An Australian–led study has found that a diet high in short–chain fatty acids acetate and butyrate was able to provide protection against type 1 diabetes in laboratory models. Researchers from Monash University’s Biomedicine Discovery Institute, the Walter and Eliza Hall Institute and CSIRO, with national and international collaborators, led the research, which was published in the journal Nature Immunology.

The specialised diet developed by CSIRO and Monash University researchers 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. This process of fermentation produces acetate and butyrate which, when combined, provided complete protection against type 1 diabetes.

Dr Eliana Mariño from Monash Biomedicine Discovery Institute said the Western diet affected our gut microbiota and decreased the production of the short–chain fatty acids acetate and butyrate.

“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 promotes immune tolerance,” Dr Mariño said.

“We found this had an enormous impact on the development of type 1 diabetes,” she said.

Professor Charles Mackay from Monash University, who initiated the research, said the study highlighted how non–pharmaceutical approaches including special diets and gut bacteria could treat or prevent autoimmune diseases such as type 1 diabetes.

“We are at the dawn of a new era in treating human disease with medicinal foods,” Professor Mackay said.

Professor Len Harrison from the Walter and Eliza Hall Institute, who was involved in the study, said the findings provided more evidence of the importance of diet in maintaining a healthy immune system and preventing inflammatory diseases.

“Changes in our diet, with less variety of natural foods and more processed foods, have led to our gut microbiome becoming much less complex and diverse, and less anti–inflammatory,” said Professor Harrison, who is also a clinician at the Royal Melbourne Hospital.

“This approach of feeding short–chain fatty acids to mimic a super high–fibre diet is directly translatable to humans. A proposal for a clinical trial in humans with type 1 diabetes had already been drafted.”

The researchers noted that the diet was not just about eating vegetables or high–fibre foods but involved specialised food, and would need to be managed by dietitians and clinicians.

The researchers are expanding their efforts to investigate the diet’s effect on obesity and other inflammatory diseases including cardiovascular disease, type 2 diabetes, asthma, food allergies and inflammatory bowel disease.