Why Does SIBO Keep Coming Back After Treatment? — Tests that help read these cases

The standard SIBO breath test gives the surface diagnosis but says little about the upstream lesion. Tests that add mechanistic information include: GI-MAP or comparable stool microbiome panel. Looking specifically for: Akkermansia muciniphila and Faecalibacterium prausnitzii levels (proxies for the obligate anaerobic core), Methanobrevibacter smithii (methane-dominant pattern), Desulfovibrio (H2S pattern), beta-glucuronidase activity (mucosal inflammation), and secretory IgA (barrier and immune status). Organic Acids Test (OAT). Particular attention to: 3-hydroxypropionic acid (B12-related metabolism), succinic acid and fumaric acid (TCA cycle markers), kynurenic and quinolinic acid (inflammation and tryptophan diversion), and 8-OHdG (oxidative damage to DNA, a proxy for the inflammatory tone driving the substrate failure). Standard inflammatory panel. hs-CRP, ferritin, fibrinogen. Elevated ferritin in the absence of iron overload is a particularly useful marker of low-grade inflammation that is driving the substrate failure. Zonulin if available. Direct marker of barrier permeability. LBP and CD14 if accessible. Markers of endotoxin translocation. These are not always available in standard panels but are useful in cases where they can be obtained. I write more about reading lab panels through the Host Capacity Model lens in the Lab Result Interpreter tool and in the relevant