Antibiotics damage beneficial gut bacteria and often prevent the microbiota from fully recovering to its original state.

“These are not drugs designed in any way to spare the bacteria that live in our gutmost. Antibiotics that we take are in fact designed to be in broad spectrum to kill a wide variety of microbes so that they can be used for many different types of infection. What we're finding is that these antibiotics do wreak havoc in our guts. So many of the microbes that are beneficial that inhabit us are killed by these antibiotics, and what we're finding is that often the microbiota....there is or it is able to rebound, but often it is not able to rebound exactly as it was before.”