I don't feel that gut dysbiosis is _the_ root cause. I think it can be _a_ trigger, just as any other immune system activating event can be a trigger. My ME seemed to start as a type IV food sensitivity. Food poisoning from spoiled coconut milk seems to have cured my type IV reaction, and I think it most likely that that cure was due to altering bacterial populations, so I do accept the importance of microbiome health. However, all the other things (diet, fibre, antibiotics) I've done that should have altered bacterial populations didn't have any effect on the ME symptoms (nor did the type Iv sensitivity cure), so I don't believe that my ME symptoms are due to gut issues. I still believe ME is some feedback loop in the immune system that is stuck in an abnormal state. Gut issues are just a possible trigger for that, and solving the gut issues won't undo the triggering event. It might avoid future triggering events if you otherwise manage to switch the cells back to normal function. One thing someone (not suffering from lethargy and brainfog) might look into is ME/CFS patients with radical gut alteration (surgical removal or whatever). Did radical gut alteration have an effect on the ME/CFS? That could be useful evidence for this debate.