As you can understand and see I am on a razors edge when it comes to talking about this stuff, and even more so with this in the medical field. It was really the "20% is not unusual" part that skewered me in the brain because before I posted this no one here probably heard of this gene and its strong effect on the microbiome and diet.
And now I just want to add, for your interest, that Mood Disorders are not fundamentally neurological, I am sorry to say, but in fact they are immune disorders which affect neurology. You would do the mentally ill a huge favor by sending your patients to rheumatology for care.
It has been 50 years since my mother was diagnose with Bipolar Disorder and here I am now, with the same issues, and they are pretty much prescribing the same meds and looking at it in the same way. So whenever I meet a neurologist I have to express my frustration because you need to think about mood disorders in a radically new way if something is to change and being nice did not change anything. And now, when I find things out that help me I get no help from my doctors, just a "glad that worked for you" and the cold shoulder when I ask for more testing.