Scientists at Arizona State University have developed an experimental urine test that may help detect autism in children significantly earlier than current screening methods.

The test identifies 17 microbial metabolites — chemical byproducts linked to gut bacteria — and was able to distinguish children with autism from neurotypical children with about 90% accuracy in a small clinical study.

Researchers observed that most autistic participants showed elevated levels of several of these metabolites compared to typically developing children, suggesting a strong biological signal connected to the condition.

The findings were published in Molecular Psychiatry and are based on a sample of 99 children aged between 2 and 11, including 52 diagnosed with autism and 47 without the condition.

Several of the most elevated compounds were linked to tryptophan metabolism, an amino acid involved in producing neurotransmitters such as serotonin and dopamine, which play key roles in mood regulation, cognition, and behavior.

Researchers believe disruptions in these metabolic pathways may be associated with symptoms commonly seen in autism, including social communication challenges and sensory or behavioral differences.

Unlike current diagnostic approaches — which rely heavily on behavioral observation, developmental history, and questionnaires and can take months or years — the urine test is designed as a single, quick biological screening tool.

The study suggests that early biological detection could help reduce delays in diagnosis and allow earlier access to behavioral therapies and developmental support.

Scientists also proposed a potential subtype of autism linked specifically to microbial metabolites, though they emphasized that this classification is still experimental and requires further validation.

Researchers caution that the findings are preliminary and based on a limited sample size, and larger studies will be needed before the test can be considered for clinical use.