Ya, I start taking brewer's yeast last month.
It doesn't cure my POIS but it helps in a more specific way.
My POIS is accompanied with sleeping disorder, namely I kind of have delayed sleep phase syndrome.
After taking just a few flakes of brewer's yeast (by Lesaffre, France) each night before I go to bed, and one capsule of niacin (Nature's Way 100mg) every four days in the morning, I have much better sleep, and the nocturnal emission that I used to have is substantially lessened.
I'm planning to try Vit-B1, B3, B6, and B12 in near future, because I think it is the vitamin B in the yeast that helps, but they have to be in the right proportion.
Let's experiment them together.