Have you heard about the gut-brain connection in autism? Researchers have discovered that there may be a link between gut bacteria (the microbiome) and the brain, which could contribute to certain challenging behaviors, such as aggression, emotional meltdowns, and self-injury, in autism.
For many children with autism spectrum disorder (ASD), coping with irritability is an ongoing challenge that can significantly impact daily life and the lives of their loved ones. Irritability may manifest in different ways, such as aggressive behavior, meltdowns, or isolation. Today there are few safe and effective medications to help manage these behaviors. However, fascinating new research has demonstrated that we may find answers in the gut – our microbiome.
Before we dive into how this gut-brain connection may lead to a new approach to treating autism-related irritability, let’s focus on some relevant terminology. First, what do we mean by “the gut”? The gut includes the main organs that make up your digestive tract. The gut microbiome includes bacteria, viruses, fungi, and other microorganisms living in the digestive tract. These microorganisms in our gut make metabolites from the food we eat that can move out of the gut, into the bloodstream and into our brains.
How is this connected to autism?
Studies have shown that there is a significant difference in the gut bacteria of children with autism compared to those children who are not on the autism spectrum. This difference changes the blood levels of certain substances, known as metabolites, that are produced by bacteria in the gut. When these substances enter the bloodstream and reach the brain, they may potentially contribute to characteristics often associated with autism, such as irritability.
Based on this research, a clinical trial is underway to study AB-2004, a potential treatment for managing irritability associated with autism that leverages how the brain and gut (the microbiome) are connected. AB-2004 is an investigational therapy designed to reduce the substances that earlier research has shown may be linked to ASD-associated characteristics. AB-2004 is designed to act in the gut only, selectively absorbing metabolites before they enter the bloodstream and reach the brain. Since AB-2004 works in the gut and does not enter other bodily tissues, it lessens the potential for side effects across other parts of the body.
In 2020, Axial Therapeutics, a company near Boston, MA, in collaboration with the California Institute of Technology, conducted a clinical trial of AB-2004 that enrolled 30 adolescents diagnosed with ASD. The study’s primary goals were to determine if:
- AB-2004 was safe and well-tolerated
- Levels of certain metabolites decreased after taking AB-2004
- Any behavior changes were observed
This study was an open-label clinical trial. The term “open-label” means that the participants in the study and the research physicians knew that all participants were given AB-2004. There were no placebo controls in this study. Each of the 30 adolescents participating in the study received AB-2004 3 times daily for 8 weeks.
Overall, AB-2004 was well tolerated without any safety concerns. AB-2004 reduced several key microbial metabolites implicated in autism and showed evidence of improving key co-occurring conditions, including irritability and anxiety.
Now, based on this growing body of scientific evidence showing bacterial substances produced by bacteria commonly found in the gut can contribute to characteristics like irritability and anxiety, researchers and physicians are advancing AB-2004 through the next stage of clinical development.
Axial Therapeutics is currently enrolling participants in the Tapestry Autism Study, the phase 2b study of AB-2004.
If your child is diagnosed with ASD and is struggling with behaviors such as aggression, isolation, self-injury, and meltdowns, they may qualify to participate in the Tapestry Autism Study. The study is currently enrolling children 5-17 years old in 29 states in the U.S. The study is also being conducted in Australia and New Zealand for children 13-17 years old, with the aim to expand the age range in these countries soon. If successful, AB-2004 may be a new approach to treating autism-related irritability by leveraging the microbiome, offering families an alternative to antipsychotic medications.
Are you interested in learning more? Take the next step. Visit https://www.theautismstudy.com/study to see if your child qualifies.
“A New Therapy to Reduce Anxiety, Irritability and Gastrointestinal Issues in Autistic Individuals.” Autism Advocate Parenting Magazine, Aug. 2022, pp. 38–40.
“Data & Statistics on Autism Spectrum Disorder.” Centers for Disease Control and Prevention, 2 Mar. 2022, https://www.cdc.gov/ncbddd/autism/data.html.
Stewart Campbell, A., Needham, B.D., Meyer, C.R. et al. “Safety and target engagement of an oral small-molecule sequestrant in adolescents with autism spectrum disorder: an open-label phase 1b/2a trial.” Nat Med, 28, 528–534, 14 Feb. 2022. https://doi.org/10.1038/s41591-022-01683-9
“The Tapestry Study Clinical Trial: Home.” Clinical Trial Site, https://www.theautismstudy.com/.
This article was featured in Issue 151 – Building a Support Network