Xylitol is a neat food; it is a sugar alcohol.

Xylitol kills some harmful micro organisms like S. Mutans and Candida Albicans.

Xylitol will shift fecal bacteria from gram-negative (covered in a layer of slime) to gram-positive (no slime, healthier).

Xylitol will cause diarrhea but it's a good kind of diarrhea, plan accordingly.

I had brain fog from AS until I changed my diet to no starch and now finally keto

I won't as these things are so experimental. But I will give you an assertion that body and mind influences each other. More so from the body's side than from the mind's