Barley hordeins and ultra-low gluten barley breeding
What it found
Barley hordeins are the gluten proteins that trigger reactions in people with celiac disease and non-celiac gluten sensitivity.
Researchers have bred barley mutants with very low hordein levels, and new genomic techniques could help move these traits into more barley varieties.
What they found
Studies in people
Hordeins and reactions
Hordeins are the gluten proteins in barley. They trigger adverse reactions in people with celiac disease or non-celiac gluten sensitivity.
Beta-glucan and health
Barley contains beta-glucan, a dietary fibre that can help lower cholesterol and reduce the risk of cardiovascular diseases and diabetes. Some low-hordein mutants have low beta-glucan levels, which is unwanted for food use.
Animal and lab studies
Low-hordein barley mutants
Barley mutants with missing or reduced hordeins have been produced through traditional breeding and genetic modification. Some mutants have undesirable traits like lower yield and shrunken kernels.
Other findings
Peptides linked to celiac
The authors identified 105 hordein peptides connected to celiac disease. Most of these peptides bind to the HLA-DQ2 receptor.
Ultra-low gluten barley
Researchers developed an ultra-low gluten barley line called Kebari that has gluten content under 5 ppm. It took 14 years to develop and is limited to beer-making barley.
New genomic techniques
New genomic techniques like CRISPR and bridgeRNA could speed up the transfer of ultra-low gluten traits to other barley cultivars. They could also help remove unwanted traits from existing mutants.
What the authors conclude
- They conclude that new genomic techniques, especially bridgeRNA-based genome editing, could accelerate the transfer of ultra-low gluten traits to other barley cultivars.
- They suggest that patients with celiac disease should have access to barley's beneficial health traits, like beta-glucan, without the risk of consuming gluten.
- They advise that creating non-allergenic hordein proteins would be an endless endeavour due to the sheer number of possible epitopes and peptides, so deleting hordeins or developing new therapeutics may be more feasible.
How it was done
Barley is a major global cereal, but its hordeins cause adverse reactions in people with celiac disease and non-celiac gluten sensitivity. The only current treatment for these conditions is a gluten-free diet, which limits grain-based food and drink choices.
The authors reviewed existing research on barley hordeins, including their genetic locations and the peptides linked to celiac disease. They also examined breeding work that produced barley mutants with reduced or missing hordeins, and they assessed how new genomic techniques could be used to develop barley lines with ultra-low gluten.
What it can’t tell you
- This is a review of existing research, not a new study in people. It cannot show whether ultra-low gluten barley is safe for people with celiac disease or non-celiac gluten sensitivity.
- The paper does not report long-term health outcomes from eating ultra-low gluten barley in people.
Who paid
- Conflicts
- Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Tobias Hanak reports financial support was provided by Horizon Europe. Olga A. Andrzejczak reports financial support was provided by Independent Research Fund Denmark. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
- Authors work at
- Aarhus University, Denmark
The paper
- Title
- Barley's gluten challenge: A path to hordein-free food and malt
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Hanak T, Andrzejczak OA, Hebelstrup K, Brinch-Pedersen H (2024). Barley's gluten challenge: A path to hordein-free food and malt. Plant physiology and biochemistry. doi:10.1016/j.plaphy.2024.109174Free full textPubMed 39362126DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error