Public interest in gut health is at an all time high and scientific research into the complex interactions between your gastrointestinal system and almost every other aspect of your health is moving forward at an extraordinarily fast pace.
Now, the latest in a long line of studies attesting to the widespread benefits of nurturing your GI health, has found that a high fibre diet may actually help to prevent Type 1 diabetes.
More than 20 million people worldwide are affected by Type 1 diabetes, often referred to as ‘juvenile onset’ because most are diagnosed before the age of 14. It is an autoimmune condition where the immune system attacks the insulin-producing cells in the pancreas. Lifelong treatment includes regular insulin injections to keep blood sugar levels balanced.
In this new study, researchers from Monash University in Melbourne, led by immunologist Charles Mackay, created a fibre-rich diet, which promotes the body’s production of crucial short chain fatty acids (SCFAs) – acetate and butyrate.
Mice bred specifically to develop Type 1 diabetes were fed either a normal or fibre-rich diet for 30 weeks. More than 70% of the mice fed a normal diet developed Type 1 diabetes, whereas the high fibre diet almost entirely protected against the condition. The diet was rich in a specific type of fibre that comes from high amylose corn starch. This type of fibre is resistant to digestion in the upper intestine, and instead is fermented into acetate and butyrate by bacteria in the large intestine, or colon.
Acetate and butyrate may work in different ways to modify the immune response that attacks pancreatic cells. The researchers found that acetate seemed to reduce the number of immune cells primed to attack the pancreas, whereas butyrate enhanced the production of other cells that dampen down the immune reaction.
Lead researcher Charles Mackay commented on the results,
“What we saw was dramatic. When we give the (fibre-rich) diet to mice that spontaneously develop type 1 diabetes, we could almost completely eliminate their disease.”
Short chain fatty acids (SCFAs) are produced when friendly gut bacteria ferment fibre in your colon. They are the main source of nutrition for cells in your colon and are known to dampen down the immune system. They are considered to have the potential to support a range of disorders from asthma to irritable bowel syndrome (IBS) and now this new study shows tremendous promise for the potential to prevent Type 1 diabetes.
Whilst it’s too early to know whether the results of this animal study will translate into humans the initial signs are hugely encouraging.
The researchers concluded:
“We think our study establishes the concept that we can stop a disease with natural medicinal food.”
And since the health benefits of eating a fibre-rich diet are widespread, it makes perfect sense to increase your intake anyway. The amount and type of fibre consumed affects the bacterial composition in your gut, which in turn affects the production of SCFAs. To get more fibre in your diet, increase your intake of fruits, vegetables and legumes.
Here’s a summary of the best types of fibre to include in your diet to encourage the production of SCFAs in your colon:
• Resistant starch - grains, barley, rice, beans, under-ripe bananas, legumes & potatoes (cooked then cooled)
• Pectin – apples,apricots, carrots & oranges
• Fructooligosaccharides (FOS) – onions, garlic, bananas & asparagus
• Inulin – onions, garlic, leeks, artichokes, wheat, rye, asparagus
• Arabinoxylan – cereal grains
• Guar gum – guar beans (legumes)
Mackay CR, Harrison LC et al. Gut microbial metabolites limit the frequency of autoimmune T cells and protect against Type 1 diabetes. Nature Immunology 18, 552-562 (2017) doi: 10.1038/ni.3713. Published online 27 March 2017