Microbes are an integral part of most, if not all multi-cellular organisms. In fact, these organisms are the way they are because of the tiny partners they house within and on them. These microbes constitute the microbiome: an “invisible organ” weighing approximately 2.5 to three kilograms in an adult human and much more in larger animals.
This unique body part was made visible with the advent of modern molecular imaging technologies. In my book Microbiomes and their Functions, I explore how it works in partnership with other visible organs and engages in a variety of physiological functions essential for the development and survival of the hosts.
Microbiomes have been part of all these organisms from the beginning, and have evolved in tandem with them, just as their visible organs have.
