Featured Research

from universities, journals, and other organizations

Probiotic therapy alleviates autism-like behaviors in mice

Date:
December 5, 2013
Source:
California Institute of Technology
Summary:
Autism spectrum disorder (ASD) is diagnosed when individuals exhibit characteristic behaviors, decreased social interactions, and impaired communication. Curiously, many with ASD also suffer from gastrointestinal issues, like abdominal cramps and constipation. Guided by this co-occurrence of brain and gut problems, researchers are investigating a bacterium that alleviates GI and behavioral symptoms in autistic-like mice, introducing a potentially transformative probiotic therapy for autism and other neurodevelopmental disorders.

Autism spectrum disorder (ASD) is diagnosed when individuals exhibit characteristic behaviors that include repetitive actions, decreased social interactions, and impaired communication. Curiously, many individuals with ASD also suffer from gastrointestinal (GI) issues, such as abdominal cramps and constipation.
Credit: Image courtesy of California Institute of Technology

Autism spectrum disorder (ASD) is diagnosed when individuals exhibit characteristic behaviors that include repetitive actions, decreased social interactions, and impaired communication. Curiously, many individuals with ASD also suffer from gastrointestinal (GI) issues, such as abdominal cramps and constipation.

Using the co-occurrence of brain and gut problems in ASD as their guide, researchers at the California Institute Technology (Caltech) are investigating a potentially transformative new therapy for autism and other neurodevelopmental disorders.

The gut microbiota -- the community of bacteria that populate the human GI tract -- previously has been shown to influence social and emotional behavior, but the Caltech research, published online in the December 5 issue of the journal Cell, is the first to demonstrate that changes in these gut bacteria can influence autism-like behaviors in a mouse model.

"Traditional research has studied autism as a genetic disorder and a disorder of the brain, but our work shows that gut bacteria may contribute to ASD-like symptoms in ways that were previously unappreciated," says Professor of Biology Sarkis K. Mazmanian. "Gut physiology appears to have effects on what are currently presumed to be brain functions."

To study this gut-microbiota-brain interaction, the researchers used a mouse model of autism previously developed at Caltech in the laboratory of Paul H. Patterson, the Anne P. and Benjamin F. Biaggini Professor of Biological Sciences. In humans, having a severe viral infection raises the risk that a pregnant woman will give birth to a child with autism. Patterson and his lab reproduced the effect in mice using a viral mimic that triggers an infection-like immune response in the mother and produces the core behavioral symptoms associated with autism in the offspring.

In the new Cell study, Mazmanian, Patterson, and their colleagues found that the "autistic" offspring of immune-activated pregnant mice also exhibited GI abnormalities. In particular, the GI tracts of autistic-like mice were "leaky," which means that they allow material to pass through the intestinal wall and into the bloodstream. This characteristic, known as intestinal permeability, has been reported in some autistic individuals. "To our knowledge, this is the first report of an animal model for autism with comorbid GI dysfunction," says Elaine Hsiao, a senior research fellow at Caltech and the first author on the study.

To see whether these GI symptoms actually influenced the autism-like behaviors, the researchers treated the mice with Bacteroides fragilis, a bacterium that has been used as an experimental probiotic therapy in animal models of GI disorders.

The result? The leaky gut was corrected.

In addition, observations of the treated mice showed that their behavior had changed. In particular, they were more likely to communicate with other mice, had reduced anxiety, and were less likely to engage in a repetitive digging behavior.

"The B. fragilis treatment alleviates GI problems in the mouse model and also improves some of the main behavioral symptoms," Hsiao says. "This suggests that GI problems could contribute to particular symptoms in neurodevelopmental disorders."

With the help of clinical collaborators, the researchers are now planning a trial to test the probiotic treatment on the behavioral symptoms of human autism. The trial should begin within the next year or two, says Patterson.

"This probiotic treatment is postnatal, which means that the mother has already experienced the immune challenge, and, as a result, the growing fetuses have already started down a different developmental path," Patterson says. "In this study, we can provide a treatment after the offspring have been born that can help improve certain behaviors. I think that's a powerful part of the story."

The researchers stress that much work is still needed to develop an effective and reliable probiotic therapy for human autism -- in part because there are both genetic and environmental contributions to the disorder, and because the immune-challenged mother in the mouse model reproduces only the environmental component.

"Autism is such a heterogeneous disorder that the ratio between genetic and environmental contributions could be different in each individual," Mazmanian says. "Even if B. fragilis ameliorates some of the symptoms associated with autism, I would be surprised if it's a universal therapy -- it probably won't work for every single case."

The Caltech team proposes that particular beneficial bugs are intimately involved in regulating the release of metabolic products (or metabolites) from the gut into the bloodstream. Indeed, the researchers found that in the leaky intestinal wall of the autistic-like mice, certain metabolites that were modulated by microbes could both easily enter the circulation and affect particular behaviors.

"I think our results may someday transform the way people view possible causes and potential treatments for autism," Mazmanian says.


Story Source:

The above story is based on materials provided by California Institute of Technology. The original article was written by Jessica Stoller-Conrad. Note: Materials may be edited for content and length.


Journal Reference:

  1. ElaineY. Hsiao, SaraW. McBride, Sophia Hsien, Gil Sharon, EmbrietteR. Hyde, Tyler McCue, JulianA. Codelli, Janet Chow, SarahE. Reisman, JosephF. Petrosino, PaulH. Patterson, SarkisK. Mazmanian. Microbiota Modulate Behavioral and Physiological Abnormalities Associated with Neurodevelopmental Disorders. Cell, 2013; DOI: 10.1016/j.cell.2013.11.024

Cite This Page:

California Institute of Technology. "Probiotic therapy alleviates autism-like behaviors in mice." ScienceDaily. ScienceDaily, 5 December 2013. <www.sciencedaily.com/releases/2013/12/131205141900.htm>.
California Institute of Technology. (2013, December 5). Probiotic therapy alleviates autism-like behaviors in mice. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2013/12/131205141900.htm
California Institute of Technology. "Probiotic therapy alleviates autism-like behaviors in mice." ScienceDaily. www.sciencedaily.com/releases/2013/12/131205141900.htm (accessed August 1, 2014).

Share This




More Mind & Brain News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Dieting At A Young Age Might Lead To Harmful Health Habits

Dieting At A Young Age Might Lead To Harmful Health Habits

Newsy (July 30, 2014) Researchers say women who diet at a young age are at greater risk of developing harmful health habits, including eating disorders and alcohol abuse. Video provided by Newsy
Powered by NewsLook.com
It's Not Just Facebook: OKCupid Experiments With Users Too

It's Not Just Facebook: OKCupid Experiments With Users Too

Newsy (July 29, 2014) If you've been looking for love online, there's a chance somebody has been looking at how you're looking. Video provided by Newsy
Powered by NewsLook.com
How Your Face Can Leave A Good Or Bad First Impression

How Your Face Can Leave A Good Or Bad First Impression

Newsy (July 29, 2014) Researchers have found certain facial features can make us seem more attractive or trustworthy. Video provided by Newsy
Powered by NewsLook.com
Losing Sleep Leaves You Vulnerable To 'False Memories'

Losing Sleep Leaves You Vulnerable To 'False Memories'

Newsy (July 27, 2014) A new study shows sleep deprivation can make it harder for people to remember specific details of an event. 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:

More Coverage


Research Linking Autism Symptoms to Gut Microbes Called 'groundbreaking'

Dec. 19, 2013 A new study showing that feeding mice a beneficial type of bacteria can ameliorate autism-like symptoms is "groundbreaking," according to a commentary piece about the ... read more
from the past week

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