I started drinking Yakult since a study found that reduced risk of respiratory tract infections. My insomnia seemed to improve a bit and it also seemed to reduce anxiety (which is due to nothing - no psychological stressors; it seems to be related to dysautonomia symptoms).
So I did a quick internet search and found this thoughtful news article on a research study that found Yakult improved sleep:
massivesci.com/articles/mic...
link to original research article: