In most instances, the infections occurred after a person took antibiotics — which can wipe out the bacteria in the gut, making room for fungi like yeast to flourish ...
While the above is very plausible, it is rather unbelievable that a person could have enough Brewer's Yeast and fermentable material in their gut (or intestinal tract) to produce a significant amount of ethanol.
As a reference, packages of fresh beer yeast contain about one billion cells, which is enough to inoculate five gallons of wort.[1] (Wort is pre-fermented beer.)
You don't have to get it from drinking beer - consider the frequency of yeast infections among women, which is not correlated with employment at breweries or bakeries.
While the above is very plausible, it is rather unbelievable that a person could have enough Brewer's Yeast and fermentable material in their gut (or intestinal tract) to produce a significant amount of ethanol.
As a reference, packages of fresh beer yeast contain about one billion cells, which is enough to inoculate five gallons of wort.[1] (Wort is pre-fermented beer.)
1. http://www.wyeastlab.com/hb_productdetail.cfm?ProductID=16