I, Superorganism

Many advances in science arise from a newly realised complexity in the functioning of living systems. This applies to this very good popular account of the human microbiome - the huge internal population of microorganisms that contribute to digesting our food, making essential vitamins, breaking down toxins, metabolising drugs and influencing our hormones and immune system. The field is interdisciplinary, involving such experts as molecular geneticists, microbial ecologists, infectious disease specialists and immunologists. The book answers the question of what it means to be a superorganism and tells the story of this emerging field. Advances in DNA sequencing have played an important role and the Human Microbiome Project is a natural successor to the Human Genome Project.

Perhaps the most important activity takes place in the gut where the number of organisms would require a ladle while for the rest of the body combined, a teaspoon would suffice. Scientists are having to go beyond the war metaphor of the innate immune system in discussions of the adaptive immune system, suggesting a co-evolutionary process with shifting populations of microbiota related to our diets. Turney also refers to the network of nervous system connections between the gut and the brain. In terms of general advice, he follows Michael Pollan in recommending 'eat food, not too much, mostly plants', adding that fermented food is useful - it is good to remember that we are a habitat for a large array of other species. It is clear that this field is an important development in systems biology and reinforces the significance of cooperation along with competition.