A 61-year-old man has taken the term "beer belly" a little too literally after being diagnosed with an infection that mimics the signs of intoxication.
It all began when the man checked himself into a Texas emergency room complaining of dizziness, reports NPR.
A breath test soon revealed he was almost five times over the legal limit, yet the man claimed he hadn't taken a sip of (alcohol) that day.
Doctors were stumped, but put it down to the man being a closet alcoholic.
But one team of medical professionals were determined to solve the mystery.
"He would get drunk out of the blue - on a Sunday morning after being at church, or really, just anytime," says Barabara Cordell, the dean of nursing at Panola College in Carthage, Texas. "His wife was so dismayed about it that she even bought a Breathalyzer."
Isolated in a hospital room for 24 hours, Cordell and gastroenterologist Dr. Justin McCarthy fed the man carbohydrate-rich foods, with regular blood-alcohol checks along the way.
After the series of tests conducted by the pair, the man's intestinal tract was found to be acting like his own brewery.
Thanks to an overabundance of brewer's yeast in the man's gut, that's how.
Or, an infection more commonly known as Saccharomyces cerevisiae, or "auto-brewery syndrome", as reported in the International Journal of Clinical Medicine.
Here's how it worked: when the man consumed starch - like pasta, or fizzy drinks - the yeast fermented the sugars into ethanol, essentially turning him into a drunkard.