People inside a model of an intestine in Dresden, Germany. Photo: Getty
Show Hide image

Intelligent stomachs: what if your gut could remember what you had eaten?

Welcome to the world of synthetic biology.

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.

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 16 July 2015 issue of the New Statesman, The Motherhood Trap

Getty Images.
Show Hide image

Why Theresa May won't exclude students from the net migration target

The Prime Minister believes the public would view the move as "a fix". 

In a letter to David Cameron shortly after the last general election, Philip Hammond demanded that students be excluded from the net migration target. The then foreign secretary, who was backed by George Osborne and Sajid Javid, wrote: "From a foreign policy point of view, Britain's role as a world class destination for international students is a highly significant element of our soft power offer. It's an issue that's consistently raised with me by our foreign counterparts." Universities and businesses have long argued that it is economically harmful to limit student numbers. But David Cameron, supported by Theresa May, refused to relent. 

Appearing before the Treasury select committee yesterday, Hammond reignited the issue. "As we approach the challenge of getting net migration figures down, it is in my view essential that we look at how we do this in a way that protects the vital interests of our economy," he said. He added that "It's not whether politicians think one thing or another, it's what the public believe and I think it would be useful to explore that quesrtion." A YouGov poll published earlier this year found that 57 per cent of the public support excluding students from the "tens of thousands" target.

Amber Rudd, the Home Secretary, has also pressured May to do so. But the Prime Minister not only rejected the proposal - she demanded a stricter regime. Rudd later announced in her conference speech that there would be "tougher rules for students on lower quality courses". 

The economic case for reform is that students aid growth. The political case is that it would make the net migration target (which has been missed for six years) easier to meet (long-term immigration for study was 164,000 in the most recent period). But in May's view, excluding students from the target would be regarded by the public as a "fix" and would harm the drive to reduce numbers. If an exemption is made for one group, others will inevitably demand similar treatment. 

Universities complain that their lobbying power has been reduced by the decision to transfer ministerial responsibility from the business department to education. Bill Rammell, the former higher education minister and the vice-chancellor of Bedfordshire, said in July: “We shouldn’t assume that Theresa May as prime minister will have the same restrictive view on overseas students that Theresa May the home secretary had”. Some Tory MPs hoped that the net migration target would be abolished altogether in a "Nixon goes to China" moment.

But rather than retreating, May has doubled-down. The Prime Minister regards permanently reduced migration as essential to her vision of a more ordered society. She believes the economic benefits of high immigration are both too negligible and too narrow. 

Her ambition is a forbidding one. Net migration has not been in the "tens of thousands" since 1997: when the EU had just 15 member states and the term "BRICS" had not even been coined. But as prime minister, May is determined to achieve what she could not as home secretary. 

George Eaton is political editor of the New Statesman.