It sounds like a scene from a nightmare or horror story: The authorities pull you over for DUI. You have not been drinking, and you tell them so. However, they do not believe you. When tested, your results show an elevated BAC.

Though it may seem unbelievable, this precise scenario once played out for a driver in North Carolina. Law enforcement took the driver, a man in his 40s, to the hospital after he refused a breathalyzer test. Hospital staff tested his blood alcohol level and found it to be approximately 2.5 times the legal limit.

The test results did not lie, but neither did the driver. It was true that he had had nothing to drink. His own body produced the alcohol found in his bloodstream.

Rare medical condition

It turns out that the man has a rare medical condition called gut fermentation syndrome, also known as auto-brewery syndrome. Excess yeast in the upper digestive tract reacts chemically with carbohydrates from the patient’s food, and alcohol is the product.

Perhaps understandably, the condition is often misunderstood and sometimes underdiagnosed. However, an ABS patient is likely to respond to antifungal medication that kills the yeast and relieves the symptoms.

An alteration to the digestive tract’s environment can provide a habitat in which the yeast can grow. Researchers at the Richmond Medical Center in New York studied the man from North Carolina and concluded that a previous course of antibiotics caused the alteration.

Similar symptoms

Part of the reason why ABS may go undiagnosed is that the symptoms it produces are identical to those of inebriation, including the following:

  • Gait changes
  • Drowsiness
  • Sour-smelling breath

Though the worldwide medical community has been aware of the condition since 1912, the first reported cases in the United States showed up in the 1980s. Patients with ABS may meet with skepticism from family members, medical professionals and law enforcement, who may think that they are lying to conceal a covert drinking habit or avoid DUI arrest.