There is an attempt in the paper at an explanation. However, the paper does not answer any of the questions raised.

Even if all of the biochemistry described were absolutely true, it would not explain the primary biochemical faults in the medical disorders referred to, such as the grossly insufficient biosynthesis of acetycholine in dementia, the reduction of tyrosine3-monoxygenase levels down to as little as 5% in Parkinson's Disease, and the excess rather than deficiency of serotonin in Narcolepsy. It would also not explain why only and specifically the suggested medical disorders were caused or why despite there being dozens of cell types in the nervous system with the same elements as those described, that dozens of medical disorders were not simultaneously caused by a negative response to gluten.

There presently remains major gaps in the biochemical theory, and a number of obvious inconsistencies.