Did you know that over half the cells in your body are not actually human? You and I contain masses of bacteria, fungi, viruses and archaea. They live in every part of us - on our skin, in our hair, in our mouths, in our bloodstream, in our lungs, and most especially in our digestive tract. Having just read Ed Yong's fascinating book, I Contain Multitudes , along with a few articles, I now have a much clearer idea of how much I don't know about this subject. Of course, there are lots of people who know way more than me but I also have an idea of how little anyone knows. For instance, how many non-human cells are there in our bodies? One rather complicated article I read estimates the number is within the range of 3.8-10 13 - that is, somewhere between 38 and 100 trillion cells. They estimate that the ratio of non-human to human cells in our bodies is somewhere around 1.3:1 in the 'average man', 2.2:1 in the 'average woman', and 2.3:1 in a young infant,
'Contemplating the teeming life of the shore, we have an uneasy sense of the communication of some universal truth that lies just beyond our grasp.' - Rachel Carson