It can take six months to regain a normal microbiome—the essential bacteria that live in our stomach—after using antibiotics, and chances are good that not all of the microbes present before the antibiotics were administered will return.
Researchers in Copenhagen conducted a small study (12 men) that examined gut diversity after a single course of antibiotics. They used three drugs considered antibiotics of last resort: meropenem, gentamicin, and vancomycin.
