Featured Research

from universities, journals, and other organizations

Gut microbes affect MicroRNA response to bacterial infection

Date:
December 10, 2013
Source:
American Society for Microbiology
Summary:
When it comes to fighting off pathogens like Listeria, your best allies may be the billions of microorganisms that line your gut, according to new research. The study reveals that germ-free mice are more susceptible to infection with the foodborne pathogen Listeria monocytogenes than mice with conventional intestinal microbiota.

When it comes to fighting off pathogens like Listeria, your best allies may be the billions of microorganisms that line your gut, according to new research published in mBio, the online open-access journal of the American Society for Microbiology. The study reveals that germ-free mice are more susceptible to infection with the foodborne pathogen Listeria monocytogenes than mice with conventional intestinal microbiota.

Related Articles


The authors were also able to show that expression of five intestinal microRNA (miRNA) molecules decreases in conventional mice upon Listeria infection while it did not in germ-free mice, indicating that the gut microbiota may determine, at least in part, how the mouse genome expression is reprogrammed in the gut and how the animal responds to an infection.

"We were surprised by the robustness of the intestinal miRNA signature in germ-free mice and conventional mice," says corresponding author Pascale Cossart of the Institut Pasteur in Paris, France. "Our results show that even very small variations in miRNA expression can have important outcomes," for the health of the animals, says Cossart.

In recent years, researchers have come to recognize that the gut microbiota is an indispensable partner in the development of an animal's immune response and in maintaining its internal stability, but few studies have addressed the impact the microbiota has on miRNA expression during bacterial infections. Cossart and her colleagues approached the matter using the system they know best: Listeria infection. L. monocytogenes is a frequent contaminant of raw milk products, and a highly publicized outbreak traced to Listeria-contaminated cantaloupe left 30 people dead in the fall of 2011.

Previous studies in Cossart's lab have shown that during infection with Listeria, the bacterium AND the host both reprogram their protein manufacturing using small non-coding RNA molecules like miRNA -- pieces of genetic material that are used to selectively regulate the creation of proteins. Here, the researchers used conventional mice and germ-free mice to address the question of whether -- and how -- the gut microbiota has an effect on the course of infection and on the production of these regulatory miRNA molecules.

When it comes to susceptibility to infection, the results were unequivocal: 24 hours after infection, germ-free mice harbored 10,000 times more L. monocytogenes bacteria in their small intestines and about 1,000 times more Listeria in their mesenteric lymph nodes than did the conventional mice.

At the level of miRNA, however, the differences were not immediately evident: the most highly expressed miRNAs were produced at the same levels in both types of mice and they didn't change much after infection. Nevertheless, the production of five miRNAs decreased after infection only in the conventional mice, indicating that the presence of the microbiota influences the level of miRNA expression.

"We found that even though the intestinal miRNA signature is globally stable, Listeria infection can affect the host miRNA response in a microbiota-dependent manner," says Cossart. When paralleled with the lower susceptibility of the conventional mice to infection, these down-regulated regulatory molecules present an intriguing result, write the authors.

Cossart says that this study and others indicate that miRNA may be involved in protecting the host from infection, but their precise role isn't yet clear. She notes that although this study was conducted in mice, miRNA and the protein coding gene targets they regulate may be very similar in mice and in humans. Cossart and her colleagues are planning to follow up on the work to try and figure out what impacts the changes in miRNA expression mean for the networks of protein-coding genes they regulate.


Story Source:

The above story is based on materials provided by American Society for Microbiology. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. Archambaud, O. Sismeiro, J. Toedling, G. Soubigou, C. Becavin, P. Lechat, A. Lebreton, C. Ciaudo, P. Cossart. The Intestinal Microbiota Interferes with the microRNA Response upon Oral Listeria Infection. mBio, 2013; 4 (6): e00707-13 DOI: 10.1128/mBio.00707-13

Cite This Page:

American Society for Microbiology. "Gut microbes affect MicroRNA response to bacterial infection." ScienceDaily. ScienceDaily, 10 December 2013. <www.sciencedaily.com/releases/2013/12/131210072129.htm>.
American Society for Microbiology. (2013, December 10). Gut microbes affect MicroRNA response to bacterial infection. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2013/12/131210072129.htm
American Society for Microbiology. "Gut microbes affect MicroRNA response to bacterial infection." ScienceDaily. www.sciencedaily.com/releases/2013/12/131210072129.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
Powered by NewsLook.com
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins