Disclosure: most of this information was compiled from content contributed by my graduate courses at Metropolitan State University of Denver

Did you know that your body may contain more microbial cells than human cells? While the often-cited ratio of 10:1 bacterial-to-human cells is vastly overestimated. (with more refined estimates arriving at a ratio of 1.3:1), there is little doubt that the microorganisms living on and within us have profound effects on our physiology. In fact, the enhanced functions that we, as hosts, receive from this symbiotic relationship with our friendly flora justify a description of humans as "supraorganisms."

The human intestine is home to a diverse ecosystem of hundreds of bacterial species, which rely on energy and nutrients provided by our diet to meet their own biological needs. A diet rich in microbiota-accessible carbohydrates (i.e., fermentable fibers) is important for maintaining a healthy and diverse gut microbiota. On the other hand, disturbances to the composition and/or function of the gut microbiome have been implicated in the development of numerous diseases ranging from colon cancer and inflammatory bowel disease to diabetes and cardiovascular disease.

Here are a few definitions to keep in mind:

• The gut microbiota is the collection of microorganisms residing within the gastrointestinal tract. These microorganisms include bacteria, viruses, protozoa, and archaea. Most research to date has focused specifically on the gut bacteria residing in the colon, such as bifidobacteria and lactobacilli.

• The term gut microbiome is used to describe the collective genomes of these microbes. Most research these days uses genetic sequencing methods to identify the specific bacteria present in a sample. Genetic data can also be used to examine the metabolic capabilities of an individual bacterium or of an entire bacterial community.

  
  

Research into the human microbiome has grown exponentially over the past two decades. If you search "microbiome" in PubMed, you will see that only 81 articles referenced the microbiome in 2000. Fast forward to 2020, that number had risen to 20,101. It’s difficult to keep up to date on all of the latest research in this field. At the same time, there's never been a more exciting time to learn about the trillions of microbes living inside us!

To learn more about the microbiome, I’ve compiled several resources for you. These resources include a sampling of my favorite podcasts and videos from doctors, scientists and researchers who have devoted considerable time and effort to better understand the role of the microbiome. I intend to continue adding to these lists as I stumble across valuable content.

Suggested Podcasts

• Gab Fundaro, PhD – Gut Microbiome, Bacterial Diversity & the Impact of Diet & Probiotics from Sigma Nutrition Radio

• Probiotics: Scam or Superfood? from Science vs Podcast

• How to Fix Your Gut Bacteria to Prevent Heart Attacks with Dr. Stanley Hazen from the Doctor’s Farmacy Podcast

• Supporting the Vaginal Microbiome, The Root Cause of Acne, and Why Your Dog has Leaky Gut with Kiran Krishnan from the Broken Brain Podcast

• Is Brain Fog Caused by your Microbiome? With Dr. Todd LePine from the Doctor’s Farmacy Podcast

• Understanding How the Microbiome Affects Every Aspect of Your Health from the Doctor’s Farmacy Podcast

Suggested Videos

This is a fascinating talk by world-renowned microbiome expert Rob Knight, PhD originally presented at the 2019 Future of Individualized Medicine Conference. An important takeaway: the number of different types of plants a person eats has a stronger impact on their gut microbiome than any other variable (including age, sex, antibiotic use, etc.) that has been measured. This is why it’s so important to eat a variety of fruits and veggies as part of your diet!

Here is a less scientifically-dense video by Rob Knight, PhD but is still very interesting and worth a watch!

Watch this video for an easy-to-understand introduction to nutrition and the microbiome by one of the leading experts in the field, Dr. Justin Sonnenburg.

This interview with Drs. Erica and Justin Sonnenburg covers several topics related to the gut microbiome and its role in human health and disease. Drs. Erica and Justin Sonnenburg together run The Sonnenburg Lab in the Department of Microbiology and Immunology at Stanford University. Their research covers many areas related to the gut microbiota and its interactions with the host.

The Sonnenburgs have also written a book, The Good Gut: Taking Control of Your Weight, Your Mood, and Your Long-term Health. I haven’t read it, but it’s received some great reviews.