"Further, nearly every one of us carries pathogens, but in healthy individuals they simply coexist with their host and bacterial neighbors. Now the mystery is why they sometimes turn deadly, and under what conditions -- which could change how we think about the ways in which microorganisms cause disease. With microbiome from healthy individuals sequenced and defined, now scientists are plunging into disease-specific research, exploring how the gut's microbes might affect inflammatory bowel disease, or how the skin's microorganisms might play a role in psoriasis and other diseases."
Glenn D. Braunstein, M.D.: Gut Check: Science Probes Frontier Within Us Made Up of Millions and Billions of Microbes