While research linking gut microbiome, bacteria located inside the intestines, to intestinal-related health conditions including obesity, diabetes and colon cancer comes as no surprise, a recent study tying gut bacteria to certain neurological disorders has garnered the title “groundbreaking.” Researchers from the California Institute of Technology revealed that the manipulation of gut microbes in mice can actually control the onset of autism-like behaviors.

In this new autism study featured in the journal Cell, lead researcher Elaine Hsiao and her colleagues from CalTech examined how gut microbes influence the cognitive abilities, emotional state, and mental health of autistic mice. Through maternal immune activation, the research team induced autism-related symptoms and neurology in the offspring of pregnant mice. When compared against a control group of healthy mice, autistic mice showed signs of altered gut microbes.

Furthermore, when the autistic mice were fed the immune boosting microbe, Bacteroides fragilis, autism-like behavior stopped. Mice that received this experimental probiotic therapy were able to reduce stress levels, more likely to communicate with other mice and less likely to repetitively dig up dirt. Now, the research team looks forward to testing this probiotic treatment on people suffering from autism during clinical trials slated to start within the next two years.

"To our knowledge, this is the first report of an animal model for autism with comorbid GI dysfunction. The B. fragilis treatment alleviates GI problems in the mouse model and also improves some of the main behavioral symptoms," said Hsiao. "This suggests that GI problems could contribute to particular symptoms in neurodevelopmental disorders."

Professor Rob Knight from the University of Colorado, Boulder, called the investigation being done by the CalTech researchers “groundbreaking” in a commentary piece published in the same issue of Cell. Professor Knight along with Research Associate Dorota Porazinska and doctoral student Sophie Weiss, also from CU-Boulder, wrote, "The broader potential of this research is obviously an analogous probiotic that could treat subsets of individuals with autism spectrum disorder.”

Professor Knight also provides commentary pieces for the Autism Microbiome Consortium, a newly formed interdisciplinary consortium combining the expertise of the nation’s leading neurologists, psychiatrists, epidemiologists, pediatricians, and microbiologists. Considering most people affected by an autism spectrum disorder also suffer from gastrointestinal complications, this group of health and science professionals are interested in furthering our understanding of autism’s link to trillions of microbes found in the human body.

Thanks to Professor Knight’s American Gut Project, people with an autism spectrum disorder can now have their gut microbes sequenced free of charge. American Gut by Human Food Project is regarded as the “World's largest open-source science project to understand the microbial diversity of the Global Gut,” including over 6,000 members. This study funded by crowd sourcing has already risen over $360,000 in the 36 weeks it has been operating.

Source: McBride S, Hsien S, Sharon G, Hyde E, McCue T, Hsiao E. “Microbiota Modulate Behavioral and Physiological Abnormalities Associated with Neurodevelopmental Disorder.” Cell. 2013.