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 Great apes communicate cooperatively
25.05.2016 | Max-Planck-Institut für Ornithologie

nachricht Rice study decodes genetic circuitry for bacterial spore formation
24.05.2016 | Rice University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Computational high-throughput screening finds hard magnets containing less rare earth elements

Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.

The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of...

Im Focus: Atomic precision: technologies for the next-but-one generation of microchips

In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.

In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two...

Im Focus: Researchers demonstrate size quantization of Dirac fermions in graphene

Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices

Quantum mechanics is the field of physics governing the behavior of things on atomic scales, where things work very differently from our everyday world.

Im Focus: Graphene: A quantum of current

When current comes in discrete packages: Viennese scientists unravel the quantum properties of the carbon material graphene

In 2010 the Nobel Prize in physics was awarded for the discovery of the exceptional material graphene, which consists of a single layer of carbon atoms...

Im Focus: Transparent - Flexible - Printable: Key technologies for tomorrow’s displays

The trend-forward world of display technology relies on innovative materials and novel approaches to steadily advance the visual experience, for example through higher pixel densities, better contrast, larger formats or user-friendler design. Fraunhofer ISC’s newly developed materials for optics and electronics now broaden the application potential of next generation displays. Learn about lower cost-effective wet-chemical printing procedures and the new materials at the Fraunhofer ISC booth # 1021 in North Hall D during the SID International Symposium on Information Display held from 22 to 27 May 2016 at San Francisco’s Moscone Center.

Economical processing

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

Challenges of rural labor markets

20.05.2016 | Event News

International expert meeting “Health Business Connect” in France

19.05.2016 | Event News

 
Latest News

LZH shows the potential of the laser for industrial manufacturing at the LASYS 2016

25.05.2016 | Trade Fair News

Great apes communicate cooperatively

25.05.2016 | Life Sciences

Thermo-Optical Measuring method (TOM) could save several million tons of CO2 in coal-fired plants

25.05.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>