A medical research article, published last year, has identified similarities between the structures of gluten and pathogenic bacterial proteins. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8430993/ As our bodies employ identification of such similarities in protein structure for recognising when an infection has become a threat to our health. When it does it is meant to trigger an inflammatory response to try to reduce the severity of the infection. That would help to explain why mast cell presence is raised in the intestines of people suffering from coeliac disease. https://pubmed.ncbi.nlm.nih.gov/27619824/ I don't know about others, who also suffer from severe reactions to gluten, but many of my own symptoms have involved my own bodies inflammatory responses to infection.