Experts Dismiss Gut Microbiome as Cause of Autism

According to experts, the long-held belief that the gut microbiome causes autism is not supported by scientific evidence. Developmental neurobiologists state that despite widespread attention on the gut-autism connection, there is no causal link between the two.

While it is known that people with autism often have higher rates of digestive issues, researchers say this does not mean the gut microbiome is the root cause of the neurodevelopmental condition. They argue that autism is a strongly genetic disorder, and much of its heritability remains unexplained by gene mutations identified so far.

The researchers reviewed previous studies comparing the gut bacteria of people with and without autism, as well as mouse model and clinical trial data. They found the results to be largely flawed and unconvincing, with small sample sizes and inappropriate study designs. Even in the most highly cited studies, the number of participants ranged from just 7 to 43, far below the thousands recommended for statistical significance.

The experts conclude that the theory of the gut causing autism has reached a dead end. They suggest that if people continue to research this area, they must start conducting studies in a much more rigorous way. The researchers also note that having autism can affect one's diet, which in turn can impact the microbiome, rather than the other way around.