Eating a diet high in fibre and vitamin A can reconfigure both your gut and immune system to better fight allergies to food substances like peanuts, according to new research.
Researchers from Monash University in Melbourne investigated the affects of a high-fibre diet in mice allergic to peanuts and found that they were protected against the allergy and the symptoms associated. The study was published today in Cell Reports.
“This suggests that fibre promotes peanut tolerance via the actions of its metabolites – specifically, short-chain fatty acids – on immune cells involved in food tolerance,” Mr Jian Tan, a PhD student and co-author of the study, tells New Scientist.
Mr Tan and his colleagues bred mice with an artificial peanut allergy and fed them a high-fibre diet to see the effects on their microbiota, or bacteria, in the gut and colon and their immune systems.
They found the fibre helped reshape the microbiota to protect against food allergies and that transferring this ‘good bacteria’ into mice without it helped to reduce their food allergy symptoms.
“The results of this study could be important because Australian children have the highest recorded rate of food allergies in the world so we need to work out how to treat them,” says Mr Tan.
It’s likely that compared to our ancestors, we’re eating unbelievable amounts of fat and sugar, and just not enough fibre.
According to the Australian Bureau of Statistics, around 17 per cent of Australians (3.7 million people) have a food allergy or intolerance of some kind, and that peanut allergies accounted for 1.4 per cent of food allergies.
“It’s likely that compared to our ancestors, we’re eating unbelievable amounts of fat and sugar, and just not enough fibre,” says Dr Laurence Macia, immunologist and study co-author.
“And these findings might be telling us that we need that high-fibre intake, not just to prevent food allergy, but possibly other inflammatory conditions as well.”
Fibre can be obtained from wholegrain cereals, wheat bran, legumes and dried fruits, and vitamin A is found in fruits and vegetables like spinach, carrots, apricot and animal sources such as butter.
The researchers found that, thanks to an improved microbiota population in the digestive tract, the fibre was also more readily broken down into short-chain fatty acids.
An increased level of short-chain fatty acids was found to have a regulatory effect on the immune system’s dendritic cells, which are largely responsible for whether or not an allergic reaction to a food allergen takes place.
“My theory is that the beneficial bacteria that predominate under consumption of fibre promotes the development of regulatory T cells, which ensures the bacteria have a healthy, anti-inflammatory system to thrive in,” says Dr Macia.
There's plenty of evidence to support digestive health playing a key role in the prevention and treatment of food allergies, and this includes having strong colonies of 'good' bacteria in the gut.
The short-chain fatty acids, alongside vitamin A, helped to ‘switch off’ these dendritic cells to stop their allergic response.
The findings are significant because it could allow immunologists to design new treatment therapies that involve delivering short-chain fatty acids into the gut and colon to alter immune cell activity.
Ms Tracie Hyam Connor, a practising nutritionist, tells SBS that this link between digestive health and food allergies could help to expand treatment options.
“There's plenty of evidence to support digestive health playing a key role in the prevention and treatment of food allergies, and this includes having strong colonies of 'good' bacteria in the gut,” she says.
“Any new valid research findings deliver important opportunity to expand on current treatments and advice for people with food allergies.”
The next step in the research will be to conduct pre-clinical trials to see whether the observed anti-allergy effect of a high-fibre diet can be replicated in humans, as well as determining the type and form of fibre that would need to be provided.
Learn more about our microbiota with Dr Michael Moslet's Guts.