The human microbiome is the dark matter of biology: we know it’s there and critically balances health from disease. We can broadly examine microbe members with advanced DNA sequencing methods and infer their species makeup. With several doses of antibiotics, we can even observe what happens when we temporarily lose our trillions of symbiotic microbugs. Spoiler: the results, ranging from depressive symptoms to upset guts, aren’t pretty.
Yet despite 15 years of research, the human microbiome remains a mysterious ecosystem invisibly thriving on our skin, guts, mouths, and private areas. A single microbiome can contain several dozens of species of microbes, co-existing in intermingled jumbles and chemically communicating with each other—and us—through a variety of biomolecules, the identities of most yet unknown.