Nav: Home

Scientists identify a new way gut bacteria break down complex sugars

March 22, 2017

New light has been shed on the functioning of human gut bacteria which could help to develop medicines in the future to improve health and wellbeing.

Scientists have found that single microorganisms in the human gut have the ability to disassemble the most complex of carbohydrates in our diet.

It is the first time such a discovery has been made and it is hoped that this may be used to one day identify new pre- and pro-biotic products to enhance people's health.

Led by Professor Harry Gilbert, from the Institute for Cell and Molecular Biosciences at Newcastle University, UK, the study is published today (Wednesday) in the leading academic journal, Nature.

Bacteria in the large bowel - the human gut - has a major impact on health and physiology as they help to disintegrate substances in food that we cannot digest, such as starches and fibre.

The main source of nutrients available to the gut bacteria are carbohydrates from the human diet, which the body is unable to metabolise.

The most complex of these carbohydrates is the plant polysaccharide, 'rhamnogalacturonan II (RG-II)', which can also be found at elevated levels in red wine.

Previously it was thought that only groups of bacteria would be able to metabolise and breakdown RG-II, reflecting its complex structure. However, this research shows that single organisms present in the gut also have the ability to do this.

Professor Gilbert said: "Our research reports how a highly complex biological process in the body is achieved.

"This is an exciting step forward in the understanding of how human gut bacteria work and has implications for future research."

The team of international scientists found that RG-II is metabolised through the action of a type of bacterial enzyme, known as glycoside hydrolases, which target the complex carbohydrates sugars in the large bowel.

The bacteria that can metabolise RG-II contain several genes that encode proteins that previously had no known action until now. The group have shown that seven of these genes produce glycoside hydrolases - which split the glycosidic linkage that joins sugars together in polysaccharides - and contribute to the breakdown of RG-II.

Each of these seven glycoside hydrolases are founding members of a novel enzyme family. Three of the glycoside hydrolases that contribute to RG-II degradation break glycosidic linkages that have not previously been shown to be susceptible to biological attack, and these enzymes display novel catalytic functions.

Professor Gilbert said: "This study has potential applications as understanding how this highly complex carbohydrate, which is an integral component of our diet, is utilised offers opportunities for developing new pre- and pro-biotic strategies to improve human health.

"There is much more exciting work to be done in this area. To fully understand the mechanisms by which complex carbohydrates are utilized by human gut bacteria is relevant to medicine as this microbial community has a significant impact on the body."
-end-
Reference

Complex pectin metabolism by gut bacteria reveals novel catalytic functions

Didier Ndeh, Artur Rogowski, Alan Cartmell, Ana S. Luis, Arnaud Baslé, Joseph Gray, Immacolata Venditto, Jonathon Briggs, Xiaoyang Zhang, Aurore Labourel, Nicolas Terrapon, Fanny Buffetto, Sergey Nepogodiev, Yao Xiao, Robert A. Field, Yanping Zhu, Malcolm A. O'Neill, Breeanna R. Urbanowicz, William S. York, Gideon J. Davies, D. Wade Abbott, Marie-Christine Ralet, Eric C. Martens, Bernard Henrissat and Harry J. Gilbert

Nature. Doi: 10.1038/nature21725

Newcastle University

Related Bacteria Articles:

Conducting shell for bacteria
Under anaerobic conditions, certain bacteria can produce electricity. This behavior can be exploited in microbial fuel cells, with a special focus on wastewater treatment schemes.
Controlling bacteria's necessary evil
Until now, scientists have only had a murky understanding of how these relationships arise.
Bacteria take a deadly risk to survive
Bacteria need mutations -- changes in their DNA code -- to survive under difficult circumstances.
How bacteria hunt other bacteria
A bacterial species that hunts other bacteria has attracted interest as a potential antibiotic, but exactly how this predator tracks down its prey has not been clear.
Chlamydia: How bacteria take over control
To survive in human cells, chlamydiae have a lot of tricks in store.
Stress may protect -- at least in bacteria
Antibiotics harm bacteria and stress them. Trimethoprim, an antibiotic, inhibits the growth of the bacterium Escherichia coli and induces a stress response.
'Pulling' bacteria out of blood
Magnets instead of antibiotics could provide a possible new treatment method for blood infection.
New findings detail how beneficial bacteria in the nose suppress pathogenic bacteria
Staphylococcus aureus is a common colonizer of the human body.
Understanding your bacteria
New insight into bacterial cell division could lead to advancements in the fight against harmful bacteria.
Bacteria are individualists
Cells respond differently to lack of nutrients.

Related Bacteria Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...