Daily bread: if gluten’s not for you

People forced to avoid gluten could soon have their bread (and cake) and eat it. Now there are strains of wheat that do not produce the forms of gluten that trigger a dangerous immune reaction in as many as 1 in 100 people.

Because the new strains still contain some kinds of gluten, though, the wheat can still be used to bake bread. “It’s regarded as being pretty good, certainly better than anything on the gluten-free shelves,” says Jan Chojecki of PBL-Ventures in the UK, who is working with investors in North America to market products made with this wheat.

Gluten is the general term for all the proteins in wheat and related cereals. During baking, these proteins link up to form elastic chains, which is what holds breads and cakes together as they rise.

But some people have an autoimmune condition called coeliac disease. Their immune systems respond incorrectly to gluten, which damages the gut lining and can lead to diarrhoea, vomiting, malnutrition, brain damage and even gut cancers.


Not all gluten proteins trigger this response, though: the main culprit is a group called gliadins. So Francisco Barro’s team at the Institute for Sustainable Agriculture in Cordoba, Spain, set about getting rid of them.

Acceptable bread

They used a genetic modification technique to remove 90 per cent of the gliadins in wheat. They did this by adding genes that trigger a process called RNA interference, which stops specific proteins being made. But because the gliadin genes themselves remain intact, in theory, there is a risk that the wheat could start making the crucial proteins again.

So Barro’s team next tried using CRISPR gene-editing to get rid of the genes entirely. This is a huge task because there are no fewer than 45 copies of the gene for the main gliadin protein that causes problems. Nevertheless, Barro’s team report that they have already managed to knock out 35 of the 45 genes.

More genes need to be disabled before the CRISPR strain is ready for testing, but it should be worth all the effort: the team have already shown that the GM wheat strain makes an acceptable bread. It cannot be used for making large sliced loafs, but is good enough for baguettes and rolls, says Chojecki.

“Some people will be very happy with this,” says Sarah Sleet, head of patients’ group Coeliac UK, not least because sticking to a gluten-free diet is difficult.

However, others may not want to eat genetically modified foods, or to take the risk that some immune-triggering components remain in the wheat, Sleet says.

Small trials of the GM wheat involving 10 and 20 people with coeliac disease are already being carried out in Mexico and Spain. “All I can say is that the results are very encouraging,” says Chojecki.

Journal reference: Plant Biotechnology Journal, DOI: 10.1111/pbi.12837

Read more: Would ‘good gluten’ foods work for people who eat gluten-free?

This article appears in print under the headline “Modified wheat for gluten-free bread”