Bacterial gene copy number can affect substance metabolism, as seen with digoxin metabolism by a microbe.

“and one of the reasons why that drug fell from being first line is because the efficacy sort of had such a wide broad range across people so it's hard to know what's the right amount to to prescribe to somebody wait does it treat arhythmia is or heart failure it's heart failure yeah yeah yeah anyway that's how long I've been away from the game um and and I'm no clinician so I but but what they found was that there's a microbe that can metabolize dexin so people who needed higher doses to have efficacy St St many had over five it could metabolize your doxin less than five it couldn't”