I have long thought that there is a connection between oversupply and yeast.
I've considered the abundance of foremilk and the sugar. It seems logical.
I've also considered the sensitivity of nipple thrush.  The fragile nipple
becoming so hypersensitive that this causes an oversupply.  I guess it could
depends on what came first the thrush or the oversupply.  I've seen it both
ways.  When the thrush comes first that's when some mothers then notice the
oversupply to be problem.

Pat Lindsey, IBCLC
Pediatrics Plus, Orlando, FL