Academics from the university’s Biomedicine Discovery Institute led an international study that found – for the first time – that a diet yielding high amounts of the short-chain fatty acids acetate and butyrate provided considerable diabetes benefits.
Autoimmune type 1 diabetes occurs when autoreactive T cells attack and destroy the cells that produce insulin.
The diet developed by researchers used resistant starches – found in many foods including fruit and vegetables – that pass through to the colon where they are broken down by microbiota. This process of fermentation produces acetate and butyrate which, when combined, provided protection against type 1 diabetes.
“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 Dr Eliana Mariño.
“We found this had an enormous impact on the development of type 1 diabetes,” she said.
The findings were published today, March 28, in the journal Nature Immunology.
The paper stated: “Feeding mice a combined acetate and butyrate-yielding diet provided complete protection, which suggested that acetate and butyrate might operate through distinct mechanisms.
“Acetate markedly decreased the frequency of autoreactive T cells in lymphoid tissues, through effects on B cells and their ability to expand populations of autoreactive T cells. A diet containing butyrate boosted the number and function of regulatory T cells, whereas acetate- and butyrate-yielding diets enhanced gut integrity and decreased serum concentration of diabetogenic cytokines such as IL-21.”
Professor Charles Mackay, 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.
“The findings illustrate the dawn of a new era in treating human disease with medicinal foods,” Professor Mackay said.
“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,” he said.
The researchers are hoping to gain funding to take the findings into type 1 diabetes into clinical research. Professor Mackay, Dr Mariño and collaborators around Australia are expanding their research to investigate diet’s effect on obesity and other inflammatory diseases including cardiovascular disease, type 2 diabetes, asthma, food allergies and Inflammatory Bowel Disease.
This research was supported by the Juvenile Diabetes Research Foundation, the Diabetes Australia Research Trust and the Australian National Health and Medical Research Council.
Source: Nature Immunology
“Gut microbial metabolites limit the frequency of autoimmune T cells and protect against type 1 diabetes”
Authors: Charles Mackay, et al.