A diet rich in high-fibre foods, such as fruits, vegetables, legumes and whole grains, encourages the production of short-chain fatty acids that are beneficial for the immune system and may help protect against the onset of Type 1 diabetes, a study shows.

The findings showed that the western diet, which lacks dietary fibre affects human gut microbiota and the production of short-chain fatty acids acetate or butyrate. The specialised diet uses starches – found in many foods including fruit and vegetables – that resist digestion and pass through to the colon or large bowel where they are broken down by microbiota (gut bacteria).

This process of fermentation produces acetate and butyrate which, when combined, provided complete protection against Type 1 diabetes, the researchers said.

“Our research found that eating a diet which encourages the gut bacteria that produce high levels of acetate or butyrate improves the integrity of the gut lining, which reduces pro-inflammatory factors and promote immune tolerance,” said Eliana Marino researcher at Monash University in Australia. “We found this had an enormous impact on the development of Type 1 diabetes,” Marino added.

The study, published in the journal Nature Immunology, highlighted how non-pharmaceutical approaches including special diets and gut bacteria could treat or prevent autoimmune diseases such as Type 1 diabetes.

“The materials we used are something you can digest that is comprised of natural products – resistant starches are a normal part of our diet. The diets we used are highly efficient at releasing beneficial metabolites. I would describe them as an extreme superfood,” explained Charles Mackay, professor at Monash University.

However, the diet was not just about eating vegetables or high-fibre foods but involved special food and a special process and would need to be managed by nutritionists, dietitians and clinicians, Mackay noted.