Sep 29 2017

GM Wheat for the Gluten Sensitive

gluten (1)Celiac disease is a serious disorder that affects about 1% of the population worldwide. The disease results from an immune reaction to gliadin, which is part of the gluten protein found in wheat, rye, and barely. Glutens are stretchy proteins that give breads their sponginess and allow breads to rise.

Those with celiac disease make antibodies to gliadin, which causes inflammation of the lining of the small intestine and a number of painful and harmful symptoms. It can now be accurately diagnosed with blood tests for the anti-gliadin antibodies, but the only treatment is a life-long diet free of any gluten.

Gluten has also caught the attention of the clean-eating food fad crowd, who have convinced many people they have non-celiac gluten sensitivity. As I discussed previously, this entity is controversial at best and probably doesn’t exist. However, it is always important to point out that many people who end up falling into an ultimately false diagnosis may have a different real disease. Some people who now get labeled as gluten sensitive may actually have wheat allergies. There are other possible culprits as well, such as FODMAPs (fermentable, oligo-, di-, monosaccharides, and polyols).

Regardless, life for those with celiac disease can be challenging. The diet is rigorous, and even the smallest amount of gluten can trigger a reaction in those truly sensitive. 

Genetic Modification to the Rescue

Researchers are attempting to address this situation by creating a genetically modified wheat that produces gluten without the gliadin component that triggers the immune response. They recently published the results of their initial work. Essentially they identified 45 genes in wheat that are related to gliadin, and they used CRISPR to silence or remove them. They report:

The -gliadin gene family of wheat contains four highly stimulatory peptides, of which the 33-mer is the main immunodominant peptide in celiac patients. We designed two sgRNAs to target a conserved region adjacent to the coding sequence for the 33-mer in the -gliadin genes. Twenty-one mutant lines were generated, all showing strong reduction in -gliadins. Up to 35 different genes were mutated in one of the lines of the 45 different genes identified in the wild type, while immunoreactivity was reduced by 85%.

A “33-mer” is simply a protein component made of 33 amino acids (proteins are basically folded chains of 20 different amino acids). In one of the mutant lines created they were able to silence 35 of the 45 genes used to produce gliadin, with an 85% reduction in the immune response. They plan to continue their work to silence all 45 genes, which will hopefully result in 100% reduction in immune response.

The resulting wheat will not be exactly like regular wheat, but it will still have gluten, just not as spongy as regular gluten. It can apparently be used to make some breads and other wheat products and could be a huge boon to those with celiac disease.

Similar efforts are under way to use genetic modification techniques to make other foods safer for some or all of the population. One target of extensive research is peanuts. Peanut and tree nut allergies are common and can be fatal. Research is under way to identify the genes that code for the allergy-causing proteins, and then CRISPR them away.

This will prove challenging, however, and will likely take longer than rosy predictions. Because nut allergies can be severe, you really have to get all the allergy causing genes. I will then be necessary to either completely segregate the hypoallergenic nuts, or completely replace the regular varieties. Further, it remains to be seen what the resulting nuts will be like in terms of taste and nutrition.

But still, these all seem like solvable problems. The reduction in health-care costs from treating unintended nut allergic reactions is probably worth the cost of research and development.

There are already GMO potato varieties that have reduce acrylamide, which is a compound that can increase the risk of cancer when it is cooked.

These types of genetic changes, it should be pointed out, do not involve inserting new genes into crops but just silencing or removing existing genes. Because of this the risk of unintended consequences is small.

These examples show the potential of genetic modification to make our food safer, and reduce health-care costs. This, of course, adds to the potential harm caused by ideological opposition to genetically modified organisms.

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