This story sounds a bit off, but it could just be because of the girl's medical ignorance. Similar situations have been documented in the medical literature. The best example I can think of off the top of my head was of a Japanese man, I believe, who was overdosed with antibiotics. The high doses of antibiotics killed off the natural fauna of his intestinal tract. For those of you that don't know, the human gut is filled with an incredible amount of symbiotic microorganisms such as bacteria that aid in digestion (they can digest materials that our enzymes can't, they produce vitamins, they're also the reason lactose intolerance really sucks). Back to the story: So, in effect, the man's intestines were sterilized leading to pretty serious digestive problems. To solve the problem, physicians "reseeded" his bowels with new bacteria. However, the procedure sort of backfired in that a non-native strain of bacteria was introduced that produces ethanol as a waste product. The end result was that the man got plastered every time he ate sugary foods.
In the end, they figured out their mistake, killed off the bacteria again, and started over.
I learned about this story in cell biology. Hopefully I didn't screw up too many of the details.