You are what you eat

This phrase has been knocking around Europe since the early nineteenth century, but was made popular in the Anglophone world by Dr. Lindlahr, writer of a number of popular foodie books in the middle of the twentieth century. A phrase which remains very much in the minds of those who work hard to improve the diets of others, perhaps their children and family, perhaps some wider circle.

To which some of us would respond, well yes, fair enough, but you need to remember about genes. As well as what we eat, we are also what our genes say. And as Ungar reminded us in the talk noticed at reference 2, as far as the size of your teeth goes, you are pretty much stuck with what the genes say.

All of which was given an interesting new twist, at least to me, by the recent PLOS paper at reference 3.

The claim there is that over half the cells in our bodies are actually micro-organisms, with each of the various species of micro-organisms involved having its own genome, genomes which add up to something which is orders of magnitude bigger than our own. Furthermore, each person, each group of people, has a shifting population of such micro-organisms. A population which manages to be unique as well as shifting, as good as DNA, an earprint (Simenon is keen on these) or a fingerprint.

A lot of these organisms live in the gut, from where they are now being shown to have an intimate relationship with things going on in the brain (amongst other places), and may well affect things like the way you feel or your mood. Or the way that you respond to this or that drug therapy.

Put more fancifully, what we think of as a human being is little more than a fancy host for lots of small beings in the gut. Rather as termites might live in a tower, maggots might live in a corpse or humans might live in a city. We might have fancy ideas about our place in the world, in the universe even, but the bugs know better.

While the authors of the paper at reference 3 draw more erudite conclusions about the need for changes in the worlds of art and science.

PS: people that work with trees have known about all this for a long time, with trees having a complicated relationship with all the micro-organisms which live within range of their root systems. See references 5 and 6.

Reference 1: https://www.wearewhatweeat.co.nz/.

Reference 2: http://psmv3.blogspot.co.uk/2018/03/dental-affairs.html.

Reference 3: How the microbiome challenges our concept of self - Tobias Rees, Thomas Bosch, Angela E. Douglas – 2018.

Reference 4: https://www.termiteweb.com/termite-nests/.

Reference 5: Woodlands – Oliver Rackham – 2010.

Reference 6: http://pumpkinstrokemarrow.blogspot.co.uk/search?q=oliver+rackham.