Positive Results from a Microbiome Treatment Trial for Autism

April 09, 2020

Axial Biotherapeutics Drug Passes Safety Test, May Reduce Irritability, Anxiety, Social Withdrawal

Results of a novel microbial-inspired drug study look promising at reducing the core symptoms of autism. Adolescents with the condition had lowered scores on irritability, anxiety and social withdrawal while on the medication. 

The drug, called AB-2004, works on the gut-brain axis. Communication between the bacteria in the gut and the brain impacts the way the brain develops and functions as well as behavior. The composition of the bacteria and other organisms of the autistic gut microbiome differs from those without the disorder.

AB-2004 removes harmful metabolites such as 4-EPS from the gastrointestinal (GI) tract that are generated from certain kinds of gut bacteria. These metabolites can create a leaky gut allowing harmful substances to enter the bloodstream and then the brain, affecting brain function. This could lead to symptoms of autism

In this just-completed early phase human clinical trial, Axial reports the study met the primary endpoints of safety and tolerability with no drug-related adverse events noted. Adherence to the three-times-per-day dosing regimen was greater than 90%. The drug can be administered by mouth. 

Significant reductions in plasma and urinary levels of several key microbial metabolites were observed, which indicate that AB-2004 is positively acting on the lining of the gastrointestinal tract. On the behavioral outcomes, Axial reported that –

Twenty-six teenagers with autism were part of the study, which was an open-label design without a control group. Treatment lasted for 8 weeks. The study was conducted in Australia.

In an earlier study by Axial using an animal model of autism, AB-2004 “demonstrated the ability to repair leaky gut and improve repetitive behavior, anxiety, and ASD-related sensorimotor gating deficits by removing key microbial metabolites” in a mouse with autistic-like features.

Last year researchers at Arizona State University reported that Microbiota Transfer Therapy (MTT) using healthy, neurotypical donors led to long term improvements in autism-associated symptoms in children with the disorder. These researchers are now enrolling adults with autism for a clinical trial of MTT.

Also in 2019, researchers at the California Institute of Technology, including Sarkis Mazmanian, an Axial scientific founder and director, released a study that found that mice with transplanted microorganisms from children with ASD exhibited behaviors similar to those that are characteristic of autism in humans. The brains of the mice that received microbiota from autistic children showed lower levels of metabolites affecting gamma-aminobutyric acid (GABA) receptors in the brain, which help regulate communication between brain cells. 

Axial Biotherapeutics is a biopharmaceutical company dedicated to building a unique class of treatments focused on the interaction between the brain and the gut. The company has built a pipeline of novel small molecules addressing the significant unmet patient needs associated with Autism Spectrum Disorder (ASD) and Parkinson’s Disease (PD). 

With the safety and tolerability trial successfully completed, Axial will launch a placebo controlled clinical trial this year in adolescents with autism.


Axial Biotherapeutics. Axial Biotherapeutics Announces Positive Topline Results from Phase 1b/2a Clinical Trial of AB-2004 for the Treatment of Autism Spectrum Disorder. Businesswire. April 02, 2020 08:00 AM Eastern Daylight Time. 

Human Metabolome Database. Metabocard for 4-Ethylftphenylsulfate (HMDB0062551)

Hsiao EY, McBride SW, Hsien S, et al. Microbiota modulate behavioral and physiological abnormalities associated with neurodevelopmental disorders. Cell. 2013;155(7):1451–1463. doi:10.1016/j.cell.2013.11.024. 

Axial Biotherapeutics. Axial Biotherapeutics Presents New Preclinical Data from AB-2004. May 2, 2019. 

Kang DW, Adams JB, Coleman DM, et al. Long-term benefit of Microbiota Transfer Therapy on autism symptoms and gut microbiota . Sci Rep . 2019;9(1):5821. Published 2019 Apr 9. doi:10.1038/s41598-019-42183-0. 

David McNamee. Autism and the gut microbiome: Further evidence strengthens link, Medical News Today. May 31, 2019. 

Show Buttons
Hide Buttons