CFS and other patients can flip between insomnia and hypersomnia within 24 hrs without any apparent cause. My hypothesis is a shift in the bacteria associated with each. My model is that specific symptoms are associated with specific clusters of bacteria. This means that we end up with hundreds of subset of CFS patients 🙁 making a standard treatment for CFS becoming a naive hope for many researchers, MD’s and patients.
I have experienced hypersomnia in past relapse, with sleeping 14-16 hrs at a time and waking up very unrefreshed. My normal healthy sleep pattern is about 6-7 hours.
For CFS, the most probable cause is A brain injury (due to infection) or a neurological disease…. The rapid flipping between insomnia and hypersomnia is better explained by a microbiome shift (Osler’s Principle)
- Recurrent hypersomnia is cited with Kleine-Levin syndrome with a positive SIBO results [June 2018]
- [A young boy with periodic strange behavior and hypersomnia: Kleine-Levin syndrome]. 
- A variant of the Kleine-Levin syndrome precipitated by both Epstein-Barr and varicella-zoster virus infections.  — Ah, same virus that are associated with CFS
- Kleine-Levin syndrome following acute non-specific encephalitis.
- A case of PANDAS with Kleine-Levin type periodic hypersomnia. – streptococcal infections
- Circadian disorganization alters intestinal microbiota.  is the closest that I could locate — although it approaches it in the opposite direction.
NS – normal Sleep Pattern, S – Altered Sleep Pattern, FS – High Fat
We do not know for sure which bacteria may be associated from the above charts. Looking at contributed samples with symptoms.
Looking at sleep insomnia http://microbiomeprescription.com/Data/SymptomExplorer?site=gut&filter=79
- Low Actinomycetales, Enterobacteriales (which includes E..Coli), Marvinbryantia, Gammaproteobacteria are very common
And at prolonged sleep,