A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Spring, 2019 | Number 2, Volume 33

ASD fecal transplants lead to symptoms of autism in mice

Article Body

Colonization with gut microbes from individuals with autism spectrum disorders(ASD) causes mice to develop symptoms of autism, a new study reports. 

Gil Sharon and colleagues transplanted human stool from individuals with and without ASD into the guts of “germ-free” mice with no gut bacteria, and then studied offspring from each group. The researchers used a tracking system to monitor the behavior of the mice. In addition, they recorded how often the mice buried marbles in their cages—a sign of repetitive behavior—and used ultrasonic microphones to listen to the animals’ communications. 

The researchers found that the offspring colonized with microbes from individuals with ASD exhibited deficits in social behavior, abnormalities in vocal interactions, and repetitive behaviors. For example, the mice did not produce as many ultrasonic squeaks as control mice, and did not wrestle, push, and sniff other mice as frequently. In addition, they buried far more marbles than the control mice. 

The brains of offspring colonized with microbes from individuals with ASD exhibited alterations in gene splicing, and the researchers detected an altered pattern of metabolites in the colons of the mice. In particular, levels of 5-amino valeric acid (5AV) and taurine were lower. In a follow-up experiment, the researchers gave these two metabolites to another group of mice bred to exhibit autistic-like behavior, and found that the social skills of the mice improved and their repetitive behaviors lessened. 

The researchers note that more studies are needed to determine if their findings will translate into human treatments. However, they are hopeful that in the future, microbiota-based interventions such as probiotics, fecal microbiota transplantation, or supplementation with metabolites may prove to be effective therapies for ASD.


Citations

“Human gut microbiota from autism spectrum disorder promote behavioral symptoms in mice,” Gil Sharon, Nikki Jamie Cruz, Dae-Wook Kang, Michael J. Gandal, Bo Wang, Young-Mo Kim, Erika M. Zink, Cameron P. Casey, Bryn C. Taylor, Christianne J. Lane, Lisa M. Bramer, Nancy G.Isern, David W. Hoyt, Cecilia Noecker, Michael J. Sweredoski, Annie Moradian, Elhanan Boren-stein, Janet K. Jansson, Rob Knight, Thomas O.Metz, Carlos Lois, Daniel H. Geschwind, RosaKrajmalnik-Brown, and Sarkis K. Mazmanian, Cell, May 30, 2019 (free online). Address: GilSharon,[email protected]