Full text of microbiologist Elaine Hsiao’s talk: Mind-Altering Microbes: How the Microbiome Affects Brain and Behavior at TEDxCaltech conference.
Listen to the MP3 Audio here: Mind-altering microbes – how the microbiome affects brain and behavior by Elaine Hsiao at TEDxCaltech
So it never ceases to amaze me that each of us carries around a 3-pound mass of cells in our heads that controls literally everything we do. Importantly though, the brain doesn’t act in isolation from the body, but rather responds to the needs and experiences of each of our organ systems.
Now, here is a staggering statistic that some of you may have heard before.
Our bodies are comprised of 10 times more microbial cells than our own human eukaryotic cells. These microbes, which are primarily bacteria, but also viruses and protozoa, they are part of our normal flora and they make up what’s called the commensal microbiome.
In the intestines there are a hundred trillion of these bugs, reflecting over 10,000 unique species, and contributing 150 times more genes than our own human genomes. It’s even estimated that, collectively, these microbes would weigh 2 to 6 pounds, which is up to twice the weight of an average adult human brain.
More and more we are learning that these commensal microbes that make up us have co-evolved to play fundamental roles in normal brain development and function.