Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New findings connect diet and intestinal bacteria with healthier immune systems

30.10.2009
Insoluble dietary fibre, or roughage, not only keeps you regular, say Australian scientists, it also plays a vital role in the immune system, keeping certain diseases at bay.

The indigestible part of all plant-based foods pushes its way through most of the digestive tract unchanged, acting as a kind of internal broom. When it arrives in the colon, bacteria convert it to energy and compounds known as ‘short chain fatty acids’. These are already known to alleviate the symptoms of colitis, an inflammatory gut condition. 1

Similarly, probiotics and prebiotics, food supplements that affect the balance of gut bacteria, reduce the symptoms of asthma and rheumatoid arthritis, also inflammatory diseases. Until now no-one has understood why.

Published tomorrow in Nature, breakthrough research by a Sydney-based team makes new sense of such known facts by describing a mechanism that links diet, gut bacteria and the immune system.

PhD student Kendle Maslowski and Professor Charles Mackay from the Garvan Institute of Medical Research, in collaboration with the Co-operative Research Centre for Asthma and Airways, 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,

“The notion that diet might have profound effects on immune responses or inflammatory diseases has never been taken that seriously” said Professor Mackay. “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.”

“We’re also now beginning to understand that from the moment you’re born, it’s incredibly important to be colonised by the right kinds of gut bacteria,” added Kendle. “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.”

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.

There is plenty of evidence to suggest that bacteria and their by-products play an important role in people. An American study published in Nature in 2006 2 compared the bacteria in the guts of obese and lean people. The obese people were put on a diet, and as they lost weight their bacteria profile gradually came to match that of the lean people.

Another study 3 looked at what diets might do to short chain fatty acid levels. Obese people were put on three different diets over time – high, medium and low fibre – and there was a direct correlation between the level of carbohydrate, or fibre, in the diet and the level of short chain fatty acids.

The conclusions drawn from the current research provide some of the most compelling reasons yet for eating considerably more unprocessed whole foods - fruits, vegetables, grains, nuts and seeds. 4

Dietary fibre, of course, has many known health benefits in addition to those discussed above, including reduced risk of cardiovascular disease and certain cancers 5, and various health organizations around the world recommend daily minimum levels. 6 It is certain that the majority of people in countries like Australia, the United States and Britain eat much less fibre than they need to stay healthy.

“The role of nutrition and gut intestinal bacteria in immune responses is an exciting new topic in immunology, and recent findings including our own open up new possibilities to explore causes as well as new treatments for inflammatory diseases such as asthma”, said Professor Mackay.

ABOUT The Cooperative Research Centre for Asthma and Airways (CRCAA)

The Cooperative Research Centre for Asthma and Airways (CRCAA) is one of the 48 cooperative research centres established under the Australian Government’s Cooperative Research Centre Program. The CRCAA is a joint venture between two medical research institutes, four universities and two pharmaceutical companies. The CRCAA undertakes research with the aim of developing improved therapies and diagnostic tools for the treatment of asthma and other airways diseases. The research partners in the CRCAA are Monash University, the Garvan Institute of Medical Research, the University of Sydney, the University of Newcastle, the University of Western Australia, and the Woolcock Institute of Medical Research.

ABOUT GARVAN

The Garvan Institute of Medical Research was founded in 1963. Initially a research department of St Vincent's Hospital in Sydney, it is now one of Australia's largest medical research institutions with nearly 500 scientists, students and support staff. Garvan’s main research programs are: Cancer, Diabetes & Obesity, Immunology and Inflammation, Osteoporosis and Bone Biology, and Neuroscience. The Garvan’s mission is to make significant contributions to medical science that will change the directions of science and medicine and have major impacts on human health. The outcome of Garvan’s discoveries is the development of better methods of diagnosis, treatment, and ultimately, prevention of disease.

Alison Heather | EurekAlert!
Further information:
http://www.garvan.org.au
http://www.garvan.org.au/news-events/news/new-findings-connect-diet-and-intestinal-bacteria-with-healthier-immune-systems.html

More articles from Health and Medicine:

nachricht Why might reading make myopic?
18.07.2018 | Universitätsklinikum Tübingen

nachricht Unique brain 'fingerprint' can predict drug effectiveness
11.07.2018 | McGill University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>