Diet plays a more important role than genetics in shaping the microbiome in mice

Today is December 31st which means it’s time to make our New Years Resolutions! Luckily for all of us, a new paper by Peter Turnbaugh’s laboratory gives us good reason to make improving our diet an important goal for the New Year. Dr. Turnbaugh and colleagues at Harvard University and University of California, San Francisco have shown that diet plays the dominant role over genetics in shaping the gut microbiome in mammals. 

Published in Cell Host and Microbe, the team of scientists used several strains of mice to investigate whether diet or the genetics of the mice played a more important role in what bacteria colonized the gut.  They exposed the mice to a low-fat, plant-based (LFPP) diet and a high-fat, high-sugar (HFHS) diet. When mice were given the HFHS, an increase in Firmicutes bacteria and a decrease in Bacteroidetes bacteria was seen, regardless as to what their genetic background was.  When the LFPP diet was given, the shift went in the other direction.  Further investigation needs to be done to better understand whether diet plays a direct role in shaping the bacterial communities in the gut or if it is due to an indirect role that the food has on the entire body of the host.

Another important takeaway from the study was that most changes to the microbiome are reversible. This means that once you shift to a new diet, the microbiome changes with the new diet and the new microbial communities are established within 3 days of exposure to the new diet.  However, the microbiome does remember past dietary patterns.  They leave an imprint on the microbial communities in the gut and some bacterial species are dependent on prior consumption.  

Dr. Turnbaugh suggests that in the future it may be possible to design diets that shape the microbiome in ways that are therapeutically beneficial.  He also states that due to this finding that diet plays a more important role than genetics on establishing gut bacteria, diets won’t need to be tailored to every individual person and specific diets may be useful for most people. 

So while you make your New Years Resolution to eat better and have a healthier diet, know that you are not only impacting your nutritional intake but you are also shaping your microbiome.

We wish all of our readers a happy and healthy New Year. This has been a particularly exciting first year for us and we look forward to another great year ahead.  

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The views expressed in the blog are solely those of the author of the blog and not necessarily the American Microbiome Institute or any of our scientists, sponsors, donors, or affiliates.