Taken from lowoxalate.info.. a very informative site
Yeast Overgrowth
It is likely the tie to yeast infections involves a problem in the immune system and its ability to recognize yeast overgrowth and respond. Oxalate is known to impair carboxylase enzymes producing symptoms equivalent to biotin or biotinidase deficiency. The literature on those conditions is clear that when carbxylases are impaired, it is easy to get runaway problems with yeast. Perhaps this explains why some people on the low oxalate diet would lose this inhibition, resulting in a loss of their tendency towards chronic candidiasis. If this reduction of yeast doesn't seem to be working in the first months of LOD when "dumping cycles" may come more frequently, then it certainly might make sense to increase the level of biotin in the diet (with a supplement that furnishes biotin in mgs rather than mcgs) to see if that also helps keep back yeast by enhancing carboxylase activity.