Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists find key to growth of "bad" bacteria in inflammatory bowel disease

08.02.2013
Research is the first to shed light on how harmful gut bacteria thrive in the intestine
Scientists have long puzzled over why “bad” bacteria such as E. coli can thrive in the guts of those with inflammatory bowel disease (IBD), causing serious diarrhea. Now UC Davis researchers have discovered the answer—one that may be the first step toward finding new and better treatments for IBD.

The researchers discovered a biological mechanism by which harmful bacteria grow, edge out beneficial bacteria and damage the gut in IBD. This new understanding, published in the Feb. 8 issue of Science, may help researchers develop new treatments for IBD with fewer side effects than current therapies.

IBD begins when “good” bacteria are mistakenly killed by the immune system, while harmful bacteria multiply — resulting in inflammation and damage to the intestines, and chronic episodes of abdominal pain, cramping, diarrhea and other changes in bowel habits. It’s estimated that IBD, which includes ulcerative colitis and Crohn’s disease, affects 1.4 million people in the U.S., according to the Centers for Disease Control and Prevention.

In test-tube and animal studies, the researchers found that potentially harmful bacteria in the intestine called Enterobacteriaceae use nitrate — a byproduct formed during the intestinal inflammation in IBD — to grow and thrive. Enterobacteriaceae strains include certain E. coli bacteria, which can worsen the intestinal damage of IBD. Eventually, the intestines of those with IBD become overrun by harmful bacteria, and the numbers of normal good bacteria in the gut decrease.

“Much like humans use oxygen, E. coli can use nitrate as a replacement for oxygen to respire, produce energy and grow,” said lead author Andreas Baumler, a professor of medical microbiology and immunology at UC Davis.

“In IBD, nitrate produced by inflammation in the gut allows E. coli to take a deep ‘breath,’ and beat out our beneficial microbes in the competition for nutrients,” he said.

The inflammation in the intestines of those with IBD leads to the release of nitric oxide radicals that are powerful in attacking bacteria, Baumler explained. Yet these nitric oxide radicals are also very unstable, and eventually decompose into nitrate, which can be used by bacteria like E. coli to thrive and grow. By contrast, good bacteria in the gut grows through fermentation — a much slower process.

Determining the reasons why bacteria like E. coli can edge out good bacteria in the gut is crucial for determining new ways to halt the IBD disease process, according to Baumler. Current treatments for IBD suppress the immune response through antibiotics, corticosteroids or other powerful immune-modifying drugs. But long-term side effects can limit their use and their effectiveness for IBD patients.

The UC Davis team’s research indicates that targeting the molecular pathways that generate nitric oxide and nitrate, as well as other molecules that feed harmful gut bacteria, could calm down and normalize the intestinal environment in IBD, Baumler noted. They are already doing research with one candidate drug that could halt the multiple pathways by which harmful bacteria thrive in IBD.

“The idea would be to inhibit all pathways that produce molecules that can be used by bacteria such as E. coli for respiration and growth,” Baumler said. “Essentially you could then smother the bacteria.”

Other study authors include Sebastian E. Winter, Maria G. Winter, Mariana N. Xavier, Parameth Thiennimitr, Victor Poon, A. Marijke Keestra, Ina Popova, Sanjai J. Parikh, Renee M. Tsolis, and Valley J. Stewart of UC Davis; and Richard C. Laughlin, Gabriel Gomez, Jing Wu, Sara D. Lawhon, and L. Garry Adams of Texas A&M University.

This work was supported by the California Agricultural Experiment Station and Public Health Service grants AI089078, AI076246 and AI088122 along with a scholarship from the Faculty of Medicine, Chiang Mai University, Thailand.

About UC Davis Health System
UC Davis Health System is improving lives and transforming health care by providing excellent patient care, conducting groundbreaking research, fostering inter-professional education, and creating innovative partnerships with the community. The academic health system includes one of the country's best medical schools, a 619-bed acute-care teaching hospital, an 800-member physician's practice group and the new Betty Irene Moore School of Nursing. It is home to a National Cancer Institute-designated comprehensive cancer center, an international neurodevelopmental institute, a stem cell institute and a comprehensive children's hospital. Other nationally prominent centers focus on advancing telemedicine, improving vascular care, eliminating health disparities and translating research findings into new treatments for patients. Together, they make UC Davis a hub of innovation that is transforming health for all.

Carole Gan | EurekAlert!
Further information:
http://www.ucdmc.ucdavis.edu
http://healthsystem.ucdavis.edu

More articles from Life Sciences:

nachricht Gut microbiome regulates the intestinal immune system, researchers find
19.12.2018 | Brown University

nachricht Greener days ahead for carbon fuels
19.12.2018 | DOE/Lawrence Berkeley National Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New megalibrary approach proves useful for the rapid discovery of new materials

Northwestern discovery tool is thousands of times faster than conventional screening methods

Different eras of civilization are defined by the discovery of new materials, as new materials drive new capabilities. And yet, identifying the best material...

Im Focus: Data storage using individual molecules

Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.

Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

New megalibrary approach proves useful for the rapid discovery of new materials

19.12.2018 | Materials Sciences

Artificial intelligence meets materials science

19.12.2018 | Materials Sciences

Gut microbiome regulates the intestinal immune system, researchers find

19.12.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>