Australian Researchers Discover Link Between Bacterial Exposure And Celiac Disease
Source: Thailand Medical News Jan 08, 2020 4 years, 11 months, 2 weeks, 1 day, 12 minutes ago
Researchers from Monash University, Australia have identified bacterial exposure as a potential environmental risk factor in developing
coeliac disease, a hereditary
autoimmune-like condition that has a global incidence of about 1.1% of the world population.
In Australia, it is estimated that half of all Australians are born with one of two genes that cause
coeliac disease, and approximately one in 40 are likely to develop the condition.
Individuals with
coeliac disease must follow a lifelong
gluten-free diet, as even small amounts of
gluten can cause health problems.
Although environmental factors are known to trigger
Coeliac Disease in those with the genetic predisposition, exactly how that works has remained unclear.
Medical scientists from the Monash Biomedicine Discovery Institute (BDI) and ARC Centre of Excellence in Advanced Molecular Imaging, have now provided a molecular foundation for microbial
or
bacterial exposure as a potential environmental factor in the development of
coeliac disease.
The research findings, done in collaboration with researchers at Leiden University Medical Centre and the Walter and Eliza Hall Institute of Medical Research, have been published in the journal
Nature Structural and Molecular Biology.
Dr. Hugh Reid, from Monash University, a co-lead researcher said the team showed, at the molecular level, how receptors isolated from
immune T cells from
coeliac disease patients can recognise protein fragments from certain
bacteria that mimic those fragments from
gluten.
Prior
exposure to such
bacterial proteins may be involved in the generation of aberrant recognition of
gluten by these same T cells when susceptible individuals eat cereals containing
gluten, he said.
He told
Thailand Medical News, "In
coeliac disease you get aberrant reactivity to
gluten and we have provided a proof-of-principle that there's a link between
gluten proteins and proteins that are found in some
bacteria. That is, it's possible that the
immune system reacts to the
bacterial proteins in a normal
immune response and in so doing develops a reaction to gluten proteins because, to the
immune system, they look indistinguishable ie like a mimic."
He said the findings could eventually lead to diagnostic or therapeutic approaches to
coeliac disease.
Coeliac or
celiac disease is caused by an aberrant reaction of the
immune system to
g
luten, a protein which occurs naturally in grains such as wheat, rye, barley and oats, and therefore is typically found in bread, pastries and cakes.
Immune system cells, known as T cells, regard
gluten as a foreign substance, and initiate action against it.
In individuals with
Celiac Disease, activation of these T cells leads to an inflammatory response in the small intestine causing a wide range of symptoms including diarrhoea, bloating and malabsorption of nutrients, to name a few.
Individuals with
coeliac disease must follow a lifelong
gluten-free diet, as even small amounts of
gluten can cause health problems. If left untreated, the disease can cause serious issues including malnutrition, osteoporosis, depression and infertility, and there is a small increased risk of certain forms of cancer, such as lymphoma of the small bowel.
Reference : Jan Petersen et al, T cell receptor cross-reactivity between gliadin and bacterial peptides in celiac disease, Nature Structural & Molecular Biology (2019). DOI: 10.1038/s41594-019-0353-4
