It’s not as rigorous as a controlled double-blind clinical trial, but you can definitely experiment as an individual by trying different combinations on different days and looking for patterns. One example is the common recommendation to introduce new foods to babies one by one so any food allergies are more apparent.
It's a single comment covering an unspecified time frame with no explanation of how much research, tracking, etc was involved. It's the TLDR of their experience in hopes of nudging people in the right direction and saying, in essence, "anecdotally, fixing my own gut issues has correlated with fewer mood issues. Here is some food for thought if you want to try to do the same."
The OP isn't selling anything, so it's not infomercial logic which is designed to get you to buy a product.
The gut is complex. I wouldn't expect one single thing to fix it.
It's a very thorough comment, iterating very specifically a dozen 'medical solutions' down to a 'weighted rating out of 10' (!) of the value each one of them.
Again - I'm not doubting anyone's intentions, but I'm fully doubting the veracity of all of this.
'Self Medicating N = 1 Belief' - is extremely common among people.
Even among diligent, intelligent people who actually can and do 'research'.
But with a single 'blind spot' in self awareness, it goes awry with these kinds of 'beliefs'.
Everyone who works out at the gym consistently has a 'belief' about a lot of things.
There are dozens of magazines and quasi health magazine's offering these kinds of solutions.
It's frankly as old as time and probably more common than not.
... 'this is how they worked, to varying degree'?
One thing I can understand. Was sick -> did this -> was better.
But a 'regime', it feels like infomercial logic though I doubt doubt the author's motivations.