Given there are cases of sudden onset autism being resolved with antifungals, it’s at least not implausible that fecal transplants could be effective too.

There are so many claims of autism being cured in a couple people with different drugs or supplements out there.

They’re always followed by thousands of self-experimenters where nobody can reproduce the result.

The explanation is almost always placebo effect. A parent or doctor is so convinced that they’ve found a cure that they change assume it worked, change their behavior toward the autistic person, and believe that a dramatic change has occurred.

This is also why the placebo arm of every autism study also shows improvement.

No. No chance. It's completely implausible. This is reflected in their actual Phase II trial - NCT06503978 - whose primary endpoint is relieving GI symptoms. It's far from curing autism. It is idiosyncratic to target this population. They could do the same trial with healthy adults, but of course, twice daily massive laxatives is not something very marketable. The reason this product is the way it is is because ASD kids cannot really say no.