Here’s a creepy thought. About half the cells in your body are not human. The rogue agents are bacteria, fungi and archaea. Your body is teeming with these tiny intruders. Anywhere between 500 and 1,000 species have made a home within your folds, ducts, flaps and chambers, and they’re each present in their billions.
Even your human cells are not entirely your own. Many mothers retain cells from their babies in a process known as microchimerism. These cells function and divide alongside the mother’s native cells, yet remain genetically distinct.
Such remnants can be passed on to further babies, and even linger into the next generation. Cells from your grandmother might loiter in your abdomen; a tincture of your uncle may sequester in your spleen.
Your body is entirely your own - WRONG!