I don't claim to know the answer or rather answers here but:
I do think that when it comes to SIBO the combination of betaine HCL + ox bile + digestive enzymes is a good idea.
The acid issues many pwme/cfs have are pretty well known. The problems we have with bile production and enzyme production seem to be explained by Chris Armstrong's work.
The acid is of course needed to steralise the gut and to provide the right environment (pH 2) for pepsin to break proteins into peptide fragments. Pancreatic enzymes then break these down into amino acids and peptide fragments that are further digested by peptidases at the brush border.
http://www.vivo.colostate.edu/hbooks/pathphys/digestion/smallgut/absorb_aacids.html
http://www.vivo.colostate.edu/hbooks/pathphys/digestion/pancreas/exocrine.html
I take creon 25000 (which is a pancreatic extract
https://www.nps.org.au/medical-info/medicine-finder/creon-25-000-capsules) which presumably gets me to the brush border but no further and I am a bit concerned about what we do to aid that last stage of digestion if our guts are a mess.
When these things are not working proteins will make ther way into the gut that is dominated by protein digesting bacteria.
The same of couse goes for fats, only I think bile plus pancreatic lipase takes us all the way to the end, and should stop fats from entering the colon in unusually large amounts.
The bile is also good at clearing some bacteria out of the small intestine - though as probiotic bacteria is selected for its resistance to bile it may be the very kind that is most likely to set up residence in the small intestine ... hmmm. Anyway bile can work as a kind of local antibiotic for a lot of bacteria.
So Betaine HCL + oxbile + pancreatic enzymes is a good start for SIBO and issues in the large intestine.
There are still issues with inflamation that can be addressed with Maes's protocol; there are issues with permeability that can be addressed too
and damn I am fading so may have to come back to this, but I think that Ken Lasessen's suggestions re probiotics are pretty good places to start
https://cfsremission.com/. But given the issues so many of us seem to have with paracellular permeability I think that it is important to fix that before taking a lot of probiotics.