Navigation Links
Stress wrecks intestinal bacteria, could keep immune system on idle
Date:4/11/2011

COLUMBUS, Ohio Stress not only sends the human immune system into overdrive it can also wreak havoc on the trillions of bacteria that work and thrive inside our digestive system.

New research suggests that this may be important because those bacteria play a significant role in triggering the innate immune system to stay slightly active, and thereby prepared to quickly spring into action in the face of an infection.

But exactly how stress makes these changes in these bacteria still isn't quite clear, researchers say.

"Since graduate school, I've been interested in how stress affects the bacteria naturally in our bodies,' explained Michael Bailey, an assistant professor of dentistry and member of the Institute for Behavioral Medicine Research at Ohio State University.

"Even though we've known that stress changes these bacteria, we didn't really understand what that meant or if there was any sort of biological function associated with effects on these bacteria."

The new study appears in the current issue of the journal Brain, Behavior and Immunity.

The human digestive tract is a universe filled with microbes. There are probably 100 trillion bacteria in the average human, 90 percent of which live mainly in the intestine. They easily outnumber human cells 10-to-one in each person.

Bailey and colleagues turned to mice to better understand the roles that bacteria play in immune balance. They ran a series of experiments using a common stressor for these animals. For two hours daily for six days, an aggressive mouse was placed in a cage of a group of more docile mice.

At the end of the string of experiments, blood samples were taken from both stressed animals and matched mice from a control group, along with samples of material from inside each animal's intestine. The blood samples were analyzed to detect the levels of two biomarkers used to gauge stress a cytokine called interleukin-6 (IL-6) and a protein called MCP-1 that summons macrophages, or scavenger cells, to the site of an infection.

From the intestinal samples, Bailey's team could determine the relative proportion of at least 30 types of bacteria residing there.

Compared to the control mice, the stressed animals showed two marked differences: The proportion of one important type of bacteria in the gut Bacteroides fell by 20 to 25 percent while another type Clostridium increased a similar amount. Also, levels of the two biomarkers, IL-6 and MCP-1, jumped 10-fold in the stressed mice, compared to controls.

The researchers then treated stressed mice with broad-spectrum antibiotics that could kill as much as 90 percent of the intestinal bacteria for a short period. When they again looked at the two immune biomarkers in the stressed mice, they saw only a doubling of IL-6 and MCP-1 an increase only one-fifth as much.

"We know now that if we knock the population of bacteria down with antibiotics, we don't have the same innate immune response," Bailey said. "That showed that the bacteria are involved in the ability of stress to prime the innate immune system."

He said that the research shows that some of the changes in systemic immunity in the body can be influenced by changes in these bacterial colonies, a result that reinforces the idea that they have a broader effect on the immune response.

The next step, the researchers say, is to better understand the roles that the bacteria play in activating the immune system, and to determine if other factors are playing a key role in the process.


'/>"/>

Contact: Michael Bailey
Michael.bailey@osumc.edu
614-293-4277
Ohio State University
Source:Eurekalert

Related biology news :

1. Conservationists develop coral stress test to identify reefs of hope in climate change era
2. Parenting stress affects new mothers’ postpartum lifestyle
3. Green genes in yeast may boost biofuel production by increasing stress tolerance
4. Drug prevents post-traumatic stress syndrome
5. Social stress leads to atherosclerosis
6. Stress takes its toll in Parkinsons disease
7. Plants and animals under stress may provide the key to better stock market predictions
8. Childhood adversity may lead to unhealthy stress response in adult life
9. Walnuts, walnut oil, improve reaction to stress
10. John P. Holdren addresses climate change, stressing need for international cooperation
11. Training the trainers: How to minimize stress when horses are first ridden
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/14/2017)... June 15, 2017  IBM (NYSE: IBM ) is introducing ... event dedicated to developing collaboration between startups and global businesses, ... 15-17. During the event, nine startups will showcase the solutions ... various industries. France ... market, with a 30 percent increase in the number of ...
(Date:4/24/2017)... Janice Kephart , former 9/11 ... Partners, LLP (IdSP) , today issues the following ... March 6, 2017 Executive Order: Protecting the ... be instilled with greater confidence, enabling the reactivation ... applications are suspended by until at least July ...
(Date:4/13/2017)... , April 13, 2017 According to a new ... Authentication, Identity Analytics, Identity Administration, and Authorization), Service, Authentication Type, Deployment Mode, ... IAM Market is expected to grow from USD 14.30 Billion in 2017 ... (CAGR) of 17.3%. ... MarketsandMarkets Logo ...
Breaking Biology News(10 mins):
(Date:8/15/2017)... ... August 15, 2017 , ... JULABO USA introduces its ... new website makes it easy to navigate through the site whether you’re in ... detailed product information, educational industry content and visit the company’s social media accounts, ...
(Date:8/11/2017)... ... , ... A staple in the community for more than 60 years, Bill ... including a new digital marketing strategy and updated logo. , As part of the ... with the South Texas Blood & Tissue Center for the month of August. ...
(Date:8/10/2017)... ... August 09, 2017 , ... ... applications in the clinic is here. The team at Capricor Therapeutics, Inc. utilized ... medium for clinical studies. , Dr. Travis Antes, head of analytical development ...
(Date:8/10/2017)... , ... August 10, 2017 , ... ... agreement establishing Kinokuniya Company Ltd. as its exclusive sales representative for SPIE Journals ... representative for the SPIE Digital Library in Japan. , “We look forward to ...
Breaking Biology Technology: