


[iii] Kenny, DJ, et. al. Cholesterol metabolism by uncultured human gut bacteria influences host cholesterol levels.  Cell Host & Microbe. 2020. 28(2):245-257.

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