At Arizona State University's Biodesign Institute in Tempe, researchers have cracked open a simple but powerful clue hidden in children's urine: a biological fingerprint that could identify autism risk years before traditional diagnoses catch up. The discovery centers on 17 microbial metabolites—tiny molecules produced by gut bacteria—that paint a strikingly different picture in children with autism compared to their typically developing peers.
The research matters because autism spectrum disorder remains difficult to diagnose in young children, and earlier identification could unlock access to interventions when developing brains are most malleable. The new screening tool, called the Microbially-Derived Metabolite (MDM) System, measures these compounds in urine samples from children ages two to eleven, offering doctors a biological shortcut to early detection that neither guessing nor behavioral observation alone can provide.
The numbers tell a compelling story. In a study published in Molecular Psychiatry, Arizona State University scientists and collaborators tested urine from 52 children with autism and 47 typically developing children across four U.S. states—Arizona, Massachusetts, Tennessee, and Texas. The results were striking: nearly all children with autism had at least one metabolite level soaring far beyond what the research team found in control groups. Some measured 100 to 1,000 times higher than baseline. On average, children with autism showed about three elevated metabolites, while typically developing children showed none. During trials, the urine test achieved 90% sensitivity—correctly identifying nine out of ten children with autism—and 100% specificity, meaning it never falsely flagged children without autism.
Christina Flynn, the study's first author and a recent Arizona State University Ph.D. graduate in chemical engineering, articulated the promise plainly: "80 to 90% of children with autism have extremely high levels of one or more microbially derived metabolites." The elevated compounds come from specific amino acids—tyrosine, tryptophan, and phenylalanine—that feed into critical neurotransmitter pathways. What made researchers sit up was that these metabolites are essentially altered versions of serotonin and dopamine, the very neurotransmitters that regulate mood, cognition, and memory.
This connection may explain why children with autism often struggle with social communication, anxiety, depression, and attention issues. President's Professor James Adams, a corresponding author and researcher with the Biodesign Center for Health Through Microbiomes, emphasized the insight: "These are two key neurotransmitters that affect mood, cognition and memory. This could explain many of the symptoms and co-occurring symptoms in children with autism." Adams, who is also the father of an adult daughter with autism, sees this not as mere academic interest but as a pathway to better lives.
The research hints at something deeper still—that reducing these metabolite levels might ease the daily struggles many children with autism face. Flynn now directs the newly launched CLIA-certified Autism Diagnostics Laboratory and serves as a senior research scientist for Gut Brain Axis Therapeutics, positioning the discovery to move from journal pages into clinical practice. The team acknowledges that further validation is needed due to the moderate sample size, but the urgency is clear: earlier screening could mean earlier intervention, and that timing matters profoundly for children still developing.