Counterargument
What if MCAS is not gut-driven?
Many MCAS cases are genetic, structural, post-traumatic, or idiopathic — not driven by gut dysfunction.
Where it is valid
Hereditary alpha-tryptasemia, systemic mastocytosis, post-vaccine onset, post-trauma onset, clearly extra-gut triggers.
What it challenges
The HCM claim that gut-barrier and metabolite stress can amplify MCAS-pattern symptoms.
Host Capacity Model response
HCM applies only to the subset of MCAS-pattern cases where no clearly independent primary cause is identified and where gut-axis features are present. Gate 1 is designed to surface non-fit cases before engagement.
Unresolved questions
- What fraction of MCAS-pattern cases are primarily gut-mediated vs primarily mast-cell-intrinsic?
- Which clinical features best discriminate the subsets?
Evidence that would resolve this
- Stratified cohort studies linking gut-barrier markers to mast-cell activation indices.