New study: Gut microbiota may differ early in life in individuals with neurodevelopmental disorders

January 26, 2026

Individuals with neurodevelopmental disorders such as autism and ADHD may have a different gut microbiota compared with others. This is shown in a new large-scale study that followed children from infancy into adulthood.

The research is based on the Swedish ABIS cohort (All Babies in Southeast Sweden) and includes more than 16,000 children born between 1997 and 1999. Researchers analyzed stool samples collected during the first year of life and compared gut microbiota composition with later diagnoses of neurodevelopmental conditions.

The result?

The results show that differences in gut microbiota were detectable very early in life, long before any clinical signs of neurodevelopmental disorders appeared. Certain bacterial groups were less abundant, while others were more prevalent among children who later received diagnoses such as autism, ADHD, communication disorders, or intellectual disability.

What this means

The researchers emphasize that the study does not demonstrate causality, but rather an association. This means that an altered gut microbiota cannot be said to cause neurodevelopmental disorders. However, the findings support the hypothesis that early biological development — including interactions between the gut, the immune system, and the brain — may be involved in the development of these conditions.

The study also highlights that early-life factors influencing the gut microbiota, such as antibiotic exposure, diet, and environmental influences, warrant further investigation. While the findings raise the possibility that gut microbiota could one day contribute to early risk assessment or preventive strategies, the researchers stress that such applications are still far in the future.

The study was conducted by researchers from Linköping University and the University of Florida and was published in 2024 in the scientific journal Cell.