I had other symptoms too not just fatigue. So then Googling around, finding a lot of bad info or info that's obviously hocus pocus etc and slowly filtering down to "gut bacteria play a role in this, interesting". So then you gotta sift through the probiotics BS industry stuff and tried different "down to earth - not hocus pocusy" brands/strains. Really hard to find good info though if you don't really look for it.
You can see it in other posts from me. I think the histamine intolerance part was fixed by the Bacillus subtilis that's in what I take. Though some of the regular lacto bacillus strains certainly helped crowd out whatever was in me before. But some lactk Bacillus actually create histamine. For exame I could not drink Actimel.i can attest to the fact that it has live bacteria that make it to the gut alive because actimel gives me headaches (literal headaches not figure of speach)
I currently use Garden of Life Primal Defense Ultra. Because of the subtilis in it and not having too many histamine creating lacto strains. May or may not help you but did it for me.
I started with 1 a day and worked up to 3 a day over some weeks. I felt like crap for about 2 weeks. Like having a cold sick. Just no nose running and such. Then better than ever. Now I take one in the morning and one in the evening.
Oh and so I don't forget shortly after I also started keto. Real keto w/ less than 20g carbs. Did blood tests that confirmed I was in ketosis. That's the "and feeding them right" part. Did it for about a year which normalized all my off blood markers except for cholesterol which also improved but not below what is condered normal. Did it for a year. Now I no longer do keto but keep the sugar mostly away.
You can see it in other posts from me. I think the histamine intolerance part was fixed by the Bacillus subtilis that's in what I take. Though some of the regular lacto bacillus strains certainly helped crowd out whatever was in me before. But some lactk Bacillus actually create histamine. For exame I could not drink Actimel.i can attest to the fact that it has live bacteria that make it to the gut alive because actimel gives me headaches (literal headaches not figure of speach)