Every inch of our body, inside and out, is oozing with bacteria. In fact, the human body carries 10 times the number of bacterial cells as human cells. Many are our friends, helping us digest food and fight off infections, for instance. But much about these abundant organisms, upon which our life depends, remains mysterious. New research finally cracks the code of a fundamental process bacteria use to defend themselves against invaders.

Source: Scientists resolve debate over how many bacteria fight off invaders