A case study published in the medical journal Annals of Internal Medicine reported of the first ever known case of a living human being suffering from "urinary auto-brewery syndrome," a rare condition in which alcohol naturally brews within the bladder due to the fermentation of yeast.
The odd medical condition was discovered in a 61-year-old Pittsburgh woman, who came in to receive treatment for liver damage and poorly managed diabetes at the University of Pittsburgh Medical Centre Presbyterian Hospital.
Doctors had initially denied the patient a liver transplant, assuming she was lying about having no history of alcohol abuse after urine tests kept coming in positive for high amounts of alcohol (ethanol).
"Initially, our encounters were similar, leading our clinicians to believe that she was hiding an alcohol use disorder," her doctors explain in the case report.
"However, we noted that plasma test results for ethanol and urine test results for ethyl glucuronide and ethyl sulfate, which are the metabolites of ethanol, were negative, whereas urine test results for ethanol were positive."
"Furthermore, in addition to consistently denying having consumed alcohol, the patient did not appear to show signs of intoxication during visits to the clinic, even though her urine showed high levels of ethanol content."
The woman's condition is similar to a rare disorder called "auto-brewery syndrome" (ABS), in which simply eating carbohydrates causes intoxication, when microbes ferment in the gastrointestinal tract, turning into alcohol.
In addition to a high ethanol content, physicians were also surprised to find very high levels of glucose in the woman's blood, a condition called hyperglycosuria.
"These findings led us to test whether yeast colonising in the bladder could ferment sugar to produce ethanol," the researchers wrote
"We concluded that the discrepant test results were best explained by yeast fermenting sugar in the bladder," the authors wrote.
They also identified the yeast Candida glabrata in the woman's urine. This microbe is part of the normal microbiome in humans and is closely related to brewer's yeast, according to the report.
Until this case report, the only other known cases of urinary auto-brewery syndrome were one found in a cadaver, and another found during in-vitro testing.
However, it is quite possible that more cases have presented before without doctors noticing, given the peculiar nature and difficulty of diagnosis of the condition.
"The experience we describe here of two liver transplant teams at different institutions demonstrates how easy it is to overlook signals that urinary auto-brewery syndrome may be present," the report said.
"Clinicians must be diligent about paying close attention to medical record documentation and laboratory results and should always investigate in the event of incongruences."