Modern technology is making it possible for medical scientists to analyze inhabitants of our innards that most people probably would rather not know about. But the resulting information could one day save your health or even your life.

I’m referring to the trillions of bacteria, viruses and fungi that inhabit virtually every body part, including those tissues once thought to be sterile. Together, they make up the human microbiome and represent what is perhaps the most promising yet challenging task of modern medicine: Determining the normal microscopic inhabitants of every organ and knowing how to restore the proper balance of organisms when it is disrupted.

Proof of principle, as scientists call it, has already been established for a sometimes devastating intestinal infection by the bacterium Clostridium difficile. This infection, popularly called C. diff, often occurs when potent antibiotics wipe out the normal bacterial inhabitants of the gut that otherwise keep it in check.

When all else fails to clear up a recurrent C. diff infection, treatment with a fecal transplant from a healthy gut presumed to contain bacteria that can suppress C. diff activity is often highly effective, with a cure rate in excess of 90 percent.