Many headlines and stories (including some of ours) have been saying that a "double agent" infiltrated al-Qaida in the Arabian Peninsula and foiled a plot to get another underwear bomb aboard a U.S.-bound passenger jet.
But we've been looking at definitions of spy terms and think that based on what we have been told so far, the person at the center of the story wasn't a double agent.
What if it's not just our genes or our lifestyle, exactly, that makes us skinny or fat, healthy or sick? What if it's also the makeup of the bacterial ecosystem that inhabits our gut?
A growing pile of scientific studies is pointing us in that direction. Researchers in this hot new field describe the microbes in our gut as a vital organ that's as essential as our liver or kidneys. They're finding that this organ, which they call the "microbiome," varies greatly from person to person.