For myself, their is VERY, VERY little doubt in my mind that my CFS is caused by my gut.
To have such "VERY, VERY little doubt" in this circumstance is very, very bad scientific thinking.
You have taken a series of herbs which you found improved your ME/CFS. You state those herbs are: basil, olive leaf extract, ceylon cinnamon, thyme, oil of oregano, neem, cumin and clove powder. I am not doubting that these herbs did make a substantial improvement to your health.
However, then you suddenly jump to the conclusion that "my CFS is caused by my gut".
But your conclusion is a leap of faith. Any given herb (or drug, or supplement) will have dozens if not hundreds of effects in the body. Thus if you benefit from a herb, it's very hard to know why, unless you investigate further with lots of medical tests to try to determine what might be happening. And even then it is hard to figure out what the mechanism of benefit might actually be.
The initial reason you took those herbs may have been for their antibacterial effects. But the reason they improved your health may be due to something else entirely. That's just how these things work.
If you take some time to investigate the multiple mechanism of action of each of the herbs you are taking (which may take many months of intensive research, if you are up to that), then you will see that these herbs in addition to antibacterial effects, also have immunomodulatory effects, antioxidant effects, anti-inflammatory effects, antiviral effects, and countless other physiological effects.
I am not denying that it could be the antibacterial effects of these herbs which are helping you. But nobody can be sure of that, so to proclaim you have "VERY, VERY little doubt" is at odds with reasoned thinking.
I had a similar situation: I found great improvements in my ME/CFS from taking
high-dose selenium. I originally took selenium because I read some papers indicating it had an antiviral effect against coxsackievirus B, which is a virus I have as an active infection. However, the reason selenium works so well for me may in fact be nothing to do with its antiviral effects. Selenium has hundreds of effects in the body, and the benefits I experienced could come from any of these other effects. It's just a fact of life that you often cannot easily know why a particular medication is helping you.