When a 61-year-old man from Texas showed up to a nearby hospital complaining about feeling drunk, though he had not taken a sip of alcohol that day, doctors wrote it off as closet alcoholism. After blowing 0.37 percent on a breathalyzer test while insisting he had not been drinking, the former home brewer drew the attention of gastroenterologists Dr. Barbara Cordell and Dr. Justin McCarthy.

"He would get drunk out of the blue — on a Sunday morning after being at church, or really, just anytime," Cordell explained. "His wife was so dismayed about it that she even bought a Breathalyzer."

The research team made sure that the man was not in possession of any liquor and isolated him in a hospital room for a period of 24 hours. Even after consuming only food rich in carbohydrates, the man still ended up with a 0.12 blood alcohol content on his blood test.

During further testing, Cordell and McCarthy discovered a buildup of a certain type of yeast, Saccharomyces cerevisiae, in the man’s intestinal tract. The condition, dubbed gut fermentation syndrome or auto-brewery syndrome, causes starch to ferment sugar and thus produces ethanol. Essentially, the man’s stomach was his own brewery.

The man was finally cured with a low-carbohydrate diet and a steady regimen of antifungals to help combat the yeast buildup. The book Alcohol in Health and Disease identifies a case in Japan that involved 39 women who suffered from an intestinal abnormality that caused them to become intoxicated after a meal high in carbohydrates.