Scientists have grasped the importance of the microbiome just as modern lifestyles are ravaging it.
What is the greatest advance in scientific understanding of the human body so far this century? With due respect to the progress made in human genetics, oncology and neuroscience, my answer is appreciation of the microbiome: the vast population of microbes that live within all of us and play a vital role in our health and wellbeing.
Although microbiologists have known for many decades that everyone hosts resident bacteria, beneficial and malign, their diversity and biological significance are only now becoming clear as scientists deploy new techniques of molecular biology to probe the microbiome. A healthy adult is made up of about 10tn human cells; microbial cells are smaller but there are 10 times more of them, weighing in at 3lb in total, roughly the same as the brain.
Recent research shows that the hundreds of microbial species populating this teeming inner world play essential roles in the most fundamental processes of our lives, from digestion to immune response and even behaviour. Imbalances in the microbiome, caused by aspects of the modern lifestyle such as medication, sanitation and diet, have been linked with diseases from obesity and diabetes to asthma and eczema. . .