Soon, there will be no denying that it was you who finished the milk. Biological engineers at the Massachusetts Institute of Technology (MIT) have tweaked human gut microbes to work as a biochemical memory system. The bacteria are equipped with the equivalent of a computer’s circuit components to encode a record of what you consume into a bacterium’s DNA.
The research isn’t primarily aiming to deduce who ate what, however. The tweaked bacteria take chemical signals from their environment as an input to create outputs that are an indicator of health. They might turn on a fluorescent protein, say, so that laboratory analysis can detect problems.
Researchers suggest that their primary use will be in identifying (and perhaps even treating) bowel disease and colon cancer. It is likely that programmable bacteria will also find other applications. They are, in effect, an in-stomach sensor that could tell your body anything. “Stop eating this stuff – it’s killing you,” they might say.
The bacterium might simply let you know when you have had enough to eat. Or, if you eat the wrong stuff, it could release chemicals that act as painful stimuli. People with addictions could have bacterial reactions – such as nausea – triggered by the problem substance. The bugs could even be made to produce a pharmaceutical treatment in the body: when they detect a problem, they could feasibly synthesise a chemical solution.
It is unfortunate that the field of synthetic biology has adopted a name with negative connotations. The term “synthetic” can trigger concerns similar to those evoked by “genetic modification”. That’s why UK government funding for synthetic biology is now tied to responsible innovation that proceeds while taking public concerns into account. Though the field is led by US researchers, the UK comes in second, producing about a tenth of the world’s output in papers on synthetic biology.
As with genetic modification, there is little need to panic. Indeed, in some areas, synthetic biology should alleviate public concerns. In a paper published this month, German researchers point out that the tools of synthetic biology can do away with the need for transporting dangerous pathogens around the world – a risky practice. Instead, the pathogen’s genome can be sequenced where it is found and its genetic code emailed to labs for re-creation and analysis in a safe environment.
New advances in synthetic biology are arriving all the time. Last month, researchers at Harvard University unveiled a bacterium with a body clock. E coli doesn’t normally have any kind of circadian rhythm, but when the researchers implanted a protein-based clock mechanism from another organism, the E coli turned a fluorescent protein on and off in a regular, 24-hour cycle. It’s a relatively short step from there to having a gut bacterium that will create and release insulin-regulating drugs or other medicines on a daily schedule.
The new work brings this possibility closer. Although E coli is not a great human companion, the bacterium used in the MIT study is a standard, problem-free inhabitant of the human gut. So, synthetic biology has just got personal. It was only last year that Pamela Silver told Harvard Magazine, “Biological machines and biological computers – all of that should soon become a reality.” This is a field that is progressing rapidly. Steal food while you still can.