What I Found in My Clients' Tests After Long COVID — And Why It Changes Everything — Finding #5: When the Microbiome Reorganizes Around the Wrong Organisms

In a separate post-COVID/post-infectious case: the microbiome test showed Prevotella copri at 44% dominance of the entire bacterial community. In a healthy gut, no single species dominates to this degree. Prevotella copri at that level &#8212; after a viral insult &#8212; is a signal of community collapse and reorganization around an inflammatory organism. The beneficial bacteria that produce neurotransmitter precursors and butyrate were severely reduced. The OAT on this client showed high hippuric acid &#8212; a marker of aromatic fermentation from a dysbiotic community. And the symptoms mapped exactly: immediate brain fog after eating, lasting 2-3 hours, POTS-like cardiovascular instability, inability to tolerate fermentable foods. Not because the food was the problem. Because the gut-brain axis had been destabilized from below &#8212; every meal was triggering a microbial metabolite and immune activation cascade that the autonomic nervous system was no longer equipped to buffer.