I believe eating brewers yeast could result in a vaginal yeast infection.  We
all have yeast in our bodies, and it's not a problem when it's keep at a
 minmum.  Several things can influence it's growth  and over-growth, like
antibiotics, hormonal changes of pregnancy, diet (especially rich in sugar or
YEAST), birth control pills and anything that weakens the immune system. Try
reading  Dr. William Crook's book, "The Yeast Connection"  for a better
understanding of how and what yeast can do.   Reading Dr. Crook's book gives
a clearer understanding of why we see so much yeast today and just how it can
impact our health.  His diet is worth considering for a mother  who has
problems with yeast.  I wish more physicians had a better understanding of
yeast and breastfeeding and recognized the importance of treating mother and
baby EVEN WHEN THE BABY shows no visible signs of thrush.
Warmly,
Pat Lindsey, IBCLC, LLLL
Chuluota, FL