Millions of us go on vacation every year only to be struck down with a spot of runny tummy. What should have been a fun time is ruined by the inability of our guts to deal with foreign bacteria, particularly in water and food.
But perhaps not forever. One day we might take a pill in the days leading up to our trip to prepare for the microbial onslaught. The solution? Genetically altered bacteria that can sense “bad” bacteria and put an end to it.
The concept comes from Harvard’s Wyss Institute, which recently won a $4.7 million grant from the Defense Advanced Research Projects Agency (DARPA). “The basic idea is to have bacteria that are genetically engineered and that live in your gut and will sense when there is inflammation and then activate a response that is directed against the type of bacteria that causes travelers to get sick,” says Jeff Way, a senior staff scientist at Wyss.
We’re familiar with probiotic foods that balance beneficial and harmful bugs in our stomachs, but Wyss’s work is more sophisticated than that. Its synthetic bacteria sense for chemicals that bugs give off when they want to kill other bugs. “We can basically take the sensing system that pathogens normally use to know when to grow, and engineer it into probiotic, harmless bacteria and produce a useful response,” Way says.
And that’s not all. The research also looks to deal with a big obstacle to greater use of bioengineered organisms: that they might escape into the environment after their intended use. The bacteria, which come as a sort of combo-pack, are designed to work only in a specific environment and nowhere else, limiting the potential for harm.
“You would like to give people pills that consist of bacteria and have some therapeutic function, but once they get pooped out, they basically have to die, because you don’t want them in the ecosystem contaminating person-to-person, and so on,” Way says.
Potentially, Wyss self-destructing beneficial bacteria could have uses in fields like energy, where bugs are used to grow biofuels, or for cleaning up fields sprayed with too many pesticides. “We anticipate that in five years time a lot of people will be re-synthesizing whole bacterial genomes and that our concept could hugely generalizable,” Way says.