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LESSON 4 · The Microbe Within

More Than Defense

Your microbes do more than fight invaders — they also manufacture vitamins your body cannot make on its own. Gut bacteria produce much of your vitamin K, needed for blood clotting, along with several B vitamins that support energy and nerve function.

Wipe out these populations with antibiotics and you lose more than protection: you temporarily lose a small, built-in supplement factory most people never know they have.