What Diet Is The Most Beneficial for Our Microbiome?

It feels like every week there’s a new fad miracle diet that promises to cure diseases.  One week certain foods that are labeled “bad” can be suddenly considered a key element to nutrition.  From the Cabbage Soup Diet to the Atkins Diet, supporters usually claim that their ailments were healed by simple substitutions or restrictions, but how do these diets affect our intestinal microbiome?  More importantly, does the diversity and health of our microbiome affect our overall health? And what is the microbiome anyway?

A research team from the University of California had a few of these same questions and decided to delve deep into recent microbiome literature in order to further investigate what sort of impact the bacteria living in our intestines can have on our overall health. The intestinal microbiome is the microorganism ecosystem that resides in your gut, and it is comprised of not only bacteria, but viruses, fungi, and protozoa as well.  As more and more research studies are being published, there is an increasing amount of evidence linking a healthy diet and a healthy gut to positive overall health. A great number of microbiome studies are completed using 16s rRNA amplicon sequencing.  16s rRNA sequencing is the most common method used to study the microbiome due to its low cost.  However, it only provides microbial identification, not function.  Although more expensive, shotgun metagenomic sequencing sequences the whole bacterial genome.  Through shotgun metagenomic sequencing, microbial identification and gene composition can be analyzed.  This in turn allows researchers to draw conclusions of the functionality of different genes.

Through their literature review, Singh et al. found that the Western Diet is proven to be detrimental not only to the microbiome, but to the host’s overall health.  The Western Diet, characterized as a high intake of red meat, processed meat, refined foods including sugar, high fructose corn syrup, and grains, and of course fried food results in a significant reduction in beneficial bacteria and an increase in cardiovascular disease, diabetes, obesity, and inflammation.  Alternatively, the front runner for a healthy microbiome was the Mediterranean diet.  The Mediterranean diet is comprised of a high intake of fruits and vegetables, legumes, and nuts, moderate amount of whole grains and red wine, higher intake of protein from plant sources rather than animal, and reduced intake of red meat while focusing on lean meats such as chicken and fish.  The Mediterranean diet resulted in an increase in healthy microbiome bacteria including  Lactobacillus, Bifidobacterium, and Prevotella.  Subsequently, people who follow this diet have a significant decrease in cardiovascular disease, obesity, diabetes and inflammation.

As research has indicated, what is good for our gut microbiome is good for our overall health.