It literally just means allowing a molecule into a cell. And if that molecule is a gene editor, then it can edit genes. So we’re really at the early days of trying to figure out, for all the microbes in the human gut, how do they allow molecules to get in? And the answer is, it’s different for different bugs. So in the future I think it’ll come down to understanding which bugs need to be manipulated and how they are best able to take up these editing molecules.
Well, we already use things like antibiotics, which kill off multiple different kinds of bugs in the microbiome—including the one that’s causing you to be sick, but others as well—and there are clearly consequences of that. Crispr is safer, because the precision allows you to target not all the bugs at once but one particular type. And not only that, but one particular gene in one particular bug.