For hundreds of years, doctors have used digoxin to treat people whose hearts are failing. The drug – a modified version of a chemical from foxglove plants – makes the heart beat more strongly, slowly, and regularly. Or, at least, that’s what it usually does. In one patient out of every ten, digoxin doesn’t work. Its downfall is a gut bacterium called Eggerthella lenta, which converts the drug into an inactive and medically useless form. Only some strains of E. lenta do this. In 2013, Peter Turnbaugh showed that just two of the bacterium’s genes distinguish the problematic drug-deactivating
...more
