Study strengthens ties between autism symptoms and gut microbes

Study strengthens ties between autism symptoms and gut microbes

December 19, 2013

December 19, 2013

Scientific evidence is mounting that the trillions of microbes that call the human body home can influence our gut-linked health, affecting our risk of obesity, diabetes and colon cancer, for example. 

But more recently, researchers are discovering that gut microbes also may affect neurology—possibly impacting a person’s cognition, emotions and mental health.

A new study showing that feeding mice a beneficial type of bacteria can ameliorate autism-like symptoms is “groundbreaking,” according to University of Colorado Boulder Professor Rob Knight, who along with Arizona State University Professor Rosa Krajmalnik-Brown, were co-authors of a commentary piece about the research appearing in the current issue of the journal Cell.

“Given the complexity of gut microbial communities, estimated to contain 500–1,000 species that considerably expand our metabolic potential beyond what the human genome encodes, it is perhaps unsurprising that they can influence many aspects of our physiology and gut-linked health and disease,” wrote Krajmalnik-Brown and Knight in the editorial. 

The study underscores the importance of the work being undertaken by the newly formed Autism Microbiome Consortium, which includes Knight as well as commentary co-authors Jack Gilbert of the University of Chicago and Rosa Krajmalnik-Brown of the Biodesign Institute at Arizona State University. The interdisciplinary consortium—which taps experts in a range of disciplines from psychology to epidemiology—is investigating the autism-gut microbiome link.

The autism study, lead by Sarkis Mazmanian and Paul Patterson, was published today in the same issue of Cell, strengthens the recent scientific understanding that the microbes that live in your gut may affect what goes on in your brain. It is also the first to show that a specific probiotic may be capable of reversing autism-like behaviors in mice.

“The broader potential of this research is obviously an analogous probiotic that could treat subsets of individuals with autism spectrum disorder,” wrote the commentary authors, who also included CU-Boulder Research Associate Dorota Porazinska and doctoral student Sophie Weiss. 

For the new Cell study, led by Elaine Hsiao of the California Institute of Technology, the researchers used a technique called maternal immune activation in pregnant mice to induce autism-like behavior and neurology in their offspring. The researchers found that the gut microbial community of the offspring differed markedly compared with a control group of mice. When the mice with autism-like symptoms were fed Bacteriodes fragilis, a microbe known to bolster the immune system, the aberrant behaviors were reduced. 

The Autism Microbiome Consortium hopes to broaden the understanding of the links between microbial communities and autistic individuals, who tend to suffer from more gastrointestinal problems than the general public. 

People with autism spectrum disorder who would like to have their gut microbes sequenced can do so now through the American Gut Project, a crowdfunded research effort led by Knight. 

The consortium also includes James Adams of Arizona State University, Catherine Lozupone and Kimberly Johnson of CU-Boulder, Mady Hornig of Columbia University, John Alverdy of the University of Chicago and Janet Jansson of Lawrence Berkeley Lab.

For more information on gut autism related research projects at ASU visit http://krajmalnik.environmentalbiotechnology.org/ or http://autism.asu.edu