A new study has claimed that dietary fibre deters immune system from over-reacting, causing diseases such as asthma.

An international team has carried out the study and found that insoluble dietary fibre, or roughage, not only keeps one fit but plays a vital role in the immune system, keeping certain diseases at bay.

Foods high in dietary fibre include fruits, grains, nuts, vegetables and seeds.

In their study, researchers, led by Garvan Institute of Medical Research, have demonstrated that GPR43, a molecule expressed by immune cells and previously shown to bind short chain fatty acids, functions as an anti-inflammatory receptor.

Team leader Prof Charles Mackay said: “The notion that diet might have profound effects on immune responses or inflammatory diseases has never been taken that seriously.

“We believe that changes in diet, associated with western lifestyles, contribute to the increasing incidences of asthma, Type 1 diabetes and other autoimmune diseases. Now we have a new molecular mechanism that might explain how diet is affecting our immune systems.”

Mice that lack the GPR43 gene have increased inflammation, and poor ability to resolve inflammation, because their immune cells can’t bind to short chain fatty acids, the researchers found in their study.

Co-researcher Kendle Maslowski said: “The kinds of foods you eat directly determine the levels of certain bacteria in your gut.

“Changing diets are changing the kinds of gut bacteria we have, as well as their by-products, particularly short chain fatty acids. If we have low amounts of dietary fibre, then we’re going to have low levels of short chain fatty acids, which we have demonstrated are very important in the immune systems of mice.”

The findings have been published in the ‘Nature’ journal.

Keywords: USscientific studiesasthma

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