Why Dysbiosis, SIBO, Hydrogen Sulfide Intolerance, MCAS, and Long COVID May All Be Downstream of a Single Event — The core claim

So here is the whole model in three sentences. Dysbiosis is often the consequence, not the cause. The colonocyte's loss of bioenergetic control — its inability to burn butyrate, consume oxygen, protect its iron-sulfur clusters, clear sulfide, and recycle its antioxidants — is what lets the ecosystem flip and then locks it in place through self-reinforcing loops. The microbiome matters, but the host terrain decides what the microbiome is allowed to become. The future of chronic gut care cannot only be about killing pathogens, adding probiotics, and raising butyrate. The deeper, harder, more honest question is the one this model is built to ask: Does the host still have the biological capacity to sustain the ecosystem we are trying to rebuild? That question is the core of the Host Capacity Model. And in my experience with complex cases, it is the question that finally explains the people who never got better when everyone was only ever looking at the bugs.