Let's start gently. As with many other stories on the microbiome, this article quotes the oft cited "fact" of a 10:1 ratio of microbial cells to human cells.
By some estimates the body has between 35 and 100 trillion cells with only 1 in 10 belonging to tissues and organs and the rest belonging to the microbiome.This has been refusted by a great article in the Boston Globe by Peter Andrey Smith in September 2014 (long before this was published): Is your body mostly microbes? Actually, we have no idea. Yes, I and many others cited this 10:1 ratio before the Globe. But seeing it cited in this from December 2014 suggests Chopra and Tanzi aren't really paying attention to microbiome science.
The next comment I find a bit off is the follwing:
Our personal human genome also determines the composition of our microbiome, which in turn can influence metabolism and propensity for weight gain.Sure. Our genes influence out microbiome. But "determines the composition" is way to strong a statement.
But the things that got to me most were many of the comments supposedly about evolution. I list some of them below:
- This varying ecosystem isn't populated by foreign invaders and pathogens but by colonies closely connected to human evolution.
- I don't even know what this is supposed to mean. These are not "colonies" first of all. And second, what does "connected to human evolution" even mean? And wouldn't pathogens be connected to human evolution?
- The microbiome interfaces between the human body and the outside world in complex ways, but the gist is that human DNA has evolved in cooperation with microbial DNA. This fact is more important than the interactions that cause diseases created by invading bacteria and viruses.
- Re "human DNA has evolved in cooperation with microbial DNA". Well, sure. Some of the microbes we live with are mutualists. But most likely only a limited number of mutualistic interactions are going on. This sounds like a Gaia type of model, with no evidence.
- And then "This fact is more important than the interactions that cause diseases created by invading bacteria and viruses." Really? More important than the plague? Than malaria? Aids? Cholera. TB? Worms? And more. This sounds really silly.
- Mitochondria actually have their own genomes inherited from the mother without change.
- Umm - no mitochondria mutate and change, well, all the time.
- Some of the most archaic microorganisms on Earth survive today in our microbiome.
- This is without any justification. First of all - what does "most archaic" mean? And second, if it means what I think it means (organisms that have features like those from billions of years ago) - well - no - the human microbiome does not have a lot of such organisms. This is just complete hooey.
- It would appear that the genome and the microbiome cross-talk, a conversation that has been continuing for billions of years with no signs of stopping.
- What does this even mean? In what way has the human microbiome been interacting with the human genome for billions of years. In what way have human ancestors been interacting with microbiomes for billions of years?
Yes, the microbiome is important. But this "essay" is filled with nebulous pseudoscientific comments about the microbiome all, apparently, to sell an upcoming book and related activities
"In an upcoming book we are co-authoring, Super Genes, we will present the latest findings as well as a lifestyle program devoted to what we call Self-Directed Biological Transformation"
Right now, I don't think Chopra and Tanzi show any evidence they really understand the microbiome .. doesn't bode well for their book and lifestyle program.
Post a Comment