Bacteria In Control Of Life, Death, & Evolution?

Pathological bacteria are only 5% of the bacterial population. The other 95% promote the health and well-being of Earth. The digestive tract holds trillions of archaebacteria from over 4 1/2 billion years ago. When in danger, bacteria create shells for protection. Are humans evolved shells in order to protect the bacteria from atmospheric oxygen? Life forms are descended from prokaryote archaebacteria, for whom oxygen is unnecessary. After millions of years of evolution, can bacteria now di...