Danik,
It’s new. The premise of small intestine bacterial overgrowth (SIBO) being an issue in autism is true, although hard to prove. I don’t believe all kids with gut problems have SIBO. The confirmation test for SIBO is hydrogen and methane breath testing which is really hard to do in special needs children. You can read about the Nemechek Protocol right off his website. I don’t know what other resources are out there other than his book.
I do think more children could benefit from Rifaximin which is the primary antibiotic for SIBO. However, SIBO is more than just Rifaximin, but also includes digestive support, large bowel intervention, etc. One of the things about the Nemechek Protocol which is interesting is his advocating for Inulin fiber. Inulin is commonly contraindicated in SIBO. So, the question is, is it truly SIBO or something else?
I would suggest reading his book and see if it makes sense to you. I am not saying he is wrong, but usually these types of protocols catch fire for a while and then lesson with enthusiasm overtime as parents find it either is not helpful or causes problems.
Dr. Woeller