I am currently doing a cycle of different species of probiotics and noted two had significant cognitive impact on me:
- Align ( Bifidobacterium infantis 35624 ) resulted in a very noticeable shift to being a lot more relaxed and laid back, longer sleeps.
- Mutaflor (E.Coli Nissle 1917) resulted in more energy, focus, shorter sleep.
As an aside, a friend was finally persuaded to take 20,000 IU/day of Vitamin D3, she reported within 5 days that she is sleeping a lot harder and not dealing with a tendency towards insomnia.
Just three random observations — your mileage may vary.