Why Does SIBO Keep Coming Back After Treatment? — Frequently asked questions about recurrent SIBO

How long does substrate restoration take to produce relief from SIBO symptoms? Three to six months for the first measurable improvements, six to twelve months for the full clinical response. The timeline is set by the biology of SLC5A8 demethylation, Fe-S cluster biogenesis, and microbial community reorganization. Faster response suggests a different mechanism was dominant in the case. Do antimicrobials still have a role under the Host Capacity Model approach? Yes, but sequenced differently. Antimicrobials are used after substrate restoration is underway, when the host can sustain the result. Antimicrobials used before substrate restoration produce the recurrence pattern this article describes. The timing matters more than the choice of antimicrobial. Why has high-dose butyrate supplementation not helped me? Most likely SLC5A8 silencing. The transporter that carries butyrate into the colonocyte is methylated, and the cell cannot access the substrate even when it is present. This is a known mechanism that is not measured by standard testing but can be inferred from the clinical pattern of butyrate non-response despite intact butyrate-producing taxa on stool testing. Is the Host Capacity Model recognized by mainstream gastroenterology? Not yet. The framework synthesizes established findings from microbial ecology, mitochondrial biology, and epigenetics into a coherent clinical fr