Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sick from your stomach: Bacterial changes may trigger diseases like rheumatoid arthritis

12.06.2012
The billions of bugs in our guts have a newfound role: regulating the immune system and related autoimmune diseases such as rheumatoid arthritis, according to researchers at Mayo Clinic and the University of Illinois at Urbana-Champaign.

Larger-than-normal populations of specific gut bacteria may trigger the development of diseases like rheumatoid arthritis and possibly fuel disease progression in people genetically predisposed to this crippling and confounding condition, say the researchers, who are participating in the Mayo Illinois Alliance for Technology Based Healthcare.

The study is published in the April 2012 issue of PloS ONE.

"A lot of people suspected that gut flora played a role in rheumatoid arthritis, but no one had been able to prove it because they couldn't say which came first — the bacteria or the genes," says senior author Veena Taneja, Ph.D., a Mayo Clinic immunologist. "Using genomic sequencing technologies, we have been able to show the gut microbiome may be used as a biomarker for predisposition."

The roughly 10 trillion cells that make up the human body have neighbors: mostly bacteria that often help, training the immune system and aiding in digestion, for example. The bacteria in the intestines, in addition to a relatively small number of other microorganisms (the gut microbiome), outnumber human cells 10-to-1.

Researchers found that hormones and changes related to aging may further modulate the gut immune system and exacerbate inflammatory conditions in genetically susceptible individuals.

Nearly 1 percent of the world's population has rheumatoid arthritis, a disease in which the immune system attacks tissues, inflaming joints and sometimes leading to deadly complications such as heart disease. Other diseases with suspected gut bacterial ties include type I diabetes and multiple sclerosis.

Researchers with the Mayo Illinois Alliance for Technology Based Healthcare say that identifying new biomarkers in intestinal microbial populations and maintaining a balance in gut bacteria could help physicians stop rheumatoid arthritis before it starts.

"This study is an important advance in our understanding of the immune system disturbances associated with rheumatoid arthritis. While we do not yet know what the causes of this disease are, this study provides important insights into the immune system and its relationship to bacteria of the gut, and how these factors may affect people with genetic susceptibilities to disease," says Eric Matteson, M.D., chairman of rheumatology at Mayo Clinic, who was not a study author.

Dr. Taneja and her team genetically engineered mice with the human gene HLA-DRB1*0401, a strong indicator of predisposition to rheumatoid arthritis. A set of control mice were engineered with a different variant of the DRB1 gene, known to promote resistance to rheumatoid arthritis. Researchers used these mice to compare their immune responses to different bacteria and the effect on rheumatoid arthritis.

"The gut is the largest immune organ in the body," says co-author Bryan White, Ph.D., director of the University of Illinois' Microbiome Program in the Division of Biomedical Sciences and a member of the Institute for Genomic Biology. "Because it's presented with multiple insults daily through the introduction of new bacteria, food sources and foreign antigens, the gut is continually teasing out what's good and bad."

The gut has several ways to do this, including the mucosal barrier that prevents organisms — even commensal or "good" bacteria — from crossing the lumen of the gut into the human body. However, when commensal bacteria breach this barrier, they can trigger autoimmune responses. The body recognizes them as out of place, and in some way this triggers the body to attack itself, he says.

These mice mimic human gender trends in rheumatoid arthritis, in that females were about three times as likely to generate autoimmune responses and contract the disease. Researchers believe these "humanized" mice could shed light on why women and other demographic groups are more vulnerable to autoimmune disorders and help guide development of new future therapies.

"The next step for us is to show if bugs in the gut can be manipulated to change the course of disease," Dr. Taneja says.

The study was funded by the Mayo-Illinois Alliance for Technology Based Healthcare and a grant from the U.S. Department of Defense.

Co-authors include Andres Gomez; Carl Yeoman, Ph.D.; and Margret Berg Miller, Ph.D., all of University of Illinois; David Luckey; Eric Marietta, Ph.D.; and Joseph Murray, M.D., all of Mayo Clinic.

About Mayo Clinic
Mayo Clinic is a nonprofit worldwide leader in medical care, research and education for people from all walks of life. For more information, visit www.mayoclinic.com and www.mayoclinic.org/news.

Sam Smith | EurekAlert!
Further information:
http://www.mayo.edu
http://www.mayoclinic.org/news

More articles from Health and Medicine:

nachricht Investigators may unlock mystery of how staph cells dodge the body's immune system
22.09.2017 | Cedars-Sinai Medical Center

nachricht Monitoring the heart's mitochondria to predict cardiac arrest?
21.09.2017 | Boston Children's Hospital

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: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>