System · Cluster
Gastrointestinal
The gut sits at a crossroads of long COVID: a possible viral reservoir, a disturbed microbiome, a leaky barrier, and a serotonin factory wired to the brain. This cluster connects the gut symptoms to those mechanisms.
Short version: the GI cluster covers gut symptoms, dysbiosis, barrier permeability, butyrate depletion, the gut-serotonin axis, and gut-directed treatments.
What this cluster covers
Gastrointestinal problems were among the earliest long COVID symptoms reported, and the gut turns out to connect to far more than digestion. These pages map that web.
- GI symptoms — diarrhea, nausea, pain, altered habits
- Gut dysbiosis — the disturbed microbiome
- Intestinal barrier permeability — the leaky gut wall
- Reduced short-chain fatty acids — depleted butyrate
- Gut-serotonin axis — the gut-brain chemical link
- SIM01 synbiotic — the gut treatment with trial support
What we don't know
Honest about the edges of the evidence. These are open questions, not settled answers.
References
Every reference is free to read in full.